CN85204630U - Oxidation-resistant w-re thermocouple - Google Patents

Abstract

The utility model belongs to a measuring element for high temperature. In order to solve the problem of oxidation of tungsten-rhenium thermal couple wire, improve service life, overcome the defect of prime tungsten-rhenium thermal couple which can work only in protective atmosphere or inert atmosphere, enlarge range of use and replace platinum-rhodium thermal couple for high price, an antioxidation sleeve or a coat made of zirconium-titanium analytical pure hydrides is additionally arranged in an ordinary assembling tungsten-rhenium thermal couple in the utility model which has the function of releasing hydrogen to adsorb oxygen and nitrogen in high temperature and can make the couple work cyclically, continuously and accurately in high-temperature air or oxidizing atmosphere.

Description

Oxidation-resistant W-Re thermocouple

The utility model belongs to resistant to elevated temperatures temperature element.

As everyone knows, W-Re has appearred in this century in thermometry be thermopair, and it has shown very big advantage since coming out.For example: its fusing point height, elevated temperature strength is big, and corrosion resistivity is good, and thermoelectrical potential is big; With the platinum rhodium is that thermopair is compared, and its cost is low, life-span height, temperature adaptation wide ranges.Therefore having greatly the platinum rhodium is the gesture of thermopair replacement.But also there are a lot of stubborn problems at present, limited its development and popularization.One of its major issue is anti-oxidant problem.W-Re is that thermopair can adapt to high temperature, and naked silk can be at reactor, the firing chamber of turbine engine, the Apollo Personnel investigation Program of protective atmospheres such as 2600 ℃ high vacuum, hydrogen, argon " thermometric under the thermoshield effect of No. 11 airships.The W-Re of assembling is a galvanic couple because of sleeve pipe is subjected to the restriction of heatproof, can only be at 1100～1800 ℃ vacuum drying oven, hydrogen, inert atmosphere stove thermometric, and almost can not in the high temperature air in same temperature territory, oxidizing atmosphere, work.Know according to investigations; for solving anti-oxidant problem; adopt the method for protective finish more in the prior art, as used carbonide, nitride; boride; silicide, intermetallic compounds etc. all are difficult to conform to the W-Re thermo wires because of physical properties such as thermal expansivity; when the Circularly liftable thermometric, be prone to crackle and make protection failure.In addition, along with the propelling of building of the four modernizations, the Ferrous Metallurgy of China, casting, chemical industry, electronics, non-ferrous metal, glass, pottery, industry such as cement are just developing rapidly, and using expensive platinum rhodium in these industries in large quantities is thermopair, expend greatly, require consumingly to go to replace it with inexpensive novel temperature element.

The design's purpose is to be the anti-oxidant problem of thermopair for solving W-Re; employing is in the inner way that installs anti-oxidant cover or protective finish additional of assembling; make the usable range of W-Re galvanic couple unrestricted; improve the life-span; the metal platinum of conserve expensive; reduce the thermometric expense, give full play to the advantage of W-Re galvanic couple, progressively substituting the platinum rhodium is thermopair.

The utility model takes in common assembling Wolfram rhenium heat electric couple zirconium to be housed, titanium is analyzed pure hydride (ZrH ₂, TiH ₂) anti-oxidant cover or apply with oxidation resistant coating, and add sealing and make.Hydride such as zirconium, titanium has absorption hydrogen below 400 ℃ the time, discharges the characteristics of hydrogen in time more than 800 ℃.1865 ℃ of the fusing points of zirconium, 3650 ℃ of boiling points, it has the effect of adsorb oxygen, nitrogen, carbon monoxide, carbon dioxide at high temperature.Like this, mainly be dry hydrogen at the surrounding space of the W-Re thermo wires of condition of high temperature lower seal assembling, promptly formed its desired ideal environment condition.Proof is being arranged in the experience in nitrogen atmosphere, the W-Re thermo wires is in 1400 ℃～1500 ℃ work some months, and its temperature measurement error only ± 5 ℃.The design's assembling W-Re is that thermopair has been accumulated work more than 400 hours in 1100～1800 ℃ of high temperature airs, oxidizing atmosphere, does not damage as yet.This has illustrated that it can substitute the platinum rhodium in quite wide scope be thermopair.

