JPH04347489A - Rapid cooling furnace - Google Patents

Abstract

PURPOSE:To provide a rapid cooling furnace, capable of improving a cooling speed effectively compared with a traditional furnace without enlarging the size of a device. CONSTITUTION:A surge tank 2 is surrounded by a heat insulating material 5 and the tank 2 is filled with cooling gas to precool the whole of the tank 2 together with the gas, then, a valve 3c is opened to introduce the cooling gas into the main body 1 of a furnace to apply thermal surge on a work W to be treated.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rapid cooling furnace that can be used as an industrial furnace, a quenching furnace, or the like.

0002

BACKGROUND OF THE INVENTION Some recent quenching furnaces are designed to cool a workpiece that has been subjected to high-temperature treatment by spraying cooling gas thereon. An example is a furnace body that needs to be cooled, a container for sending cooling gas into the furnace body, a cooling part for bringing cold heat into this container, and a valve for directing the gas in this container. A device is known that is equipped with a circulation means for feeding the fuel into the furnace body and returning it again for circulation. Then, when the furnace body reaches a stage where cooling is required, the cooling section and the valve are turned on at the same time, and heat exchange between the cooling section and the surrounding cooling gas is started, cooling the cooling gas while passing through the valve. It is fed to the furnace body and returned again for circulation.

0003

[Problem to be Solved by the Invention] However, in the above configuration, the cooling rate depends exclusively on the capacity of the cooling section, so there is a problem that the cooling section must be made very large in order to increase the cooling rate. In addition, since the cooling section is operated only when cooling is to be started, there is also the problem that it is difficult to perform cooling in a pulsed manner.

[0004] The present invention does not increase the size of the device, and
It is an object of the present invention to provide a rapid cooling furnace that can effectively improve the cooling rate compared to conventional ones.

[0005]

[Means for Solving the Problems] In order to achieve the above object, the present invention employs the following configuration.

That is, the rapid cooling furnace according to the present invention includes a furnace body that needs to be cooled, a container for holding cooling gas having a cooling part that can bring cold heat into the inside, and a cooling gas held in the container. the container is surrounded by a heat insulating material, and the entire container is provided with a gas transfer means for pumping the heated gas into the furnace main body when the valve is opened. The furnace is characterized in that it is configured to be able to store cold heat brought in by the furnace, and after the container is precooled, a valve is opened to forcefully feed cooling gas into the furnace main body.

[0007]

[Operation] With this structure, the cooling gas is sufficiently precooled in the container by the time the valve is opened. Therefore, when the cooling gas is pumped into the furnace main body, it is possible to apply a much larger heat surge to the processed material than in the past. Furthermore, since cold heat is stored throughout the container, even if the size of the cooling section is the same as in the past, the heat capacity and heat exchange area are much larger than in the past. Therefore, the cooling efficiency during heat exchange with the cooling gas is improved, and the cooling effect can be maintained for a long time.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

This rapid cooling furnace is constructed by connecting a furnace body 1 and a surge tank 2, which is a container, through a gas transfer means 3 and a gas return means 4. The furnace body 1 has a chamber 12 for accommodating the processed material W inside the furnace shell 11, and a cooling gas introduced through a gas inlet 11a opened in the furnace shell 11 is provided around the chamber 12. The cooling gas is allowed to flow into the chamber 12 through the hole 12a, and then flowed out through the gas outlet 11b provided in the furnace shell 11. The surge tank 2 is surrounded by a heat insulating material 5 and is almost completely thermally isolated from the outside. A heat exchanger 6 serving as a cooling section is disposed inside. The heat exchanger 6 includes a pipe 6a that is routed inside the surge tank 2 and has both ends connected to a refrigerator (not shown), which serves as a flow path for fluorocarbons, etc., and the pipe 6a is connected to an inner wall 2a of the surge tank 2 to heat the and a cross-shaped heat exchange plate 6b for connection. The cold heat brought into the heat exchanger 6 from the outside can be stored in all parts of the tank 2, including the tubes 6a, the heat exchange plate 6b, and the inner wall 2a of the surge tank 2. Further, a gas cylinder 7 is connected to this surge tank 2 via a valve 7a, so that a necessary amount of cooling gas can be appropriately filled into the surge tank 2 and held within the tank 2. The gas transfer means 3 has a fan 3a which is driven by a motor 8 disposed in the surge tank 2, and has a gas outlet 2b opened on the surge tank 2 corresponding to the air blowing direction of the fan 3a. The gas outlet 2b is connected to the gas inlet 11 of the furnace body 1.
This is due to the structure in which the pipe 3b is communicated with the pipe 3b. An electromagnetic on-off valve 3c is interposed in the pipe 3b. The gas return means 4 has a gas inlet 2c opened on the surge tank 2 and upstream of the heat exchanger 6.
c communicates with the gas outlet 11b of the furnace body 1 via a pipe 4a. An electromagnetic on-off valve 4b is interposed in the pipe 4a. Note that the fan 3a and motor 8 are also thermally connected to the heat exchanger 6.

