JP3739233B2 - Exhaust type batch oven - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a batch heat treatment furnace.
[0002]
[Prior art]
For example, a batch heat treatment furnace is used for a binder removal treatment of a ceramic molded body formed into a specific shape using a binder and a secondary vulcanization treatment of rubber. The heat treatment using the heat treatment furnace is for accelerating a target chemical reaction in the debinding treatment or vulcanization treatment, and the batch heat treatment furnace is used to keep the whole furnace uniformly at the reaction temperature. It is used for.
That is, the batch type heat treatment furnace uses a mechanism in which the furnace atmosphere gas is heated by a heater provided in the furnace and the furnace atmosphere gas is forcibly circulated in the furnace by a fan provided in the furnace. The inside can be maintained at a uniform temperature.
In the case where a gaseous flammable chemical substance such as an organic solvent is generated by the reaction, an inert gas is used as the atmosphere gas in the furnace instead of the atmosphere.
[0003]
[Problems to be solved by the invention]
However, in a conventional batch heat treatment furnace, the amount of hot air exhausted is suppressed in order to maintain a soaking state in the furnace. For this reason, if a gaseous chemical substance is generated from the object to be heated and stays in the furnace, the concentration of the gaseous chemical substance increases or the gaseous chemical substance resolidifies and adheres to the wall surface in the furnace. Inevitable.
Depending on the type of gaseous chemical substance, there is a risk of ignition and explosion by contact with the heater. For this reason, a mechanism for exhausting a part of the furnace air containing a gaseous chemical substance to the outside at a predetermined pressure or a treatment using an inert gas as a medium is required as a heat treatment restriction or as an explosion-proof measure. When these measures are taken, there is a problem that costs are high.
On the other hand, it is conceivable to increase the exhaust amount of hot air to prevent the concentration of gaseous substances in the furnace from increasing, but in this case, there is a problem that it is difficult to maintain temperature accuracy.
[0004]
In view of the conventional problems as described above, an object of the present invention is to provide an exhaust-type batch oven capable of heat-treating an object to be heated that generates a gaseous flammable substance while maintaining temperature accuracy. To do.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, an exhaust-type batch oven according to the present invention has an air vent on a wall surface, an inner tank for storing an object to be heated, an intake means for sucking outside air, and a heater for heating the sucked outside air A hot air generating mechanism, an upper chamber for storing the inner tub with a gap, a lower chamber for storing the hot air generating mechanism, the upper chamber and the lower chamber, and a partition from the upper chamber. An outer tub provided with a partition plate for restricting the entry of hot air into the lower chamber, a hot air supply path for supplying hot air from the lower chamber to the upper chamber, and provided in the hot air supply path, A stirring fan that circulates hot air through a gap between the tank, an exhaust hole provided in the upper part of the outer tank, and an exhaust mechanism having an exhaust amount adjustment valve communicated with the exhaust hole. is there.
According to the exhaust-type batch oven having the above-described configuration, hot air can be generated in the lower chamber of the outer tank by the hot air generating mechanism, and this hot air can be supplied to the upper chamber through the hot air supply path by the stirring fan. In addition, since the partition plate can prevent the entry of hot air from the upper chamber to the lower chamber, the heater of the hot air generating mechanism provided in the lower chamber is a gas generated from the heated object placed in the inner tank of the upper chamber There is no contact with chemicals.
Further, since the hot air generating mechanism sucks the outside air and heats it, the heated outside air can be replaced with a part of the hot air discharged by the exhaust mechanism. For this reason, it is possible to suppress an increase in the concentration of the gaseous chemical substance in the furnace and to maintain temperature accuracy.
[0006]
In the exhaust-type batch type oven, it is preferable that the stirring fan also serves as the intake means.
In this case, since the agitating fan sucks outside air and simultaneously blows hot air from the lower chamber to the upper chamber, energy is saved as compared with the case where an intake means is provided separately from the agitating fan.
[0007]
The exhaust batch type oven, normally aspirated stirred fans outside air, power failure only, the inlet means is preferably sucks the outside air by the emergency power source (claim 3).
