JPS60262914A - Gas-cooling apparatus of gas-cooled vacuum furnace - Google Patents

Abstract

PURPOSE:To provide the titled apparatus capable of cooling rapidly the inside of a furnace with high cooling efficiency by circulating forcibly a cooling gas with a fan provided in the furnace, and arranging an inner cooler and an outer cooler in front and in the rear of the fan to cool the cooling gas. CONSTITUTION:A heating chamber R is formed by a heat-insulating wall 13 and doors 15 and 16 in the main body 11 of a gas-cooled vacuum furnace having a furnacd lid 12. An article A is placed in the furnace, and heated with a heater 14. Then said doors 15 and 16 are opened, a fan 18 of the gas-cooling apparatus is operated by a motor 17, and the cooling gas is circulated in the furnace to cool rapidly the inside of the furnace. The cooling gas, blown by said fan 18 and heated by the Joule heat of the fan, is cooled by an outer cooler 20, then passed through the outside of a baffle 2 and the heat-insulating wall 13, passed through the inside of the heating chamber R in the direction as shown by the arrow, cooled by an inner cooler 19, and sucked by the fan 18. Consequently, the whole region of a cooling cycle in the furnace can be cooled rapidly with high cooling efficiency.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a gas cooling device that rapidly cools the inside of a high-temperature gas-cooled vacuum furnace by circulating cooling gas inside the furnace.

[Prior art]

First, the cliff-cooled vacuum furnace 9 will be explained. This furnace is a so-called gas-cooled vacuum heat treatment furnace, and the high-temperature interior of the furnace is rapidly cooled by circulation of cooling gas.

Conventionally, the gas cooling device for such a furnace is as shown in Fig. 3(a).
(b) It was constructed to be represented by K. Figure (e)
This device consists of a 7-amp 1 that forcibly circulates cooling gas from the direction of the arrow in the figure into the heating chamber R of the furnace containing the goods, and a cooling gas provided in front of the fan 1 that cools the cooling gas that enters the fan 1. The structure includes a cooler 2 that On the other hand, the device shown in FIG. 7(b) has the cooler 2 in the device shown in FIG.
It is designed to cool the cooling gas emitted from the

However, both of these devices have the following problems.

That is, in the former device, although the cooling gas entering the fan 1 can be cooled by the cooler 2 and kept at a constant temperature, the cooling gas is heated by the heat of the fan 10, so the cooling gas does not drop below a certain temperature. Therefore, the cooling rate becomes slow especially when the cooling in the 5 furnaces progresses and reaches the final stage of cooling. On the other hand, the latter device
Since the cooling gas pipe cooler 2 is used to lower the temperature, the cooling efficiency is good at the final stage of cooling. However, the temperature of the cooling gas entering the fan 1 differs greatly between the start and end of cooling, especially in the early stage of cooling because the cooling gas is high temperature and low density.
Anne 1 is inefficient.

As described above, the former device has poor cooling efficiency in the final stage of cooling, and the latter device has poor cooling efficiency in the initial stage of cooling.

[Purpose of the invention]

An object of the present invention is to provide a gas cooling device for a gas-cooled vacuum furnace that can maintain high cooling efficiency over the entire cooling cycle from the initial stage of cooling in the furnace to the final stage of cooling.

[Structure of the Invention] A gas cooling device for a gas-cooled vacuum furnace according to the present invention includes a 7-amplifier for forcedly circulating cooling gas in the furnace, and a fan provided in front of the fan to cool the cooling gas entering the fan. It has an inner cooler and an outer cooler that is located behind the fan and cools the cooling gas coming out of the fan.

〔Example〕

Embodiment f of the present invention will be described below based on FIGS. 1 and 2.

In the figure, reference numeral 11 denotes the main body of the gas-cooled vacuum furnace, and the front side (left side K in FIG. 1) of the main body is provided with a furnace lid 12. Main body 11
A heating chamber R is formed inside by a heat insulating wall 13, and the article A placed in this heating chamber R is heated by a heater 14. 15 and 16 are doors that can open and close the heating chamber R, respectively. A fan 18 that is rotationally driven by the Tanabata 17 is provided on the rear side of the main body 1 (on the left side in FIG. 1). This 7 Anne 18 is
Cooling gas introduced into the furnace after heating the heating chamber R is forced to circulate within the furnace. The circulation path runs in the direction of the arrow in FIG. This is a series of paths that pass through the heating chamber R and then send it to the outside of the heating chamber R again.

