SU756146A1 - Exothermic furnace - Google Patents

Description

The invention relates to heating devices using the heat of exothermic chemical reactions and can be used to obtain permanent connections by the method of soldering, the production of alloys of various materials, etc. in weightless conditions.

Known exothermic furnace containing a cylindrical, provided with end caps case with coaxially placed on its inner wall layers of peripheral - thermal insulation and internal - getter, and enclosed in a perforated shell annular exothermic heater, forming a central cylindrical channel for the heated object. The cavity for placing the exothermic heater is directly communicated with the cavity of the gas absorber [1].

This device is closest to the invention in its technical essence and the achieved result.

The disadvantage of this device is that it does not provide reliable operation when using exothermic mixtures with high temperature chemical reactions, in which products are released

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not only in the form of gases and water vapor, but also in the form of smoke, fog and vapors of solids. All these products enter the cavity with the gas absorption material and impair its properties.

In addition, the device contains exothermic heater rigidly connected to the housing, which excludes the possibility of its replacement and, consequently, repeated use of the housing with insulation and a getter.

The aim of the present invention is to improve the reliability and safety of the device by protecting the gas absorption material from the direct effects of the products of exothermic chemical reactions in the form of liquid and solid particles (smoke and aerosols).

This goal is achieved by the fact that between the getter layer and the heater an additional layer of gas-permeable thermal insulation is installed with a perforated shell on the side of the heater, which forms an annular gap with the latter.

The drawing shows the proposed exothermic furnace, a longitudinal section.

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756146

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The exothermic furnace contains a cylindrical housing 1 with end caps 2 and 3. On the inner wall 4 of the housing there are layers 5 and 6 of thermal insulation and a gas absorber respectively coaxially with the housing in a perforated shell 7 there is an annular exothermic heater 8 forming a central cylindrical channel for the heated object 9. Between layer 5 gas getter and heater 8 coaxially placed a layer 10 of gas-permeable insulation, which on the side of the heater 8 is adjacent perforated shell 11, forming with a heater m 8 annular gap 12:

The end caps 2 and 3 consist of two thin metal discs, between which the insulating material 13 is laid. The caps 2 and 3 are attached to the body 1 with hinges 14 and spring locks 15. The caps 2 and 3 have annular grooves in which sealing gaskets 16 are laid The exothermic furnace has brackets 17 for fastening at the workplace. The perforated shell 7 is closed by annular plates 18 and 19. Inside the shell 7 are placed briquettes 20 of the exothermic mixture, packed in a glass 21c with covers 22 and 23. Plates 18 and 19 fasten the shell 7 with the sleeve 24. 'Between the plate

18 and a lid 22, as well as between the plate

19 and a gas permeable insulating material is placed on the lid 23. The covers 22 and 23, the shell 7 and the shell 11 are made with perforations and provide the passage of gaseous products of chemical reactions to the gas absorption material 6. The heated objects are placed inside the sleeve 24. The ignition device 25 is fixed on the lid 22 of the cup 21. A current lead 26 is mounted on the plate 18. A current lead 27 is fixed on the inner disk of the lid 2 and is connected to the connector 28 with a wire. hemispheres KSSB-3 heat insulation material based on quartz fiber with a high-temperature inorganic bond was used as heat insulation. In the exothermic heater 8 is used pressed briquettes 20 a mixture of magnesium with iron ·: ·! 1LINE. A platinum-palladium catalyst was used as a gas absorption ’. The outer shell 7, the cover 22, 23, the sleeve 24 and the plate 18 and 19 of the heater 8 are made of sheet tantalum.

Exothermic furnace works as follows.

After the exothermic furnace is equipped with a heater 8 and heated objects, covers 2 and 3 hermetically close and pour a pulse of electric current to the ignition device 25, which initiates an exothermic chemical reaction in briquettes 20. As a result of a chemical reaction, the exothermic mixture turns into a solid burning slag and heat is generated, which using the sleeve 24 is transferred to objects of heating. Volatile products of exothermic chemical reactions out of the glass 21 through the holes in the covers 22 and 23, and then through the gas-permeable insulation and the openings of the shell 7 - into the annular gap between the heater and the shell 11 and, further, through the layer 10 of gas-permeable insulation to the getter layer 6. Hermetically Closed caps 2 and 3 exclude the release of chemical reaction products from the exothermic furnace. After the oven cools, the covers 2 and 3 are opened, the heated objects and, if necessary, the exothermic heater 8 are removed. For reuse, the new exothermic heater and heated objects are inserted into the exothermic furnace, the covers 2 and 3 are closed and the furnace is ready for operation.

Due to the tightness of the body of the exothermic furnace, the possibility of pollution of the surrounding atmosphere is excluded and the safety of the operators is ensured. Introduction to the exothermic furnace of an additional layer of gas-permeable insulation with perforated shells on the heater side prevents contamination of the getter 6 with solid and liquid particles released from the exothermic mixture during operation of the furnace, which increases its reliability and safety.

The presence of a gap between the heater and the perforated shell of an additional layer of gas-permeable thermal insulation allows you to reuse the case with thermal insulation and gas-absorbing material, replacing the spent heater and heated objects.

Claims (1)

Formula invent. An exothermic furnace containing a cylindrical body with end lids with coaxially placed on its inner wall layers of peripheral heat insulation and internal gas getter, and an annular exothermic heater enclosed in a perforated shell, forming a central cylindrical channel for a heated object, characterized in that in order to increase reliability and safety of work, a layer of gas-permeable thermal insulation with an additional layer is installed between the getter layer and the heater; rforirovannoy shell side of the heater, forming with the latter an annular gap.