NL2033134B1

NL2033134B1 - Premix gas burner deck plate

Info

Publication number: NL2033134B1
Application number: NL2033134A
Authority: NL
Inventors: Bus Marc; Verhoogt Mathieu; Marino Josef Hogenbirk Camillo
Original assignee: Bekaert Combustion Tech Bv
Priority date: 2022-09-26
Filing date: 2022-09-26
Publication date: 2024-04-03

Abstract

The invention pertains to a premix gas burner deck plate, comprises: - a gas passage area, and - a heat transfer area, wherein the premix gas burner deck plate has a first plate thickness in the gas passage area and a second plate thickness in the heat transfer area, which second plate thickness is larger than the first plate thickness, and Wherein the premix gas burner deck plate comprises a gas outflow channel which is adapted to during use supply premix gas to a combustion zone, which gas outflow channel is arranged in the gas passage area and extends through the first plate thickness from the distribution chamber side of the premix gas burner deck plate to the combustion zone side of the premix gas burner deck plate, and wherein the premix gas burner deck plate is made of cast aluminium.

Description

P35957NLOO/NBL

Premix gas burner deck plate

The invention pertains to a premix gas burner deck plate, a premix gas burner comprising the premix gas burner deck plate, a heating appliance comprising the premix gas burner and a method for manufacturing the premix gas burner deck plate.

A premix gas burner deck plate in accordance with the invention is of the type that is used in premix gas burners for heating appliances such as heater systems for buildings or domestic hot water systems. Traditionally, such premix gas burners use a premix burner gas that contains for example methane mixed with air. Currently, in order to reduce carbon dioxide emissions, developments are going on to add hydrogen to the premix burner gas, or even to replace the methane by hydrogen entirely.

In use, the premix gas burner deck plate deck of a known premix gas burner often reaches a high maximum temperature of at least 500°C, often even up to more than 800°C.

High burner deck temperatures increase the risk of flashback, in particular if the fuel gas is or contains hydrogen, as the hot burner deck may ignite the premix gas inside the burner, upstream of the premix gas burner deck plate, which is highly undesirable from a safety point of view. In addition, the premix gas burner deck plates of the type to which the invention pertains are often used in modulating heater systems, in which the thermal load on the burner varies significantly during relatively short time spans. This causes changes in the burner deck temperature, and therewith the amount of thermal expansion and the magnitude of thermal stresses in the burner deck of the premix gas burner. These varying stresses are a major cause of thermal fatigue. Often, special designs are necessary to deal with the varying temperatures.

The invention aims to provide an improved premix gas burner deck plate, which has a reduced risk of flashback.

This object is obtained by a premix gas burner deck plate, which premix gas burner deck plate has a distribution chamber side and a combustion zone side, which distribution chamber side and combustion zone side are located on opposite sides of the premix gas burner deck plate, which premix gas burner deck plate further comprises: - a gas passage area, and - a heat transfer area,

wherein the premix gas burner deck plate has a first plate thickness in the gas passage area and a second plate thickness in the heat transfer area, which second plate thickness is larger than the first plate thickness, and wherein the premix gas burner deck plate comprises a gas outflow channel which is adapted to during use supply gas to a combustion zone, which gas outflow channel is arranged in the gas passage area and extends through the first plate thickness from the distribution chamber side of the premix gas burner deck plate to the combustion zone side of the premix gas burner deck plate, and wherein the premix gas burner deck plate is made of cast aluminium.

The premix gas burner deck plate according to the invention has a distribution chamber side and a combustion zone side, which distribution chamber side and combustion zone side are located on opposite sides of the premix gas burner deck plate. When the premix gas burner deck plate is arranged in a premix gas burner, the distribution chamber side of the premix gas burner deck plate faces towards a gas distribution chamber of the premix gas burner, 50, in upstream direction of the flow of the premix gas. When the premix gas burner deck plate is arranged in a premix gas burner, the combustion zone side of the premix gas burner deck plate faces towards a combustion zone in which the actual combustion of the premix gas takes place, so, in downstream direction of the flow of the premix gas.

The premix gas burner deck plate according to the invention comprises a gas passage area and a heat transfer area. Premix gas passes from the distribution chamber side of the premix gas burner deck plate to the combustion zone side of the premix gas burner deck plate via the gas passage area. The heat transfer area is designed for effective heat transfer, with the aim of avoiding high burner deck temperatures in the premix gas burner deck plate.

The premix gas burner deck plate has a first plate thickness in the gas passage area and a second plate thickness in the heat transfer area. The second plate thickness is larger than the first plate thickness. For example, the first plate thickness is 0.5 millimeters (mm) up to and including 1.5 millimeters (mm), for example 1 millimeter (mm). For example, the second plate thickness is 1.5 millimeters (mm) to 10 millimeters (mm), e.g. 2 mmilimeters (mm) up to and including 7 millimeters (mm), for example 2.5 millimeters (mm) to 6 milolimeters (mm) 5 millimeters (mm), e.g. 5 millimeters (mm) or 3 millimeters (mm). Of course, in case the first thickness is 1.5 mm, the second thickness is more than 1.5 mm. For example, the first thickness is 1 mm and the second thickness is 3 mm.

The premix gas burner deck plate comprises a gas outflow channel which is adapted to during use supply premix gas to the combustion zone, in which combustion zone the combustion of the premix gas takes place during use of the premix gas burner deck plate in a premix gas burner. The combustion zone is usually present adjacent to but just outside of the premix gas burner in which the premix gas burner deck plate is arranged. The gas outflow channel is arranged in the gas passage area and extends through the first plate thickness from the distribution chamber side of the premix gas burner deck plate to the combustion zone side of the premix gas burner deck plate.

For example, the gas outflow channel has a circular cross-sectional shape, with a diameter that is either constant or varies over the length of the gas outflow channel. In case the diameter varies over the length of the gas outflow channel, the gas outflow channel is for example tapered. The taper angle of the gas outflow channel is optionally at least 6°, for example at least 9°, optionally at least 12°. The diameter at an end of the gas outflow channel, e.g. at the end with the smallest diameter, is for example 0.6 mm — 1.0 mm, e.g. 0.8 mm. In case the diameter is constant over the length of the gas outflow channel, the diameter at an end of the gas outflow channel 12 is for example 0.6 mm — 1.0 mm, e.g. 0.8 mm.

In accordance with the invention, the premix gas burner deck plate is made of cast aluminium, e.g. pressure die cast aluminium (including high pressure die cast aluminium) or sand cast aluminium. Cast aluminium has a high thermal conductivity, which makes that it is effective in transferring heat away from the premix gas burner deck plate.

Cast aluminium is an example of a metal having a thermal conductivity coefficient at room temperature of at least 80 W/(mK) and having a Young'’s modulus for tension at room temperature of 150GPa or less. Alternatively, instead of aluminium, another metal having a thermal conductivity coefficient at room temperature of at least 80 W/(mK) and having a

Young's modulus for tension at room temperature of 150GPa or less can be used for the premix gas burner deck plate according to the invention. The Young's modulus for tension at room temperature of 150GPa or less allows that material stresses remain at levels that can be considered acceptable for a viewpoint of thermal fatigue.

Instead of cast aluminium, another metal having the same properties in terms of at least thermal conductivity and Young's modulus at room temperature with respect to compression and to tension can be used.

