DE2021044A1 - Thermocouple wire and a thermocouple or thermal detector using the same - Google Patents

Description

. Patent attorney · Berlin, April 25, 197ο

Dipl.-In ₉ . H. Tiacher ^{Pr / Iia} Berlin 33 (Grunewald) HerbertFtr. 22 Tel. Β 87 72 37

lall.-no. 272/939 - ο

EGYESÜLT IZZOLAMPA ES VIIiMMOSSAGI RESZVENYTARSAG Budapest IV, Vaoi ut 77 - HUNGARY

THERMOCOUPLE WIRE AND SIN DSNSSLBSN VSRWENDSND6S THEBMOBLEKENT OR THEHMODBTBKiTOR.

The invention relates to novel thermocouple wires and to thermocouples or thermal detectors (in particular Thermal immersion probe, thermocouple fitting, measuring brick).

In the case of temperature measurements using a thermocouple, the technical! Has not been resolved problem practically, the cold spot above 2000 ⁰ C dad achmel-

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arranged at any distance from the measuring point tffr. The reason for this is, on the one hand, that the heat and corrosion protection of longer legs could not be achieved economically, and on the other hand, that the ^{alloys which melt above a temperature of 2,000 °} C. have anti-corrosion coatings. Despite all the improvements, they are somewhat more brittle than those of platinum-based thermocouples, but which can only be used up to a lower temperature limit. The materials mentioned that ^{melt above 2000 °} C. are primarily the alloys of tungsten, molybdenum and rhenium. OfcfcfAi 4ie when measuring high temperatures great benefits aufwei a s / äuT A nwendungsgebiet en thermocouples with platinum-based consequently not be used everywhere, ImMw,

The object of the invention is to eliminate the disadvantages described and in the Herateilung an improved, from existing above a temperature of 2000 ⁰ C-melting metals or alloys ■ thermocouple wire.

It was recognized that if the thermocouple wire consists of two or more strands, at least one strand being in a spiral shape in relation to the wire axis. arranged igt (i.e. the thermal element wire made of two or more strands by stranding and / or spiraling has been trained), numerous essential new technical effects can be achieved. The main advantage consists in the fact that the wire produced in this way is (partially or completely) covered with a protective coating of the heat transfer factor K j> than 600 kcal / m h ° C can be easily coated can; In addition, the person with this (from ver. Protective coating coated wire without breakage or flaking dea The coating can also be subjected to a bending force

These advantages mean with such thermoel -

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Thermocouples manufactured without the wires that the thermocouple legsjl can be formed longer than before and this with a well-adhering, thinner, uniform surface-closing coating can be provided can.

As the material of the strands can be appropriate. Tungsten, molybdenum or rhenium alloys can be used. One or more oxides can be used as a coating - in a manner known per se - u.zw. SiOg, AIgCK, BeO, ThOg, HfO ₂ , CaO, MgO.

Can be as thermocouples containing tungsten, molybdenum and rhenium provided with corrosion protection not only advantageous over 2000 ⁰ C. (up to about 2600 ⁰ C) but below a temperature of 2000 ⁰ C undzwar from 600 ⁰ C comparable \ applies not come only the above-mentioned, but also other conventional ceramic coatings for such purposes. _:

These coated legs are also after coating bendable and can therefore be used in any fittings. By spiraling or VeraeilSnrf the resistance of the legs to mechanical loads is increased to such an extent that, for some purposes, a corresponding strength even without the addition of rhenium can be achieved, thereby reducing the manufacturing cost. The thermal conductivity of the with insulating eaf oxide enamel coated thighs is in the case of the stranded solution is much lower than that of the simple one. Legs of identical length and diameter, whereby the from the heat dissipation resulting errors in the case of a not deep immersion in the area of the heat measurement substantially, is reduced. Beyond these benefits the thermocouples produced in this way can also be viewed as parallel-connected thermocouple batteries which can also compensate for that small thermal voltage scatter, which is caused by the

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Scattering of the material of the legs is caused,

For the sake of clarity, we note that thermocouples made up of three or more legs are already used for stiffening purposes were used. In contrast, the thermocouple according to the invention has only two legs, which are, however, au3 consist of several strands, which, however, does not result in a deformation effect, but on the contrary, flexibility is achieved.

At the same time, however, much longer legs can be used than either with non-stiffened legs Thermocouples with two legs and one strand per leg or even with stiffened thermocouples three or more legs and also one strand per Leg. . ,

It is also noted that although the protective coating is known per se (e.g. from the Hungarian patent specification 156 022), with the known use just the Heat measuring point was covered with such a coating, while within the meaning of the present invention a thermocouple Establish where at least 20 # the length of the leg, or even the entire leg with a protective cover is covered.

The thermocouple wire according to the invention can also be produced in continuous operation and indeed in this way « that the stranding or spiraling of the strands directly the coating follows.

