AU2021290996A1

AU2021290996A1 - Hot-metal-part insulating element for preventing or reducing the formation of heavy-metal compounds which are harmful to the environment and/or to health

Info

Publication number: AU2021290996A1
Application number: AU2021290996A
Authority: AU
Inventors: Ingrid Lipp
Original assignee: Individual
Current assignee: Individual
Priority date: 2020-06-16
Filing date: 2021-06-16
Publication date: 2023-03-02
Also published as: EP4244472A1; WO2021255125A1

Abstract

The present invention relates to a textile or partly metal hot-metal-part insulating element (also referred to herein as "insulating element") for preventing or reducing the formation of heavy-metal compounds which are harmful to the environment and/or to health, which hot-metal-part insulating element is in the form of an insulation mattress, insulation cushion/pillow, insulation mat, insulation sleeve, insulation shaped part, insulation element, insulation hood, insulation blanket, glass woven-fabric shaped mat, insulation cassette, hard cover elements or the like and is used to thermally insulate hot metal parts in a temperature range of 20°C to 750°C.

Description

Hot-metal-part insulating element to prevent or reduce the formation of heavy-metal compounds which are harmful to the environment and/or health.

Technical Field

The present invention relates to a textile or partially metallic, preferably separable, hot-metal part insulating element (also referred to herein as "insulating element") for preventing and/or reduction of the formation of heavy-metal compounds which are harmful to the environment and/or health, which is in the form of an insulating mattress, insulating cushion/pillow, insulating mat, insulating sleeve, insulating molded part, insulating element, insulating hood, insulating blanket, glasss fabric molded mat, insulating cassette, hardcover elements or the like and is used for the thermal insulation of hot-metal-parts in a temperature range from 20°C to 750°C.

State Of The Art

In principle, various types of insulating elements or systems are known which are used for thermal insulation and/or soundproofing, but also as heat protection for internal combustion engines (such as engines of motor vehicles, commercial vehicles, construction machinery, rail vehicles and ship engines), hot engine parts, components of exhaust systems such as diesel particulate filters, turbochargers, catalytic converters, silencers, SCR systems and their associated components, as well as gas and steam turbines, generators, combined heat and power plants and similar units. These known insulating elements are used in diesel particulate filters, turbochargers, catalytic converters, mufflers, SCR systems and their associated components, as well as gas and steam turbines, generators, as well as the supply and discharge lines belonging to all the above-mentioned systems.

These well-known insulation elements or insulation systems usually consist of an envelope of textile sheet materials using E-glasss, ECR-glasss, basalt or other high-temperature materials, in each case with or without metal wire reinforcement, in each case with or without different coatings and/or chemical impregnations as well as, towards the cold side, with laminations of plastic films and/or metal foils, enclosing one or more layers of insulating material, usually also consisting of E-glasss, ECR-glasss, basalt, rock wool or other high-temperature materials selected and designed to withstand the operating temperatures of the object to be insulated and also having good thermal and acoustic insulation properties.

Consequently, the known insulation elements or insulation systems serve to provide thermal insulation and/or sound insulation and/or heat protection, to maintain the temperature in the system, to protect nearby components from heat or heating or overheating, or to meet other application requirements, e.g. sound insulation, contact protection, fire protection, occupational health and safety, and other.

The construction of these insulating elements or systems takes place in various designs, such as pillow form, i.e. consisting of an innerfabric (so-called hot side), one or more inner insulating materials and an outer fabric (so-called cold side), or mattress form, i.e. consisting of an inner fabric (so-called hot side), one or more layers of insulating material in the form of insulating mats, loosely filled insulating materials or combinations thereof, an outer fabric (so-called cold side) and a so-called fabric web (side part), which connects the inner and outer fabric and gives the insulating element its box-like or mattress-like shape.

Other forms of presentation are mentioned herein and are not described in detail here.

In recent years, the use of E-glasss fabrics, ECR-glasss fabrics, HR-glasss fabrics, basalt fabrics, calcium silicate fabrics, each with and without wire reinforcement, as support and cladding fabrics has proven successful for temperatures in the range from 20°C to 750°C. Also preferred in this temperature range are insulating compounds, thermal cement, spray insulation, solid insulation, rock wool mats, E-glasss mats, ECR-glasss mats, HR-glasss mats, basalt mats, mineral fiber mats.

In order to achieve temperature-resistant practicality and durability, these are partially, in particular the hot-side fabric, provided with special coatings and/or impregnations. The outer, i.e. cold-side fabric, is often provided with a water-repellent and/or oil-repellent coating and/or impregnation and/or laminated with a plastic film and/or metal foil. In some cases, the outer sides are provided with a metallic reinforcement.

For temperatures in the range of 20°C to 750°C E-glasss needle mats, ECR glasss needle mats, HR glasss fiber mats, so-called Superwool products, rock wool, basalt, ceramic fibers or similar insulating materials have proven to be suitable as insulating materials.

All the above-mentioned, currently preferred insulating fabrics and all the above-mentioned high-temperature insulating materials have a not inconsiderable mass content of more than 5 wt.-% in total of alkali metals and/or alkaline earth metals and/or compounds thereof (in particular oxides thereof), in particular more than 5 wt.-% in total of calcium, magnesium and/or compounds thereof (in particular oxides).

Typically, thermal insulating materials with a high content of calcium silicate, a composite oxide of calcium oxide and silicon oxide, are used for hot parts because calcium silicate is considered a low-cost material with good heat resistance, thermal insulation and corrosion resistance. Commercially available thermal insulating materials contain the composite oxide calcium silicate as the main component.

During the dismantling or replacement of insulation elements or insulation systems that have been in use in plants sheathed with them (i.e. hot parts), as known from the prior art, dusts and/or deposits of heavy-metal compounds that are harmful to health and the environment, in particular chromium compounds, here in particular chromium(VI) compounds, for example in the form of calcium chromate (often in the form of yellow powder), are now found to settle between the plant part to be insulated and the insulation.

These can be detected as residues both on the insulated components, on the surface of the inner fabric of these insulation elements or insulation systems, within the insulation elements or insulation systems, and on the surface of the insulation used.

It is known that when chromium-containing materials, such as hot-metal parts, come into contact with oxygen, small quantities of the gaseous chromium(VI) compounds CrVIO 3 or CrVIO2 (OH) 2 are formed at high temperatures (up to 600 °C), possibly with the addition of steam. Cr03 is only slightly thermodynamically stable and decomposes again at a temperature of 200°C into Cr(III) and 02.

The skilled person is also aware of scientific publications on the formation of Cr(VI)-containing compounds from Cr-containing materials, which are based on an oxidation of chromium, in particular Cr(III) to Cr(VI), in the presence of oxygen and CaO. Research findings on the causes of the formation of chromium (VI) on insulated hot parts Industrial plants in the high temperature range are based on the fact that Cr(VI)-containing compounds form on the contact surface of hot parts made of chromium-containing metal and calcium-containing and/or sodium-containing insulating materials.

Sayano et al. (2015) report an increase in the formation of Cr(VI) compounds, which undoubtedly correlates with increasing temperature, increasing contact time and increasing chromium content of the steel. The formation of Na 2 CrO4 and a characteristic yellow layer of CaCr04, which had been deposited on an insulating material containing sodium and/or calcium, is clearly demonstrated, and its formation is explained with the following reaction equation:

Cr 2 3 + CaO + 1.5 02 -- 2 CaCrO 4

Approaches to prevent the formation of such heavy-metal compounds that are harmful to health and the environment are known, for example, from patent specification JP2012220174A. This proposes a hot-metal-part, in particular one containing chromium, with a sheet of metal, in particular iron or nickel, the sheet being formed inseparably on the surface of the hot-metal-part. Only on this sheet metal is a heat-insulating material applied, which contains at least calcium, potassium, magnesium or sodium. As a result, it was found that by forming the sheet on the surface of the hot-metal-part and thus between the hot-metal-part containing chromium to be insulated and the heat-insulating material, the formation of hexavalent chromium can be suppressed. The disadvantage here is that these hot-metal-parts have to be coated with this sheet, preferably directly ex works by the manufacturer himself. Subsequent coating of hot-metal-parts already in use is time-consuming, cost-intensive and difficult to implement on site.

Patent specification JP2011232021A takes a comparable approach and proposes coating a chromium-containing metal hot part with a film of ceramic and applying to this film a heat insulating material containing at least calcium, potassium, magnesium or sodium. However, disadvantageously, this layer also usually has to be applied directly to the chromium-containing metal hot part by the manufacturer. For this purpose, a solution containing a ceramic precursor must be applied to the surface of the metal hot part, and the film must be formed by decomposition of the ceramic precursor as a result of heat treatment.

The heating of hot-metal parts (e.g. engines/turbines), high continuous temperatures (400 °C

750 °C) and, if necessary, the effect of moisture, appear to promote the process of the formation of heavy-metal compounds. However, the continuous temperature of these metal hot parts is not so high that these formed heavy-metal compounds, especially chromium(VI) compounds, volatilize/burn. Temperatures of more than 1,000°C are required for this.

The amount of heavy-metal compounds formed cannot be predicted/limited, as each metal hot part is in use under different conditions and thus exposed to different influences.

Heavy-metal compounds, in particular chromium compounds, here especially chromium(VI) compounds are considered to be highly harmful to health and the environment. They can cause incurable diseases, are considered to be of particular concern, carcinogenic and mutagenic and, depending on the concentration and contact, can lead to death.

The present invention is therefore based on the technical problem of providing an insulating element or insulating system for use at temperatures in the range from 20°C to 750°C which, when used as intended, prevents the formation of heavy-metal compounds which are harmful to health and the environment, in particular chromium compounds, very preferably chromium(VI) compounds, or reduces the formation in such a way that the resulting concentration of these compounds does not give rise to any risks which are harmful to health and the environment or which can be averted by suitable, reasonable protective measures.

According to the invention, this problem is solved by a preferably textile or partially metallic hot-metal-part insulating element (1), in particular one that can be separated from the hot metal-part to be insulated, for preventing or reducing the formation of heavy-metal compounds that are harmful to the environment and/or to health according to claim 1, which is formed at least in one layer or single layer and thus comprises at least one first outer layer (2) (also referred to herein as lower outer layer), wherein the first outer layer (2) is designed as a direct contact layer for a hot-metal-part to be insulated when the metal hot part insulating element is used as intended, wherein the hot-metal-part insulating element (1) comprises by its three-dimensionality (when used as intended) at least the following:

- a lower outer side (3) (herein also referred to as the hot side) which (when the metal hot part insulating element is used as intended) is formed as a direct contact surface for a metal hot part to be insulated, and

- an upper outer side (4) (herein also referred to as the cold side) arranged opposite the contact surface for the metal hot part,

wherein the first outer layer (2) comprises alkali metals or alkaline earth metals and compounds thereof, but at least calcium and calcium compounds (in particular calcium oxide) with a mass content of less than 5 wt-%, i.e. the first outer layer (2) consists of materials or insulating materials which comprise alkali metals or alkaline earth metals and compounds thereof, but at least calcium and calcium compounds (in particular calcium oxide) with a mass content of less than 5 wt.-%.

Preferably, at least the first outer layer (2) or lower outer layer is low in alkali metal and/or alkaline earth metal, i.e. the lower outer layer has less than 5 wt.-% of an alkali metal, alkaline earth metal or compounds (in particular oxides thereof).

According to a particularly preferred embodiment, at least the first outer layer (2) or lower outer layer (2) is free of alkali metals and/or alkaline earth metals. For example, the first outer layer (2) consists of a film or a textile fabric, in particular a metal foil, especially preferably a metal mesh, in particular stainless steel mesh or a stainless steel foil or aluminum foil.

Advantageously, at least the lower outer layer (2), which is low in calcium, preferably free of calcium, particularly preferably low in alkali metal and/or alkaline earth metal, very particularly preferably free of alkali metal and/or alkaline earth metal, prevents the occurrence of environmental and/or health hazards when the hot-metal-part or the hot-metal-appliance is used as intended. of the hot-metal-part or of the hot-metal-apparatus at operating temperatures in the range from 20 °C to 750 °C, in particular in the range from 200 °C to 750 °C, very preferably in the range from 400 °C to 750 °C, the formation of heavy metal compounds (in particular chromium compounds, very particularly chromium(VI) compounds) which are harmful to the environment and/or to health and which are formed as a result of chemical reactions between the metallic material of the hot-metal-part or of the hot-metal apparatus and the steel reinforcements in the insulating elements is prevented. the steel reinforcements in the insulating elements and the conventional insulating element or insulating material, in particular the alkali metals, alkaline earth metals or their compounds (in particular oxides) contained therein, during the intended use of the metal hot part (see Fig. 1).

In addition, the use of the hot-metal-part insulating element (1) with the structure according to the invention advantageously reduces or even prevents corrosion of the hot-metal-part - which occurs more frequently in particular in the presence of moisture or water (e.g. rainwater, condensation water, condensation water and ice formation) - due to the chemical reaction between the metallic material of the hot-metal-part and the conventional insulating elements, in particular with the alkali metals, alkaline earth metals and their compounds (in particular oxides) contained therein. In this context, corrosion is understood to be the chemical reaction of a hot-metal-part with its environment (e.g. with the insulating material), which causes a measurable change in the hot-metal-part or its structural condition and can lead to an impairment of its function.

