JP3720784B2 - Hot air circulation oven - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a hot air circulation oven that performs a heat treatment such as a binder removal treatment of a ceramic material.
[0002]
[Prior art and problems to be solved by the invention]
As the hot air circulation type oven, there is an inert gas oven in which, for example, an inert gas heated by a heater is used as hot air to perform a binder removal treatment of a ceramic material. In such an inert gas oven, the processing object such as the ceramic material is disposed in the furnace body main body, and the furnace port provided in the furnace body main body is closed by the furnace port door at a high temperature (max. 600 ° C.). The inert gas is circulated in the furnace body to heat treat the object.
[0003]
However, in the conventional inert gas oven as described above, the interior of the furnace body is circulated inside the gap formed between the door and the furnace body when the furnace mouth is closed by the furnace door. In some cases, a high temperature inert gas flows and the inert gas comes into contact with the surface of the furnace door, the surface of the furnace body, or the like surrounding the gap. As a result, sublimates such as a binder were precipitated from the inert gas and caused a problem that they adhered to the surface of the furnace door surrounding the gap.
[0004]
In view of the conventional problems as described above, the present invention can prevent hot air from flowing into the gap between the furnace body and the furnace port door, and thus the surface of the furnace port door surrounding the gap. An object of the present invention is to provide a hot air circulation type oven capable of preventing the sublimate contained in the hot air from adhering to the above.
[0005]
[Means for Solving the Problems]
The present invention comprises a furnace body, a furnace door that opens and closes a furnace opening provided in the furnace body, and a heating tank provided in the furnace body. A hot air circulation type oven that heats an object to be processed in the heating tank by circulating hot air, and the furnace port door is closed between the furnace port door and the furnace body body when the furnace port door is closed. A purge gas introducing means for introducing a predetermined purge gas that prevents the hot air from flowing into the gap is provided in the gap that is formed and communicates with the interior of the furnace body, and the purge gas introducing means removes the purge gas from the gap. The internal pressure of the gap is made higher than the internal pressure of the heating tank by supplying the gas into the inside of the heating tank, and the purge gas introducing means has a supply pipe arranged in the heating tank ( Claim 1).
[0006]
In the hot air circulation oven configured as described above, the purge gas introduction means introduces a predetermined purge gas into the gap, thereby preventing the hot air inside the furnace body from flowing into the gap. Can do.
[0007]
Further, in the hot-air circulating oven (Claim 1), the furnace body is attached to one of the furnace body main body and the furnace port door, and the furnace body is opened in the gap when the furnace port door closes the furnace port. it is not preferable with a sealing member for sealing the interior of the furnace body in contact with the body and the other one of the surface of the furnace outlet door. In this case, the purge gas introduced into the gap by the purge gas introduction means prevents the hot air from flowing into the gap, and the seal member and each surface of the furnace body main body in contact with the hot air are exposed to the hot air. Can be prevented, and the interior of the furnace body can be reliably sealed by the seal member.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the hot-air circulating oven of the present invention will be described with reference to the drawings. In addition, in the following description, the case where it applies to the inert gas oven which heats and circulates inert gas inside a furnace body is illustrated and demonstrated.
FIG. 1 is a horizontal cross-sectional view showing the main configuration of an inert gas oven according to an embodiment of the present invention. In the figure, the inert gas oven of the present embodiment includes a furnace body 1 having a substantially U-shaped cross section and a furnace port A for opening and closing a rectangular furnace port A formed on the substantially U-shaped opening side. And a door 2. The oven has a hot air flow to the gap B against a frame-like gap B formed between the door 2 and the furnace body 1 when the furnace port A is closed by the furnace door 2. A blow-out pipe 3 and a supply pipe 4 are provided as purge gas introduction means for introducing a predetermined purge gas such as N ₂ gas that prevents the inflow of N ₂ . The furnace body 1 is provided with a supply port and an exhaust port (not shown). When the furnace port A is closed by the furnace port door 2, the air inside the body is replaced with an inert gas such as argon gas. To do. Moreover, the heat insulating material 5 is attached to the inside of the furnace body main body 1 and the furnace port door 2, respectively.