Examples of (aluminium) materials that are suitable for use in the premix burner deck plate according to the invention are EN-AC44300 (EN AC-AISi12(Fe), Werkstoff no. 3.2582),

EN-AC 42100 (EN AC Si7Mg0.3, Werkstoff no. 3.2371, LM25), EN-AC43000 (EN AC-AL

Si10Mg(a), Werkstoff no. 3.2381).

Tests of the premix gas burner deck plate according to the invention have indicated that the premix gas burner deck plate according to the invention performs well with respect to the risk of the occurrence of flash back.

It is suspected that this may be due to that the relatively small plate thickness near the gas outflow channels prevents significant local cooling by the premix gas flowing through the gas outflow channel. The relatively thin plate near the gas outflow channels is not so effective in terms of heat transfer (that requires a larger plate thickness), so the gas passage area through which the gas outflow channels extend remains rather hot. As a consequence, the premix gas is not heated very much during its passage through the gas outflow channel. So, the premix gas leaves the gas outflow channel and enters the combustion zone at a relatively low temperature.

The flame speed which occurs during combustion is directly linked to the premix gas temperature. A lower temperature of the premix gas results in a lower flame speed, which makes that the actual flames will be relatively far from the premix burner deck plate. This reduces the total heat load on the premix gas burner deck plate. This, together with the larger place thickness in the heat transfer area of the premix burner deck plate, makes that the overall temperature of the premix gas burner deck plate remains relatively low, despite the warmer and thinner gas passage area. This relatively low overall burner deck temperature could be the explanation for the good performance in terms of the risk of the occurrence of flash back.

It is suspected that the use of cast aluminium (or another metal material with similar relevant properties in terms of e.g. thermal conductivity and Young’s modulus for tension) helps to achieve this good performance because of its relatively high thermal conductivity, which is useful for the effectiveness of the heat transfer areas.

Tests have also shown that the premix gas burner deck plate according to the invention can be manufactured well and at relatively limited costs from the cast aluminium, in particular pressure die cast aluminium, even when it is desired to limit the number and/or intensity of further manufacturing steps {such as drilling or machining).

In an embodiment of the premix gas burner deck plate in accordance with the invention, the gas passage area comprises a plurality of gas outflow channels.

Preferably, the gas outflow channels in the gas passage area are arranged in a predetermined pattern, e.g. in a predetermined pattern that allows for or is even optimised for the combustion of a premix gas in which the fuel gas is or contains hydrogen.

In an embodiment of the premix gas burner deck plate in accordance with the invention, the premix gas burner deck plate comprises a plurality of gas passage areas, and each gas passage area comprises at least one gas outflow channel.

Optionally, at least one gas passage area comprises a plurality of gas outflow channels.

Optionally, multiple gas passage areas comprise a plurality of gas outflow channels

Optionally, all gas passage areas comprise a plurality of gas outflow channels.

Optionally, multiple gas passage areas are grouped together in a gas discharge zone.

Optionally, multiple or all gas passage areas are arranged in a central gas discharge zone, which is for example arranged at a distance from a circumferential edge of the premix gas burner deck plate, for example in the center of the premix gas burner deck plate.

Optionally, the premix gas burner deck plate comprises a plurality of gas discharge zones, wherein multiple gas discharge zones comprise multiple gas passage areas, and wherein optionally all gas discharge zones comprise multiple gas passage areas.

In an embodiment of the premix gas burner deck plate in accordance with the invention, the premix gas burner deck plate has a circumferential edge, and the premix gas burner deck plate comprises a plate rim area adjacent to at least a part of the circumferential edge. In this embodiment the premix gas burner deck plate has a third plate thickness in the plate rim area, which third plate thickness is larger than the first plate thickness, optionally equal to or larger than the second plate thickness.

So, in this embodiment, the premix gas burner deck plate has a plate rim area that is thicker than the plate thickness in the gas passage areas. Optionally, in the plate rim area the premix gas burner deck plate is as thick or even thicker than in the heat transfer areas of the premix gas burner deck plate. This supports the transfer of heat away from the premix gas burner deck plate during use, which in turn helps to keep the premix gas burner deck plate relatively cool and therewith reduces the risk of flashback.

Optionally, in this embodiment, the premix gas burner deck plate further comprises a plurality of gas passage areas, and each gas passage area comprises at least one gas outflow channel. Optionally, at least one gas passage area comprises a plurality of gas outflow channels. Optionally, multiple gas passage areas comprise a plurality of gas outflow channels. Optionally, all gas passage areas comprise a plurality of gas outflow channels.

Optionally, multiple gas passage areas are grouped together in a gas discharge zone, which gas discharge zone is arranged closer to a center of the premix gas burner deck plate than the plate rim area. Optionally, multiple or all gas passage areas are arranged in a central gas discharge zone, which central gas discharge zone is arranged closer to a center of the premix gas burner deck plate than the plate rim area.

Optionally, the plate rim area extends along the entire circumference of the premix gas burner deck plate. Optionally, in that case, the gas passage area or multiple gas passage areas or all gas passage areas is/are arranged in a central gas discharge zone are surrounded by the plate rim area.

In an embodiment of the premix gas burner deck plate according to the invention, the premix gas burner deck plate comprises multiple heat transfer areas.

Optionally, multiple heat transfer areas are in thermal contact with each other.

Optionally, all heat transfer areas are in thermal contact with each other.

In an embodiment of the premix gas burner deck plate in accordance with the invention, at least one gas outflow channel is tapered.

So, in this embodiment, the cross-sectional size of the gas outflow channel varies over the length of the gas outflow channel, in such a way that it either increases or decreases from one end of the gas outflow channel to the other end of the gas outflow channel. For example, if the gas outflow channel has a circular cross-section, the diameter of that circular cross- section is larger on one end of the gas outflow channel than on the other end of the gas outflow channel.

For example, the tapered gas outflow channel widens (or, in case of multiple tapered gas outflow channels: the tapered gas outflow channels widen) from the combustion zone side of the premix gas burner deck plate to the distribution chamber side of the premix gas burner deck plate. Good burner deck performance has been observed with this configuration.

Optionally, in this embodiment, the premix gas burner deck plate comprises a plurality of gas outflow channels. Optionally, multiple gas outflow channels of the plurality of gas outflow channels are tapered. Optionally, all gas outflow channels of the plurality of gas outflow channels are tapered.

An advantage of this embodiment is that a premix gas burner deck plate in accordance with this aspect of the invention contributes to easy removal of the premix gas burner deck plate from a die when the premix gas burner deck plate is made by pressure die casting and the gas outflow channels are formed in the pressure die casting process.

In an embodiment of the premix gas burner deck plate in accordance with the invention, a passage rim area is provided around at least one gas passage area, and the premix gas burner deck plate has a fourth plate thickness in the passage rim area. The fourth plate thickness is larger than the first plate thickness, optionally equal to or larger than the second plate thickness. Optionally, in case a plate rim area is present, the fourth plate thickness is equal to the third plate thickness.

It is suspected that this contributes to obtaining the desired temperature distribution over the premix gas burner deck plate during use.

In an embodiment of the premix gas burner deck plate in accordance with the invention, the combustion zone side of the premix gas burner deck plate is planar. So, in this embodiment, the combustion zone side of the premix gas burner deck plate is devoid of protrusions and indents.

It is suspected that this contributes to obtaining a relatively low burner deck temperature of the premix gas burner deck plate during use.

In an embodiment of the premix gas burner deck plate in accordance with the invention, the premix gas burner deck plate is manufactured by machining a cast aluminum plate.