As can be seen herein for the skilled person, the hot-metal-part insulating element (1) is separably connected to the hot-metal-part to be insulated. As used herein, a hot-metal-part insulating element (1) that is separable from the hot-metal-part to be insulated means that it is not fixedly connected to the hot-metal-part, for example, not by welding, a sintering process, by burning out or the like. Accordingly, the hot-metal-part insulating element (1) is detachable, removable or separable from the surface of the hot-metal-part to be insulated, in particular easily removable without damaging the hot-metal-part, in particular its surface. This allows that the inserted hot-metal-part insulating element can be easily removed after its wear and can be replaced, for example, by another hot-metal-part insulating element. Alternatively, this allows the insulated hot-metal-part to be disposed of without much separation effort. However, the fact that the hot-metal-part insulating element (1) is separably connected to the hot-metal-part to be insulated does not (necessarily) exclude that the hot-metal-part insulating element (1) is, for example, glued to the surface of the hot-metal-part to be insulated, since common adhesives can be removed from the surface of the hot-metal-part to be insulated by simple treatment with a solvent, preferably a liquid solvent, without damaging its surface.

The preposition "separable" thus specifies the hot-metal-part insulating element in its capacity as a modular, removable and/or non-fixed hot-metal-part insulating element with respect to the application or attachment to the hot-metal-part according to the invention.

Further advantageous embodiments and further developments result from the subclaims as well as from the description with reference to the figures.

Detailled description oft he current invention

The present invention is based on the finding that alkali metals and/or alkaline earth metals and compounds therewith, in particular calcium and compounds therewith, act as oxidizing agents with respect to heavy metals, such as chromium, which is used, for example, in steels, and thus promote the formation of highly toxic metal compounds, for example, in the form of metal vapors and metal dusts. The inventors of the present invention have also found that this effect occurs more strongly when hot-metal-parts whose materials contain such heavy metals are operated at temperatures in the range from 20°C to 750°C, in particular in the range from 200°C to 750°C, such as for example at temperatures around 250°C, around 300°C to 700°C, very preferably in the range from 400°C to 750°C, in particular in each case up to 700°C, 650°C, very preferably up to 600°C.

Different investigations seem to confirm the assumption that the formation of heavy metal compounds harmful to health and the environment, in particular chromium compounds, especially chromium(VI) compounds, is directly related to the use of conventional alkali metal- and alkaline earth metal-containing insulation elements and/or insulation systems and thus to the coexistence of alkali metal or alkaline earth metal elements and/or their oxides.

According to the definition in engineering and chemistry, the term "heavy metal" includes metals (only non-ferrous metals) with a density > 5 g/cm3. Many heavy metals, especially lead, cadmium, chromium, cobalt, copper, molybdenum, nickel, mercury, selenium, and zinc can be highly toxic to animals and humans as a metal, metal ion, or in a chemically bound state.

The toxic effect of heavy metals can be strongly dependent on the oxidation state or the chemical compound of the heavy metal. An example of this is chromium, which is non-toxic in elemental form, essential as chromium(III), and toxic and carcinogenic as chromium(VI).

An example of a specific transformation of "non-toxic" heavy metal compounds into heavy metal compounds that are harmful to the environment and/or health due to the chemical reaction between the metallic material of the hot-metal-part and the conventional insulation elements containing calcium oxide (CaO) is the oxidation of chromium(III) into chromium(VI) in the presence of oxygen (02) and temperatures in the range of 200°C to 1,000°C, especially 200°C to 600°C:

Cr0")203 + 2CaO + 3/2 02 -- 2CaCr(v)0 3

In addition, it was found that the maximum of chromium(III) oxidation to chromium(VI) occurs in the presence of calcium oxide as well as in the presence of magnesium oxide (MgO) and the alkali metal hydroxides potassium hydroxide (KOH) and sodium hydroxide (NaOH), which are formed from the corresponding oxides in the presence of water, and the consequent leaching of chromium (VI) compounds harmful to health and the environment from hot-metal-parts - sheathed or insulated with materials containing these compounds - in the range between 150°C and 800°C when conventional insulation elements are used (see Figure 1).

Hot-metal-part

In the context of the present invention, the term "hot-metal-part" refers to metallic hot appliances (e.g., internal combustion engines or steam or gas turbines) and metallic components (e.g., inlet and outlet systems of hot appliances) that reach, generate, or are operated at an operating temperature in the range of 20°C to 750°C during intended use.

The skilled person understands in the context of the invention that the intended use of the hot-metal-part depends on its field of application and the upper operating temperatures, as defined herein, of the materials from which the hot-metal-part is formed and, accordingly, at an operating temperature in the range of 20°C to 750°C, in particular in the range of 200°C to 750°C, such as for example at temperatures up to 300°C, up to 350°C, up to 400°C, up to 450°C, up to 500°C, up to 550°C, up to 600°C, up to 650°C or up to 700°C, very preferably in the range from 400°C to 750°C, in particular in each case up to 700°C, 650°C, very preferably up to 600°C.

The hot-metal-parts insulated with the hot-metal-part insulating element (1) according to the invention consist of steel or cast steel, which in particular has alloy components containing heavy metals such as chromium, nickel, molybdenum, titanium or niobium. Examples include chromium steel (for hot-metal-parts with operating temperatures of 100 to 300°C), e.g. for heating systems, turbines; chromium-vanadium steel (for hot-metal-parts with an upper operating temperature of up to 220°C); chromium-nickel steel (for hot-metal-parts with an upper operating temperature of up to 550°C), e.g. for machine and apparatus construction. Further examples of high-temperature steels containing heavy metals and examples of applications can be found in Table 1 below.

Table 1: Examples of high-temperature steels containing heavy metals

Steel grade Application example Upper operating temperature

WStE 26 bis 36 Fittings, armatures 350-400°C WStE 39 bis 51 15 MnNi 63 Fittings, forgings in power generation 350°C 20 MnMoNi 55 equipment 400°C

19 Mn 5 Fittings, valves, flanges in steam generator and 500°C

15 Mo 3 apparatus engineering 500°C

13 CrMo44 500°C

10 CrMo 910 500°C

14 MoV63 550°C

26 NiCrMoV 8 5 Low pressure steam turbines

26 NiCr 11 5 300-350°C

26 NiCrMoV 14 5

26 CrMoNiV 49 Medium-pressure and high-pressure steam turbines 530-550°C 30 CrMoNiV 5 11

X 12 CrNiMo 12 Compressors and compressor blades 550°C

X 21 CrMoV 12 1 Fittings, steam and gas turbine rotors 580-600°C

X 19 CrMoVNb 11 1 Rods, blades, rings, discs for gas turbines 580-600°C

X6CrNiTi18-10 Heat exchanger 800°C

Examples of hot-metal-parts in the sense of the present invention are combustion engines (such as engines of motor vehicles, commercial vehicles, construction machines, rail vehicles or ship engines), engine hot-parts, components of exhaust gas systems such as diesel particle filters, turbochargers, catalytic converters, silencers, SCR systems and their associated components, as well as gas and steam turbines, generators, combined heat and power units and similar aggregates, as well as supply and discharge lines belonging to all the aforementioned systems.

Also, for example, in geothermal power generation turbines are used as hot-metal-parts, where (water) steam is used as the working fluid with about 180°C as the lower limit. In this case, the turbines of geothermal steam power plants must be adapted to the temperatures that arise and insulated accordingly.

Insulation materials

When selecting the material for thermal insulation of hot-metal-parts, the purpose of the insulation must be considered. Thermal insulation means insulation systems against heat radiation or heat loss for hot-metal-parts (e.g. equipment and hot-metal-parts) as well as for reduction of surface temperature, which are operated above ambient temperature. Depending on the operating temperature of the hot-metal-part to be insulated, different materials used for the insulating element are used for thermal insulation.

In principle, the specialist knows how to select the appropriate materials, using selection criteria that include, for example, properties of the material such as thermal conductivity, application limit temperature, water vapor permeability, hydrophobic properties, flow resistance, fire behavior, mechanical properties, vibration behavior, acoustic properties, proportion of organic constituents, e.g., in the case of air separation plants. e.g. in air separation plants, mold resistance in damp rooms, corrosion behavior, e.g. low content of water-soluble chloride ions in combination with stainless austenitic steels, storability, transportability, processability, aging resistance, cost of the material used and disposal/recycling. For this purpose, the person skilled in the art refers to known tables. These include, for example, DIN 4140, which deals with the design of insulation for operational systems in industry and technical building equipment. The VDI 2055 series of guidelines is a guideline for calculating, checking the properties of insulation materials and the thermal properties of insulation systems.

The individual components of the hot-metal-part insulating element can be in the form of layers, bundles, woven fabrics, knitted fabrics, braids, nonwovens, felts, cardboards, papers, needle mats, stitch-bonded mats, mats, sheets, consolidated fibers, similar layers, loose fibers, powders, granulates or in the form of an insulating mass or solid insulation.

According to the invention, low-calcium, preferably low-alkali metal and/or alkaline earth metal-free, particularly preferably calcium-free, very particularly preferably alkali metal and/or alkaline earth metal-free materials are in particular S-glasss, M-glasss, Q-glasss, D-glasss, aluminoborosilicates, aluminosilicates, aluminafibre, silica, carbon and thermally stabilized intermediates on the way to carbon fibres, cellulose, textile fibres (natural fibres, synthetic fibres), metal fibres (e.g., strands, wires, filaments), silica, silica, silica, silica, silica, silica. strands, wires, filaments), metals, metal alloys, plastic-coated metals, metal-coated plastics, plastics or mixtures thereof, which are suitable for the thermal insulation of hot-metal-parts at operating temperatures in the range from 20°C to 750°C, in particular in the range from 200°C to 750°C, very preferably in the range from 400°C to 750°C.

A material used for the insulating element, in particular an insulating material or an insulating material support or an insulating element coating material, is low in calcium within the meaning of the present invention if it contains calcium, calcium ions and/or calcium compounds (in particular calcium oxide) with a mass content of less than 5 wt. %, preferably in the range from 0 to 4 wt.-%, particularly preferably in the range from 0 to 3 wt.-%, very particularly preferably in the range from 0 to 2 wt.-%, 0 to 1.5 wt.-%, 0 to 1 wt.-%, or 1 to 2 wt.-%. For the purposes of the present invention, materials are free of calcium if they contain calcium, calcium ions and/or calcium oxide only as unavoidable impurities totaling not more than 0.50 wt.-%, particularly preferably totaling not more than 0.25 wt.-%, most preferably totaling not more than 0.10 wt.-%.

A material low in alkali metals and/or alkaline earth metals used for the insulating element, such as an insulating material or insulating material support or insulating element coating material, is characterized in that these alkali metals, alkaline earth metals and their oxides are present in a mass content of less than 5 % by wt. %, preferably in the range from 0 to 4 wt.-%, particularly preferably in the range from 0 to 3 wt.-%, most preferably in the range from 0 to 2 wt.-%, 0 to 1.5 wt.-%,

0 to 1 wt.-%or 1 to 2 wt.-%. For the purposes of the present invention, alkali metal-free or alkaline earth metal-free materials are those which contain alkali metals and alkaline earth metals or their compounds (in particular oxides thereof) only as unavoidable impurities totaling no more than 0.50 wt.-%, particularly preferably no more than 0.25 wt.-%, very especially preferably no more than 0.10 wt.-%.

Particularly advantageous such materials that can be used for the insulating element are S glasss, M-glasss, Q-glasss, D-glasss, aluminoborosilicates (e.g. variant 1: Si02 with 94-97 wt.-%, A1203 with 3-6 wt.-%, others < 1 wt.-%; variant 2: Si02 with 54 wt.-%, A1203 with 46 wt. %; variant 3: Si02 with 54 wt.-%, A1203 with 43 wt.-% and Cr203 with 3 wt.-%), aluminosilicates, aluminafibre and silicate glasss, since these are, on the one hand, low in alkali metal or alkali metal-free and, in addition, are characterized in part by increased moisture resistance and/or strength.

S-glasss (S = Strength) is an aluminum silicate glasss that is suitable for high mechanical requirements at high temperatures.

M-glasss (M = Modulus) is a glasss containing berrylium that is used for the highest mechanical requirements due to its increased stiffness (modulus of elasticity).

Q-glasss (Q = quartz) refers to fibers/filaments made of quartz glasss (Si02), which are usually used at very high temperatures of up to 1,450°C (e.g. as fire protection).

D-glasss (D = Dielectric) is a borosilicate glasss.

Silicate glasss is defined as fibers/filaments with a mass content of Si02 of more than 94%. The remaining mass fractions are accounted for by A1203 and about 1.5% by other constituents, the proportion of alkali metals, alkaline earth metals and their compounds (especially oxides therewith) being limited by the ranges defined herein. Silicate glasss is preferably obtained by chemical leaching, whereby (alkaline earth) metal constituents are removed.

Materials otherwise commonly used for thermal insulation of hot parts at operating temperatures in the range of 20°C to 750°C, such as artificial mineral fibers, in particular from E-glasss, ECR-glasss, C-glasss, basalt, calcium silicate fibers, CMS fibers (calcium magnesium silicate), rock wool, slag wool, ceramic fibers, have a mass content of oxides of sodium, potassium, calcium, magnesium and barium in total of more than 5 wt.-%. % by weight and are therefore not suitable as materials low in calcium, preferably low in alkali metals and/or alkaline earth metals, particularly preferably calcium-free, very preferably alkali metal-free and/or alkaline earth metal-free materials.

Conventional ECR glasss (> 15 wt.-% CaO), E glasss (> 15 wt.-% CaO) and/or C glasss (> 10 wt.-% CaO), in particular for components of the hot-metal-part insulating element according to the invention, which are in direct contact with the hot-metal-part to be insulated, are thus ruled out as materials for the insulating element. The aforementioned materials (e.g. as a layer, ply or filler) are also ruled out for the hot-metal-part insulating element if they have direct or indirect contact (e.g. leaching due to moisture) with the hot-metal-part or other components of the hot-metal-part insulating element containing heavy metals.

