SU1733878A1 - Electric furnace of gas pressure control device - Google Patents

Abstract

The invention relates to a technique for the treatment of products by the method of hot isostatic pressing. The electric furnace contains a heat insulating cap in the form of a hermetic case and a heat insulating cover, a heater from the bottom, side and arched parts. The housing is made up of individual segments, which are hermetically interconnected by compensators, and heat insulating modules installed on its inner and outer surfaces. The thermal insulation of the lid is mounted on a plate, which is suspended on a beam located inside the housing, and is closed at the bottom by an insulating layer, and the gap between the plate and the modules is closed by plates. The side part of the heater is made in the form of separate segment blocks installed with a gap on the support ring and interconnected by compensators, and the arch part rests loosely on the side and is fixed against possible displacements. 5 il. (L

Description

The invention relates to powder metallurgy and can be used in the processing of various products by the method of hot isostatic pressing (HIP).

A device for high pressure and high temperature is known, which contains a heat insulating protective sheath and a heater, the heat shield is made in the form of several metal caps arranged coaxially, and the space between them is filled with heat insulating material.

The drawback of the device is the presence of significant (especially for large diameters of the working space) thermal deformation of metal caps, and the internal caps are deformed to a much greater degree than the external ones, due to the difference in their temperatures. This leads to compaction of the heat insulating material in the interlayers between the caps during the first heating cycle, sintering of the material and the appearance of gaps between the inner cap and thermal insulation in subsequent cycles, and this sharply reduces the heat insulating efficiency due to an increase in the intensity of convective heat transfer. In addition, with an increase in the diameter of the device, in particular up to 2-3 m, the complexity of manufacturing such coaxial caps and their subsequent assembly increases significantly.

The gas chamber of the gas stove, containing a heat insulating cap consisting of a hermetic case and a cover, is equipped with X | | Sl

with

SCO VI 00

i

thermal insulation, and a heater located inside the cap, consisting of side, bottom and arched parts, in which the cap is made in the form of coaxially arranged muffles with thermal insulation, the inner muffle made of composite carbon-carbon material, and the thermal insulation is carbon fibers. This solution allows drastically reducing the thermal deformation of the inner muffle and, in combination with carbon fiber heat insulation, virtually eliminates the possibility of cracks in the lining. The implementation of this solution is combined with a significant increase in the cost of the lining and the inability to use such an electric furnace in modes with hot loading and unloading of the processed products due to the active interaction of carbon materials with air oxygen at temperatures above 450 ° C.

The purpose of the invention is to simplify the design of the heat insulating cap, increase the uniformity of heating, eliminate the effect of thermal deformation on the deterioration of the quality of heat insulation during operation and increase the reliability of the electric furnace as a whole.

The goal is achieved by the fact that, in a gas-furnace electric furnace containing a heat insulating cap in the form of a cylindrical body and a heat insulating cap, a heating device in the form of a coaxial, side and bottom heaters installed inside the cap, the heat insulating cap body is made in the form of a shell made from U-shaped segments, hermetically interconnected by flexible compensators and filled with thermal insulation, and segmented thermal insulation is installed on the inner and outer walls of the housing thermal modules, the heat insulation of the lid is made in the form of a plate with a heat insulating layer, which is connected to the inner surface of the heat insulating modules mounted on the inner wall of the housing, through segment plates with pins immersed in the heat insulating layer that are radially mounted for movement relative to the plate, the plate is suspended on a support beam fixed on the body of the heat insulating cap and closed on top with an additional layer of heat insulation, the side heater is made in the form of the support ring and segment blocks installed on it, interconnected by compensators, and the roof heater freely resting on the side one, is fixed from

displacement and has the freedom of thermal displacements.

FIG. 1 shows a gas-oven oven, a longitudinal section; in fig. 2 - cylindrical body, cross section; in fig. 3 - heater, cross section; in fig. 4 - elements of a round plate; in fig. 5 is a cross section of a heat insulating cap with elements of a cylindrical body,

thermal insulation and suspended segment modules

The gas-oven electric furnace consists of a cylindrical body 1 of the inner 2 and outer 3 segment heat-insulating modules, the inner ones being mounted on brackets 4, and the outer straps are clamps 5, the arch portion of the lining formed on a round plate 6 equipped with a heat-insulating protective layer 7 fixed by a metal round sheet 8, with the round plate suspended from the beam 9, fixed on the brackets 4 and covered from above with additional layers of screen-fiber insulation 10 and the cover 11, hermetically connected the cylindrical body 1. The design of the housing is rotationally symmetrical sleeve is formed of separate sections of the U-shaped section

19, interconnected hermetically flexible compensators 20. The flanges 28 are welded to the shell from two sides.