[0009]
A flat partition member 6 having left and right edges 6 a and 6 b is provided inside the furnace body 1, and a heater and a sirocco fan (not shown) are disposed below the partition member 6. Yes. In addition, a space above the partition member 6 forms a heating tank C in which an object to be processed such as a ceramic material is disposed. On the right side of the figure of the heating tank C, a blow-out wind tunnel portion D through which inert gas flows from below to above the partition member 6 is formed. In addition, a suction wind tunnel E through which inert gas flows from the upper side to the lower side of the partition member 6 is provided on the left side of the heating tank C. The inert gas heated by the heater is sirocco faned to arrows P, Q, and R in the figure. By sequentially flowing in the direction shown, the oven performs a heat treatment such as a debinding process on the object in the heating tank C.
[0010]
The furnace door 2 is attached to the furnace body 1 through a hinge 2a provided at the left end of the figure, and the handle 2b side in the clockwise direction of the figure around the hinge 2a. Is rotated to open the furnace port A, and the workpiece is carried into and out of the heating tank C.
Further, a graphite packing 7 is attached to the inner surface 2 c of the furnace door 2 in a frame shape, and the packing 7 comes into contact with the inner surface 1 a of the furnace body 1 so that the gap B is closer to the body 1 side. The opening is closed to prevent the inert gas from flowing into the gap B from the heating tank C (see also FIG. 2).
[0011]
The blow-out pipe 3 is constituted by, for example, a rectangular tube, and is fixed to the inner surface 1a in a frame shape so as to surround the furnace port A. In addition, as shown in FIG. 2, the blowing pipe 3 is provided with a plurality of blowing holes 3a for blowing purge gas toward the gap B at a predetermined interval, and the purge gas is arranged in the direction of the arrow x in FIG. Is flowing.
The supply pipe 4 is constituted by, for example, a cylindrical pipe, and supplies purge gas to the blowing pipe 3 from the outside of the furnace body. Specifically, the supply pipe 4 is connected to a purge gas supply source, and penetrates the furnace body 1 in an airtight manner. The penetration part 4a is attached to the body 1 and is branched from the penetration part 4a to the left and right to be heated. It has the branch parts 4b and 4c arrange | positioned in the tank C. FIG. The leading ends of these branch portions 4b and 4c are bent at a substantially right angle, and are inserted into the U-shaped notch 7a (FIG. 2B) of the graphite packing 7 into the frame-shaped blowing tube 3. On the other hand, they are connected at two places on the left and right. These blowing pipe 3 and supply pipe 4 supply the purge gas into the gap B, whereby the internal pressure of the gap B is made higher than the internal pressure of the heating tank C.
[0012]
Further, as shown in FIG. 2A, the furnace door 2 is provided with a silicon packing 8 as a seal member, and when the packing 8 is closed in the gap B when the furnace port A is closed. The inside of the furnace body 1 is sealed by contacting the contact surface 1b provided on the furnace body 1 side. Further, on the back side of the contact surface 1b, a cooling pipe 10 through which cooling water circulates is provided in a state of being covered with a heat conduction promoting material 9, and the silicon packing 8 is cooled below its allowable temperature and deteriorated. Occurrence is suppressed.
[0013]
In the inert gas oven of the present embodiment configured as described above, the blowout pipe 3 and the supply pipe 4 (purge gas introducing means) supply the purge gas into the gap B, whereby the internal pressure of the gap B is set to the internal pressure of the heating tank C. Therefore, the high temperature inert gas circulating in the heating tank C can be prevented from flowing into the gap B. As a result, it is possible to prevent the high temperature inert gas from being cooled by coming into contact with the furnace door 2 surrounding the gap B and the inner surfaces 2c, 1a of the furnace body 1 and so on, and thus sublimating the binder from the inert gas. It is possible to prevent the matter from depositing and adhering to the inner surfaces 2c and 1a. Further, since the sublimate does not adhere to the inner surfaces 2c and 1a, unlike the conventional example, it is possible to omit the cleanup work for wiping and removing the attached sublimate. As a result, the maintenance work of the oven can be performed easily and with a longer interval, and the performance of the oven can be maintained over a long period of time. Further, since the sublimate does not adhere, for example, the sublimate attached when the door is opened and closed does not peel off and enter the inside of the furnace body 1, and the object to be processed in the furnace body 1 is contaminated with the sublimate. Therefore, it is possible to prevent a reduction in processing quality of the object to be processed.