Typical compositions of glassses are listed in Table 2 below:

Table 2: Typical compositions of glassses

Oxid E-Glass [%] ECR-Glass C-Glass [%]A-Glass [%]AR-Glass S-Glass [%]D-Glass

[%] [%] [%] SiO2 52-56 54-62 64-68 63-72 55-75 64-66 74,0 A1203 12-16 9-15 3-5 0-6 0-5 24-25 B203 5-10 - 0-6 0-8 3-12 - 22,5 CaO 16-25 17-25 11-15 6-10 1-10 0-0,2 MgO 0-5 0-4 2-4 0-4 - 9,5-10 BaO - - 0-1 - - Li20 - - - - 0-0,15 Na20 + K20 0-2 2-5 7-10 14-16 11 -21 0-0,2 3,5 Ti02 0-1,5 - - - - Fe2O3 0-0,8 0-0,8 - - - 0-0,1 F2 0-1 - - - -

In order to prevent or reduce the formation or release of heavy metal compounds that are harmful to health and the environment, in particular chromium compounds, more preferably chromium(VI) compounds at high operating temperatures, the materials used for the insulating element contain sodium as an alkali metal and/or sodium compounds (in particular sodium oxide or sodium hydroxide) with a mass content of less than 5 wt.- % by weight, preferably in the range from 0 to 4 wt.-%, particularly preferably in the range from 0 to 3 wt. %, very particularly preferably in the range from 0 to 2 wt.-%, 0 to 1.5 wt.-%, 0 to 1 wt.-%, or 1 to 2 wt.-%.

It is clear from Fig. 1 that it is particularly preferred that the materials defined herein which are used for the insulating element contain potassium as an alkali metal and/or potassium compounds (in particular potassium oxide or potassium hydroxide) with a mass content of less than 5 wt.-%, preferably in the range of 0 to 1 wt.-%, or 1 to 2 wt.-%. % by weight, preferably in the range from 0 to 4 wt.-%, particularly preferably in the range from 0 to 3 wt. %, very particularly preferably in the range from 0 to 2 wt.-%, 0 to 1.5 wt.-%, 0 to 1 wt.-%, or 1 to 2 wt.-%.

According to a particularly preferred embodiment, the materials used for the insulating element have magnesium as an alkaline earth metal, magnesium ions and/or magnesium compounds (in particular magnesium oxide) with a mass content of less than 5 wt.-%, preferably in the range from 0 to 4 wt.-%, particularly preferably in the range from 0 to 3 wt. %,very preferably in the range from 0 to 2 wt.-%, 0 to 1.5 wt.-%, 0 to 1 wt.-%, or 1 to 2 wt. %,as a result of which the formation or release of heavy metal compounds harmful to health and the environment, in particular chromium compounds, more preferably chromium(VI) compounds, is prevented or reduced at high operating temperatures.

However, the above-mentioned materials containing calcium, in particular alkali metals, alkaline earth metals and their compounds with a mass content of more than 5 wt.-% can be used if they are provided with functional impregnations and/or coatings and/or laminations which are subject to a direct chemical reaction, in particular a reaction between alkali metals, alkaline earth metals and their compounds with a mass content of more than 5 wt. % by weight can be used if they are provided with functional impregnations and/or coatings and/or laminations which counteract a direct chemical reaction, in particular a reaction between alkali metals, alkaline earth metals and their compounds with a heavy metal or a heavy metal compound to form heavy metal compounds which are harmful to health and the environment, as defined herein, when used as intended, so that the formation of heavy metal compounds which are harmful to health and the environment, e.g. chromium compounds, in particular chromium(VI) compounds, is prevented. chromium compounds, in particular chromium(VI) compounds, is prevented or reduced to such an extent that the resulting concentration of these compounds does not pose any risks to health and the environment or poses risks that can be averted by suitable, reasonable protective measures. This impregnation, coating and/or lamination thus has the advantageous effect, recognizable to the skilled person, that the resulting, i.e. impregnated, coated and/or laminated, aforementioned materials containing calcium, in particular alkali metals, alkaline earth metals and their compounds with a mass content of more than 5 wt.-%, are gas-tight and/or water-tight. This also prevents gaseous heavy metal species, in particular gaseous chromium compounds, from coming into direct contact with the materials containing calcium, in particular alkali metals, alkaline earth metals and their compounds with a mass content of more than 5 wt.-%.

The impregnation, coating and/or lamination preferably has a layer thickness of 5 to 120 pm.

Suitable laminations include, for example, metal foils (e.g., aluminum foils, stainless steel foils, copper foils, titanium foils or others) or plastic foils (e.g., silicone foils, PTFE foils, polyimide foils, PVDF foils, polyamide-imide foils, PEEK foils, PPS foils, PPSU foils, PES foils, PSU foils, PEI foils or others).

According to a preferred embodiment, the starting materials, i.e. the materials containing calcium, in particular alkali metals, alkaline earth metals and their compounds with a mass content of more than 5 wt.-%, which are conventionally used for the production of hot part dam elements, are coated with a layer of metals, preferably evaporable aluminum. Aluminum is particularly suitable because it ensures excellent product protection, can be easily processed and forms an ideal, preferably pore-free barrier against external influences.Suitable functional impregnations and/or coatings are based, for example, on silica, aluminum oxide, zirconium oxide, titanium oxide, silicon carbide or layered silicate (e.g. vermiculite).

According to a particularly preferred embodiment, the layered silicate is selected from the group of materials comprising the two-layer clay minerals (1: 1-layered silicates), in particular the layered silicates belonging to the kaolinite-serpentine group without cell-damaging and/or carcinogenic effect, preferably kaolinite, serpentine, as well as three-layered clay minerals (2:1-layered silicates), in particular beidellite, montmorillonite, vermiculite, illite, saponite, smectite, laponite (e.g., laponite XLG, laponite XLG, laponite XLG, laponite XLG, laponite XLG). e.g. Laponite XLG, XLS resp. RD, RDS), Montmorillonite, Muscovite, Nontronite, Pyrophyllite, Saponite, Talc or Hectorite.

The basic structure of phyllosilicates has the following structural formula: [Si 2 O5 2 n] n-,

whereas x = 1,5 und n = 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22 or 24

Aa - Bb - Cc - Dd - [(SiO 4-)]n [AI0 3]m (OH)z

wheras

A = H, Li, NH 4 , Na and/or K;

B = Be, Mg, Ca, Sr, Ba, Zn, Fe, Mn;

C = B, Al, Ga;

D = Ti, Zr;

0:5 x:5 2 and 0:5 n 5 24 and 05 m < 4,

0 5a 4,

0 5b 4,

0o5 c < 4,

0o5 d < 4,

(a+b+c+d-z) = n(4-2x) + 3m;

It has been shown that the proportion of A is reduced as much as possible in order to minimize the proportion of Na and/or K. For this reason, preferably 0 a 2, very preferably 0 a 5 1, in particular 0 a 5 0.5, ideally a = 0 (although the skilled person knows that the presence of traces and/or impurities of Na and/or K cannot be completely excluded).

According to a particularly preferred embodiment of the present invention, A = H, Li, and/or NH4, so that the structural formula has no Na or K.

It has been shown that the proportion of A is reduced as much as possible in order to minimize the proportion of Ca and/or Mg. For this reason, preferably 0 b5 2, very preferably 0 b 1, in particular 0 b 5 0.5, ideally b = 0 (although the skilled person knows that the presence of traces and/or impurities of Ca and/or Mg cannot be completely excluded).

According to a particularly preferred embodiment of the present invention, B = Sr, Ba, Zn, Fe, It may also be provided that the materials containing calcium, in particular alkali metals, alkaline earth metals and their compounds with a mass content of more than 5 wt.-%, are pretreated in a chemical process in such a way that they no longer contain calcium, in particular alkali metals, alkaline earth metals and their compounds with a mass content of more than 5 wt.-%. This includes, for example, special leaching processes and the like.

Nevertheless, the above-mentioned materials containing calcium, in particular alkali metals, alkaline earth metals and their compounds with a mass content of more than 5 wt.- % by weight, can also be used, for example, as heat-insulating filler materials in the form of loose fibers, powder, granules, insulating compound or in any other technically useful form of presentation described herein in a first inner layer (7) and/or in at least one second inner layer (8), since in this case there is no direct contact between the metallic surface of the hot metal-part to be insulated and these materials and/or if indirect contact (e.g. leaching due to moisture) with the hot-metal-part is required. leaching by moisture) to the hot-metal-part or other components of the hot-metal-part insulating element containing heavy metals can be ruled out.

Particularly preferred are fibers/filaments consisting of the materials S-glass, M-glass, Q glass, D-glass, aluminoborosilicates, aluminosilicates, alumina fibers, silica fibers, carbon fibers, cellulose fibers, textile fibers (in particular natural fibers, synthetic fibers), textile- metallic fibers made of metal (e.g. aluminum), metal alloys (e.g. steel wool), plastic-metallic fibers (e.g. polyamide) or metal alloys (e.g. polypropylene). steel wool), plastic-coated metal, metal-coated plastic or a core completely sheathed with metal, and plastic fibers, such as para-aramid, meta-aramid, PBI, PBO, polyimide, polypropylene, polyamide or polyester fibers, which are suitable for the thermal insulation of hot-metal-parts at operating temperatures in the range from 20°C to 750°C, in particular in the range from 200°C to 750°C, very preferably in the range from 400°C to 750°C. Aluminum silicate wool or polycrystalline wool are also suitable as materials low in alkali metals or alkaline earth metals. In addition, polyurethane/polyisocyanurate rigid foam (PUR/PIR), polystyrene particle foam (EPS) and extruder foam (XPS) as well as flexible elastomeric foam (FEF) are particularly suitable as materials for insulation in the low temperature range from 20°C to 150°C.

Suitable natural fibers for textiles and textile fabrics include fibers of plant origin, fibers of animal origin and man-made fibers made from natural polymers. Fibers of plant origin include in particular seed fibers such as cotton and kapok, leaf fibers such as hemp, jute, ramie, flax (linen) and others, hard fibers such as sisal and others. Fibers of animal origin have proven to be especially fine animal hair, such as sheep wool, alpaca wool, cashmere wool, angora wool, camel hair, and others; coarse animal hair, such as horsehair, cattle hair, pig bristles, and others; and silks, such as mulberry silk, tussah silk, and others. Man-made fibers from natural polymers are especially regenerated cellulose, such as viscose, rayon, modal,lyocell, cupro; from cellulose esters, such as acetate, triacetate; protein fibers, such as casein fibers; alginate; chitin and bio-based polyamides.

meta-aramid, para-aramid; polyacrylics (PAN); modacrylics (MAC); polytetrafluoroethylene (PTFE); polyethylenes (PE, UHMW-PE, HM-PE; HP-PE); polypropylene (PP); polychlorides (CLF; PVC); elastanes (EL, EA/ELAS, PUE); polybenzoxazole (PBO); Polybenzimidazole (PBI); Polyurea; Melamine (MEL); Polyphenylene sulfide (PPS); Trivinyl; Elastolefin (EOL); Elastomultiester (ELE); Polyvinyl alcohol (PVA;PVAL); Vinylal (PVAL); Polycarbonate (PC); Polystyrene (PST, PS)).

It is understood that the materials defined herein that can be used for the insulating element can also be used within a layer or layer or as a thermal insulating filler material also combined, for example loose or as hybrid materials.

The material that can be used for the insulating element can also be surface modified, e.g. it can contain an organic sizing or another modification, such as polydimethylsiloxane (PDMS), hexamethyldisilazane or alkylsilanes.

A preferred fiber diameter is preferably in the range of 3 pm to 30 pm, more preferably 6 pm to 17 pm, most preferably between 6 pm and 9 pm.

The fibers used are either length-limited (so-called staple fibers or chopped fibers) or continuous (filaments).

In addition, IR opacifiers can be added to the materials that can be used for the insulation element, for example in the form of powder. Suitable materials include C, SiC, ilmenite, zirconium silicate, iron oxide, TiO2, ZrO2, manganese oxide and iron titanate.

Granules and powders, such as fumed silica, aerogels, silicone resins (e.g. polymethylsiloxanes or polyalkylphenylsiloxanes and their copolymers with alkyd, acrylic or polyester resins or polyethers), polyfluorocarbon compounds, acrylic compounds, acrylates and polyurethanes are also suitable as thermal insulation fillers. , polyfluorocarbon compounds, acrylic resins, oligomeric siloxanes, organosilanes, silicic acid esters or silicates with hydrophobic additives, silicates, stearates, kerosenes, fatty acids, fatty acid esters, wax esters, ceresins, bitumen, alkyd resins, acrylate copolymers (e.g. also organosilicon acrylate copolymers) , styrene copolymers (e.g. butadiene-styrene copolymers or carboxylated butadiene-styrene copolymers) , polyvinyl acetate , polyvinyl propionate , polystyrene acrylates , vinyl chloride copolymers , vinyl acetate copolymers , vinyl terpolymers

, polyolefins, ethylene copolymers , propylene copolymers , thermoplastic polymers and polymer blends (e.g. e.g. of polyethylene or polypropylene and ethylene/vinyl acetate or ethylene/acrylate copolymers, optionally silane-crosslinked to increase the softening temperature) and carbon. The materials used for the insulating element can be used individually or in combination.

Layered silicates such as vermiculite (also in expanded form) are also suitable as heat insulating filler materials in the form of granules and powders.