Having solved anti-oxidant problem is that the wide world has been opened up in the use of thermopair for W-Re just.The W-Re that in thermometry, adopts the design be thermopair with prior art in W-Re idol and platinum rhodium idol compare and shown following advantage: 1. adopting assembling is thermopair with the W-Re of anti-oxidant cover or band oxidation resistant coating; solved anti-oxidant problem; overcome the requirement that in protective atmosphere and inert gas, to work; and can in high temperature air or oxidizing atmosphere, use; open and expanded usable range, having created replacement platinum rhodium is the precondition of thermopair.2. compare with platinum rhodium galvanic couple and have higher mission life, the design's product recycles through up to a hundred times, and accumulation surpasses 400 hours man-hour, damages as yet.3. the cost of comparing it with platinum rhodium galvanic couple is very low, and both differ tens times, and according to Shan County, Henan chemical fertilizer factory report, it is that the thermocouple temperature measurement annual fee needs 100,000 yuan that this factory uses the platinum rhodium, uses the W-Re galvanic couple instead and then only needs several thousand yuan.

Fig. 1, Fig. 2, Fig. 3 are the structural drawing of three embodiment of the design.Fig. 1 is a preferred plan.(1) one sleeve pipe wherein can adopt (CT-1) of GB2935-82 corundum matter or nonstandard metallic ceramics matter; (2)-pad of thermo wires; (3)-and corundum matter insulation tube, its specification and thermo wires diameter coupling; (5), (6)-low-temperature end sealing, available hard material (gypsum or heatproof compound) or soft material (heatproof lute in or strain clay), not high to seal request, the both can seal off under the common room temperature environment, and can reset anti-oxidant cover or application layer again; (7)-thermo wires; (8), (9)-location snap ring, make with the W-Re thermo wires.(4), (4 '), (4 ") are coexist the mutually forms of the different practices among three kinds of embodiment of content.(4)-zirconium, titanium etc. analyze pure hydride (ZrH ₂, TiH ₂) the anti-oxidant cover made, be shaped as the thin walled tube of both ends open, it is analyzed pure hydride, bonding agent (gum arabic), thinning agent compounds such as (dimethylbenzene) by zirconium, titanium and is pressed into, must be before the assembling through 150 ℃ ± 10 ℃ bakings 5 hours, with Ex-all moisture content, its length, thickness are decided according to assembling space.Should be placed on during thermometric in the warm territory that is in more than 800 ℃.In Fig. 2, Fig. 3 (4 '), (4 ")--oxidation resistant coating; they all are to use the anti-oxidant compound identical with (4) to dilute a little; (4 ') are to be coated on the insulation tube, (4 ") are to be coated on the inwall of sleeve pipe, and requiring of the thickness of its coating and length and first kind of embodiment is identical.

Claims (3)

1, a kind of can in 1100 ℃～1800 ℃ high temperature airs or oxidizing gas, work for a long time, and the W-Re of being made up of thermo wires, insulation tube, anti-oxidant measure and sleeve pipe is a thermopair, the anti-oxidant measure that it is characterized in that it is taked in the insulation tube outside both ends open, thin-walled to be housed, and analyzes pure hydride (ZrH by the zirconium titanium ₂, TiH ₂), the anti-oxidant cover formed of cementing agent, thinning agent, and all sealing between insulation tube and the ferrule openings end and between insulation tube bared end and the thermo wires with encapsulant.

2, a kind of can in 1100 ℃～1800 ℃ high temperature airs or oxidizing gas, work for a long time, and the W-Re of being made up of thermo wires, insulation tube, anti-oxidant measure and sleeve pipe is thermopair, and the anti-oxidant measure that it is characterized in that it is to adopt to be covered with on insulation tube or sleeve pipe by zirconium, titanium to analyze pure hydride (ZrH ₂, TiH ₂), the oxidation resistant coating formed of cementing agent, thinning agent, and all sealing between insulation tube and the ferrule openings end and between insulation tube bared end and the thermo wires with encapsulant.

3, be thermopair by claim 1 or 2 described W-Res, it is characterized in that its sealing can be adopted hard material or soft material, the both can seal off under the common room temperature environment, and can reset anti-oxidant cover or application layer again.

Images