For example, the final thickness of the gas passage area or gas passage areas is obtained by machining and the gas outflow channel or gas outflow channels is/are formed by drilling, punching or laser cutting. Optionally, the final thickness of the heat transfer area(s) is obtained by machining as well.

In this embodiment, the material of the premix gas burner deck plate has a structure which is typical for cast parts which are later machined to the desired shape.

In an embodiment of the premix gas burner deck plate in accordance with the invention, the premix gas burner deck plate is manufactured by forging and/or pressing a cast aluminum plate.

Optionally, the rough shape of the premix gas burner deck plate is obtained by forging and/or pressing, and the final thickness of the gas passage area or gas passage areas is obtained by machining and the gas outflow channel or gas outflow channels is/are formed by drilling, punching or laser cutting. Optionally, the final thickness of the heat transfer area(s) is obtained by machining as well.

In this embodiment, the material of the premix gas burner deck plate has a structure which is typical for cast parts which are later forged/pressed and then machined to the desired shape.

In an embodiment of the premix gas burner deck plate in accordance with the invention, at least the heat transfer area(s) and/or the gas passage area(s) of the premix gas burner deck plate are manufactured by a pressure die casting process, for example a high pressure die casting process.

In this embodiment, the premix gas burner deck plate is generally formed in a pressure die casting process. For example, different material thicknesses are provided for the gas passage area(s) and the heat transfer area(s). Optionally, the pressure die cast premix gas burner deck plate is machined after pressure die casting in order to make sure the required manufacturing tolerances are met, but in this embodiment the general shape of the premix gas burner deck plate is obtained by pressure die casting.

In this embodiment, the material of the premix gas burner deck plate has a structure which is typical for pressure die cast parts.

Optionally, in this embodiment, also the gas outflow channel(s) of the premix gas burner deck plate is/are formed in the pressure die casting process. Optionally, a plurality of the gas outflow channels of the premix gas burner deck plate is formed in the pressure die casting process. Optionally, all gas outflow channels of the premix gas burner deck plate are formed inthe pressure die casting process.

The design of the premix gas burner deck plate is suitable for manufacturing by a pressure die cast process, e.g. a high pressure die cast process. This allows the premix gas burner deck plate according to the invention to be manufactured at relatively low costs and relatively high speeds, in particular when single shot (high) pressure die casting is used. The premix gas burner deck plate according to the invention allows manufacturing using single shot pressure die casting, e.g. single shot high pressure die casting. Optionally, the die comprise multiple mould cavities so that multiple premix gas burner deck plates can be cast in one single shot.

In an embodiment of the premix gas burner deck plate in accordance with the invention, the premix gas burner deck plate comprises a plurality of gas passage areas, and each gas passage area comprises at least one gas outflow channel, and multiple gas passage areas are arranged in a gas discharge zone. In this embodiment, the premix gas burner deck plate further has a circumferential edge. The premix gas burner deck plate further comprises a plate rim area adjacent to at least a part of the circumferential edge and at least partly surrounding the gas discharge zone. The premix gas burner deck plate has a third plate thickness in the plate rim area, the third plate thickness being larger than the first plate thickness, optionally equal to or larger than the second plate thickness.

This embodiment is particularly suitable for use in a premix gas burner which is designed in such a way that during use the gas discharge zone is subjected to compression stress. The arrangement of the gas discharge zone with the gas passage areas with relatively small local plate thickness in combination with the plate rim area with larger plate thickness allows to design the premix gas burner such that the plate rim area stays relatively cool and the gas discharge area is relatively warm. In addition, the thicker plate rim area provides additional strength.

Thermal expansion of the gas discharge area is this way limited, which results in compression stresses in the gas discharge area of the premix gas burner deck plate.

Compression stresses are far less likely to induce thermal fatigue cracking than tensile stresses, so having compression stresses in the area where the gas outflow channels (and therefore the stress concentrations due to holes in the premix gas burner deck plate) is likely to contribute to a longer life span of the premix gas burner deck plate from a fatigue point of view. In addition, tests carried out by the applicant seem to suggest that the Young's modulus for compression (sometimes also referred to in the art as compression modulus or elasticity modulus for compression) of cast aluminium (e.g. pressure die cast aluminium or sand cast aluminium) is significantly lower than the Young's modulus for tension, even as much as 1.5 — 2 times lower, up to 3 times lower. As a result of this, the compression stresses in the gas discharge area can be expected to be relatively low. This also contributes to a longer life span of the premix gas burner deck plate from a fatigue point of view.

In an embodiment of the premix gas burner deck plate in accordance with the invention, the premix gas burner deck plate is at least partly provided with a coating, e.g. an anti- corrosion coating. For example, a coating is used which provides protection against sulphur induced corrosion. Sulphur containing substances are sometimes added to fuel gas as odorants, but they may cause corrosion of metals, in particular when they are combusted with oxygen, and react with water H2SO, is formed, which can be highly corrosive.

Optionally, the coating is present at least on a part of the combustion zone side of the premix gas burner deck plate and/or on an inner wall of the gas outflow channel.

Optionally, a surface roughness is provided on the premix gas burner deck plate prior to applying the coating, e.g. during a pressure die casting process or sand casting process in which the premix gas burner deck plate is formed.

In an embodiment of the premix gas burner deck plate in accordance with the invention, the premix gas burner deck plate comprises a curved portion having a radius of curvature, and multiple gas outflow channels are provided in the curved portion, each of the gas outflow channels in the curved portion having a longitudinal axis. In this embodiment, the longitudinal axes of all gas outflow channels in the curved portion are parallel to each other.

Optionally, the longitudinal axis of at least one of the multiple gas outflow channels in the curved portion extends in the radial direction of the radius of curvature.

In an embodiment of the premix gas burner deck plate in accordance with the invention, multiple gas outflow channels are provided in the premix gas burner deck plate, each of the gas outflow channels having a longitudinal axis. In this embodiment, the longitudinal axes of all gas outflow channels are parallel to each other.

In an embodiment of the premix gas burner deck plate in accordance with the invention, the gas outflow channel has an inner wall and the gas passage area has an outer surface at the distribution chamber side of the premix gas burner deck plate, and the inner wall of the gas outflow channel meets the outer surface of the gas passage area at the distribution chamber side of the premix gas burner deck plate via a rounded edge.

Optionally, multiple gas outflow channels each have an inner wall and the gas passage area has an outer surface at the distribution chamber side of the premix gas burner deck plate, and the inner wall of each gas outflow channel meets the outer surface of the gas passage area at the distribution chamber side of the premix gas burner deck plate via a rounded edge.

Optionally, all gas outflow channels each have an inner wall and the gas passage area has an outer surface at the distribution chamber side of the premix gas burner deck plate, and the inner wall of each gas outflow channel meets the outer surface of the gas passage area at the distribution chamber side of the premix gas burner deck plate via a rounded edge.

It is suspected that this embodiment contributes to further reducing the risk of flashback, possibly because a smooth flow of premix gas into the gas outflow channel(s) is obtained and negative local pressure at the entrance into the gas outflow channel(s) is reduced or avoided.

The invention further pertains to a premix gas burner comprising a premix gas burner deck plate according to the invention.

In an embodiment of the premix gas burner in accordance with the invention, the premix gas burner comprises a gas distribution chamber, which gas distribution chamber is at least partly delimited by the premix gas burner deck plate.

For example, the premix gas burner in this embodiment further comprises a premix gas supply which is adapted to supply premix gas to the gas distribution chamber.