Hot-metal-part insulating element

For the purposes of the invention, the term "hot-metal-part insulating element" means a thermal insulation for hot-metal-parts (as defined herein) which are used against heat radiation as heat protection (e.g. with respect to components located in the vicinity) or heat loss to maintain the temperature in the system in the case of hot-metal-parts which are operated above the ambient temperature, preferably at temperatures in the range from 20°C to 750°C, in particular in the range from 200°C to 750°C, very preferably in the range from 400°C to 750°C.

The thickness of the hot-metal-part insulating element according to the invention ranges from 6 pm (e.g. foils) to 150 cm, 0.5 mm to 100 cm, preferably in the range from 1 to 90 cm, 1 to 80 cm, 1 to 70 cm, 1 to 60 cm, 1 to 50 cm, 1 to 40 cm, particularly preferably from 10 to 300 mm, 10 - 250 mm, 10 to 200 mm, 10 to 150 mm, very particularly preferably from 10 to 140 mm, to 130 mm, to 120 mm, to 110 mm, to 100 mm, to 90 mm, to 80 mm, to 70 mm, to 60 mm, to 50 mm, to 40 mm, to 30 mm, to 20 mm, respectively.

The hot-metal-part insulating element according to the invention is formed at least in a single layer or in a single layer, so that it comprises at least one so-called outer layer (2), which is formed as a contact surface for a hot-metal-part.

The insulation element according to the invention can also be of multilayer design, preferably of two, three, four, five or more layers or of multilayer design. A multilayer insulation is an insulation made of several layers of the same material (also material mixtures), while a multilayer insulation is an insulation made of several layers, where at least two layers are made of different materials (also material mixtures).

The choice of whether the hot-metal-part insulating element according to the invention is single-layered/single-layered or multi-layered/multi-layered, the choice of materials used and the determination of the thickness of the hot-metal-part insulating element are based on the energy efficiency to be achieved by the hot-metal-parts to be thermally insulated.

The basis for the determination of insulation layer thicknesses, for example according to the guideline VDI 2055 sheet 1, are operational and economic requirements as well as legal requirements and regulations of environmental protection, e.g. the Energy Saving Ordinance (EnEV).

Operational requirements are, for example: compliance with a specified upper limit for heat flux density or total heat loss, compliance with a specified surface temperature to protect against burns and to reduce the risk of ignition and to prevent condensation and ice formation, limitation of the temperature change of a medium within a specified time for a stationary medium, e.g. temperature drop in a container, or within a specified distance for a flowing medium, e.g. temperature drop in a pipe. From an economic point of view, capital expenditure and heat loss costs should result in a minimum for the insulation layer thickness to be determined; it is necessary to optimize between capital expenditure for increasing energy efficiency and costs caused by heat loss.

According to a preferred embodiment, the hot-metal-part insulating element (1) comprises at least one second outer layer (5) (also referred to herein as the upper outer layer), which (when the hot-metal-part insulating element is used as intended) is arranged opposite the first outer layer (2), the second outer layer (5) having calcium and calcium compounds (in particular calcium oxide) with a mass content of less than 5 wt.-%.

Preferably, the second outer layer (5) or upper outer layer is also formed with a low alkali metal and/or alkaline earth metal content, i.e. the upper outer layer has less than 5 wt.-% of an alkali metal, alkaline earth metal or compounds thereof (in particular oxides thereof).

According to a particularly preferred embodiment, the second outer layer (5) or upper outer layer (5) is free of alkali metal and/or alkaline earth metal.

The individual layers of the insulating element can be joined together by suitable joining techniques. For example, the layers can be sewn, welded, stitched, glued, needled, stapled, bonded or connected by other joining methods. If necessary, it is also possible to dispense with a joining technique of the individual layers to one another, e.g. by suitable folding or folding together, or to use a combination of the above-mentioned joining techniques.

The layers or plies of the hot-metal-part insulating element according to the invention can also be joined to a single-layer or multilayer or single-layer or multilayer side wall (6) or a corresponding side part, thus giving the hot-metal-part insulating element a box-like or mattress-like shape. The side wall can be formed, for example, as a separate side part connected to the lower outer layer (2) and the upper outer layer (5) by suitable joining techniques described herein, or by so-called darts of the lower outer layer (2) or the upper outer layer (5). Other forms of presentation are also conceivable and are not described in detail herein. The side wall (6), together with the first outer layer (2) and the second outer layer (5), provides a so-called sheathing of the hot-metal-part insulating element, which spans a free space that can be filled by at least one first inner layer.

The first inner layer and further inner layers of the hot-metal-part insulating element can be formed in any technically useful form described herein.

The first inner layer and further inner layers of the hot-metal-part insulating element can, for example, be loosely filled or in the form of loose fibers, nonwovens, mats, sheets, felts, bundles, papers or cardboards, in one or more layers, or in one or more layers, preferably of low-calcium or calcium-free insulating materials, particularly preferably of insulating materials low in alkali or alkaline earth metals or free of alkali or alkaline earth metals, very particularly preferably of silicate fibers. Silicate fibers, as asbestos-free and inorganic products, advantageously contain no toxic or irritating substances and, compared with biosoluble fibers, exhibit excellent temperature resistance up to 1200°C. Thus, the silicate fiber can advantageously serve as insulation material even in case of fire. The silicate fiber is preferably used as loose fiber, paper, cardboard, bundles, preferably as nonwoven, particularly preferably as felt, most preferably as in the form of a fiber mat as an insulating material.

The fineness, i.e. the average diameter, of the preferably used silicate fiber as insulating material of the hot-metal-part insulating element is, for example, 4 to 17 pm preferably 4 to 13 pm particularly preferably 4 to 11 pm most preferably 6 to 9 pm. A fineness defined in this way advantageously avoids penetration into the lungs and mechanically triggered itching, which can otherwise occur during assembly of the elements.

The SiO2 content of the silicate fiber is typically between 85 and 99%, preferably between 90 and 99%, particularly preferably between 92 and 99%, most preferably between 94 and 98%. The remaining percentages are distributed between A1203 and others, it being clear that the proportion of alkali metals, alkaline earth metals and their compounds (especially oxides therewith) is limited by the ranges defined herein.

The fiber mat as an embodiment of the insulation material of the hot-metal-part insulating element containing, for example, silicate fibers, which is produced, for example, by needling fibers and fiber materials (as defined herein) or as stitch-bonded fabric of fiber materials (as defined herein), may contain binders with up to 5 wt.-%, preferably up to 4%, particularly preferably up to 3%, up to 2%, up to 1%, most preferably < 1% or binder-free.

The fiber mat preferably comprises or consists of silicate fibers having a fiber length of from 1 mm to 1000 mm, preferably from 1 to 500 mm, 1 to 400 mm, 1 to 300 mm, 1 to 200 mm, particularly preferably between 1 to 190 mm, 1 to 180 mm, 1 to 170 mm, 1 to 160 mm, 1 to 150 mm, 1 to 140 mm, 1 to 130 mm, 1 to 120 mm, very preferably 1 to 110 mm, 1 to 100 mm, 1 to 90 mm, 1 to 80 mm, 1 to 70 mm, 1 to 60 mm, 1 to 50 mm, 1 to 40 mm, 1 to 30 mm, 1 to 20 mm, 1 to 10 mm. A limited fiber length defined in this way advantageously allows loose layering of the fiber material, so that improved thermal insulation properties can be achieved by the insulating cavities obtained.

The thickness of the fiber mat as one embodiment of the hot-metal-part insulating element is typically between 1 to 150 mm preferably 1 to 140 mm, 1 to 130 mm, 1 to 120 mm, 1 to 110 mm , 1 to 100 mm particularly preferably 3 to 90 mm, 3 to 80 mm, 3 to 70 mm, very preferably 5 to 60 mm, 5 to 50 mm, 5 to 40 mm, 5 to 30 mm, 5 to 25 mm, 10 to 25 mm, 12.5 to 25 mm, 15 to 25 mm, 15 to 20 mm, 10 to 20 mm, 5 to 20 mm.

The density of the fiber mat as an embodiment of a silicate fiber of the insulating material of the hot-metal-part insulating element is preferably between 50 and 500 kg/m3 preferably between 50 and 400 kg/mi 3 , 50 and 300 kg/mi 3 , particularly preferably between 50 and 290 kg/mi 3, 50 and 280 kg/mi 3, 50 and 270 kg/mi 3 , 60 and 260 kg/mi 3 , 70 and 250 kg/mi 3 , very preferably between 80 and 240 kg/mi 3 , 80 and 230 kg/m3 ,80 and 220 kg/m3 ,80 and 210 kg/m,90 and 200 kg/m,100 and 200 kg/m 3,110 and 190 kg/m 3 ,120 and 195 kg/m3 ,130 and 180 kg/m,130 and 170 kg/m,130 and 160 kg/mi 3. Such a defined density advantageously enables a low weight of the entire hot-metal-part insulating element, which is an important criterion of applicability, especially in the case of large-area thermal insulation requirements of mechanically unstable hot elements such as downpipe systems. The weight of the fiber mat necessarily results from the thickness of the fiber mat and its density.

The fiber mat, described herein as an embodiment of the insulating material of the hot-metal part insulating element, can be used, for example, raw, without further pretreatment, preferably thermally desized, particularly preferably preshrunk residual shrinkage < 5%, < 4%, < 3%, < 2%, < 1%, most preferably thermally desized and preshrunk residual shrinkage <5%,<4%,<3%,<2%,<1%.

Suitable materials that can be used for the sidewall or the first and each additional inner layer are those defined herein. As described above, the one or the further inner layers can be selected according to need and application. According to a preferred embodiment, the single-layer or multilayer or single-layer or multilayer sidewall (6) is low in calcium, very preferably low in alkali metal and/or alkaline earth metal, preferably free of alkali metal and/or alkaline earth metal. As already described above, the presence of moisture or water (e.g. rainwater, condensation, condensation water and ice formation) can lead to the observation of increased leaching of heavy metal compounds or precursor compounds thereof which are harmful to health and the environment. From this consideration, it proves to be particularly advantageous if the entire sheathing of the insulating element according to the invention consists of materials which contain alkali metals, alkaline earth metals and their oxides with a mass content of less than 5 wt.-%, i.e. alkali metals, alkaline earth metals and their oxides with a mass content of less than 5 wt.-%. % by weight, i.e. low in alkali metals and/or alkaline earth metals, very advantageously free of alkali metals and/or alkaline earth metals, so that all possible (outwardly directed) contact surfaces or contact points of the hot-metal-part insulating element which can come into contact with the metal surface of the hot-metal-part do not thereby contribute to the formation of toxic (heavy) metal vapors and (heavy) metal dusts during the intended use of the hot-metal-part.

According to a preferred embodiment, the outer layer of the hot-metal-part insulating element comprises a metal mesh, in particular stainless steel mesh, or a foil, in particular a metal foil, more preferably stainless steel foil. At least the hot-metal-part insulating element is preferably wrapped with such a foil. When foils are used, the hot-metal-part insulating element is in this respect a "closed system" towards the outside of the hot-metal-part, so that direct contact between the hot-metal-part and the materials used for the insulating element is prevented.

A "closed system" is to be understood here as a chemical barrier which advantageously prevents the exchange of substances between the hot-metal-part and the insulating materials of the insulating element as well as the surrounding, in particular with the hot metal-part, or at least the penetration of substances, preferably toxic heavy metal compounds or precursors thereof. Advantageously and in particular compared to conventional porous insulation systems such as calcium silicates or ceramics (e.g. JP2011232021A), this substance barrier enables the exchange of substances, in particular moisture and/or by-products of the hot metal parts such as metallic derivatives, to be prevented or at least minimized. In this way, on the one hand, the formation of heavy metal compounds harmful to health and the environment is counteracted or prevented and, at the same time, the corrosion of the hot-metal-part is reduced under the given ambient conditions of the hot-metal-part.

Corrosion represents one of the central technical hurdles in large-scale industry. To date, almost all insulating materials are degraded by corrosion in the medium or long term. With the hot-metal-part insulating element according to the invention, a corrosion-protective and flexible insulation is provided, the latter technically promoting the former. The synergy of corrosion protection and the flexibility of the hot-metal-part insulating element results from the fact that the interaction of the corrosion-promoting influences of thermal (seasons, times of day, technically induced temperature fluctuations), actinic (cosmic radiation), mechanical (vibration, abrasion) or chemical (industrial by-products, humidity, gases) nature is advantageously cancelled.

A "closed system" further advantageously allows a possible filling of the hot-metal-part insulating element or other layers and/or layers in the first or second inner layer to be made of insulating materials low in alkali metals and/or alkaline earth metals without hesitation. Preferably, the hot side is a stainless steel mesh, i.e. slightly heat permeable, which positively influences the heat entry "hot on insulation material" to ensure effective thermal insulation. To prevent direct heat transfer hot/cold, it is advantageous if the cold side and side wall are a non-full metal layer.

According to a preferred embodiment, the hot-metal-part insulating element (1) has a sheathing, wherein the sheathing comprises the following components, which are provided as a separation of the insulating element from the environment:

- a first outer layer (2) formed as a direct contact surface for the hot-metal-part,

- a second outer layer (5) arranged opposite the first outer layer (2), and

- optionally at least one side wall (6) which connects the first outer layer (2) and the second outer layer (5) and thus gives the hot-metal-part insulating element a box like or mattress-like shape,

whereas the sheathing of the hot-metal-part insulating element are consisting of materials which contain alkali metals, alkaline earth metals and compounds thereof with a mass content of less than 5 wt.-%, i.e. are low in alkali metals and/or alkaline earth metals, very advantageously free of alkali metals and/or alkaline earth metals.

It is understood that the individual components of the sheathing, namely the lower outer layer (2), the upper outer layer (5) and one or more side walls (6), can each be designed independently of one another as single or multiple layers or single or multiple layers. The individual layers can also be joined together by suitable aforementioned joining techniques.