[0014]
Moreover, in this embodiment, since high temperature inert gas can be prevented from flowing into the inside of the gap B, the silicon packing 8 and its contact surface 1b that are appropriately cooled by the cooling water in the gap B are heated at a high temperature. It is possible to effectively prevent the sublimate from adhering to the silicon packing 8 and the contact surface 1b and to securely seal the interior of the furnace body 1 with the packing 8. can do. As a result, it is possible to suppress the deterioration of the silicon packing 8 as much as possible to improve its life, and to prevent the deterioration of the sealing performance of the oven and the deterioration of the processing quality of the object to be processed due to this. Moreover, since the inside of the furnace body 1 can be reliably sealed, leakage of the purge gas to the outside can be prevented.
[0015]
In the above description, the case where the inert gas oven is used to circulate the inert gas inside the furnace body has been described. However, the present invention is not limited to this, and includes a wet gas containing water vapor and other chemical components. The present invention can be applied to a hot air circulation type oven that heats an object to be processed by circulating an atmosphere gas. In the above description, the structure using the blowing pipe 3 fixed to the inner surface 1a in a frame shape so as to surround the furnace port A has been described. However, the present invention provides a case where the furnace port door closes the furnace port. And a purge gas introduction means for introducing a predetermined purge gas into a gap formed between the furnace door and the furnace body main body and communicating with the interior of the furnace body main body, and the furnace body main body within the gap. Any configuration may be used as long as it can prevent the hot air from flowing in, and the purge tube may be blown out from the supply pipe 4 toward the gap B so that the blow-out pipe 3 is omitted .
[0016]
Further, in the above description, the configuration in which the purge gas flows in the direction of the arrow x in FIG. 2A has been described, but the present invention is not limited to this, and the blowout is performed near the contact surface 1b of the furnace body 1. A configuration in which a purge gas is allowed to flow in a direction opposite to the x direction may be provided by providing a pipe.
In the above description, the configuration in which the silicon packing 8 is provided inside the furnace port door 2 has been described. However, the present invention is not limited to this, and a sealing member is provided so as to contact the inside of the furnace port door 2. You may attach to the said contact surface 1b and seal the inside of the furnace main body 1 with the said member.
[0017]
【The invention's effect】
The present invention configured as described above has the following effects.
According to the hot air circulation type oven of claim 1, since the hot air inside the furnace body can be prevented from flowing into the gap between the furnace body and the furnace door, the hot air Can be prevented from adhering to the surface of the furnace door surrounding the gap. As a result, an oven maintenance operation can be easily performed, and a long-life oven that can maintain performance over a long period of time can be configured.
[0018]
Moreover, according to the hot-air circulation type oven described above , each surface of the sealing member and the furnace body main body in contact with the sealing member can be prevented from being exposed to hot air. Adhering to each surface can be effectively prevented, and the interior of the furnace body 1 can be reliably sealed by the sealing member. As a result, it is possible to suppress the deterioration of the sealing member and the deterioration of the sealing performance of the oven and the processing quality of the object to be processed over a long period of time, and it is possible to prevent the purge gas from leaking to the outside.
[Brief description of the drawings]
FIG. 1 is a horizontal cross-sectional view showing a main configuration of an inert gas oven according to an embodiment of the present invention.
2A is an enlarged cross-sectional view of a portion surrounded by a circle II in FIG. 1, and FIG. 2B is an enlarged perspective view showing a connection portion between a blowing pipe and a supply pipe shown in FIG. .
[Explanation of symbols]
1 furnace body 1b contact surface (surface of furnace body)
2 Furnace door 3 Blowout pipe (purge gas introduction means)
4 Supply pipe (purge gas introduction means)
8 Silicon packing (seal member)
A Furnace B B Clearance

Claims (1)

A hot air comprising a furnace body, a furnace door that opens and closes the furnace mouth provided in the furnace body, and a heating tank provided in the furnace body, and circulated through the furnace body. A hot-air circulating oven that heats an object to be processed in the heating tank , and is formed between the furnace port door and the furnace body body when the furnace port door closes the furnace port, and Purge gas introduction means for introducing a predetermined purge gas for preventing the flow of the hot air into the gap is provided for the gap communicating with the interior of the furnace body, and the purge gas introduction means supplies the purge gas to the inside of the gap. Thus, the internal pressure of the gap is made higher than the internal pressure of the heating tank, and the purge gas introducing means has a supply pipe arranged in the heating tank .

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