From the gas distribution chamber, the premix gas flows through the gas outflow channel(s) of the premix gas burner deck plate to the combustion zone, where the combustion of the premix gas takes place.

Optionally, a gas distributor is arranged in the gas distribution chamber, in order to equally distribute the premix gas over multiple gas outflow channels of the premix gas burner deck plate.

In an embodiment of the premix gas burner in accordance with the invention, a premix gas burner deck plate is used which comprises a plurality of gas passage areas, and each gas passage area comprises at least one gas outflow channel, and multiple gas passage areas are arranged in a gas discharge zone. In this embodiment, the premix gas burner deck plate further has a circumferential edge. The premix gas burner deck plate further comprises a plate rim area adjacent to at least a part of the circumferential edge and at least partly surrounding the gas discharge zone. The premix gas burner deck plate has a third plate thickness in the plate rim area, the third plate thickness being larger than the first plate thickness, optionally equal to or larger than the second plate thickness.

In this embodiment, the premix gas burner deck plate is mounted into the premix gas burner in such a way that during use the gas discharge zone is subjected to compression stress.

The arrangement of the gas discharge zone with the gas passage areas with relatively small local plate thickness in combination with the plate rim area with larger plate thickness allows to design the premix gas burner such that the plate rim area stays relatively cool and the gas discharge area is relatively warm. In addition, the thicker plate rim area provides additional strength.

Thermal expansion of the gas discharge area is this way limited or even prevented, which results in compression stresses in the gas discharge area of the premix gas burner deck plate.

In addition, in this embodiment, optionally the mounting of the premix gas burner deck plate in the premix gas burner is adapted to (of even optimised to) ensure that indeed compression stress is obtained in the gas discharge zone.

Optionally, in this embodiment, the plate rim area of the premix gas burner deck plate is in thermal contact with a heat sink. The heat sink can be a dedicated heat sink element, or a part of e.g. a body of the premix gas burner, a gas distribution chamber of the premix gas burner or the like may function as a heat sink for the plate rim area. The thermal contact between the plate rim area and the heat sink may be either direct or indirect.

In an embodiment of the premix gas burner in accordance with the invention, the heat transfer area or heat transfer areas of the premix gas burner deck plate is in thermal contact with a heat sink. The heat sink can be a dedicated heat sink element, or a part of e.g. a body of the premix gas burner, a gas distribution chamber of the premix gas burner or the like may function as a heat sink for the heat transfer area or heat transfer areas. The thermal contact between the heat transfer area or heat transfer areas and the heat sink may be either direct or indirect.

In an embodiment of the premix gas burner in accordance with the invention, the premix gas burner comprises a mounting flange which allows to mount the premix gas burner to a heat exchanger, which mounting flange is designed to allow heat transfer from the premix gas burner to the heat exchanger.

Preferably, the premix gas burner is mountable to the heat exchanger in a floating manner.

The invention further pertains to a heating appliance, which is for example a heater system for a building or a domestic hot water system.

The heating appliance according to the invention comprises the premix gas burner according to the invention and a heat exchanger.

Optionally, the premix gas burner deck plate of the premix gas burner is in thermal contact with the heat exchanger.

Optionally, the premix gas burner and the heat exchanger are made of the same material.

Optionally, the premix gas burner and the heat exchanger are integral with each other, e.g. in the form of an integrally cast aluminium element.

The invention further pertains to a method for manufacturing a premix gas burner deck plate according to the invention, which method comprises: - pressure die casting the premix gas burner deck plate in a die, wherein the gas passage area and/or the gas outflow channel are formed in the die.

In case the premix gas burner deck plate comprises a plurality of gas passage areas, optionally multiple gas passage areas are formed in the die. Optionally, in that case, all gas passage areas are formed in the die.

In case the premix gas burner deck plate comprises a plurality of gas outflow channels, optionally multiple gas outflow channels are formed in the die. Optionally, in that case, all gas outflow channels are formed in the die.

The premix gas burner deck plate according to the invention is suitable for pressure die casting, e.g. for high pressure die casting. This allows high production speeds and low manufacturing costs.

Optionally, the method further comprises the step of machining the premix gas burner deck plate to the desired shape and/or required manufacturing tolerances and/or required surface roughness.

As an alternative for pressure die casting, sand casting can be used.

Advantageously, the gas passage area(s) and the gas outflow channel(s) are both formed in the die, as this reduces the number of post-casting machining actions.

In an embodiment of the method for manufacturing a premix gas burner deck plate in accordance with the invention, a tapered gas outflow channel is formed in the die during the pressure die casting.

In case the premix gas burner deck plate comprises a plurality of gas outflow channels, optionally multiple gas flow channels are tapered gas outflow channels and are formed in the die during the pressure die casting. Optionally, in that case, all gas outflow channels are tapered and are formed in the die.

Optionally, the taper angle of a tapered gas outflow channel is optionally at least 6°, for example at least 9°, optionally at least 12°.

An advantage of this embodiment is that it contributes to easy removal of the premix gas burner deck plate from a die when the premix gas burner deck plate is made by pressure die casting and the tapered gas outflow channels are formed in the pressure die casting process.

Optionally, in a variant of this embodiment, the method further comprises the step of: - after the pressure die casting, tuning a local diameter of a gas outflow channel by removing material from the premix gas burner deck plate adjacent to the tapered gas outflow channel.

The material can for example be removed by machining.

Due to the tapered shape of the gas outflow channel(s), by removing a small amount of material adjacent to the tapered gas outflow channel, the diameter of the opening of the gas outflow channel in the outer surface of the gas passage are increases somewhat. In particular the smallest opening of the tapered gas outflow channel determines the pressure drop over the gas outflow channel, which is an important parameter in the design of the premix gas burner deck plate. So, by removing more or less material adjacent to the tapered gas outflow channel, in particular on the side of the opening with the smallest diameter, the pressure drop over the tapered gas outflow channel can be finetuned.

In an embodiment of the method for manufacturing a premix gas burner deck plate in accordance with the invention, the method further comprises the step of: - after the pressure die casting, applying a coating to at least a part of the premix gas burner deck plate, wherein optionally the coating is applied at least on a part of the combustion zone side of the premix gas burner deck plate and/or on an inner wall of the gas outflow channel.

For example, a coating is used which provides protection against sulphur induced corrosion. Sulphur containing substances are sometimes added to fuel gas as odorants, but they may cause corrosion of metals, in particular when they are combusted with oxygen, and react with water H2SO, is formed, which can be highly corrosive.

Optionally, a surface roughness is provided on the premix gas burner deck plate prior to applying the coating, e.g. during the pressure die casting process or sand casting process in which the premix gas burner deck plate is formed.

The invention will be described in more detail below under reference to the drawing, in which in a non-limiting manner exemplary embodiments of the invention will be shown. The drawing shows in:

Fig. 1: schematically, a first embodiment of a premix gas burner deck plate according to the invention,

Fig. 2: schematically, a cross section of the premix gas burner deck plate according to fig. 1, along line A-A of fig. 1,

Fig. 3: schematically, a second embodiment of a premix gas burner deck plate according to the invention,

Fig. 4: schematically, a cross section of the premix gas burner deck plate according to fig. 3, along line A-A of fig. 3,

Fig. 5: schematically, an example of a design of a gas passage area as can be used in a premix gas burner deck plate according to the invention,

Fig. 6: schematically, a first embodiment of a premix gas burner according to the invention.