[0010] Then, a predetermined time before the completion of quenching etc. in the furnace body 1, cooling gas is introduced from the gas cylinder 7 into the surge tank 2 via the valve 7a with the valves 3c and 4b closed, A refrigerator (not shown) is operated to flow fluorocarbon or the like through the pipes 6a of the heat exchanger 6 to start cooling the inside of the tank 2.

According to this rapid cooling furnace, the cold heat brought into the surge tank 2 through the heat exchanger 6 by the time the heat treatment in the furnace body 1 is completed and the valves 3c and 4b are opened is transferred to the tube 6a and the heat exchanger. Heat is stored everywhere, such as the plate 6b, the surge tank inner wall 2a, and the fan 3a. Of course, the cooling gas held in the surge tank 2 is sufficiently precooled by this. Therefore, when the valves 3c and 4b are opened and the cooling gas is pumped into the furnace body 1 by the fan 3a at high pressure, a much larger heat surge can be applied to the processed material W than in the past. On the other hand, the gas whose temperature has increased by cooling the processed material W is transferred to the gas return means 4
It returns to the surge tank 2 through the raised tubes 6b and is cooled again before reaching the gas outlet 2b, and is used to cool the processed material W when it is fed to the furnace body 1 again. In this cooling gas circulation process, this rapid cooling furnace has a surge tank 2 surrounded by a heat insulating material 5, so that the entire body serves as a heat storage section and a heat exchange section, so the size of the heat exchanger 6 is smaller than the conventional one. Even if they are the same, the heat capacity and heat exchange area can be much larger than in the past, which was expected exclusively from the heat exchange section 6, and the heated gas can be rapidly cooled in a short time and the furnace body 1 can be heated. It becomes possible to effectively cool the processed material W when it is fed again.

[0012] The fan may be placed on the gas inlet side of the surge tank, and the motor may be placed substantially inside the surge tank. Further, the heat exchanger does not necessarily need to be connected to the refrigerator, and may simply be connected to the cooling water supply source. Furthermore, the fan is not limited to a centrifugal type. Furthermore, the gas may be released into the atmosphere after cooling the processed material without providing a gas return means. In addition, various modifications can be made without departing from the spirit of the present invention.

[0013]

[Effects of the Invention] Since the rapid cooling furnace of the present invention has the configuration described above, it is possible to apply a larger heat surge to the processed material, etc. at the start of cooling than in the past, without increasing the size of the equipment. The cooling effect can also be maintained for a longer period of time than in the past. Therefore, there is an excellent effect that cooling of the processed material can proceed reliably in a short period of time.

[Brief explanation of drawings]

FIG. 1 is a principle diagram showing an embodiment of the present invention.

[Explanation of symbols]

1... Furnace body 2... Container (surge tank) 3...Gas transfer means 3c...Valve 5...Insulation material 6...Cooling section (heat exchanger)

Claims (1)

[Claims] Claim 1: A furnace body that requires cooling, a container for holding cooling gas that has a cooling section that can bring cold heat into the inside, and a valve that allows the gas held in this container to be released. the container is surrounded by a heat insulating material so that the cold heat brought in through the cooling section can be stored throughout the container. A rapid cooling furnace characterized in that the cooling gas is forced into the furnace body by opening a valve after the container is precooled.