An inner cooler 19 for cooling the cooling gas entering the fan 18 is provided on the front side of the 77 fan 18, that is, the inlet side of the cooling gas to the 7 fan 18, and an inner cooler 19 is provided on the rear side of the fan 18 to cool the cooling gas entering the fan 18. Fan 1 is installed on the gas outlet side.
An outer cooler 20 is provided to cool the cooling gas emitted from the cooling gas. A buckle 21 separates the two coolers 19, 20 from each other.

Therefore, the IC that cools the inside of the furnace using this gas cooling device
Fi, cooling gas is introduced into the high temperature furnace after heating is completed, and the 77 engine 18 is driven, thereby circulating the cooling gas within the furnace. The cooling gas entering the fan 181C and the cooling gas exiting from the fan 18 are cooled by both coolers 19 and 2011C.

The inner cooler 19 cools the cooling gas that has absorbed heat while passing through the heating WLR, removes the heat, and sends it to the fan 1stc at a constant low temperature. Therefore, at the initial stage of cooling inside the furnace, the cooling gas entering the fan 18 does not have a particularly high temperature or low density. As a result, a decrease in efficiency of the fan 18 at the initial stage of cooling can be avoided. On the other hand, the outer cooler 20 has a fan 18
The cooling gas that comes out after being heated by 0 Joule heat is cooled again and the Joule heat is removed. Therefore, the temperature of the cooling gas can be lowered to a sufficiently low temperature even at the final stage of cooling inside the furnace.

In this way, the inner cooler 19 has a great effect especially at the initial stage of cooling, while the actor cooler 2
0 has a great effect at the end of cooling. As a result, if the cooling efficiency is always kept high throughout the entire range of the cooling cycle from the initial stage of cooling inside the furnace to the final stage of cooling, the items in the heating chamber R will be rapidly cooled. Ru.

By the way, for example, when the temperature of a person is 1200'C,
The temperature of the cooling gas coming out of the heating chamber R is about 600°C, about 200"C at the outlet of the inner cooler 19, and about 150"C at the outlet of the outer cooler 20.
The temperature of No. 8 never exceeds 200°C. therefore,
The operating state of the fan 18 is always stable. Further, the fan 18 uses Joule heat to raise the temperature of the cooling gas by about 30°C.

However, this Joule heat is removed by the outer cooler 20.

FIG. 2 shows temperature changes in each WK in the furnace in response to cooling time. In the figure, curve I is the temperature of the product, curve l is the temperature of the cooling gas at the outlet of heating chamber R, and curve 1tli7an1B.
Curve Wti is the cooling gas temperature at the inlet of the fan 180, and curve (2) is a change curve of the cooling gas temperature at the inlet of the heating chamber R.

Note that it was most effective to set the capacity of both coolers 19 and 20 to 70 to 80% on the inlet side of the fan 180.

〔Effect of the invention〕

As explained above, the gas cooling device for the gas-cooled vacuum furnace according to the present invention is equipped with fans on the front and rear sides for forced circulation of cooling gas in the furnace, and has a cooling capacity of 7 am. Since it is configured to cool the cooling gas that enters and the cooling gas that exits from the fan, the cooling gas that enters the fan is cooled to a certain temperature, and the Joule heat of the fan is taken away and the sufficiently cooled cooling gas is pumped into the furnace. As a result, the inside of the furnace can be rapidly cooled while maintaining high cooling efficiency over the entire cooling cycle from the initial stage of cooling in the furnace to the final stage of cooling.

[Brief explanation of drawings]

Figure 1 is a longitudinal cross-sectional view of a gas-cooled vacuum furnace equipped with the gas cooling device of the present invention, and Figure 2 is the characteristic of temperature changes in various parts of the furnace when the gas-cooled vacuum furnace of Figure 1 is cooled with gas. Figure, Figure 5 (a
, l, and (b) Fi are block configuration diagrams showing different examples of conventional gas cooling devices, respectively. 11...Body, 18...7 Ann, 19
...Inner cooler, 20...Outer cooler. Figure 1 Figure 2 =C Figure 3

Claims (1)

[Claims] In a gas-cooled vacuum furnace that circulates cooling gas inside the furnace in a high-temperature state to rapidly cool the inside of the furnace, there is a fan that forcibly circulates the cooling gas inside the furnace, and a fan that is installed in front of the fan and is connected to the fan. A gas cooling device for a gas-cooled vacuum furnace characterized by comprising an inner cooler that cools the cooling gas that enters, and an outer cooler that is provided with a pressure on the rear side of a fan and that cools the cooling gas that exits from the tank. .