Fig. 1 shows, schematically, a first embodiment of a premix gas burner deck plate 1 according to the invention. Fig. 2 shows, schematically, a cross section of the premix gas burner deck plate 1 according to fig. 1, along line A-A of fig. 1.

The premix gas burner deck plate of fig. 1 and fig. 2 has a distribution chamber side 2 and a combustion zone side 3. The distribution chamber side 2 and combustion zone side 3 are located on opposite sides of the premix gas burner deck plate 1. When the premix gas burner deck plate 1 is arranged in a premix gas burner, the distribution chamber side 2 of the premix gas burner deck plate 1 faces towards a gas distribution chamber of the premix gas burner, so, in upstream direction of the flow of the premix gas. When the premix gas burner deck plate 1 is arranged in a premix gas burner, the combustion zone side 3 of the premix gas burner deck plate faces towards a combustion zone in which the actual combustion of the premix gas takes place, so, in downstream direction of the flow of the premix gas.

The premix gas burner deck plate according to fig. 1 and fig. 2 comprises a plurality of gas passage areas 10 and a heat transfer area 5. All the recesses shown in fig. 1 are gas passage areas 10. Premix gas passes from the distribution chamber side 2 of the premix gas burner deck plate 1 to the combustion zone side 3 of the premix gas burner deck plate 1 via the gas passage areas 10. The heat transfer area 5 is designed for effective heat transfer, with the aim of avoiding high burner deck temperatures in the premix gas burner deck plate 1during use.

The premix gas burner deck plate 1 has a first plate thickness 11 in the gas passage area and a second plate thickness 6 in the heat transfer area 5. The second plate thickness 6 is larger than the first plate thickness 11. For example, the first plate thickness is 0.5 millimeters (mm) up to and including 1.5 millimeters (mm), for example 1 millimeter (mm). For example, the second plate thickness is 1.5 millimeters (mm) to 10 millimeters (mm), e.g. 2 mmilimeters (mm) up to and including 7 millimeters (mm), for example 2.5 millimeters (mm) to 6 milolimeters (mm) 5 millimeters (mm), e.g. 5 millimeters (mm) or 3 millimeters (mm). Of course, in case the first thickness is 1.5 mm, the second thickness is more than 1.5 mm. For example, the first thickness is 1 mm and the second thickness is 3 mm.

In the embodiment of fig.1 and fig. 2, the premix gas burner deck plate 1 comprises a plurality of gas outflow channels 12, each of which is adapted to during use supply premix gas to the combustion zone, in which combustion zone the combustion of the premix gas takes place during use of the premix gas burner deck plate 1 in a premix gas burner. The combustion zone is usually present adjacent to but just outside of the premix gas burner in which the premix gas burner deck plate is arranged. The gas outflow channels 12 are arranged in the gas passage area 10 and extend through the first plate thickness 11 from the distribution chamber side 2 of the premix gas burner deck plate 1 to the combustion zone side 3 of the premix gas burner deck plate 1.

In the embodiment of fig.1 and fig. 2, each gas passage area 10 comprises a plurality of gas outflow channels 12. The gas outflow channels 12 in each gas passage area 10 are arranged in a predetermined pattern that allows for or is even optimised for the combustion of a premix gas in which the fuel gas is or contains hydrogen

For example, the gas outflow channels 12 all have a circular cross-sectional shape, with a diameter that is either constant or varies over the length of the gas outflow channel 12. In case the diameter varies over the length of the gas outflow channel 12, the gas outflow channel 12 is for example tapered. The taper angle of the gas outflow channel is optionally at least 6°, for example at least 9°, optionally at least 12°. The diameter at an end of the gas outflow channel 12, e.g. at the end with the smallest diameter, is for example 0.6 mm — 1.0 mm, e.g. 0.8 mm. In case the diameter is constant over the length of the gas outflow channel 12, the diameter at an end of the gas outflow channel 12 is for example 0.6 mm — 1.0 mm, e.g. 0.8 mm.

In the embodiment of fig.1 and fig. 2, the premix gas burner deck plate 1 is made of cast aluminium, e.g. pressure die cast aluminium (including high pressure die cast aluminium) or sand cast aluminium. Cast aluminium has a high thermal conductivity, which makes that it is effective in transferring heat away from the premix gas burner deck plate.

Examples of (aluminium) materials that are suitable for use in the premix burner deck plate 1 according to the embodiment of fig.1 and fig. 2, are EN-AC44300 (EN AC-AISi12(Fe),

Werkstoff no. 3.2582), EN-AC 42100 (EN AC Si7Mg0.3, Werkstoff no. 3.2371, LM25), EN-

AC43000 (EN AC-AL Si10Mg(a), Werkstoff no. 3.2381).

In the embodiment of fig. 1 and fig. 2, the combustion zone side of the premix gas burner deck plate 1 is planar. So, in this embodiment, the combustion zone side 3 of the premix gas burner deck plate 1 is devoid of protrusions and indents.

In the embodiment of fig. 1 and fig. 2, optionally at least the heat transfer area 5 and the gas passage areas 10 of the premix gas burner deck plate 1 are manufactured by a pressure die casting process, for example a high pressure die casting process.

The premix gas burner deck plate 1 is then generally formed in a pressure die casting process. For example, different material thicknesses are provided for the gas passage areas 10 and the heat transfer area 5. Optionally, the pressure die cast premix gas burner deck plate 1 is machined after pressure die casting in order to make sure the required manufacturing tolerances are met, but in this embodiment the general shape of the premix gas burner deck plate is obtained by pressure die casting.

Optionally, also the gas outflow channels 12 of the premix gas burner deck plate 1 are formed in the pressure die casting process.

Optionally, in the embodiment of fig.1 and fig. 2, the premix gas burner deck plate 1 is at least partly provided with a coating, e.g. an anti-corrosion coating. For example, a coating is used which provides protection against sulphur induced corrosion. Optionally, a surface roughness is provided on the premix gas burner deck plate prior to applying the coating, e.g. during the pressure die casting process.

As can be seen in fig. 2, in this embodiment, each of the gas outflow channels has a longitudinal axis and the longitudinal axes of all gas outflow channels 12 are parallel to each other.

In the embodiment of fig. 1 and fig. 2, optionally all gas outflow channels 12 each have an inner wall and the gas passage area 10 has an outer surface at the distribution chamber side of the premix gas burner deck plate, and the inner wall of each gas outflow channel 12 meets the outer surface of the gas passage area 10 at the distribution chamber side of the premix gas burner deck plate 1 via a rounded edge.

Fig. 3 shows, schematically, a second embodiment of a premix gas burner deck plate 1 according to the invention. Fig. 4 shows, schematically, a cross section of the premix gas burner deck plate 1 according to fig. 3, along line A-A of fig. 3.

The embodiment of fig. 3 and fig. 4 is similar to the first embodiment as shown in fig. 1 and fig. 2, but has some additional features.

Like in the embodiment of fig.1 and fig. 2, the premix gas burner deck plate of fig. 3 and fig. 4 has a distribution chamber side 2 and a combustion zone side 3. The distribution chamber side 2 and combustion zone side 3 are located on opposite sides of the premix gas burner deck plate 1. When the premix gas burner deck plate 1 is arranged in a premix gas burner, the distribution chamber side 2 of the premix gas burner deck plate 1 faces towards a gas distribution chamber of the premix gas burner, so, in upstream direction of the flow of the premix gas. When the premix gas burner deck plate 1 is arranged in a premix gas burner, the combustion zone side 3 of the premix gas burner deck plate faces towards a combustion zone in which the actual combustion of the premix gas takes place, so, in downstream direction of the flow of the premix gas.