In order to reduce or, at best, prevent destruction of the hot-metal-part insulating element by vibration and/or relative movements of the insulating elements with respect to one another or between insulating elements and the hot-metal-part to be insulated, individual components of the hot-metal-part insulating element, i.e. at least one outer layer (2, 5) or at least one side wall (6), in whole or in part, more preferably the entire sheathing of the insulating element, more preferably the entire hot-metal-part insulating element, may be in the form of scrims, bundles, woven fabrics, knitted fabrics, braids, nonwovens, felts, cardboards, papers, needle mats, stitch-bonded mats, mats, sheets, consolidated fibers or similar layers.

In addition, the hot-metal-part insulating element may be reinforced, in whole or in part, with a woven, knitted, knitted, or otherwise fabricated metallic sheet material that absorbs vibration from the hot part to be insulated.

According to a preferred embodiment, the entire sheathing of the hot-metal-part insulating element, i.e., the first outer layer (2), the second outer layer (5), and the at least one side wall (6) is formed as a heat-insulating textile sheet, plastic film, metal foil, plastic-coated metal, metal-coated plastic, or mixtures thereof.

In this context, a textile sheet material is a scrim, bundle, woven fabric, knitted fabric, braided fabric, nonwoven fabric, felt, cardboard, paper, needle mat, stitch-bonded mat, mat, plate, consolidated fibers or similar layers.

Suitable materials for sheathing the hot-metal-part insulating element also include foils, in particular metal foils, especially preferably stainless steel foils (perforated or unperforated), or metallic fabrics.

It has proved advantageous for the sheathing of the hot-metal-part insulating element to be wholly or partly in the form of a metal foil or sheet.

On the one hand, this structure is advantageous if materials which are not low in alkali metals or alkaline earth metals or are alkali metal- or alkaline earth metal-free are used as the inner layer (7) or as the heat-insulating filler material, e.g. for cost reasons, so that they are shielded from direct contact with the hot-metal-part.

Nevertheless, this structure is particularly preferred if the hot-metal-parts to be insulated are subject to increased exposure to external moisture (e.g. rainwater, condensation and/or ice formation) or external mechanical stresses.

Furthermore, this construction allows the hot-metal-part insulating element to be joined to the hot-metal-part (as defined herein), e.g., by welding, crimping, bolting, bonding, or other joining means.

According to a preferred embodiment, the hot-metal-part insulating element may be completely or partially encased by a metallic sheath (9) in the form of a metal foil or a metal sheet (these are free of alkali and alkaline earth metals from the outset). It may also be provided in this case that the metallic jacket (9) is joined to the hot-metal-part (as defined herein), e.g. by welding, pressing, screwing, bonding, or other joining methods.

The metallic jacket (9) in the form of a metal foil or a metal sheet can be in half-shell or full shell form.

In a preferred embodiment, the hot-metal-part insulating element (1) comprises at least one first inner layer (7), wherein the at least one first inner layer (7) is in the form of a ply (i.e., single-layered or multilayered or single-layered or multilayered), as a heat-insulating filler material, or in any technically useful form described herein (i.e., for example, in the form of loose fibers, powders, granules, or insulating compound as defined herein).

If the inner layer (7) is in the form of a ply, it may be in the form of a textile sheet, plastic film, metal foil (such as stainless steel foil), plastic-coated metal, metal-coated plastic, or mixtures thereof.

In one embodiment, the hot-metal-part insulating element is a three-layer or multi-layer insulating element or system, in the form of a single-layer or multi-layer bottom outer layer (2), a single-layer or multi-layer top outer layer (5), and a single-layer or multi-layer inner layer (7). The presence of side walls (6) is not required in this structure.

Optional films, which can be used, for example, as sheathing (i.e. as the layer delimiting the hot-metal-part insulating element as such and as a whole), for laminations of the insulating materials or any other component of the hot-metal-part insulating element according to the invention, are preferably made of polymers such as. e.g. polyimide, polyaramide, polyamide, silicone, polyethersulfones / polyestersulfones, polyphenylenes, polyarylethers, polyarylesters, polyarylsulfones, especially preferably metal foils e.g. brass, tin, bronze, copper, nickel, monell, titanium, aluminum most preferably stainless steel or inconel foils. These selected materials are known to the skilled person as high performance thermal materials.

The foil used typically has a thickness between 6 pm and 500 pm preferably between 6 pm and 400 pm, 6 pm and 300 pm, 6 pm and 200 pm, 6 pm and 100 pm, particularly preferably between 6 pm and 90 pm 6 pm and 80 pm, 6 pm and 70 pm, 6 pm and 60 pm, most preferably between 6 pm and 50 pm, 6 pm and 40 pm, 6 pm and 30 pm, 6 pm and 20 pm, 6 pm and 10 pm. The preferred thickness of the films advantageously allows mechanical stability without compromising the flexibility of the hot-metal-part insulating element according to the invention.

The weight, strength, elongation of the foil used depends on the material used and its specific density and is thus also defined.

The stainless steel or Inconel foil used in a particularly preferred manner consists of a stainless austenitic steel, especially preferably of a high-temperature resistant austenitic stainless steel, most preferably of the austenitic materials 1.4571, 1.4401, 1.4404, 1.4841, 1.4845, 1.4876, 1.4878, 1.4828, 1.4301, 1.4306, 1.4435, 1.4541, 1.4016.

The foil can be smooth, perforated, embossed or calotted in its design and and advantageously enables the skilled person to make an application-specific selection.

The components of the hot-metal-part insulating element can further be formed in the technically useful presentation form of woven fabrics, bundles, and hybrid textiles. According to the invention, woven fabrics, bundles and hybrid textiles comprise (earth) alkali metal-free woven fabrics, bundles, hybrid textiles, with or without wire reinforcement, with or without impregnation or with or without coating, also microporous metal foil, preferably silicate fabric, or as a mixture thereof.

The silicate fabric of the hot-metal-part insulating element preferably selected for woven fabrics, packages and hybrid textiles has, for example, a weight per unit area of 50 to 5000 g/m 2, preferably 100 to 3000 g/m2 , particularly preferably 300 to 2000 g/m 2 , very particularly preferably 600 to 1500 g/m 2 , the preferred ranges contributing advantageously to the technical requirement of a low weight of the hot-metal-part insulating element.

The thickness of the preferred silicate fabric is generally preferably between 10 mm and 0.05 mm preferably between 9 and 0.1 mm, 8 and 0.1 mm, 7 and 0.1 mm, 6 and 0.1 mm, 5 and 0.1 mm, particularly preferably between 4 and 0.15 mm, 3 and 0.15 mm, 2 and 0.15 mm, most preferably between 1.9 and 0.2 mm, the thicknesses defined in this way advantageously enabling high stability and at the same time low weight of the silicate fabric.

The thread density of the preferred silicate fabric per thread system (warp or weft) is typically between 1 and 500 threads/10 cm, preferably between 10 and 450 threads/10 cm, particularly preferably between 20 and 400 threads/10 cm, most preferably between 30 and 300 threads/10 cm.

The weave (construction) of the silicate fabric can be any woven weave such as leno weave, sham leno weave, plain weave, twill weave, Panama weave, rep weave, atlas or satin weave, ripstop, double or multiple weave or derivatives of these weaves. Most preferably, canvas, panama, cross twill, twill, ripstop.

It is understood that each silicate fabric described herein has different strengths (between 50 N/5 cm and 10000 N/5 cm) and elongations (between 0 and 25%) in warp and weft.

The fineness of the silicate fiber of the silicate fabric used as the preferred fabric, bundle, and/or hybrid textile of the hot-metal-part insulating element is 4 to 17 pm preferably 4 to 13 pm most preferably 4 to 11 pm most preferably 6 to 9 pm, the fineness thus defined being advantageous to promote insulating voids without disposing harmful effects. In addition, the fineness has the advantage that no fragments 5 3 pm, which may be respirable, are formed.

The SiO2 content of the preferably selected silicate fiber is, for example, between 85 and 99% preferably between 90 and 99% particularly preferably 92 and 99% very particularly preferably between 94 and 98%. The remaining percentages are distributed among A1203 and others, it being clear that the proportion of alkali metals, alkaline earth metals and their compounds (in particular oxides therewith) is limited by the ranges defined herein.

A preferred silicate fiber is present as a staple fiber, filament, textured filament, roving, or mixture thereof.

The thread of the silicate fiber of the silicate fabric used as the preferred fabric, bundle, and/or hybrid textile of the hot-metal-part insulating element made from the silicate fiber is present as a single yarn, preferably as a plied yarn or multiple plied yarn, and may be formed without wire reinforcement, but preferably with wire reinforcement. In this case, the wire reinforcement typically consists of 1 to 100 wires which are present individually or as a wire bundle, preferably 1 to 90, 1 to 80, 1 to 70, 1 to 60, 1 to 50 wires, particularly preferably 1 to 40, 1 to 30, 1 to 20, 1 to 10 wires, most preferably 1 to 9, 1 to 8, 1 to 7, 1 to 6, 1 to 5, 1 to 4, 1 to 3, 1 to 2 wires, wherein the wire bundles of the optional wire reinforcement described herein function particularly advantageously for the structural stability of the silicate fiber.

The diameter of the wire of a wire reinforcement of a thread of a silicate fiber of the preferably used silicate fabric of the hot-metal-part insulating element according to the invention is, for example, between 1 mm and 0.01 mm preferably between 0.9 mm and 0.01 mm, 0.8 mm and 0.01 mm, 0.7 mm and 0.01 mm, 0.6 mm and 0.01 mm, 0.5 mm and 0.01 mm, particularly preferably between 0.4 mm and 0.05 mm, 0.3 mm and 0.05 mm, 0, 2 mm and 0.05 mm, very preferably between 0.19 mm and 0.1 mm, 0.18 mm and 0.1 mm, 0.17 mm and 0.1 mm, 0.16 mm and 0.1 mm, 0.15 mm and 0.1 mm, 0.14 mm and 0.1 mm, 0.13 mm and 0.1 mm, 0.12 mm and 0.1 mm, 0.11 mm and 0.1 mm, the diameters of the wire defined herein serving expedient stability of the silicate fiber without exhibiting particulate and thus potentially harmful properties.

As material for the wire of a wire reinforcement of a thread of a silicate fiber of the preferably used silicate fabric of the hot-metal-part insulating element according to the invention serve all metals and their alloys, such as brass, tin, bronze, copper, nickel, Monell, titanium, aluminum, iron raw, iron galvanized, Inconel, steel, duplex steel, stainless steel, martensitic steels, ferritic steels, austenitic steels. Preferably of a stainless austenitic steel, more preferably of a high temperature resistant austenitic stainless steel, most preferably of the materials 1.4571, 1.4401, 1.4404, 1.4841, 1.4845, 1.4876, 1.4878, 1.4828, 1.4301, 1.4306.

The yarns/twists used for the silicate fabric of the hot-metal-part insulating element according to the invention generally preferably have a fineness of 11 tex (tex = g/1000 m) to 3000 tex, preferably from 34 tex to 2700 tex, particularly preferably 68 tex to 2500 tex very particularly preferably from 140 tex to 2000 tex.

The silicate fabric used is provided either without wire reinforcement, preferably with wire reinforcement in warp or weft, very preferably with wire reinforcement in warp and weft, whereby the stability of the silicate fabric can be advantageously modified.

Wire reinforcement of the silicate fabric of the hot-metal-part insulating element of the invention is achieved either by a wire-reinforced yarn as described herein or by weaving in wires as described herein. The wire reinforcement occurs in warp or weft preferably in both yarn systems. It is typically done in each individual yarn or as each individual yarn or at a spacing of up to 100 consecutive yarns. Preferably at a spacing of 90, 80, 70, 60, 50, 40, 30, 20, 10 most preferably at a spacing of 9, 8, 7, 6, 5 most preferably at a spacing of 4, 3, 2, 1 threads, wherein the density of silicate fabric can be advantageously modified by the preferred spacing of the individual threads.

The silicate fabric of the hot-metal-part insulating element according to the invention described herein is used both raw preferably thermally desized, particularly preferably preshrunk, most preferably thermally desized and preshrunk.

In the respective appearance, the selected silicate fabric can be provided with impregnations, e.g. based on polyacrylate, polyvinyl acetate, polyurethane, silicone or a vermiculite dispersion, e.g. to improve the fabrication properties. Impregnations are less preferred, since decomposition products that are harmful or hazardous to health may be formed and evaporate during initial heating.

The silicate fabric used in the hot-metal-part insulating element according to the invention can, for example, be provided with coatings on one or both sides, e.g. based on polyacrylate, polyvinyl acetate, polyurethane, silicone or a vermiculite dispersion, in order to improve the ease of fabrication or to protect against vibration-induced abrasion, but this is preferably not done, since decomposition products that are harmful or hazardous to health may be formed and evaporate during initial heating.

The silicate fabric used in the hot-metal-part insulating element according to the invention can also be designed with a smooth, embossed (e.g. coarse-grain embossing), perforated or calotted foil, such as an aluminum foil, titanium foil, stainless steel foil or other temperature resistant foil as vibration or trickle protection, whereby it can be laminated on one or both sides. However, this is preferably not done, since decomposition products of the laminating adhesives used, e.g. based on polyacrylate, polyvinyl acetate, polyurethane, silicone, which may be harmful or hazardous to health, may be formed and evaporate during initial heating. Alternatively, a film described herein is bonded to the silicate fabric on one or both sides, e.g. by sewing.

Of the optional layers described herein, at least one must be present as the so-called bottom layer. If two or more different or identical layers or plies are present, they may occur in any sequence, but preferably as in the sequence of the description.