In this case, since the intake means can be operated by the emergency power supply at the time of a power failure, the gaseous chemical substance does not stay in the furnace even at the time of a power failure.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a cross-sectional view showing an embodiment of an exhaust-type batch oven according to the present invention. This exhaust-type batch type oven includes an inner tank 1 for storing the object A to be heated, an outer tank 3 for storing the inner tank 1 and a hot air generating mechanism 2 for supplying hot air to the inner tank 1, The exhaust mechanism 5 is configured to exhaust a part from the furnace.
[0009]
The outer tub 3 has a ceiling portion 3a composed of heat insulating walls, a floor portion 3b, both side surface portions 3c and 3d, a rear surface portion 3e, and a front door (not shown) for taking in and out the object A to be heated. And a partition plate 41 that partitions the interior of the outer tub 3 into an upper chamber 31 and a lower chamber 32 at an intermediate position, and hot air that allows hot air to flow from the lower chamber 32 to the upper chamber 31. And a supply path 42. The inner tub 1 is disposed in the upper chamber 31, and the hot air generating mechanism 2 is disposed in the lower chamber 32.
[0010]
The inner tub 1 is composed of a ceiling portion 3a, a floor portion 1b, and both side surface portions 1c and 1d of the outer tub 1. A gap S3 is provided between the floor portion 1b and the partition plate 41. Similarly, gaps S1, S2 are also provided between the side surface portions 1c, 1d and the side surface portions 3c, 3d of the outer tub 3. Is provided.
The front and rear end portions of the floor portion 1b and the side surface portions 1c and 1d of the inner tub 1 are in contact with the rear surface portion 3e of the outer tub 3 and the front door. In addition, a large number of ventilation holes 11 are provided on both side surface portions 1 c and 1 d of the inner tank 1. The vent holes 11 allow the furnace air to circulate along the hot air circulation path a flowing from the right gap S1 into the inner tank 1 and from the inner tank 1 to the left gap S2 in the figure.
[0011]
The hot air generating mechanism 2 includes an axial fan 21 and a heater 22. The heater 22 is provided in the hot air blowing path b from the inlet 33 provided in the lower part of the outer tub 3 to the hot air supply path 42.
The axial fan 21 is provided in the vicinity of the air inlet 33 and is operated only during a power failure by an emergency power source (not shown). The intake port 33 is provided with a filter 34. Normally, the agitating fan 43, which will be described later, sucks outside air through the filter 34 and sends it to the heater 22 by the axial fan 21 in the event of a power failure. For this reason, the gaseous chemical substance in the furnace does not come into contact with the heater 22 even during a power failure, and is safe.
[0012]
The hot air supply path 42 is provided adjacent to the partition plate 41 and below the gap S1. The hot air supply path 42 is provided with a stirring fan 43 that also serves as an intake means. The stirring fan 43 is rotatably connected to a motor 43a fixed to the outside of the side surface portion 3c of the outer tub 3, sucks outside air, sends hot air generated by the hot air generating mechanism 2 to the inner tub 1, and The hot air circulating in the inner tank 1 is prevented from flowing back to the hot air generating mechanism 2.
[0013]
An exhaust mechanism 5 for discharging a part of hot air around the hot air circulation path a to the outside of the furnace along the exhaust path c is provided at a corner of the outer tub 3 that is diagonally opposite the stirring fan 43. Yes. The exhaust mechanism 5 includes an exhaust hole 51 and an exhaust amount adjustment valve 52 communicated with the exhaust hole 51. The exhaust amount adjusting valve 52 can discharge a part of the circulating hot air to the outside only by adjusting the valve opening degree using the pressure in the furnace increased by the stirring fan 43.
[0014]
If it is the said structure, the external air attracted | sucked by the stirring fan 43 will be heated by the heater 22, and will introduce | transduce into the clearance S1 on the right side in the figure between the inner tank 1 and the outer tank 3 through the hot air supply path 42 by the stirring fan 43 as a hot air. Is done. The introduced hot air advances into the inner tub 1 from the ventilation hole 11 of the right side surface portion 1c of the inner tub 1, contacts the heated object A, and heats it.