The thermocouple wire of the invention, Cwelcher without coating has a thickness of about 250 - 500 / u) or the thermocouple can also be used without a container however, it is advisable to build them into thermal detectors together with a container · The usual ones Thermodetektoreii ^ in which the invention Thermocouple wire or thermocouple is used, the immersion probes, thermocouple fittings. However, the thermocouple according to the invention is due to its excellent heat and corrosion resistance

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also for. Embedding in the kiln wall tile suitable, where ■ the bricks built into the furnace wall carry out a continuous temperature registration. Dia according to the invention - The solution is therefore very suitable for · permanent measurements · where the cold point is far away from the measuring point target.

The thermocouple according to the invention or the application the same is illustrated, for example, in the embodiments according to FIGS. 1-3, to which, however, the invention is not restricted.

Xn Pig. 1 illustrates a measuring probe which the smoothed quartz tube 1 »the W-WRe (25 # -ige) thermocouple wire 2 according to the invention arranged therein, the hot point 3 of the thermocouple wire, the cold point 4, the electrical contacts 5 a water glass-aluminum oxide filling compound 6, and an asbestos tube 7 can be seen. As it can be seen in the figure, the feeler part of the protrudes Measuring probe quite long 0V <that isolates the cold point securing physique. The minimum projection must be 2 cm. · ·

The measuring probe according to FIG. 1 is particularly suitable for precise measurement of the temperature of the high-quality melt of small volume; only the melt is immersed in the melt Sensor attachment, the insulator not. This means that the melt is not significantly cooled down by the measurement.

In Fig. 2 is one for metallurgical and others; Industrial temperature measurements usable can be seen in which instead of the usual platinum-platinum rhodium thermocouples Thermo-thermocouple according to the invention is arranged. In the figure, which one too Cross-section according to A-A or an enlarged longitudinal section is illustrated with 10 the electrical contact, with 11 the protective ceramic tube, with 12 the two-hole tube Ceramic tube in which the thermo legs are arranged Bind, with 13 the thermo legs, and with 14 one in the

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Ceramic denotes a melted thermocouple point.

Slide made on the stranded strands of tungsten-tungsten-rhenium or tungsten Molvbdänschenkel aind with aua SiOpt AIoCU etc. Oxide of existing double enamel coated, and can be bent in a radius of 10 cm during assembly. Instead of stranding the strands, a so to speak, a partial solution is used, in which one or more strands apiralises one or more strands on one or more strands are, or the strands are arranged in any combination that at least one . none of them with the axial direction of the leg has identical direction, but in relation to it runs in a spiral line.

FIG. 3 shows a furnace wall brick designed according to the invention, in which a tungsten-molybdenum or tungsten-tungsten-rhenium thermocouple is insulated against corrosion and can withstand the temperature of the furnace for months is built in. In the figure, the drilled brick itself is shown at 20, and the two legs of the inventor at 21 dungagemäöen thermocouples, with 22 one melted in ceramic Feeler, at 23 a two-hole Karamlkröhr · » with 24 a heat-resistant steel tube, which can be used as a fix The connection head is used and with 25 the connection head self-designated.

The goat-shaped thermal probe according to Fig. Q can be installed in any oven and continuously shows that β »* is registering! mV-ft »ttr connected, the temperature of the furnace during its life.

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COPY BAD ORIGINAL ^

Claims (4)

PATENTANS PRLfCHB ' X ₉ J for the measurement of temperatures between 6OO-26OO ° C usable, a bending force auaaetzbarer and existing from metals or alloys having a melting point above 2000 ⁰ C Thermoelemenjidraht characterized geke η η i ze without t, da3 same AU3. consists of two or more strands, furthermore that at least one dis3 strand is arranged in a spiral shape relative to the wire stem, characterized by an at least partly iron protective coating known per se with a heat transfer factor of K> 600 kual / in ~ h ⁰ C. 2. thermocouple wire according to claim 1, characterized g ek e η η ζ e i c h η e t that. a) the strands consist of at least one of the following materials: W, Mo, Rheniim alloys, b) the coating consists of at least one of the following oxides: SiO ₂ , Al ₂ O ₃ , BeO, ZrO ₂ , HfO ₂ , CaO, MgO. 3 »Thermocouple thereby geke η η ζ calibrated η et that at least one of its legs consists of the thermocouple wire according to claims 1 and 2, further in that at least its measuring point and at least. 20 % of the length of the individual legs is covered with a protective coating according to claim 1, 4. Thermal sensors, in particular Taticht thermal probes, thermocouple fittings and thermal bricks g; eke η η -. ζ ei ch η et by a thermocouple according to claim 3, which is arranged protruding from the cooler body at least 2 cm ». The patent attorneys ipClSg-H.Tisch A6 No. 60/70 (§46 -PA AO) 109811/1282 BAD ORIGINAL COPY