JPH02149613A - Method for sending atmospheric gas in heat-treating furnace - Google Patents

Abstract

PURPOSE:To increase the purity of an atmospheric gas in a purge chamber and to reduce the amt. of the atmospheric gas to be supplied by supplying the atmospheric gas for pressurizing the purge chamber adjacent to a furnace main body to the purge chamber via the inside of the furnace main body. CONSTITUTION:A material 5 to be heated is placed in the purge chamber 3, the air is excluded by a vacuum pump 8, and the chamber 3 is evacuated. A valve 11 is then opened to allow the furnace main body 1 to communicate with the purge chamber 3 through a gas pipe 10. The atmospheric gas in the main body 1 is introduced into the purge chamber 3, and at the same time a valve 13 is opened to supply the atmospheric gas into the main body 1. When the pressures in the main body 1 and purge chamber 3 are equalized, a partition door 7 is opened, the material 5 is moved into the main body 1, and the partition door 7 is closed. The material 5 is then heated to a desired temp. by a heat source 2, and a specified amt. of the atmospheric gas is continuously supplied into the main body 1 through a gas pipe 9. When the heat treatment is finished, the material 5 is extracted to the outside of the furnace through the purge chamber 3. By this method, the impure gas in the main body 1 is diluted with the pressurizing atmospheric gas, and the purity of the atmospheric gas in the furnace is maintained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for supplying atmospheric gas for repressurization to a purge chamber in a furnace for heat treatment in atmospheric gas.

[Prior Art] In a heat treatment furnace for annealing metal materials or brazing products in an atmospheric gas such as N2 gas, the outside air is generally used when charging the object to be heated into the furnace body. A vacuum purge chamber is provided adjacent to the furnace body to prevent intrusion into the furnace body. That is, the object to be heated is first charged into a vacuum purge chamber, and after the air in the vacuum purge chamber is once removed by a vacuum pump,
Atmospheric gas is sent from a gas cylinder to the vacuum purge chamber to restore the pressure in the vacuum purge chamber to normal pressure, and then the object to be heated in the vacuum purge chamber is moved to the furnace body, thereby allowing outside air to enter the furnace body. is prevented. Conventionally, atmospheric gas was supplied directly to this vacuum purge chamber from a gas cylinder.

In addition, while the object to be heated is being heat-treated in the furnace body, for example, in the case of brazing, flux vapor may circulate inside the furnace, or lubricant attached to the object to be heated may evaporate. Impure gases are released into the furnace from the objects or the furnace wall, reducing the purity of the atmospheric gas.

Therefore, in order to prevent this, a certain amount of atmospheric gas is supplied to the furnace during the processing time to maintain its purity.

[Problems with conventional technology] However, in order to maintain the purity of the atmospheric gas inside the furnace body, a considerable amount of atmospheric gas must be continuously supplied during the processing time, resulting in high gas consumption and high costs. It was something. Therefore, it was necessary to improve it.

[Purpose of the Invention] Therefore, the present invention provides a heat treatment method that maintains the purity of the atmospheric gas in the furnace body and at the same time reduces the amount of atmospheric gas consumed for purity maintenance in an atmospheric heat treatment furnace equipped with a purge chamber as described above. The present invention attempts to provide a method for supplying atmospheric gas to a furnace.

[Means for Achieving the Object] In order to achieve the above-mentioned object, the atmospheric gas supply method for a heat treatment furnace of the present invention provides a purge chamber adjacent to the furnace main body, and temporarily charges the object to be heated into the purge chamber. This is an atmospheric heat treatment furnace in which the atmospheric heat treatment furnace is moved in and out of the furnace body after the process is completed, and is characterized in that atmospheric gas for repressurization in the purge chamber is fed to the purge chamber via the inside of the furnace body. .

[Effect: Each time a copurge is performed, a large amount of atmospheric gas is supplied into the furnace body, increasing the purity of the atmospheric gas within the furnace body.

Moreover, the atmospheric gas is supplied to the purge chamber for pressure recovery, so it is not wasted.

[Example 1] Next, the present invention will be explained in detail with reference to FIG.

In the figure, 1 is the furnace main body, 2 is its heat source, 3 is a purge chamber, 4 is a conveyance roller that supports the object to be heated 5, 6 is an opening/closing door provided at the charging/exit of the purge chamber 3, and 7 is the furnace main body. A partition door is provided between 1 and the purge chamber 3, 8 is a vacuum pump provided in the purge chamber 3, and 9 is a valve 18 that constantly supplies a constant amount of atmospheric gas to the furnace body 1 during heat treatment. It is an air pipe.

