KR100533633B1 - A tunnel type continuous sintering furnace having atmosphere gas circulation system - Google Patents

Abstract

The present invention provides a furnace body having an inner passage, a heating element for providing a heat source to the inner passage, an air supply for supplying an atmosphere gas from the side surface of the furnace body to the center portion, and an exhaust port for discharging the gas of the furnace body upwards. And a conveying part for transporting the accommodating part in which the unbaked ceramic product is loaded in one direction, wherein the firing part fires the ceramic product, the circulating part branching a part of the exhaust gas discharged through the exhaust port and resupplying the internal passage. And a heat exchanger branched from the exhaust port and exchanging heat with exhaust gas flowing in one direction toward the inner passage.

According to the present invention, by forming a gas flow for circulating and reusing the atmosphere gas in the furnace at the same time as the side air supply to supply the atmosphere gas to the side of the ceramic product to be fired, to prevent the non-uniformity of the atmosphere gas and gas congestion phenomenon, The effect of reducing the amount of use is obtained.

Description

Tunnel type continuous firing furnace with atmospheric gas circulation system {A TUNNEL TYPE CONTINUOUS SINTERING FURNACE HAVING ATMOSPHERE GAS CIRCULATION SYSTEM}

The present invention relates to a sintering furnace, and more particularly, by forming a gas flow for circulating and reusing the atmosphere gas in the furnace at the same time as the side air supply for supplying the atmosphere gas to the side of the ceramic product to be fired, to eliminate the unevenness of the atmosphere gas and gas The present invention relates to a tunnel type continuous firing furnace having an atmosphere gas circulation system that is prevented and improved to reduce the amount of atmosphere gas used.

In general, ceramic electronic components and other ceramic products using ceramics such as laminated ceramic capacitors, varistors, ferrites, piezo-electric bodies, etc., and other ceramic products are formed by molding ceramic raw materials into a predetermined shape. It is manufactured by manufacturing and baking the said molded object.

The effective removal of binders used during molding during the firing process of ceramic products has emerged as an important process variable to control the quality characteristics.The removal of these binders is carried out in an independent debinder process called calcining or in a plastic elevated temperature profile. This heat treatment process is performed in a tunnel type continuous firing furnace.

Figure 1 (a) is a cross-sectional view showing the internal structure of a typical tunnel continuous firing furnace, Figure 1 (b) is a plastic profile in a typical tunnel continuous firing furnace, Figure 2 is a configuration diagram of a typical tunnel continuous firing furnace.

1 and 2, the conventional firing furnace 1 is a furnace body 2 having a tunnel-type inner passage 3 of a predetermined length from the inlet to the outlet, and a heating element for providing a heat source to the inner passage 3, as shown in Figs. (4), an air supply pipe (5) having air supply pipes (5a) on the left and right sides of the furnace body (2) and supplying atmospheric gas from the side surface to the center portion, and an exhaust pipe (1) on the upper portion of the inner passage (3). 6a) and an exhaust port 6 for discharging gas in the furnace to the outside, and an accommodating portion 7 in which sheets (not shown) on which ceramic products to be fired are placed are stacked in multiple stages.

In FIG. 2, reference numeral 6b is a valve provided in the exhaust pipe 6a, 6c is an exhaust fan, 7a is a support plate, 8 is a pressure gauge for measuring the pressure inside the furnace body, and 9 is the air supply 5) Main gas supply line to supply atmospheric gas.

Accordingly, in the ceramic product loaded on the accommodating part 7, the supporting plate 7a is sequentially transferred through the inner passage 3 of the furnace body 2 by a conveying part such as a pusher. The conveyed ceramic products are gradually removed from the binder area (A) for removing the binder as the furnace temperature is gradually increased, the firing area (B) where the ceramic product is fired while the elevated temperature is kept constant, and the furnace temperature is gradually lowered. It is fired while continuously passing through the cooling zone (C) for cooling the ceramic product.

However, in the case of the conventional kiln 1, since the side gas is supplied from the side into the furnace body 2 from the side, and the gas flow of exhausting the atmosphere gas to the upper portion of the furnace body 2 is constant in one direction only. In the central portion of the housing 7 in which the ceramic product is loaded, a dead zone, which is a region in which gas flow is stagnant, is locally generated, thereby causing a spatial dispersion in the firing furnace 1.

In this case, the debinding region (A) is an essential process of thermally decomposing or sintering an organic binder contained in a ceramic product, and debinding gas such as carbon monoxide / carbon dioxide is generated, and the debinding gas is supplied to the atmosphere gas. In this case, it should be discharged from the inside of the ceramic ceramic product to the outside by the exhaust flow.

Accordingly, when the dead zone, which is a gas stagnation region, is formed in the vicinity of the accommodating portion 7 in which the ceramic product is loaded, the gas generated inside the ceramic product during the debinder process does not escape to the outside and is not exhausted to the outside. It can cause localized plastic nonuniformity caused by stagnation or concentration of debinding gas, and it can cause cracking and peeling of ceramic products and cause product defects.

Accordingly, the present invention has been made to solve the above problems, the object of the present invention is to provide a circulation system for circulating and reusing the atmosphere gas so that there is no local gas stagnation zone in the inner passage of the kiln to facilitate the exhaust of debinding gas. The present invention seeks to provide a tunnel type continuous furnace having an atmospheric gas circulation system which can improve gas flow of atmospheric gas and reduce gas consumption in a cooling zone.