In general, the side and arch heat insulating linings form the heat insulating hood of an electric furnace. The electric furnace also includes arch 12, side 13 and bottom 14 heaters, and the side heater is formed from separate segment modules 15 installed

with a gap on the ring 16 and interconnected by means of radial compensators 17, and the arbor rests on the side and is fixed against displacement by means of key guides located under

90 ° to each other, which do not prevent thermal deformations of the heater elements.

FIG. 2 shows the individual side elements of the housing 19, thermal compensators

20 and partially flanges 28.

FIG. 3 shows the heating modules 15, the support ring 16, the temperature compensators 17 and the heating elements 24

 FIG. 4 shows an element of a circular plate 6 and a node for sealing the gap between the plate and the inner segments. Compaction is achieved by installing segmented plates 26, which are fixed against possible movements by pins 27. Such

The design does not interfere with the mutual movement of the plate 6 and the plates 26 during thermal deformations, without compromising the integrity of the seal assembly.

The electric works as follows.

When heated, the expansion of the individual U-shaped segments of both the housing 1 and the lateral heater 13 does not change the diameters of either, since they are perceived as compensators. Thermal insulation modules during thermal deformations move relative to each other, without compromising the quality and operability of thermal insulation. The round plate, expanding, slides over the segments fixed on the heat insulating layer by needle pins. The arch portion of the heater expands, slides along the upper ends of the segments of the side heater, and is fixed against displacements by key joints in mutually perpendicular directions. The arched part of the cap, suspended on a power beam operating at relatively low temperatures, retains its rigidity both in the process of heating and in long-term operation at operating temperature. The tight connection of the lid with the housing prevents the formation of convective circulating gas flows.

The modular design of the side heat insulation and side heater, the use of radial thermal deformation compensators in the design of the cylindrical case and in the connecting elements of the side heater, the suspension structure of the heat insulation is especially effective when creating electric furnaces of gas-stoppers of large diameter (3 m and more), since In this case, the manufacture and installation of an electric furnace is greatly simplified. In addition, at temperatures up to 1200 ° C, the proposed design allows the use of heat-resistant alloys and steels in combination with mullite-alumina fibrous thermal insulation, which, first, makes the furnace suitable for hot

loading and unloading, increasing its productivity, and secondly, it is much cheaper than electric furnaces made on the basis of carbon materials, which differs favorably from them in high purity of the gas medium due to the absence of aggressive carbon compounds.

Claims (1)

The invention of the gas-oven electric furnace comprising a heat insulating cap in the form of a cylindrical body and a cap with thermal insulation, a heating device in the form of arched, side and bottom heaters installed in the cap, characterized in that reliability of the electric furnace by compensating for temperature deformations, the body is made in the form of a shell of U-shaped segments, hermetically interconnected by flexible compensators and filled with thermal insulation, and the segment heat insulating modules are installed on the inner and outer walls of the case; with insulating layer which is connected to the inner heat insulating layer of the housing, through the radially mounted with the possibility of moving relative to the plate segment plates with pins placed in an insulating layer, the plate is suspended on the body by means of a support beam and is made with an additional heat insulating layer located on it, the side heater is made as a support ring and segment blocks mounted on it, interconnected by compensators, and the roof heater is freely mounted on the side displacement constraints. f ъ Nl . Q  xA L uCh-U r rrlrr./ / rrV / r,  hhhchuhhh Ji.rV T,) I W x x ll % WITH: ъ CE CE Ct G d with co with -J 00 CZ U- CH d-2 P1 CHU UUUUCH UCHCH.CH V44V4V4.VN.v4kT L. J.S. CHUUU 4 X. UCH. Xv 4 N. a JlЈ. v.yv v Woooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo v / X v X Jt A xx. X .. 22 24 20 Phage.Z 25 27b 25 / I // XX XXyFigL FIG. AT