Reference numeral 10 denotes a ventilation pipe that communicates the furnace body 1 with the purge chamber 3 by opening the valve 11, and 12 an air supply pipe that supplies atmospheric gas into the furnace body 1 via the valve 13. The heated object 5 is opened and closed! 6 is first opened and placed in the purge chamber 3, and the opening/closing door 6. The partition door 7 is closed, and the vacuum pump 8 is operated to remove air from the purge chamber 3 to bring the interior of the purge chamber 3 into a vacuum or reduced pressure state. Subsequently, the valve 11 is opened to communicate the furnace body 1 and the purge chamber 3 through the vent pipe 10, and the atmospheric gas of the furnace body 1 is introduced into the purge chamber 3. At this time, the valve 13 is opened to supply atmospheric gas into the furnace body 1.

When the pressure in the furnace body 1 and the purge chamber 3 become the same, the partition door 7 is opened and the object to be heated 5 is rolled onto the conveying roller 4 and moved into the furnace body 1. Then, the partition door 7 is closed and the heat source 2 heats the object 5 to a required temperature. Meanwhile, a constant amount of atmospheric gas is continuously fed into the furnace body 1 from the air supply pipe 9. When the heat treatment is finished, the object to be heated 5
is extracted to the outside of the furnace via the purge chamber 3 again.

In this way, the atmospheric gas for restoring pressure in the purge chamber 3 is supplied through the furnace body 1 in the present invention. Therefore, the impure gas generated within the furnace body 1 is diluted by the atmospheric gas for repressurization, and the purity of the furnace atmospheric gas can be maintained.

[Embodiment 2] The embodiment shown in FIG. 2 shows an atmospheric gas heat treatment furnace in which an inlet purge chamber 3a and an outlet purge chamber 3b are provided on the outside of opposing side walls of the furnace body 1, respectively. In the figure, 15a and 15b are the entrance and exit insulation doors of the furnace body 1, 16a and 16b are the entrance and exit airtight doors of the entrance purge chamber 3a, and 17a and 17
b denotes an inlet airtight door and an outlet airtight door of the outlet purge chamber 3b. Reference numerals 14a and 14b are door pockets formed between the furnace main body 1, the inlet purge chamber 3a, and the outlet purge chamber 3b, and the outlet airtight door 16b and the inlet heat insulation door 15 are provided in the door pocket 14a.
a is housed in the door pocket 14b, and the exit side heat insulating door 15b and the entrance side airtight Q17a are housed in the door pocket 14b. In this case, although the inlet heat insulation 7i115a and the outlet heat insulation door 15b have heat insulation properties, they are not airtight and the atmospheric gas inside the furnace body 1 may flow into the door pocket 14a or the door pocket 14b. Therefore, in this embodiment, the ventilation pipe 1a is piped to the door pocket 14a, and its valve ll
By opening the door pocket 14a, the door pocket 14a and the entry side purge chamber 3a are brought into communication. In addition, the ventilation pipe 10b is connected to the door pocket 1.
4b, and by opening the valve llb, the door bag 1
4b and the outlet purge chamber 3b are communicated with each other. Since the other parts are the same as those in the previous embodiment, the same parts are given the same reference numerals and their explanations are omitted. However, this atmospheric gas heat treatment furnace is equipped with an inlet purge chamber 3a and an outlet purge chamber 3b independently. This reduces the time required for charging and extracting the heated material, increasing productivity.

[Effects of the Invention] As explained above, according to the atmospheric gas supply method for a heat treatment furnace of the present invention, the atmospheric gas in the purge chamber is reduced by supplying the atmospheric gas for repressurization to the purge chamber through the furnace main body. The purity of will naturally increase. This has the advantageous effect of reducing the amount of atmospheric gas supplied only to maintain the purity of the atmospheric gas within the furnace body.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view of a heat treatment furnace showing one embodiment of the present invention, and FIG. 2 is a vertical cross-sectional view of a heat treatment furnace showing another embodiment of the present invention.6 1... Furnace body; 3, 3a, 3b...purge chamber, 8.
...Vacuum pump, 9.12...Air pipe, to, 10
a, 10b - ventilation pipe, 11. lla, 1l
b-valve. The first ward

Claims (1)

[Claims] In an atmospheric heat treatment furnace, a purge chamber is provided adjacent to the furnace body, and the object to be heated is once charged into the purge chamber before being taken in and out of the furnace body. A method for supplying atmospheric gas to a heat treatment furnace, characterized in that the gas is supplied to the purge chamber via the purge chamber.