The premix gas burner deck plate according to fig. 3 and fig. 4 comprises a plurality of gas passage areas 10 and a heat transfer area 5. All the recesses shown in fig. 3 are gas passage areas 10. Premix gas passes from the distribution chamber side 2 of the premix gas burner deck plate 1 to the combustion zone side 3 of the premix gas burner deck plate 1 via the gas passage areas 10. The heat transfer area 5 is designed for effective heat transfer, with the aim of avoiding high burner deck temperatures in the premix gas burner deck plate 1during use.

The premix gas burner deck plate 1 has a first plate thickness 11 in the gas passage area and a second plate thickness 6 in the heat transfer area 5. The second plate thickness 6 is larger than the first plate thickness 11.

In the embodiment of fig.3 and fig. 4, the premix gas burner deck plate 1 comprises a plurality of gas outflow channels 12, each of which is adapted to during use supply premix gas to the combustion zone, in which combustion zone the combustion of the premix gas takes place during use of the premix gas burner deck plate 1 in a premix gas burner. The combustion zone is usually present adjacent to but just outside of the premix gas burner in which the premix gas burner deck plate is arranged. The gas outflow channels 12 are arranged in the gas passage area 10 and extend through the first plate thickness 11 from the distribution chamber side 2 of the premix gas burner deck plate 1 to the combustion zone side 3 of the premix gas burner deck plate 1.

In the embodiment of fig.3 and fig. 4 each gas passage area 10 comprises a plurality of gas outflow channels 12. The gas outflow channels 12 in each gas passage area 10 are arranged in a predetermined pattern that allows for or is even optimised for the combustion of a premix gas in which the fuel gas is or contains hydrogen

For example, the gas outflow channels 12 all have a circular cross-sectional shape, with a diameter that is either constant or varies over the length of the gas outflow channel 12. In case the diameter varies over the length of the gas outflow channel 12, the gas outflow channel 12 is for example tapered. The taper angle of the gas outflow channel is optionally at least 6°, for example at least 9°, optionally at least 12°. The diameter at an end of the gas outflow channel 12, e.g. at the end with the smallest diameter, is for example 0.6 mm — 1.0 mm, e.g. 0.8 mm. In case the diameter is constant over the length of the gas outflow channel 12, the diameter at an end of the gas outflow channel 12 is for example 0.6 mm — 1.0 mm, e.g. 0.8mm.

In the embodiment of fig. 3 and fig. 4, the premix gas burner deck plate 1 is made of cast aluminium, e.g. pressure die cast aluminium (including high pressure die cast aluminium) or sand cast aluminium.

In the embodiment of fig. 3 and 4, all gas passage areas 12 are arranged in a central gas discharge zone 13, which is arranged at a distance from a circumferential edge 7 of the premix gas burner deck plate 1, in this case in the center of the premix gas burner deck plate

In the embodiment of fig. 3 and 4, the premix gas burner deck plate 1 comprises a plate rim area 15 adjacent to at least a part of the circumferential edge 7. In this embodiment the premix gas burner deck plate 1 has a third plate thickness 16 in the plate rim area 15, which third plate thickness 16 is larger than the first plate thickness 11, and in this embodiment also larger than the second plate thickness 6.

In the embodiment of fig. 3 and fig. 4, the plate rim area 15 extends along the entire circumference of the premix gas burner deck plate. The gas passage areas 10 are arranged inthe central gas discharge zone 13 and are surrounded by the plate rim area 15.

In the embodiment of fig. 3 and fig. 4, a passage rim area 17 is provided around each of the gas passage areas 10, and the premix gas burner deck plate has a fourth plate thickness in the passage rim area 17. The fourth plate thickness is larger than the first plate thickness 11, and in the embodiment of fig. 3 and fig. 4, also larger than the second plate thickness 8.

In the embodiment of fig. 3 and fig. 4, the fourth plate thickness is equal to the third plate thickness 16.

In the embodiment of fig. 3 and fig. 4, the combustion zone side of the premix gas burner deck plate 1 is planar. So, in this embodiment, the combustion zone side 3 of the premix gas burner deck plate 1 is devoid of protrusions and indents.

In the embodiment of fig. 3 and fig. 4, optionally at least the heat transfer area 5 and the gas passage areas 10 of the premix gas burner deck plate 1 are manufactured by a pressure die casting process, for example a high pressure die casting process.

Optionally, in the embodiment of fig.3 and fig. 4, the premix gas burner deck plate 1 is at least partly provided with a coating, e.g. an anti-corrosion coating. For example, a coating is used which provides protection against sulphur induced corrosion. Optionally, a surface roughness is provided on the premix gas burner deck plate prior to applying the coating, e.g. during the pressure die casting process.

In the embodiment of fig. 3 and fig. 4, each of the gas outflow channels 12 has a longitudinal axis and, the longitudinal axes of all gas outflow channels 12 are parallel to each other.

In the embodiment of fig. 3 and fig. 4, optionally all gas outflow channels 12 each have an inner wall and the gas passage area 10 has an outer surface at the distribution chamber side of the premix gas burner deck plate, and the inner wall of each gas outflow channel 12 meets the outer surface of the gas passage area 10 at the distribution chamber side of the premix gas burner deck plate 1 via a rounded edge.

Fig. 5 shows, schematically, an example of a design of a gas passage area 10 as can be used in a premix gas burner deck plate 1 according to the invention, e.g. in the first embodiment of fig. 1 and fig. 2 or in the second embodiment of fig. 3 and fig. 4.

In the example of fig. 5, the gas passage 10 comprises multiple gas outflow channels 12 which are arranged in a predefined pattern.

In the example of fig. 5, the gas outflow channels 12 all have a circular cross-sectional shape, with a diameter that varies over the length of the gas outflow channel 12. In this example, the gas outflow channel 12 is tapered. The taper angle of the gas outflow channel is optionally at least 6°, for example at least 9°, optionally at least 12°. The diameter at an end of the gas outflow channel 12, e.g. at the end with the smallest diameter, is for example 0.6 mm — 1.0 mm, e.g. 0.8 mm.

Optionally, the gas passage area 10 of fig. 5 is part of a premix gas burner deck plate which is manufactured by the method according to the invention, and the gas outflow channels 12 are all formed during the pressure die casting process.

Optionally, in the manufacturing method after the pressure die casting, the local diameter of the gas outflow channels 12 at the distribution chamber side and/or of the combustion chamber side of the premix gas burner deck plate 1 is tuned by removing material from the premix gas burner deck plate adjacent to the tapered gas outflow channel, as is for example indicated by lines a and b in fig. 5. Lines a and b in fig. 5 relate to removal of the material from the combustion zone side. The material can for example be removed by machining.

Due to the tapered shape of the gas outflow channels 12, by removing a small amount of material adjacent to the tapered gas outflow channel 12, the diameter of the opening of the gas outflow channel in the outer surface of the gas passage is increased somewhat. This way, the pressure drop over the gas outflow channels 12 can be finetuned, in particular if material is removed from the end of the gas outflow channel that has the smallest diameter.

In the example of fig. 5, this is on the combustion zone side of the premix gas burner deck plate.

Fig. 6 shows, schematically, a first embodiment of a premix gas burner 20 according to the invention. This premix gas burner 20 comprises a premix gas burner deck plate 1 according to the invention, for example a premix gas burner deck plate according to fig. 1 and fig. 2 or according to fig. 3 and fig. 4.

