JPS60197815A - Charging and extracting method of material to be heated - Google Patents

Abstract

PURPOSE:To prevent the pollution of environment owing to leakage of a protective gas by replacing the inside of the respective purging chambers provided in a charging part and extracting part for materials to be heated with the protective gas and performing charging and extraction of the materials to be heated then replacing said gas with the atm. and openning the chambers to the outside. CONSTITUTION:Purging walls 2, 2' are provided on the sides of a furnace body 5 where a material W to be heated is charged into and extracted from the furnace. A hermetic door 3 is opened, the material W is put into a purging chamber 2 and the door 3 is closed in the stage of charging the material 5. A vacuum pump 13 is operated to evacuate the inside of the chamber 2 to a vacuum and thereafter a solenoid valve 12 is closed to introduce a protective gas into the chamber. A hermetic door 4 is opened and the material W is charged into the furnace body 5. The door 4 is closed and the protective gas is expelled to the outside of the chamber 2 by the pump 13 and thereafter a solenoid valve 15 is opened to introduce the atm. into the chamber 2. The door 3 is again opened and the work W is charged therein. On the other hand, the extraction of the material W is similarly executed by the similar operation in a purging chamber 2'.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for charging objects to be heated into the furnace or extracting objects to be heated from the furnace in an atmospheric heat treatment furnace. This relates to a method for charging and extracting a heated material in a device equipped with a purge chamber.

N2 atmosphere inside the furnace. Non-oxidizing gas such as Murr or 00,
In atmospheric heat treatment furnaces, where the objects to be heated are annealed or immersed in a non-oxidized state while being kept in a reducing gas such as H (hereinafter referred to as protective gas), the temperature inside the furnace is Purge chambers are provided in the charging section and the extraction section in a known manner to prevent atmospheric air from entering. In other words, the inside of the purge chamber is replaced with protective gas to prevent atmospheric air from entering the furnace during charging and extraction of heat objects, but when the purge chamber is filled with protective gas, the airtightness of the outside facing side of the purge chamber is If the reactor was opened, this protective gas could escape out of the furnace and contaminate the environment inside the factory, which was harmful to the human body and, depending on the components of the protective gas, could lead to an explosion.

The method for charging and extracting a heated object according to the present invention is to provide a purge chamber in a charging section and an extraction section of a heated object, and to reduce the pressure inside the purge chamber to a vacuum state and then introduce a protective gas. After approximately λ in the purge chamber is completely replaced with the protective gas, open the airtight door of the purge chamber on the opposite side of the furnace and move the heated object in the purge chamber into the furnace, or remove the heated object in the furnace. In an atmospheric heat treatment furnace in which objects are moved into a purge chamber, after the airtight door is closed, the pressure inside the purge chamber is reduced to a vacuum state again, and then a large sword is introduced into the purge chamber to roughly remove the inside of the purge chamber. After completely replacing the air with the atmosphere, open the airtight door on the side facing the outside of the purge chamber and move the external heated objects into the purge chamber or move the heated objects outside the purge chamber. This ensures that no trace gas leaks into the factory.

Next, an embodiment of the present invention will be described with reference to a roller hearth type heat treatment furnace, taking as an example the case of the charging part of the heated object shown in FIG. In the figure, 1 is a charging table on which the object to be heated W is placed, 2 is an airtight door 3 on the side facing the outside that is connected to the charging table 1 at one end, and an airtight door on the side facing the inside of the furnace at the other end. A cylindrical purge chamber 4 is provided, and 5 is a furnace body filled with protective gas.

A heat insulating door 6 is provided at the entrance of the furnace body 5 to block radiant heat within the furnace, and the heat insulating door 6 and the airtight door 3.4 are
They are each suspended from a pulley 7.8°9 in order to be retracted upward so as not to get in the way of the heated object W passing through. The pulley 8.9 is arranged in the compartment 10 so that the joint between the purge chamber 2 and the furnace body 5 is hermetically shielded from the outside.

U is a tank filled with protective gas, and a solenoid valve ball is provided in the piping from the tank to the purge chamber 2.

Further, 13 is a vacuum pump connected to the purge chamber 2, 14 is a solenoid valve provided in the piping, and 15 is a solenoid valve provided in the outside air introduction pipe 16. Now, when charging the object W on the charging table 1 into the furnace body 5, it is carried out in the following order.

(1) Open the airtight door 3.

(2) Move the object W to be heated from the charging table 1 to the purge chamber 2.

(3) Close the airtight door 3.

(4) Open the solenoid valve 14 and operate the vacuum pump 13 to exhaust the air inside the purge chamber 2 to the outside and reduce the pressure inside the purge chamber 2 to a vacuum state.

(5) Stop the vacuum pump 13 and close the solenoid valve 14.

(6) Opening the [magnetic valve] 2 introduces the protective gas in the tank 11 into the purge chamber 2 and replaces the inside of the purge chamber 2 with the protective gas.

(7) Close the solenoid valve 12.

(8) Open the airtight door 4.

(9) Move the excommunicated material in the purge chamber 2 into the furnace body 5.

00 airtight close 4.

θ]) The electromagnetic valve 14 is opened and the vacuum pump U is operated to discharge the protective gas in the purge chamber 2 to the outside, and the pressure in the purge chamber 2 is reduced to a vacuum state again.

Stop the Q-vacuum pump 13 and close the solenoid valve 14.

When the solenoid valve 5 is opened, a large sword is introduced into the purge chamber 2, and after the pressure inside the purge chamber 2 is restored to atmospheric pressure, the solenoid valve 5 is closed.