If the hot-metal-part insulating element has an optional so-called web, at least one of the optional layers or plies described herein must be formed as such. If two or more different or identical layers or plies are present, they may be in any sequence, but preferably as in the sequence of the description. The selection, number and sequence of the individual layers or plies of the web may be different from those of the lower ply, but are preferably identical in selection, number and sequence.

Of the optional layers or plies described herein, at least one must be present as a so-called upper outer layer. If two or more different or identical layers or plies are present, they may occur in any sequence, but preferably as in the sequence of the description. The selection, number and sequence of the individual layers or plies of the upper outer layer may differ from those of the lower layer or web, but are preferably identical in selection, number and sequence.

For protection against external environmental influences, such as oil, water or pollution, the upper outer layer of a single-layer insulation element and/or a multi-layer and/or multi-layer insulation system should consist either of a film as described herein, or of one of the fabrics described herein, in which case the latter is preferably provided with an impregnation and/or coating and/or lamination or foiling as described herein.

Each component of the insulating element according to the invention may optionally be provided with functional finishes, coatings, impregnations and/or laminations (in particular with metal foils) and may comprise and/or be made of metal fibers, strands, wires or filaments. The functional finishes with which any of the components of the insulating element according to the invention may be provided also include coatings, impregnations and/or laminations, in particular functional impregnations based, for example, on silica; alumina, zirconia, titania, silicon carbide, phyllosilicates (e.g. vermiculite) and/or coatings based on the aforementioned materials and/or laminations with, for example, metal foils (e.g. aluminum foils, stainless steel foils, copper foils, titanium foils) or plastic foils (e.g. silicone foils, PTFE foils, polyimide foils, PVDF foils, polyamide-imide foils, PEEK foils; PPS foils, PPSU foils, PES foils, PSU foils, PEI foils).

According to the invention, the separable hot-metal-part insulating element is designed as an independent functional element, which as such can be easily and individually assembled and/or easily separated from the hot element. As such, the product can advantageously be manufactured independently of the element to be insulated, manually and/or semi automatically or individually adaptable ("offset").

In order to easily adapt the separable hot-metal-part insulating element (e.g. during installation) to the shape of the hot appliance, this is designed as a textile or partially metallic hot-metal-part insulating element, preferably the hot-metal-part insulating element is constructed in such a way that its shape corresponds to the contour of the hot appliance in a form padded by the thickness of the entire hot-metal-part insulating element (offset). This makes it particularly suitable for applications on hot-metal-parts with sub-units of different service life, since in this case the relevant offset parts of the hot-part dam element can be replaced independently of one another. In particular, for the replacement of individual hot parts of particular stress with more advanced high performance steels whose alloys are increasingly changing to a high proportion of chromium, nickel, molybdenum, vanadium or others, the subject invention provides a solution for cost-effective renovation and/or retrofitting of individual hot part dam element parts.

In addition, the use of textile or part-metal separable hot-metal-part insulating elements has been found to be particularly advantageous when these are inherently low in alkali metal and/or alkaline earth metal. Particularly preferably, the textile or part-metal hot-metal-part insulating elements are free of alkali metal and/or alkaline earth metal from the outset.

In a preferred embodiment, all components, i.e. the insulating element sheathing, comprising outer layers (2, 5) and optionally side walls (6), and the inner layers (7, 8) or the insulating element filling of the hot-metal-part insulating element, consist of materials containing alkali metals, alkaline earth metals and their compounds (in particular oxides thereof) with a mass content of less than 5 wt.-%. I.e. all components consist at least of materials low in alkali metals and/or alkaline earth metals, and at best of materials free of alkali metals and/or alkaline earth metals. This structure proves to be particularly advantageous if permeable materials, such as scrims, bunches, woven fabrics, knitted fabrics, braids, nonwovens, felts, consolidated fibers or the like are used for the sheathing of the hot-metal-part insulating element and/or the hot-metal-parts to be insulated are exposed to an increased effect of external moisture (e.g., rainwater, condensation and ice formation) and thus leaching of conventional materials described herein is to be expected.

In addition, this construction is advantageous when the hot-metal-part insulating element is used for thermal insulation of hot-metal-parts which radiate heat to such an extent that even the outside temperature of the "cold side" of individual insulating elements of an insulating system may still be within a temperature window where chromium(VI) may possibly be formed even on the surface of the cold side. This often occurs in multi-layer insulation systems, for example in turbine insulation.

According to a preferred embodiment, the sheathing of the separable hot-metal-part insulating element comprises a foil, in particular a metal foil, more preferably a stainless steel foil. At least the hot-metal-part insulating element is preferably sheathed with such a foil. In both cases, the hot-metal-part insulating element is an externally "sealed system" in that, for example, the penetration of moisture into the hot-metal-part insulating element and penetration to the metallic surface of the hot-metal-part insulating element and associated leaching of (alkaline earth) metals and their compounds from the materials is prevented. Advantageously, this allows a possible filling of the hot-metal-part insulating element or other layers and/or layers in the first or second inner layer to be made of materials low in alkali metals and/or alkaline earth metals, as defined herein, without hesitation.

Thus, direct release into the environment of heavy metal compounds that are harmful to the environment and/or health is prevented because there is no direct contact between the metallic surface of the hot-metal-part insulating element and a calcium-containing layer, in particular a layer containing (earth) alkali metals. Under these circumstances, heavy metal compounds can at most only form within the hot-metal-part insulating element, e.g. at an inner contact surface of the lower/upper outer layer to the first and/or second inner layer (insulating material), whereby the release of heavy metal compounds into the environment is prevented by the way in which the sheathing is designed, namely as a "closed system" (e.g. as a film or metal foil), the sheathing acting as a barrier. However, a hot-metal-part insulating element with this structure may have to be disposed of as hazardous waste.

Alternatively, it may be provided that the lower outer layer (2), which is formed as a direct contact layer for a hot-metal-part to be insulated, or the lower outer side (3) or the hot-metal part itself, has a nubbed or corrugated or grooved surface (surface with elevations) substantially transverse or oblique to the longitudinal axis. Nubs can be used, for example, in the form of pyramids, truncated pyramids, truncated cones, endless wedges and/or hemispheres.

It has been found that a corresponding design of the surface of the lower outer layer (2) or of the hot-metal-part insulating element itself can act as a spacer between the surface of the hot-metal-part to be insulated (e.g. formed of steel) and the hot-metal-part insulating element, in particular components of this insulating element which are not made of low calcium or low-(earth) alkali metal materials. The cavity created by the additionally gained distance thereby advantageously favors the insulating effect of the outer layer.

According to a particularly preferred embodiment, the lower outer layer (2) is itself formed as a layer consisting of studs as defined above (see Fig. 13).

In both cases, the spacing between the nubs or elevations of the surface is in the range of 100 pm to 2 cm and the height of the spaced elevations is in the range of 100 pm to 2 cm.

The knobs or protrusions of the surface can have a coating of aluminum oxide, which in turn can be coated with precious metals, in particular platinum, rhodium, palladium or nanoparticles.

Individual components or all components of the separable hot-metal-part insulating element can also be connected to one another by connecting elements (10a) and thereby fixed to one another.

Thus, it can be provided that the hot-metal-part insulating element contains longitudinal or transverse seams, quilting seams or stitching, in order to thereby advantageously ensure the shaping and the dimensional stability (no slipping/shifting of the components (layers/layers) relative to each other) and thus a precisely fitting assembly.

Alternative connecting elements (10a) to connect the individual components or all components of the hot-metal-part insulating element to each other are, for example, staples, hooks, cords, straps, wires or similar suitable connecting elements.

According to a preferred embodiment of the present invention, the structure of the hot-metal part insulating element is from hot to cold when the hot-metal-part insulating element is used as intended:

- a stainless steel wire mesh, or a metal foil (perforated, non-perforated) and/or a fabric which is (earth) alkali metal free or low (hot side),

- an inner layer (7) or a heat-insulating filler material which is alkali metal-free or low in alkali metals, and

- a stainless steel wire cloth (preferably oil and water repellent coated), or a metal foil (perforated or not perforated) and/or a fabric (preferably oil and water repellent coated), which is (earth) alkali metal free or low (cold side).

The separable hot-metal-part insulating element according to the invention may be in the form of an insulating mattress, insulating cushion/pillow, insulating mat, insulating sleeve, insulating molded part, insulating element, insulating hood, insulating blanket, glass fabric molded mat, insulating cassette, hardco elements or the like.

Insulation elements are often in use for many years. The insulation elements are under continuous load day after day. Temperature changes, moisture, vibrations and leaks are all things that an insulating element has to withstand.

Therefore, the hot-metal-part insulating element according to the invention can contain an optional wire mesh, which has a certain mesh size. For example, the mesh size is from 50 x 50 mm to 0.5 x 0.5 mm, preferably 45 x 45 mm, 40 x 40 mm, 35 x 35 mm, 30 x 30 mm, 25 x 25 mm, 20 x 20 mm, 15 x 15 mm, 10 x 10 mm, particularly preferably 9 x 9 mm, 8 x 8 mm, 7 x7mm,6x6mm,5x5mm,4x4mm,3x3mm,2x2mm,1x1mm, 0.5x0.5mm, most preferably 7.4 x 8 mm, 7 x 9 mm. Such defined mesh size enables effective reduction of vibrations, so that mechanical abrasion of the hot-metal-part insulating element can be minimized, especially over long service life of the invention.

Made from a wire of the wire mesh, for example, having a diameter of 6 mm to 0.01 mm, preferably 5.5 mm, 5.0 mm, 4.5 mm, 4.0 mm, 3.5 mm, 3.0 mm, 2.5 mm, 2.0 mm, 1.5 mm 1.0 mm, particularly preferably 0.5 mm, 0.45 mm, 0.4 mm, 0.35 mm, 0.3 mm 0.25 mm, 0.2 mm, 0.15 mm, 0.1 mm, 0.05 mm, 0.01 mm very particularly preferably 0.29 mm, 0.28 mm, 0.27 mm, 0.26 mm, 0.25 mm, 0.24 mm, 0.23 mm, 0.22 mm, 0.21 mm. Such a defined diameter of the wire of a knitted wire mesh advantageously ensures high mechanical stability, which is particularly required, for example, in applications of engine-generator or exhaust hot parts.

All metals and their alloys, such as brass, tin, bronze, copper, nickel, Monell, titanium, aluminum, iron raw, iron galvanized, Inconell, steel, duplex steel, stainless steel, martensitic steels, ferritic steels, austenitic steels, serve typically as material for the wire of the wire mesh. Preferably of a stainless austenitic steel, particularly preferably of a high temperature resistant austenitic stainless steel, most preferably of the materials 1.4571, 1.4401, 1.4404, 1.4841, 1.4845, 1. 4876, 1.4878, 1.4828, 1.4301, 1.4306 completely or partially connected to the actual lower outer layer, optionally also partially or completely in the web area, to prevent or reduce vibration-induced mechanical abrasion.

In one embodiment, the hot-metal-part insulating element according to the invention comprises an optional wire mesh/screen mesh/wire mesh, which has a mesh size of 50.0 mm to 0.01 mm, preferably 45 mm, 40 mm, 35 mm, 30 mm, 25 mm, 20 mm, 15 mm, 10 mm, particularly preferably 9 mm, 8 mm, 7 mm, 6 mm, 5 mm, 4 mm, 3 mm, 2 mm, 1 mm, 0.5 mm, 0.1 mm, most preferably 0.09 mm, 0.08 mm, 0.07 mm, 0.06 mm, 0.05 mm, 0.04 mm, 0.03 mm, 0.02 mm, 0.01 mm. Such a defined mesh size of the wire cloth/sieve cloth/wire mesh enables, on the one hand, a reduction of vibrations and thus mechanical abrasion of the hot metal-part insulating element, as described above, and, on the other hand, a loosening of loosely filled fibers, so that premature fiber accumulations as well as the associated reduced thermal insulation effect can be counteracted.

The optional woven wire cloth/sieve cloth/wire mesh can be made of a wire with a diameter of (d) from 6 mm to 0.01 mm preferably 5.5 mm, 5.0 mm, 4.5 mm, 4.0 mm, 3.5 mm, 3.0 mm, 2.5 mm, 2.0 mm, 1, 5 mm 1.0 mm, 0.5 mm, 0.1 mm, particularly preferably 0.09 mm, 0.08 mm, 0.07 mm, 0.06 mm, 0.05 mm, most preferably 0.045 mm, 0.04 mm, 0.035 mm, 0.030 mm, 0.020 mm, 0.015 mm, 0.010 mm may be formed. Such a defined diameter of the wire of a woven wire cloth/sieve cloth/wire mesh is ensures advantageous technical effects as described above for knitted wire cloth.

All metals and their alloys such as brass, tin, bronze, copper, nickel, monell, titanium, aluminum, iron raw, iron galvanized, Inconel, steel, duplex steel, stainless steel, martensitic steels, ferritic steels, austenitic steels serve as material for the wire. Preferably of a stainless austenitic steel, particularly preferably of a high temperature resistant austenitic stainless steel, most preferably of the materials 1.4571, 1.4401, 1.4404, 1.4841, 1.4845, 1.4876, 1.4878, 1.4828, 1.4301, 1. 4306 are completely or partially connected to the actual lower outer layer, if necessary also partially or completely in the web area, to prevent or reduce vibration-induced mechanical abrasion and, depending on the mesh size, to prevent fibers or dusts from escaping from the subsequent layer.