In the embodiment of fig. 6, the premix gas burner 20 comprises a gas distribution chamber 21, which gas distribution chamber 21 is at least partly delimited by the premix gas burner deck plate 1.

In the embodiment of fig. 6, the premix gas burner 20 further comprises a premix gas supply 23 which is adapted to supply premix gas to the gas distribution chamber 21.

From the gas distribution chamber, the premix gas flows through the gas outflow channel(s) of the premix gas burner deck plate to the combustion zone, where the combustion of the premix gas takes place. The arrows in fig. 6 indicate the direction of the gas flow through the premix gas burner 20.

Optionally, a gas distributor 22 is arranged in the gas distribution chamber 21, in order to equally distribute the premix gas over multiple gas outflow channels of the premix gas burner deck plate.

Claims

CONCLUSIESCONCLUSIONS

1. Premix-gasbranderdekplaat, welke premix-gasbranderdekplaat een distributiekamerzijde en een verbrandingszonezijde heeft, welke distributiekamerzijde en verbrandingszonezijde zich aan tegenover elkaar liggende zijden van de premix-gasbranderdekplaat bevinden, welke premix-gasbranderdekplaat verder omvat: - een gasdoorgangsgebied, en - een warmteoverdrachtsgebied, waarbij de premix-gasbranderdekplaat een eerste plaatdikte heeft in het gasdoorgangsgebied en een tweede plaatdikte in het warmteoverdrachtsgebied, welke tweede plaatdikte groter is dan de eerste plaatdikte, en waarbij de premix-gasbranderdekplaat een gasuitstroomkanaal omvat dat is ingericht om tijdens gebruik premix gas toe te voeren aan een verbrandingszone, welk gasuitstroomkanaal is aangebracht in het gasdoorgangsgebied en zich uitstrekt door de eerste plaatdikte van de distributiekamerzijde van de premix-gasbranderdekplaat naar de verbrandingszonezijde van de premix-gasbranderdekplaat, en waarbij de premix-gasbranderdekplaat gemaakt is van gegoten aluminium.1. Premix gas burner cover plate, which premix gas burner cover plate has a distribution chamber side and a combustion zone side, which distribution chamber side and combustion zone side are located on opposite sides of the premix gas burner cover plate, which premix gas burner cover plate further comprises: - a gas passage area, and - a heat transfer area, wherein the premix gas burner cover plate has a first plate thickness in the gas passage area and a second plate thickness in the heat transfer area, which second plate thickness is greater than the first plate thickness, and wherein the premix gas burner cover plate comprises a gas outflow channel that is designed to supply premix gas during use to a combustion zone, which gas outflow channel is provided in the gas passage area and extends through the first plate thickness from the distribution chamber side of the premix gas burner cover plate to the combustion zone side of the premix gas burner cover plate, and wherein the premix gas burner cover plate is made of cast aluminum.

2. Premix-gasbranderdekplaat volgens conclusie 1, waarbij het gasdoorgangsgebied meerdere gasuitstroomkanalen omvat.2. Premix gas burner cover plate according to claim 1, wherein the gas passage area comprises several gas outflow channels.

3. Premix-gasbranderdekplaat volgens een van de voorgaande conclusies, waarbij de premix-gasbranderdekplaat meerdere gasdoorgangsgebieiden omvat, en elk gasdoorgangsgebied tenminste een gasuitstroomkanaal omvat.3. Premix gas burner cover plate according to any one of the preceding claims, wherein the premix gas burner cover plate comprises several gas passage areas, and each gas passage area comprises at least one gas outflow channel.

4. Premix-gasbranderdekplaat volgens een van de voorgaande conclusies, waarbij de premix-gasbranderdekplaat een omtreksrand omvat en waarbij de premix- gasbranderdekplaat een plaatrandgebied omvat nabij tenminste een deel van de omtreksrand, en waarbij de premix-gasbranderdekplaat een derde plaatdikte heeft in het plaatrandgebied, waarbij de derde plaatdikte groter is dan de eerste plaatdikte, optioneel gelijk aan of groter dan de tweede plaatdikte.4. Premix gas burner cover plate according to any of the preceding claims, wherein the premix gas burner cover plate comprises a peripheral edge and wherein the premix gas burner cover plate comprises a plate edge area near at least a part of the peripheral edge, and wherein the premix gas burner cover plate has a third plate thickness in the plate edge area , where the third plate thickness is greater than the first plate thickness, optionally equal to or greater than the second plate thickness.

5. Premix-gasbranderdekplaat volgens een van de voorgaande conclusies, waarbij tenminste een gasuitstroomkanaal taps toeloopt.5. Premix gas burner cover plate according to any of the preceding claims, wherein at least one gas outflow channel tapers.

6. Premix-gasbranderdekplaat volgens een van de voorgaande conclusies,6. Premix gas burner cover plate according to any of the preceding claims,

waarbij een doorgangsrandgebied is verschaft rond tenminste een gasdoorgang, en waarbij de premix-gasbranderdekplaat een vierde plaatdikte heeft in het doorgangsrandgebied, waarbij de vierde plaatdikte groter is dan de eerste plaatdikte, optioneel gelijk aan or groter dan de tweede plaatdikte.wherein a passage edge area is provided around at least one gas passage, and wherein the premix gas burner cover plate has a fourth plate thickness in the passage edge area, the fourth plate thickness being greater than the first plate thickness, optionally equal to or greater than the second plate thickness.

7. Premix-gasbranderdekplaat volgens een van de voorgaande conclusies, waarbij de verbrandingszonezijde van de premix-gasbranderdekplaat vlak is.7. Premix gas burner cover plate according to any of the preceding claims, wherein the combustion zone side of the premix gas burner cover plate is flat.

8. Premix-gasbranderdekplaat volgens een van de voorgaande conclusies, waarbij tenminste het warmteoverdrachtsgebied en/of het gasdoorgangsgebied van de premix-gasbranderdekplaat is vervaardigd door een pressure die casting proces.8. Premix gas burner cover plate according to any of the preceding claims, wherein at least the heat transfer area and/or the gas passage area of the premix gas burner cover plate is manufactured by a pressure die casting process.

9. Premix-gasbranderdekplaat volgens conclusie 8, waarbij verder het gasuitstroomkanaal van de premix-gasbranderdekplaat is gevormd in het pressure die casting proces.9. Premix gas burner cover plate according to claim 8, wherein the gas outflow channel of the premix gas burner cover plate is further formed in the pressure die casting process.

10. Premix-gasbranderdekplaat volgens conclusie 3, waarbij meerdere gasdoorgangsgebieden zijn aangebracht in een gasuitlaatgebied, en waarbij de premix-gasbranderdekplaat een omtreksrand omvat en waarbij de premix- gasbranderdekplaat een plaatrandgebied omvat nabij tenminste een deel van de omtreksrand en tenminste deels omgevende het gasuitlaatgebied, en waarbij de premix- gasbranderdekplaat een derde plaatdikte heeft in het plaatrandgebied, waarbij de derde plaatdikte groter is dan de eerste plaatdikte, optioneel gelijk aan of groter dan de tweede plaatdikte.10. Premix gas burner cover plate according to claim 3, wherein multiple gas passage areas are arranged in a gas outlet area, and wherein the premix gas burner cover plate comprises a peripheral edge and wherein the premix gas burner cover plate comprises a plate edge area adjacent to at least part of the peripheral edge and at least partly surrounding the gas outlet area, and wherein the premix gas burner cover plate has a third plate thickness in the plate edge area, wherein the third plate thickness is greater than the first plate thickness, optionally equal to or greater than the second plate thickness.

