JP2001012869A - Batch type thermal treatment equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten the time required for temperature drop at a low cost. SOLUTION: An exhaust path 1c branching from a hot blast circulation path (a) is provided to selectively open and close the exhaust path 1c and a traverse gap S3 by a switching valve 6. While the hot blast circulation path (a) is closed by the switching valve 6, a fan 4 introduces the outside air to the upper gap S1 between an inner tank 2 and an outer tank 1 through an air-supply aperture 1a and the introduced outside air into the inner tank 2. The outside air in the inner tank 2 is exhausted outside the furnace through the exhaust path 1c to quench a heating object A.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a batch type heat treatment apparatus for heating an object to be heated in a tank by a hot air circulation system.

[0002]

2. Description of the Related Art In a batch type heat treatment apparatus, a heater is provided in a space surrounded by a heat insulating wall, and the heater is energized and heated to raise the temperature in a furnace. In the type used for the purpose of raising the temperature uniformly,
A double-structured furnace is provided with an inner tank for shielding an object to be heated from radiation heat of a heater in the furnace. That is, in this type, the heater is provided in a gap between the inner tank and the outer tank, and a fan for circulating furnace air is provided adjacent to the heater. For this reason, the furnace air is heated by the heater, pushed out into the gap between the inner tank and the outer tank by the fan, enters the inner tank, and returns to the fan again. The object to be heated is uniformly heated by the air in the furnace circulating through the hot air circulation path.

In the above batch type heat treatment apparatus, the inner tank is maintained at a constant temperature in the closed outer tank. Can not. Because of this, the cooling time is long,
Since this extra time is required, there is a problem that the operation rate is lowered. Therefore, it is conceivable to forcibly cool the inside of the inner tank with a blower, but in this case, the cost is increased. In view of the above-mentioned conventional problems, an object of the present invention is to provide a batch-type heat treatment apparatus that can reduce the temperature lowering time at low cost.

[0003]

According to a first aspect of the present invention, there is provided a batch type heat treatment apparatus, comprising: a heating heater and a hot air flowing through a hot air circulation path connecting a gap between an outer tank and an inner tank and the inside of the inner tank; In a batch-type heat treatment apparatus provided with a fan for circulating air, an air supply hole for supplying outside air to the fan, an on-off valve for opening and closing the air supply hole, and branching from a hot air circulation path to discharge air in the furnace to the outside of the furnace An exhaust path to be provided, a first position provided at a branch between the exhaust path and the hot air circulation path, for circulating furnace air along the hot air circulation path, and a second position for guiding furnace air to the exhaust path. And a switching valve for switching to a position. According to the batch-type heat treatment apparatus having the above configuration, the switching valve is switched to the second position, and by opening the on-off valve of the air supply hole, the outside air is forcibly sucked by the fan through the air supply hole and introduced into the furnace. The gas can be discharged to the outside through the exhaust path without being retained in the furnace, and the temperature in the furnace can be rapidly lowered.

In the batch type heat treatment apparatus, it is preferable that the branch portion is provided in proximity to the fan. In this case, the exhaust path is branched at the end point of the hot-air circulation path, so that the sucked outside air can be ventilated throughout the furnace. For this reason, the furnace components heated by the hot air can be completely cooled, and the object to be heated can be cooled more efficiently.

[0005]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a sectional view showing one embodiment of a batch type heat treatment apparatus of the present invention. The batch type heat treatment apparatus of the present invention comprises
, An outer tub 1 for housing the inner tub 2 with a gap S therebetween, and an upper gap S between the inner tub 2 and the outer tub 1
1 and a heater 4 provided in the upper gap S1 and forcibly circulating the furnace air.

[0006] The outer tub 1 includes a ceiling portion 11 composed of a heat insulating wall, a floor portion 14, both side portions 12, 13 and a rear portion 1.
5 and a front door (not shown) for taking in and out the object to be heated A. The inner tank 2 includes a ceiling portion 21 and both side portions 22 and 23. The ceiling part 21
And the upper gap S between the upper tank 11 and the ceiling 11 of the outer tank 1.
1, lateral gaps S2, S3 are provided between the side portions 22, 23 and the side portions 12, 13 of the outer tub 1. The front and rear ends of the ceiling 21 and both side surfaces 22 and 23 of the inner tank 2 are in contact with the rear surface 15 of the outer tank 1 and the front door. In addition, a plurality of ventilation holes 2a are provided on both side surfaces 22 and 23 of the inner tank 2.
The vent holes 2a allow the furnace air to flow from one lateral gap S2 into the inner tank 2 and from the inner tank 2 to the other lateral gap S.
3 can flow. That is, the upper gap S
1. A hot air circulation path a for circulating furnace air by one lateral gap S2, the inside of the inner tank 2 and the other lateral gap S3.
Are formed.