The fineness (mesh = number of meshes per English inch) of the wire cloth/screen cloth/wire mesh is, for example, between 0.45 mesh and 1270 mesh, preferably between 0.5 mesh and 2.51 mesh, particularly preferably between 1.69 mesh and 230 mesh, especially preferably 2.79 mesh and 169 mesh, most preferably between 188 mesh and 1270 mesh. From an economic point of view, the application-oriented fineness should be selected in such a way that the material costs and the weight of the wire cloth/screen cloth/wire mesh result in a minimum.

The weave (construction) of the woven wire cloth/screen cloth/wire mesh can typically be any weave such as plain weave, twill weave, Panama weave, rep weave, atlas or satin weave, braid, ripstop, leno weave, mock leno weave, double or multiple weave or derivatives of these weaves. Most preferably plain weave, twill, braid, ripstop as these have the most rash properties under high thermal loads.

The present invention therefore also includes a separable hot-metal-part insulating element system comprising at least two optionally interconnected hot-metal-part insulating elements as defined herein. It is also possible to combine hot-metal-part insulating elements, as defined herein (i.e. the first outer layer (2) consists of materials containing alkali metals or alkaline earth metals and their compounds, but at least calcium and calcium compounds (in particular calcium oxide) with a mass content of less than 5 wt.-%) and conventional insulating elements to form an overall system. In this way, an overall system can be advantageously formed in order, on the one hand, to ensure the ease of assembly of the overall system and, on the other hand, to minimize heat transfer at the joints of the individual hot-metal-part insulating elements, especially the lower hot-metal-part insulating elements (arranged toward the hot-metal-part) due to misalignment. At the same time, this enables better shape adaptation to the hot-metal-part to be insulated. The size of the hot-metal-part insulating elements should be selected so as to permit rapid assembly and disassembly. During maintenance and repair work, small units can thus be advantageously repaired or replaced if necessary.

Irrespective of an advantageous offset of the individual hot-metal-part insulating elements of an overall system, such an overall system enables a better form fit in the whole, since especially the lower (towards the hot-metal-part) hot-metal-part insulating elements of the overall system can be positively connected to the hot-metal-part. In this case, a possible reduction in thermal insulation at any crumple zones of the hot-metal-part insulating elements positively connected to the hot-metal-part is advantageously offset by thermal insulation of the hot-metal-part insulating elements of the overall system arranged away from the hot metal-part.

A hot-metal-part insulating element of such a complete system arranged towards the hot metal-part is preferably arranged in a parcellated form-fitting manner over the individual technical parts of the hot-metal-part and is covered by the further hot-metal-part insulating element arranged away from the hot-metal-part. In this way, fast assembly and disassembly is advantageously possible, since small units can be repaired or replaced if necessary during maintenance and repair work, resulting in time and material savings.

The individual hot-metal-part insulating elements can thereby be connected by connecting elements (10b), such as clips, hooks, springs, buckles, lugs, eyelets, clamps, eyebolts, cap locks, loops, belts, tapes, cords, straps, lashing eyes, Velcro connections, overlaps, wires or similar connecting elements, which are suitable for connecting two or more insulating elements or insulating systems underneath and/or to each other, to form a hot-metal-part insulating element system. At the same time, this minimizes or, at best, prevents heat transmission in joints, gaps, butt joints, etc.

Alternatively or complementarily, the individual hot-metal-part insulating elements of the hot metal-part insulating element system may be stitched, welded, stapled, quilted, glued, needled, bonded or otherwise connected to each other.

A particular advantage in providing the hot-metal-part insulating element system in which at least two hot-metal-part insulating elements are connected underneath and/or to one another is, in particular, that this results in an insulating system that is sealed off from external environmental influences, as a result of which moisture penetration is prevented or at least minimized.

In a preferred embodiment, the hot-metal-part insulating element system comprises at least the hot-metal-part insulating element, as defined herein, as well as the hot-metal-part to be thermally insulated, wherein at least one hot-metal-part insulating element of the hot-metal part insulating element system is at least partially separably connected to the hot-metal-part via a contact side. In this context, the hot-metal-part is preferably an internal combustion engine (such as, for example, an engine of motor vehicles, commercial vehicles, construction machines, rail vehicles or ship engines), an engine hot-part, a component of exhaust gas systems such as, for example, diesel particulate filters, turbochargers, catalytic converters, silencers, SCR systems and their associated components, as well as a gas and steam turbine, a generator, a combined heat and power unit and similar units, as well as supply and discharge lines belonging to all the aforementioned systems.

In addition, the present invention comprises a hot-metal-part insulating element cassette, wherein a hot-metal-part insulating element (1), as defined herein, or a hot-metal-part insulating element system, as defined herein, is placed in or secured to a prefabricated cassette mold (13) so that it forms an insulating system closed in the direction of the hot metal-part to be insulated and can subsequently be attached as a whole to or on the hot metal-part to be insulated.

The metal hot part insulating element cassette describes a preferred embodiment of the invention, which serves merely and advantageously for fastening purposes, but not for an insulating effect. The hot-metal-part insulating element cassette may be configured, for example, as a separable metallic jacket for attaching the hot-metal-part insulating element.

In the prior art, an outer steel jacket of similar products is included as an essential feature, which significantly sells load-bearing, corrosion-resistant and shape-stabilizing functions for the overall product, for example executed as an outer layer. On the other hand, the article according to the invention is designed without a steel shell, although metallic elements may be of great technical advantage as embodiments.

In this regard, two or more of these cassettes may be joined together using suitable joining methods or joining techniques.

The present invention also provides a method for heat insulating hot-metal-parts while reducing the formation of environmentally and/or health hazardous heavy metal compounds during operation of hot-metal-parts, wherein a hot-metal-part (12) is jacketed with the hot metal-part insulating element according to any of the preceding claims.

Another aspect of the invention relates to the use of the hot-metal-part insulating element (1) as defined herein, the hot-metal-part insulating element system as defined herein, or the hot metal-part insulating element cassette as defined herein, as thermal insulation, acoustic insulation and/or heat protection of hot-metal-parts (12), in particular internal combustion engines (such as, for example, engines of motor vehicles, commercial vehicles, construction machines, rail vehicles and marine engines), hot-metal-parts of engines, components of exhaust systems such as, for example, diesel particulate filters, turbochargers, turbochargers, etc.), and the use of the hot-metal-part insulating element (1) as defined herein as a thermal insulation, acoustic insulation and/or heat protection of hot-metal-parts (12), in particular internal combustion engines (such as, for example, engines of motor vehicles, commercial vehicles, construction machines, rail vehicles and marine engines), hot metal-parts of engines, components of exhaust systems such as, for example, diesel particulate filters, turbochargers, etc.). Diesel particulate filters, turbochargers, catalytic converters, silencers, SCR systems and their associated components, as well as gas and steam turbines, generators, combined heat and power units and similar units, as well as supply and discharge lines belonging to all the above-mentioned systems in a temperature range from 20°C to 750°C, in particular in the range from 70°C to 750°C, particularly preferably in the range from 200°C to 750°C, very preferably in the range from 400°C to 750°C, in particular in each case up to 700°C, 650°C, very preferably up to 600°C.

For this purpose, it may be envisaged to use the separable hot-metal-part insulating element according to the invention in a metallic narrow shell.

According to a preferred embodiment, the hot-metal-part insulating element is used specifically for insulating hot-metal-parts or forms with them a hot-metal-part insulating element system defined herein, which are operated in a temperature range from 80 to 120°C. These include, in particular, engines (e.g. gasoline engines, diesel engines), as well as all associated supply and exhaust lines. In everyday operation, these hot-metal-parts are usually exposed to various weather conditions involving moisture or water (e.g. rainwater, condensation and ice formation). Under these conditions, contact with materials containing alkali metals and alkaline earth metals leads to the increased formation of heavy metal compounds which are harmful to the environment and/or health (see Fig. 1).

It is therefore particularly useful to insulate exhaust gas catalysts and exhaust gas ducts, such as exhausts for exhaust gases from gasoline or diesel engines, which are made from steels containing heavy metal additives, with the hot-metal-part insulating element according to the invention. For example, exhaust gases from gasoline engines reach temperatures in the range from about 800°C (idling) to about 900°C (full load). In contrast, diesel engines reach exhaust gas temperatures in the range from about 250°C (idling) to about 650°C, preferably up to about 500°C (full load). Exhaust gas catalysts of motor vehicles are operated at operating temperatures in the range of 400°C to 900°C.

According to a preferred embodiment, the separable hot-metal-part insulating element is used specifically for insulating turbines and their components. These are made of steel, and the wall temperature of a turbine during operation is in the range of 400°C to 800°C. Under these conditions, heavy metal compounds which are harmful to the environment and/or health are increasingly formed on contact with materials containing alkali metals and alkaline earth metals (see Fig. 1).

In a further preferred embodiment, the separable hot-metal-part insulating element is used specifically for insulating heat engines, such as for organic rankine cycle (ORC) systems in the temperature range from 110°C to 550°C or in steam processes at temperatures above 150°C, to prevent undesirable heat loss.

Examples

With reference to the following figures and embodiments, the present invention will be explained in more detail without limiting the invention thereto.

Thereby shows

Fig. 1: formation of chromium(VI) as a function of heating temperature in the presence of NaOH, KOH, CaO or MgO or in the absence of alkali metal/alkaline earth metal compounds and the exclusive presence of 02.

Fig. 2: the schematic structure of an insulating element (1) according to the invention in cushion form, with a lower outer layer (2), an upper outer layer (5) and a first inner layer (7).

Fig. 3: the schematic structure of the lower and upper three-dimensional outer layer (2, 5) with the lower outer side (hot side) (3) and the upper outer side (cold side) (4).

Fig. 4: the schematic structure of an insulating element (1) according to the invention in mattress form with the side wall (6) and a first inner layer (7).

Fig. 5: the schematic structure of an insulating element (1) according to the invention in mattress form with multilayer filling. With a first inner layer (7) and an at least second orfurtherinner layer(8).

Fig. 6: schematic structure of an insulating element (1) according to the invention, which is partially additionally provided with a wire sheath (9) as a vibration-protecting layer on at least one of the outer layers and/or the web, at best the entire insulating element or insulating system.

Fig. 7: the schematic structure of a cushion-shaped insulating element (1) according to the invention, which has fastening elements (11) on the lower outer layer (2) for attachment to a hot-metal-part (12) .

Fig. 8: (A), 8(B) and 8(C) the schematic structure of an insulating element (1) in mattress form according to the invention, which is additionally provided or fixed with suitable connecting elements (1Ob) on at least one of the outer layers and/or the side wall and/or in which individual or all layers are connected with suitable connecting elements (1Oa) (e.g. transverse seams). Furthermore, the overlapping flap (15) or a partial cassette (13) is shown schematically .

Fig. 9: the schematic structure of an insulating element (1) according to the invention, which is placed in or fixed in a prefabricated cassette mold (13) and then attached to the hot-metal-part to be insulated, thus forming a partially or fully closed insulating system.

Fig. 10: schematic structure of a separable hot-metal-part insulating element system in which several layers of insulating elements (1) in cushion and/or mattress form (cf. Fig. 2, Fig. 4, Fig. 5) form an overall system, the lower layer of hot-metal-part insulating elements (1) being designed according to the invention. Further layers are particularly advantageously also constructed from hot-metal-part insulating elements (1) according to the invention, but may also consist of conventional insulating elements if necessary.

Fig. 11: sectional view of a separable hot-metal-part insulating element (1) that is arranged around a hot-metal-part (12) (e.g. turbocharger) for thermal insulation purposes

. Fig. 12: the schematic structure of an insulating element (1) according to the invention, which is additionally completely or partially sheathed with a metallic jacket (9). Here the representation form of a half shell is sketched.

Fig. 13: the surface of a lower outer layer (2) formed with elevations/spacers in the form of knobs: in the form of hemispheres (Fig. 13A), endless wedges and pyramids (Fig. 13B) as well as truncated pyramids and/or truncated cones (Fig. 13C).

The insulating element in cushion form of Fig. 2, designated as a whole by (1), has a lower outer layer (2), also referred to as the hot side, an upper outer layer (5), also referred to as the cold side, and at least one first inner layer (7), also referred to as the insulating material.

For the application temperatures of the hot-metal-part or the separable hot-metal-part insulating element specified herein, the following structure in cushion form has proven particularly effective:

Example 1 - all poor or free

Optional: Wire mesh, completely or partially bonded to the actual lower outer layer, possibly also partially or completely in the web area, to prevent or reduce vibration-induced mechanical abrasion.

Lower outer layer: (earth-)alkali metal-poor or -free fabric, bundle, hybrid textile, with or without wire reinforcement, with or without impregnation or with or without coating, also microporous metal foil, preferably stainless steel wire cloth or silicate fabric, also as a mixture thereof

Inner layer (insulation): (earth) alkali metal-poor or -free insulating material, as loose fibers, fleece, mat, felt, bundles, paper or cardboard, single- or multi layered, or single- or multi-layered preferably silicate fiber mat or other (earth) alkali metal-poor or -free insulating material

Upper outer layer: (earth-)alkali metal-poor or -free fabric, bundle, hybrid textile, with or without wire reinforcement, with or without impregnation or with or without coating, also microporous metal foil, preferably stainless steel sieve fabric or silicate fabric, also as a mixture thereof, particularly preferably equipped with an oil- and water-repellent coating/lamination/foiling, which is (Earth-)alkali metal-poor or -free and has oil- or water-repellent properties.