11. Premix-gasbranderdekplaat volgens een van de voorgaande conclusies, waarbij de premix-gasbranderdekplaat tenminste deels is voorzien van een coating, bv. een anti-corrosiecoating, waarbij optioneel de coating aanwezig is op tenminste een deel van de verbrandingszonezijde van de premix-gasbranderdekplaat en/of een binnenwand van het gasuitstroomkanaal.11. Premix gas burner cover plate according to any of the preceding claims, wherein the premix gas burner cover plate is at least partly provided with a coating, e.g. an anti-corrosion coating, wherein the coating is optionally present on at least part of the combustion zone side of the premix gas burner cover plate and/or an inner wall of the gas outflow channel.

12. Premix-gasbranderdekplaat volgens een van de voorgaande conclusies, waarbij de premix-gasbranderdekplaat een gekromd gedeelte omvat met een kromtestraal, en waarbij meerder gasuitstroomkanalen zijn verschaft in het gekromde gedeelte, waarbij elk van de gasuitstroomkanalen een longitudinale as heeft, en waarbij de longitudinale assen van de gasuitstroomkanalen in het gekromde gedeelte evenwijdig aan elkaar zijn.12. Premix gas burner cover plate according to any one of the preceding claims, wherein the premix gas burner cover plate comprises a curved portion with a radius of curvature, and wherein a plurality of gas outflow channels are provided in the curved portion, wherein each of the gas outflow channels has a longitudinal axis, and wherein the longitudinal axes of the gas outflow channels in the curved part are parallel to each other.

13. Premix-gasbranderdekplaat volgens een van de voorgaande conclusies, waarbij het gasuitstroomkanaal een binnenwand heeft en het gasdoorstroomgebied een buitenoppervlak heeft aan de distributiekamerzijde van de premix-gasbranderdekplaat, en Waarbij de binnenwand van het gasuitstroomkanaal het buitenoppervlak van de het gasdoorstroomgebied aan de distributiekamerzijde ontmoet via een afgeronde rand.13. Premix gas burner cover plate according to any one of the preceding claims, wherein the gas outflow channel has an inner wall and the gas flow area has an outer surface on the distribution chamber side of the premix gas burner cover plate, and wherein the inner wall of the gas outflow channel meets the outer surface of the gas flow area on the distribution chamber side via a rounded edge.

14. Premix-gasbrander omvattende een premix-gasbranderdekplaat volgens een van de voorgaande conclusies,14. Premix gas burner comprising a premix gas burner cover plate according to any of the preceding claims,

15. Premix-gasbrander volgens conclusie 14, waarbij de premix-gasbrander een gasdistributiekamer omvat, en waarbij de gasdistributiekamer tenminste deels wordt begrensd door de premix-gasbranderdekplaat.15. Premix gas burner according to claim 14, wherein the premix gas burner comprises a gas distribution chamber, and wherein the gas distribution chamber is at least partly bounded by the premix gas burner cover plate.

16. Premix-gasbrander volgens een van de conclusies 14-15, waarbij de premix-gasbranderdekplaat een premix-gasbranderdekplaat volgens conclusie 10 is, en waarbij de premix-gasbranderdekplaat zodanig is aangebracht in de premix-gasbrander dat tijdens gebruik het gasuitlaatgebied onderworpen is aan drukspanning.16. Premix gas burner according to any one of claims 14-15, wherein the premix gas burner cover plate is a premix gas burner cover plate according to claim 10, and wherein the premix gas burner cover plate is arranged in the premix gas burner in such a way that during use the gas outlet area is subject to compressive stress.

17. Premix-gasbrander volgens conclusie 18, waarbij het plaatrandgebied van de premix-gasbranderdekplaat in thermisch contact staat met een heatsink.17. Premix gas burner according to claim 18, wherein the plate edge area of the premix gas burner cover plate is in thermal contact with a heat sink.

18. Premix-gasbrander volgens een van de conclusies 14 -17, waarbij de premix-gasbrander een montageflens omvat die toestaat de premix-gasbrander aan een warmtewisselaar te monteren, welke montageflens is ontworpen om warmteoverdracht van de premix-gasbrander naar de warmtewisselaar toe te staan.18. Premix gas burner according to any one of claims 14 - 17, wherein the premix gas burner comprises a mounting flange that allows the premix gas burner to be mounted on a heat exchanger, which mounting flange is designed to allow heat transfer from the premix gas burner to the heat exchanger. to stand.

19. Verwarmingstoestel omvattende een premix-gasbrander volgens een van de conclusies 14-18 en een warmtewisselaar, waarbij optioneel de premix-gasbranderdekplaat van de premix-gasbrander in thermisch contact is met de warmtewisselaar, en/of waarbij de premix-gasbrander en de warmtewisselaar gemaakt zijn van hetzelfde materiaal, en/of waarbij de premix-gasbrander en de warmtewisselaar integraal met elkaar zijn uitgevoerd, bv. in de vorm van een integraal gegoten aluminium element.19. Heating appliance comprising a premix gas burner according to any one of claims 14-18 and a heat exchanger, wherein optionally the premix gas burner cover plate of the premix gas burner is in thermal contact with the heat exchanger, and/or wherein the premix gas burner and the heat exchanger are made of the same material, and/or where the premix gas burner and the heat exchanger are integral with each other, e.g. in the form of an integral cast aluminum element.

20. Werkwijze voor het vervaardigen van een premix-gasbranderdekplaat volgens een van de conclusies 1-13, welke werkwijze omvat: - pressure die gieten van de premix-gasbranderdekplaat in een matrijs, waarbij het gasdoorlaatgebied en het gasuitstroomkanaal worden gevormd in de matrijs.20. Method for manufacturing a premix gas burner cover plate according to any one of claims 1-13, which method comprises: - pressure die casting of the premix gas burner cover plate in a mould, wherein the gas passage area and the gas outflow channel are formed in the mould.

21. Werkwijze volgens conclusie 20, waarbij een taps toelopend gasuitstroomkanaal wordt gevormd in de matrijs tijdens het pressure die gieten.A method according to claim 20, wherein a tapered gas outflow channel is formed in the mold during pressure die casting.

22. Werkwijze volgens conclusie 21, waarbij de werkwijze verder de stap omvat van: - na het pressure die gieten, het op maat maken van een lokale diameter van een gasuitstroomkanaal dor het verwijderen van materiaal van de premix-gasbranderdekplaat nabij het taps toelopende gasuitstroomkanaal.22. Method according to claim 21, wherein the method further comprises the step of: - after pressure die casting, tailoring a local diameter of a gas outflow channel by removing material from the premix gas burner cover plate near the tapered gas outflow channel.

23. Werkwijze volgens een van de conclusies 20-22, waarbij de werkwijze verder se stap omvat van: - na het pressure die gieten, het aanbrengen van een coating op tenminste een deel van de premix-gasbranderdekplaat, waarbij optioneel de coating wordt aangebracht op tenminste een deel van de verbrandingszonezijde van de premix-gasbranderdekplaat en/of op een binnenwand van het gasuitstroomkanaal.23. Method according to any of the claims 20-22, wherein the method further comprises the step of: - after pressure die casting, applying a coating to at least a part of the premix gas burner cover plate, wherein optionally the coating is applied to at least part of the combustion zone side of the premix gas burner cover plate and/or on an inner wall of the gas outflow channel.