RU2368463C2 - Aerostat - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: aerostat contains force container, forming working chamber, hermetically closed by top and bottom plugs with gaskets and connected to source of gas pressure, to systems of its cooling and circulation and vessel station through independent channels of feeding and pressure unloading, implemented in top plug. Aerostat also allows heat insulating cap, fixed to top plug lateral heater, bottom heater with heat insulation, installed on bottom plug on ceramic former, and table with located on it charging sleeve for treated blanks, located on bottom plug. Aerostat is outfitted by delimiting sleeve with flange, isolating are of lateral heaters from charging area with treated blanks and rigidly connected to heat insulating cap by means of nipple, built in heat insulating cap at the channel of depressurisation and rigidly fixing it to top plug of aerostat.

EFFECT: reliability enhancement of aerostat's heaters operation.

3 cl, 1 dwg

Description

The invention relates to equipment for processing materials and can most effectively be used for compacting products from granules and powders of various materials, for “healing” pores in castings and diffusion welding of materials.

An analogue of the claimed technical solution is a furnace for sintering powder under pressure, described in the invention No. 419014, M.cl. B22F 3/14, published on 03/05/1974. It contains a working chamber formed by a container and its upper and lower plugs, a heater and a heat-insulating cap mounted on the upper plug, and a bottom thermal insulation installed on the bottom plug.

The main disadvantage of the analogue is the long cooling time of the processed products.

Closest to the proposed invention is a gas thermostat (see US 2003/0197295 A1, B22F 3/15, 10/23/2003, 8 pages), containing a power container forming a working chamber, hermetically sealed by the upper and lower plugs with seals and connected to the source gas pressure, with its cooling and circulation systems and a balloon station, made in a plug through independent supply and pressure relief channels, a heat-insulating cap attached to the top plug of the side heater, and bottom heating is installed on the bottom plug on a ceramic base studio with thermal insulation and a table with a loading cup placed on it for workpieces.

The main disadvantage of the prototype is the low resistance of the ceramic parts of the heater, which during rapid cooling experience thermal shock and prematurely collapse, causing the heater to fail.

The technical result of the invention is to increase the reliability of the gas thermostat heaters.

The technical result is achieved by isolating the zone of heaters from the zone of accelerated cooling by a boundary glass with a flange that isolates the zone of side heaters from the loading zone with a heat-insulating cap by means of a nipple mounted in a heat-insulating cap on the pressure relief channel and rigidly fastening it to the upper stopper of the gas bath.

The proposed gas thermostat is shown in section in the drawing.

It includes a container 1, upper 2 and lower 3 plugs with seals 4, a side heater 5 having several heating zones, and a bottom heater 6 mounted on a ceramic stand 7, which is placed on heat-insulating plates 8 in the cavity of the table 9, mounted on the bottom traffic jam. On the table 9 is loaded with a replaceable glass 10 with blanks. Through holes were made in the glass on the side walls and in the bottom (not shown in the drawing) to cool the workpieces and reduce the temperature difference during heating. In addition, an annular heat-insulating plate 11 is placed at the end of the lower plug, which protects the plug from heat from the working area. Thermal insulation of the container and the upper tube is carried out by a heat-insulating cap 12, rigidly fixed to the upper tube 2. Through the upper tube, electric leads pass to the heater tires 13, connected to sectors 14 and further to the side heaters 5. The heaters can be wound on a frame with ceramic insulators or ceramic tubes 15 (see drawing) located around the circumference.

Split sectors 14 are attached to a ring 16 of dielectric material. The zone of side heaters - A is separated from the working zone - B, in which the workpieces are located, with a containment cup 17, between the flange of which and the lower end of the cap there is a heat-insulating high-temperature cotton wool 18, separated from the zone of heaters - A by screens 19.

The fixation of the boundary glass 17 to the cap 12 and its centering relative to the axis of the container is carried out by a nipple 20 and a nut 21.

The operation of the gas bath is as follows. In the initial position, the lower plug 3 is pulled out of the container 1. On the table 9 of the lower plug is installed a removable loading cup 10 with blanks. The lower plug rises, sealing the space inside the container 1. After evacuating the working space, the working gas is pumped into the container, the heaters 5 and 6 are turned on, and heating is carried out to the required temperature. Thanks to the bottom heater 6, the heating time and the temperature gradient in the working area are reduced. After heating the workpieces to the required temperature and holding time, the heater is turned off, the heated gas is discharged through the water-cooled top plug and heat exchanger into the cylinders of the gas system, and then gas circulation by the low-pressure compressor from the balloon station to the container and back begins. Cooled gas is supplied through the channel of the upper tube to the container 1 and then through the gaps between the cap 12 and the container it enters the lower tube 3, and from it into the working area B of the container, cooling the workpieces placed in the loading cup 10. Cooling is facilitated by holes made in the supporting protrusion of the table 9 and in the loading cup 10. Since the zone A of the side heaters 15 is insulated by a packing of heat-insulating high-temperature wool 18, the cooled gas practically does not fall into the zone of the heaters A, preventing thermal shock to ceramic parts of the heater and ensuring their slow cooling.

The cavity of the table 9 with the bottom heater 6 also cools slowly, since cold gas with a higher density cannot displace the heated gas with a lower density from the pressurized table through the gaps between the table and the lower plug 3. Therefore, the ceramic stand 7 on which is mounted the bottom heater also cools slowly and does not experience thermal shock. Thanks to the "isolation" of the heating zones, the durability of the heaters increases.

After cooling the workpieces to an acceptable temperature, the gas is pumped into the balloon station, the lower plug is lowered and the workpieces are removed from the loading cup.

The present invention improves the reliability and durability of the gas thermostat heaters during accelerated cooling of the workpieces, due to:

- supplying the gas thermostat with a boundary glass with a flange that isolates the side heater zone from the loading zone with the heat-insulating cap by means of a nipple mounted in the heat-insulating cap on the pressure relief channel and rigidly fastening it to the upper gas thermostat plug;

- supplying the gasstat with screens and gas-permeable thermal insulation to separate the zone of side heaters between the cap and the separation glass from the rest of the container cavity.

- placing the bottom heater inside the table, which is made with a support protrusion designed to center the loading cup and having side openings for circulating the working gas, the internal cavity of the table is in communication with the cavity of the power container through the gaps between the table and the bottom plug, and the bottom heater is mounted on heat-insulating plates ;

allowing to isolate a zone of heaters from a zone of accelerated cooling.

Claims (3)

1. A gas thermostat containing a power container forming a working chamber hermetically sealed with upper and lower plugs with seals and connected to a gas pressure source, its cooling and circulation systems and a balloon station through independent supply and pressure relief channels made in the upper plug, heat-insulating a cap attached to the upper cork side heater, a bottom heater with thermal insulation mounted on the lower cork on a ceramic base, and a table with a loading cup placed on it for workpieces, placed on the bottom tube, characterized in that the gas thermostat is equipped with a boundary glass with a flange that isolates the side heater zone from the loading zone with the workpieces and is rigidly connected to the heat-insulating cap by means of a nipple mounted in the heat-insulating cap on the pressure relief channel and rigidly fastening it with the top tube gas thermostat. 2. The thermostat according to claim 1, characterized in that it is equipped with screens and gas-permeable thermal insulation to separate the zone of side heaters between the cap and the boundary glass from the container cavity. 3. The thermostat according to claim 1, characterized in that the bottom heater is placed inside the table, which is made with a support protrusion designed to center the loading cup and having side openings for circulating the working gas, the internal cavity of the table is communicated with the cavity of the power container through the gaps between the table and the bottom plug, and the bottom heater is installed on heat-insulating plates.

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