. Example 2 - hot side arm or free/filling combi/cold side arm or free

Depending on the application temperature and conditions of use of the hot-metal-part or separable hot-metal-part insulating element, the following structure can be selected, for example, while ensuring the prevention or reduction of the formation of compounds containing heavy metals that are hazardous to health and/or the environment:

Inner layer (insulation): hot-side (facing the lower outer layer) (earth) alkali metal-poor or alkali metal-free insulating material, e.g. as loose fibers, nonwoven, mat, felt, bundle, paper or cardboard, in one or more layers or in one or more layers, preferably silicate fiber mat, combined with one or more layers or one or more layers of insulating materials in any technically useful form of presentation described herein, which are not (earth) alkali metal-poor or alkali metal-free, facing the upper outer layer.

Upper outer layer: (Earth) alkali metal-poor or -free fabric, bundle, hybrid textile, with or without wire reinforcement, with or without impregnation or with or without coating, also microporous metal foil, preferably stainless steel sieve fabric or silicate fabric, also as a mixture thereof, particularly preferably equipped with an oil- and water-repellent coating/lamination/foiling, which at best is (Earth) alkali metal-poor or -free and has oil- and water-repellent properties.

Example 3 - Hot side poor or free/fill combination/cold side not poor or free

Depending on the application temperature and conditions of use of the hot-metal-part or the separable hot-metal-part insulating element, the following structure can be selected to prevent or reduce the formation of compounds containing heavy metals that are hazardous to health and/or the environment:

Inner layer (insulation): hot-side (facing the lower outer layer) (earth) alkali metal-poor or free insulating material, e.g. as loose fibers, fleece, mat, felt, bundle, paper or cardboard, single- or multi-layered or single- or multi layered, preferably silicate fiber mat, combined with one or more layers or one or more layers of insulating materials in any technically useful form of presentation described herein, which are not (earth) alkali metal-poor or alkali metal-free, facing the upper outer layer.

Upper outer layer: a non-(earth)alkali metal-poor or -free fabric, bundle, hybrid textile, with or without wire reinforcement with or without impregnation or with or without coating, also microporous metal foil, preferably stainless steel sieve fabric or silicate fabric, also as a mixture thereof, particularly preferably equipped with an oil- and water repellent coating/lamination/foiling, which is at best (earth)alkali metal-poor or -free and has oil- or water-repellent properties.

Example 4 - Hot side poor or free/Filling not poor or free/Cold side not poor or free

Inner layer (insulation): One or more layers or one or more layers of insulating materials in any technically useful form of presentation described herein that are not low in or free of (earth) alkali metals.

Example 5 - Hot side poor or free/Fill not poor or free/Cold side poor or free

Depending on the application temperature and conditions of use of the hot-metal-part or separable hot-metal-part insulating element, the following structure can be selected to prevent or reduce the formation of compounds containing heavy metals that are hazardous to health and/or the environment:

Upper outer layer: a (earth) alkali metal-poor or -free fabric, bundle, hybrid textile, with or without wire reinforcement with or without impregnation or with or without coating, also microporous metal foil, preferably stainless steel sieve fabric or silicate fabric, also as a mixture thereof, particularly preferably equipped with an oil- and water-repellent coating/lamination/foiling, which at best is (earth) alkali metal-poor or -free and has oil- or water-repellent properties.

Depending on the application temperature and conditions of use of the hot-metal-part or the separable hot-metal-part insulating element, further structures are possible while ensuring the prevention or reduction of the formation of compounds containing heavy metals that are hazardous to health and/or the environment and are not described in detail here.

Figs. 4 and 5 show another embodiment of the separable hot-metal-part insulating element (1) in mattress form. The hot-metal-part insulating element comprises a lower outer layer (2), an upper outer layer (5), four webs or side parts (6), which together span a free space and thereby give the hot-metal-part insulating element a box-like or mattress-like shape. The free space is filled at least by a first inner layer (7).

For the application temperatures of the hot-metal-part or hot-metal-part insulating element specified herein, a structure in mattress form has proved particularly suitable, which is constructed like the aforementioned cushion form, but with a web, corresponding to the upper outer layer, preferably corresponding to the lower outer layer. If the lower outer layer (hot side) consists of a metallic screen mesh or a metallic foil, the optional wire mesh can be dispensed with. The structures of the pillow form described above also apply accordingly (only supplemented by web) to the mattress form.

Description of the structure of an exemplary insulating element or system according to the invention:

The separable hot-metal-part insulating element or hot-metal-part insulating element system has, for example, a single-layer or multi-layer upper outer layer (5), a single-layer or multi layer or single- or multi-layer inner layer (7; 8), a single-layer or multi-layer or single- or multi layer lower outer layer (2), which are connected by a web or side wall (6) corresponding to the insulation thickness. Both the upper outer layer (5), the inner layer (7; 8), the lower outer layer (2), and the web (6) are made of components as defined herein.

Optionally, the hot-metal-part insulating element or hot-metal-part insulating element system has on one, several or all outer layers (2; 5; 6) - the so-called sheathing - an additional partial or complete protective layer (9) (e.g. in the form of a metal wire mesh, knitted metal mesh, a metal foil or another form of representation of a material suitable as a protective layer) in order to additionally protect the insulating element against other external influences, in particular vibration, abrasion, electrostatic charging, penetration of liquids or similar influences. If necessary, this optional layer can replace one or more layers 2, 5 or 6.

Optionally, as shown in Fig. 8, the insulating element or insulating system can contain longitudinal or transverse seams (1Oa) or be provided with pins, hooks, staples, topstitching, or other suitable connection options to reduce or prevent displacement of the individual layers relative to one another, and to ensure shaping or dimensional stability and thus a precisely fitting assembly.

Also, it may be provided that the insulating element or insulating system, as shown in Fig. 8, includes connecting elements (1Ob) such as. clips, hooks, springs, buckles, lugs, eyelets, clamps, eyebolts, cap locks, loops, belts, tapes, cords, straps, lashing eyes, Velcro connections, overlaps, wires or similar connecting elements in order to connect two or more insulating elements underneath and/or to each other in order to form an insulating system, thereby minimizing or at best preventing the passage of heat in joints, gaps, butts, etc.

Optionally, as shown in Fig. 7, the insulating element can have fastening elements (11) that enable it to be fixed directly to the hot-metal-part and thus prevent displacement of individual insulating elements of an insulating system on the hot-metal-part.

Fig. 10 shows that the insulation system is made up of two or more layers of hot-metal-part insulating elements forming an overall system, at least the bottom layer (layer facing the hot metal-part) consisting of hot-metal-part insulating elements according to the invention. This ensures ease of assembly of the overall system and minimizes heat transfer at the joints, especially of the lower layer of insulating elements, by offsetting the layer above. At the same time, this allows better shape adaptation to the hot-metal-part to be insulated. The size of the insulation elements should be selected so as to permit rapid assembly and disassembly. During maintenance and repair work, small units can thus be repaired or replaced if necessary. The individual layers can be under- and/or interconnected as described above.

List of reference signs

1 separable hot-metal-part insulating element

2 lower outer layer

3 lower outer side (hot side)

4 upper outer layer (cold side)

5 upper outer layer

6 side wall (web)

7 first inner layer (insulation material)

8 second or further inner layer

9 metallic jacket

10a connecting elements as means for preventing layer displacement within a separable hot-metal-part insulating element

10b connecting elements as means for connecting separable hot-metal-part insulating elements to each other

11 fastening element

12 hot-metal-part

13 Cassette (partial or full)

14 Spacer

15 Overlap tab

Claims

1. The hot-metal-part insulating element (1), which is formed by at least a single layer and thus comprises of at least a first outer layer (2),

where the first outer layer (2) is realized as a direct contact layer for a hot-metal-part to be insulated,

wherein the hot-metal-part insulation element (1) comprises at least the following

- a lower outer side (3) formed as a contact surface for a hot-metal-part to be insulated, and

- an upper outer surface (4) arranged opposite the contact surface for the hot-metal part,

characterized in that

in that the first outer layer (2) is free of calcium, calcium ions and/or calcium compounds being present in the range from 0 to wt.-%, and

wherein the first outer layer comprises alkali metals, alkaline earth metals and their oxides with a mass content in the range of 0 to 3 wt.-%.

2. A hot-metal-part insulating element according to claim 1, wherein the hot-metal-part insulating element (1) comprises at least a second outer layer (5) arranged opposite the first outer layer (2), wherein the second outer layer (5) comprises calcium and calcium compounds with a mass content of less than 5 wt.-%, in particular alkali metals or alkaline earth metals and their compounds with a mass content of less than 5 wt.-%.

3. A hot-metal-part insulating element according to claims 1 or 2, wherein the hot-metal-part insulating element (1) comprises a sheathing,

wherein the sheathing comprises the following components:

- a first outer layer (2) formed as a contact surface for the hot-metal-part,

- a second outer layer (5) arranged opposite the first outer layer (2), and

- optionally at least one side wall (6) connecting the first outer layer (2) and the second outer layer (5),

wherein the sheathing of the hot-metal-part insulating element consists of materials which are free of calcium, wherein calcium, calcium ions and/or calcium compounds are present in the range of 0 to wt.-%, and wherein the coating comprises alkali metals, alkaline earth metals and their oxides with a mass content in the range from 0 to 3 wt.-%.

4. A hot-metal-part insulating element according to any one of claims 1 to 3, wherein the hot metal-part insulating element (1) comprises at least one first inner layer (7), wherein the at least one first inner layer (7) is in the form of a ply or thermal insulating filler material.

5. A hot-metal-part insulating element according to any one of claims 1 to 4, wherein the first outer layer (2), the second outer layer (5) and the at least one side wall (6) are formed as a textile sheet, plastic film, metal foil, plastic-coated metal, metal-coated plastic, or mixtures thereof.

6. A hot-metal-part insulating element according to any one of claims 1 to 5, wherein all components of the hot-metal-part insulating element are made of materials which are free of calcium ,

wherein calcium, calcium ions and/or calcium compounds are present in the range of 0 to wt.-%, and

wherein the first outer layer comprises alkali metals, alkaline earth metals and their oxides with a mass content in the range from 0 to 3 wt.-%.

7. A hot-metal-part insulating element according to any one of claims 1 to 6, wherein the materials comprising alkali metals, alkaline earth metals and compounds thereof having a mass content of from 0 to 3 wt. % are selected from the group consisting of S-glasss, M glasss, Q-glasss, D-glasss, aluminoborosilicates, aluminosilicates, aluminafibre, silica, carbon and thermally stabilized intermediates on the way to the carbon fibre, cellulose, textile fibres (natural fibres, synthetic fibres), metal fibres (e.g. strands, wires, filaments), metals, metal alloys, plastic-coated metals, metal-coated plastics, plastics or mixtures thereof.

8. A hot-metal-part insulating element according to any one of claims 1 to 7, wherein the individual components of the hot-metal-part insulating element are in the form of scrims, bundles, woven fabrics, knitted fabrics, braids, nonwovens, felts, cardboards, papers, needle mats, stitch-bonded mats, mats, sheets, consolidated fibers, similar layers, loose fibers, granules, or powders, or consist of sheets.

9. A hot-metal-part insulating element according to any one of claims 3 to 8, wherein the sheathing of the hot-metal-part insulating element is formed wholly or partially in the form of a metal foil or a metal sheet.

10. A hot-metal-part insulating element according to any one of claims 1 to 9, wherein the hot metal-part insulating element is sheathed by a metallic sheath (9), the metallic sheath (9) being in the form of a metal foil or a metal sheet in half-shell or full-shell form.

11. A hot-metal-part insulating element according to any one of claims 1 to 10, wherein individual components of the hot-metal-part insulating element are connected to one another by connecting elements (10a) and are thereby fixed to one another.

12. A hot-metal-part insulating element according to any one of claims 1 to 11, wherein the insulating materials comprising alkali metals, alkaline earth metals and compounds thereof with a mass content of more than 5 wt.-% are impregnated and/or coated and/or laminated.

13. A hot-metal-part insulating element according to any one of claims 1 to 12, wherein at least one outer side (2, 5 or 6) is at least partially provided with a metallic protection against direct mechanical loading, e.g. by vibration, e.g. in the form of a knitted wire fabric, a woven wire fabric or a metallic film.

14. A hot-metal-part insulating element according to any one of claims 1 to 13, wherein connecting elements (1Ob, 11) are provided on at least one outer side, enabling at least two hot-metal-part insulating elements to be connected to each other or enabling at least one hot-metal-part insulating element to be provided on the hot-metal-part, respectively.

15. A Hot-metal-part insulating element according to any one of claims 1 to 14, wherein fastening elements (11) are provided on the lower side facing the hot-metal-part .

16. The hot-metal-part insulating element system comprising at least two hot-metal-part insulating elements according to any one of the preceding claims, which are optionally connected to or underneath one another

.

17. A hot-metal-part insulating element system according to claim 16, comprising a hot-metal part and a hot-metal-part insulating element attached thereto according to any one of claims 1 to 15.

18. The hot-metal-part insulating element cassette, wherein a hot-metal-part insulating element (1) according to one of claims 1 to 15 or a hot-metal-part insulating element system according to claim 16 or 17 is placed in or fixed in a prefabricated cassette form (13), or metallic close casing, or is provided with a metallic casing in half or full shell form (9), so that this forms a closed insulating system.

19. The Method for the thermal insulation of hot-metal-parts (12), characterized in that a hot-metal-part (12) is coated with a hot-metal-part insulating element or with a hot-metal part insulating element system according to one of the aforementioned claims.

20. The use of a hot-metal-part insulating element (1) according to any one of claims 1 to 15, a hot-metal-part insulating element system according to claim 16 or 17, or a hot metal-part insulating element cassette according to claim 18 as thermal insulation, acoustic insulation and/or heat protection of hot-metal-parts in a temperature range from 20°C to 750°C.

21. The use of a hot-metal-part insulating element (1) according to any one of claims 1 to 12, in a metallic narrow casing.