Q41 Open airtight door 3.

aG A new object to be heated W is moved from the loading table 1 to the purge chamber 2, and the steps from (3) onward are repeated.

According to this charging method, when the airtight door 3 is opened after replacing the inside of the purge chamber 2 with the atmosphere as described above, no protective gas remains in the purge chamber 2. The protective gas therefore does not contaminate the surrounding area of the charging table 1.

The charging method has been explained above, but on the contrary, in order to extract the heated object W inside the furnace to the outside of the furnace, the extraction part is illustrated in Figure 2, so the extraction method can be explained according to the same figure. Explain. Note that 1' in the figure is an extraction table, but other structural members corresponding to the configuration of the loading section in FIG. 1 are given the same reference numerals with dashes 2, and their explanations will be omitted.

(1) With the airtight door / and 4/ closed, open the solenoid valve 14.
' is opened and the vacuum pump 13' is operated to exhaust the air in the purge chamber 2' to the outside and reduce the pressure in the purge chamber 2' to a vacuum state.

(2) Stop the vacuum pump B' and close the solenoid valve 14'.

(3) Opening the solenoid valve ν' introduces the protective gas from the tank 11' into the purge chamber 2', replacing the inside of the purge chamber 2' with the protective gas.

(4) Close the solenoid valve ν'.

(5) Open the airtight door 4'.

(6) Move the heated object W in the furnace body 5 to the purge chamber 2'.

(7) Close the airtight door 4'.

(8) [Open the magnetic valve 14' and operate the vacuum pump 13' to exhaust the protective gas in the purge chamber 2' to the outside and reduce the pressure in the purge chamber 2' to a vacuum state again.

(9) Stop the vacuum pump ' and close the solenoid valve 14'.

When the OQ solenoid valve 15' is opened, atmospheric air is introduced into the purge chamber 2', and after the pressure inside the purge chamber 2' is restored to atmospheric pressure, the solenoid valve 15' is closed.

Open αη airtight 1%3′.

(2) Move the heated object W in the purge chamber 2' onto the extraction table 1'.

(1, 11 Close the airtight door 3' and repeat the steps from (1) above.

In these examples, the protective gas filled in the tanks 11 and 11' was used as the replacement gas for the purge chamber 2', but in Fig. 3, the atmospheric gas in the °C furnace body 5 was used as the protective gas. exemplify something. That is, in this atmospheric heat treatment furnace, the atmospheric gas in the furnace body 5 is sucked by the compressor 17, the atmospheric gas is stored in the surge tank 18, and the purge chamber 2.2 is passed from the surge tank through the solenoid valves iz and 12'. ′ can be supplied with atmospheric gas as necessary. Reference numeral 19.20 denotes a flow control valve and a cooler connected in series to the primary side of the compressor 17. The flow control valve 19 controls the suction amount of atmospheric gas based on the signal from the pressure sensor m provided in the furnace body 5, and The atmospheric gas pressure inside the body 5 is maintained at a predetermined value. In addition, 4 is an air supply pipe that constantly supplies a fixed amount of N and gas into the furnace body 5;
Based on the signal from the CO3 concentration sensor installed in the furnace body 5, the flow control valve 5 is set at tI4 to supply endothermic gas so that the atmospheric gas in the furnace body 5 is maintained at a predetermined CO and gas concentration. This is the air supply pipe that supplies the air. In addition, KA indicates an air supply pipe that replenishes the insufficient atmospheric gas from a tank (not shown) when the atmosphere gas in the surge tank calm is insufficient, and τ indicates a safety valve in the surge tank theory. Using atmospheric gas not only reduces the consumption of protective gas, but also reduces the change in the composition of the furnace atmospheric gas during charging and extraction, thereby stabilizing the quality of the object to be heated.

According to the present invention, as described above with respect to the embodiments,
Since the airtight door on the opposite side to the outside is opened after the inside of the purge chamber is replaced with atmospheric air, the protective glass does not leak into the factory, which is a significant improvement in the working environment and prevents explosion accidents. effective.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention; FIG. 1 is a longitudinal sectional view of the charging section, FIG. 2 is a longitudinal sectional view of the extraction section, and FIG. 3 is a piping system diagram of the entire atmosphere heat treatment furnace. W... Heated object, 2.2'... Purge chamber, 3,3
'... Airtightness on the side facing the outside g, 4. a'... Airtight door on the opposite side of the furnace, 5... Furnace body, 13.13'...
・Vacuum pump, 16.16'...Outside air introduction pipe. Patent applicant: Daido Special Copper Co., Ltd.

Claims (1)

[Claims] A purge chamber is provided in the charging section and the extraction section of the material to be heated, and after the pressure inside the purge chamber is reduced to a vacuum state, a protective gas is introduced so that the inside of the purge chamber is almost completely replaced with the protective gas. In an atmospheric heat treatment furnace, the airtight door of the purge chamber on the opposite side of the furnace is opened so that the objects to be heated in the purge chamber can be moved into the furnace or the objects to be heated in the furnace can be moved into the purge chamber. After closing the door, the pressure inside the purge chamber is reduced to a vacuum state again, and then the atmosphere is introduced into the purge chamber, so that the inside of the purge chamber is almost completely replaced with atmosphere, and then the outside of the opposite side of the purge chamber is replaced with air. Charging and heating of objects to be heated in an atmospheric heat treatment furnace characterized by opening an airtight door and moving objects to be heated from outside into the purge chamber, or moving objects to be heated from the purge chamber to the outside. Extraction method.