The heater 3 is provided on the ceiling 11 of the outer tub 1.
It is provided in an upper gap S <b> 1 between the inner tank 2 and the ceiling 21. The fan 4 is also mounted on the ceiling 1 of the outer tub 1.
In the upper gap S1 between the upper part 1 and the ceiling part 21 of the inner tank 2, it is provided adjacent to the heater 3 and is rotatably connected to the motor 5 fixed on the ceiling part 11.

In the rear surface 15 of the outer tub 1, an air supply hole 1a communicating with the outside is provided at an intermediate position between the fan 4 and the ceiling 21 of the inner tub 2. This air supply hole 1
An opening / closing valve 1b is provided at the opening outside of the furnace.
By opening the on-off valve 1b, outside air can be sucked into the upper gap S1. An exhaust path 1c for discharging the furnace air to the outside of the furnace is provided on a side surface portion 12 of the outer tank 1 closer to the fan 4 and is branched from the hot air circulation path a. The inlet of the exhaust path 1c is connected to the fan 4
And is opened and closed by the switching valve 6. The outlet of the exhaust path 1c is connected to the side surface 12 of the outer tank 1.
At the upper end.

The switching valve 6 is provided with a plate-shaped body 61 having a size to close a lateral gap S3 between the side surface portion 12 of the outer tub 1 and the side surface portion 22 of the inner tub 2. 61 is connected above the entrance of the exhaust path 1c so as to be rotatable around a horizontal axis 62. For this reason, by rotating the plate-shaped body 61 of the switching valve 6 around the horizontal axis 62 to the horizontal position (second position), the side portion 12 of the outer tub 1 and the side portion of the inner tub 2 are formed. 22 can be closed, and the exhaust path 1c can be closed by rotating the plate-like body 61 from the horizontal state to the vertical position (first position).

With the above configuration, after the energization and heating of the heater 3 is completed, the plate-shaped body 61 of the switching valve 6 is rotated from the vertical state to the horizontal state, so that the space between the side surface portion 12 and the inner tank 2 is formed. When the lateral gap S3 is closed, the hot air circulation path a is shut off. Here, by opening the on-off valve 1b of the air supply hole 1a, the outside air is forcibly sucked through the air supply hole 1a by the rotation of the fan 4 and introduced into the upper gap S1. The introduced outside air is supplied to the inside of the inner tank 2 while cooling the heater 3. The outside air that has passed through the inner tank 2 is discharged to the outside along an outside air circulation path b that passes through the exhaust path 1c. Therefore, the object to be heated A placed in the inner tank 2 is rapidly cooled by the inflow of the outside air. Further, the switching valve 6, which is a branch between the exhaust path 1c and the hot air circulation path a,
Since it is provided immediately below the fan 4 which is the end point of
The sucked outside air can be ventilated throughout the furnace.
For this reason, the furnace components heated by the hot air can be completely cooled, and the object to be heated A can be cooled more efficiently.

[0011]

As described above, according to the batch type heat treatment apparatus of the first aspect, the outside air is forcibly introduced into the inner tank, and the inside air is cooled while the introduced outside air is discharged outside the furnace again. Therefore, the cooling time can be shortened. In addition, since a fan for circulating hot air can also be used as the forced exhaust means, there is no need to install a new blower outside the furnace, and the cost is low.

According to the batch-type heat treatment apparatus of the second aspect, the sucked outside air can be passed all over the furnace, so that the furnace components heated by the hot air can be completely cooled and the object to be heated can be further cooled. It can be cooled efficiently.

[Brief description of the drawings]

FIG. 1 is a sectional view showing one embodiment of a batch type heat treatment apparatus of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Outer tank 1a Air supply hole 1b Open / close valve 1c Exhaust path 2 Inner tank 3 Heater 4 Fan 6 Switching valve a Hot air circulation path S1 Upper gap

Claims (2)

[Claims] In a batch type heat treatment apparatus, a heating heater and a fan for circulating hot air are provided in a hot air circulation path connecting a gap between an outer tank and an inner tank and the inside of the inner tank. An air supply hole, an on-off valve for opening and closing the air supply hole, an exhaust path for branching from the hot air circulation path and discharging the furnace air out of the furnace, and a branch portion between the exhaust path and the hot air circulation path. And a switching valve for switching between a first position for circulating furnace air along a hot air circulation path and a second position for guiding furnace air to an exhaust path. 2. The batch type heat treatment apparatus according to claim 1, wherein said branch portion is provided near said fan.