The hot air that has come into contact with the object to be heated A is sequentially pushed out from the ventilation hole 11 of the left side surface portion 1d of the inner tank 1 into the gap S2, and stirred through the gap S3 between the floor 1b of the inner tank 1 and the partition plate 41. The fan 43 is reached. Here, since the entry of hot air to the hot air generating mechanism 2 side is restricted by the partition plate 41, the hot air that has reached the stirring fan 43 is combined with new hot air supplied from the hot air generating mechanism 2 by the stirring fan 43. Cycle again. The heated object A is maintained at a uniform temperature by the circulation of the hot air.
On the other hand, a part of the circulating hot air is discharged to the outside through the exhaust hole 51 by adjusting the valve opening degree of the exhaust amount adjusting valve 52. For this reason, the gaseous chemical substance generated from the object A to be heated is discharged outside while circulating with the hot air. Therefore, it is possible to safely perform the heat treatment of the article A to be heated while maintaining a uniform temperature without increasing the concentration of the gaseous chemical substance in the furnace.
Further, at the time of a power failure, the axial fan 21 is operated by an emergency power source, and the gaseous chemical substance in the furnace can be continuously discharged through the exhaust hole 51, so that safety can be ensured even at the time of a power failure.
[0015]
In the above embodiment, the explosion vent 6 is provided on the ceiling 3 a of the outer tub 3. This explosion vent 6 is provided as a safety measure.
[0016]
【The invention's effect】
As described above, according to the exhaust batch type heating furnace according to claim 1, since the gaseous chemical substance generated from the object to be heated does not ignite or adhere to the heater, the heat treatment is performed. The scope can be expanded and maintenance is easy. Further, since the concentration of gaseous chemical substances in the furnace can be diluted by sucking outside air, it is not necessary to use an inert gas. For this reason, cost can be reduced. Furthermore, since the hot air exhausted is always replenished with hot air heated from the outside air, temperature accuracy can be ensured. For this reason, the reliability of processing can be improved.
[0017]
According to the exhaust batch type heating furnace according to claim 2, since it is possible to suck outside air and blow and circulate hot air with only a stirring fan, it is possible to reduce costs by saving energy.
[0018]
According to the exhaust type batch type heating furnace according to claim 3, it is safe because the gaseous chemical substance does not stay in the furnace even during a power failure.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an embodiment of an evacuated batch oven according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Inner tank 11 Ventilation hole 2 Hot air generating mechanism 21 Axial fan (intake means)
22 Heater 3 Outer tank 31 Upper chamber 32 Lower chamber 41 Partition plate 42 Hot air supply path 43 Stirring fan 5 Exhaust mechanism 51 Exhaust hole 52 Exhaust amount adjustment valve S Clearance A Object to be heated

Claims (3)

An inner tub that has ventilation holes on the wall surface and stores an object to be heated;
A hot air generating mechanism comprising an intake means for sucking outside air; a heater for heating the sucked outside air; an upper chamber for storing the inner tank with a gap; a lower chamber for storing the hot air generating mechanism; An outer tub provided with a partition plate for partitioning the upper chamber and the lower chamber and restricting the entry of hot air from the upper chamber into the lower chamber ;
A hot air supply path for supplying hot air from the lower chamber to the upper chamber;
A stirring fan that is provided in the hot air supply path and circulates hot air through a gap between the outer tank and the inner tank;
An exhaust-type batch type oven comprising: an exhaust mechanism provided with an exhaust hole provided in an upper portion of the outer tub and an exhaust amount adjusting valve communicated with the exhaust hole.   The exhaust-type batch oven according to claim 1, wherein the stirring fan also serves as the intake means. Typically, agitation fan sucks external air, power failure only, exhaust batch type oven according to claim 1, wherein the intake means for sucking the outside air by the emergency power supply.

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