As a technical means for achieving the above object, the present invention

A furnace body having an inner passage, a heating element for providing a heat source to the inner passage, an air supply for supplying an atmospheric gas from the side surface of the furnace body to the center portion, an exhaust port for discharging the gas of the furnace body to the upper portion and an unbaked state In the firing furnace for firing the ceramic product having a conveying section for transporting the receiving portion in which the ceramic product is loaded in one direction,

A circulation part for branching a part of the exhaust gas discharged through the exhaust port and resupplying the internal passage;

And a heat exchanger branched from the exhaust port and heat-exchanged with the exhaust gas flowing in one direction toward the internal passage.

Preferably, the circulation part is mounted on the furnace main body so that the tip end is exposed to the gas branch line to which the exhaust gas flows from the exhaust port, and the inner passage is connected to the gas branch line and the rear end is branched exhaust gas. It consists of several circulation pipes supplied.

More preferably, the circulation pipe includes a plurality of horizontal circulation pipes installed horizontally on both left and right sides of the furnace body such that the tip thereof corresponds to the side of the housing portion, and the bottom surface of the furnace body so that the tip thereof corresponds to the lower portion of the housing portion. It consists of a plurality of vertical circulation pipes installed perpendicular to the.

More preferably, the horizontal and vertical circulation pipes are each provided with a gas supply control valve so as to adjust the gas supply amount injected into the inner passage based on the pressure value of the pressure gauge for measuring the internal pressure of the furnace body.

More preferably, the horizontal circulation pipe is disposed on a vertical line in which the air supply port is aligned.

Preferably, the heat exchanger includes a jacket surrounding an outer surface of the gas branch line, and a medium supply pipe connected to the jacket such that a heat exchange medium in contact with the exhaust gas in a non-contact manner flows inside the jacket in one direction.

More preferably, the heat exchange medium is a fluid that raises the exhaust gas supplied back to the inner passage corresponding to the debinder region to a firing temperature.

More preferably, the circulating pipe is wound with a thermocouple so as to branch off from the exhaust port and heat up the exhaust gas before re-supply to the inner passage.

More preferably, the heat exchange medium is a fluid that cools the exhaust gas supplied to the inner passage corresponding to the cooling zone to room temperature.

Preferably, the rear end side of the heat exchanger is provided with a filter member to remove the foreign matter contained in the exhaust gas branched from the exhaust port.

Preferably, a flow meter for measuring the flow rate of the exhaust gas passing through the gas branch line is provided in the middle of the length of the gas branch line.

Hereinafter, the present invention will be described in more detail.

Figure 3 is a longitudinal cross-sectional view of the tunnel type continuous firing furnace having an atmosphere gas circulation system according to the present invention, Figure 4 is a height cross-sectional view of the tunnel type continuous firing furnace having an atmosphere gas circulation system according to the present invention, Figure 5 Fig. 1 is a schematic diagram of a tunnel type continuous firing furnace having an atmospheric gas circulation system.

The firing furnace 100 of the present invention has a furnace body 2 having an inner passage 3 as in the prior art, a heating element 4 providing a heat source, and a side surface for supplying atmospheric gas from the side surface of the furnace body 2. And an air supply port (5), an upper exhaust port (6) for discharging the gas in the inner passage (3) to the upper part, and a conveying part for transporting the accommodating part (7) on which the unbaked ceramic product is loaded. Detailed description thereof will be omitted, and the same reference numerals will be given.

That is, the circulation unit 110 branches a part of the exhaust gas discharged through the exhaust port 6 in which the exhaust pipe 6a is vertically spaced at a predetermined interval in the longitudinal direction on the upper part of the furnace body 2 to ceramic. The product is circulated and supplied so as to be reused as an atmosphere gas in the inner passage 3 of the furnace body 2 in which the binder removal process and the cooling process of the product are continuously performed.

The circulation unit 110 is provided with a gas branch line 111 into which the exhaust gas branched from the exhaust pipe 6a of the exhaust port 6 flows into the inner passage 3 of the furnace body 2. The gas branch line 111 is provided with a plurality of circulation pipes 112 mounted on the furnace body 2 so that the tip of the gas branch line 111 is exposed and the exhaust gas is injected into the inner passage 3 as an atmosphere gas. Is connected to the end of.

Accordingly, the exhaust gas branched from the exhaust port 6 by the gas branch line 111 is re-supplied into the inner passage 3 through the circulation pipe 112 provided in the furnace body 2, and A gas circulation flow is formed through the exhaust port 6 to be exhausted again or branched into the atmosphere gas. In the inner passage 3 of the furnace body 2, the air supply port is provided by the amount of gas exhausted through the exhaust port 6. Atmospheric gas is continuously supplied from the outside through the air supply pipe 5a of (5).

On the other hand, the circulation pipe 112 for circulating and supplying the exhaust gas into the furnace body 2 is horizontal to the left and right sides of the furnace body 2 so that the tip of the exhaust gas is injected to correspond to the side portion of the accommodating part 7. A plurality of horizontal circulation pipes 112a and a plurality of vertical circulation pipes 112b perpendicular to the bottom surface of the furnace body 2 so that the front end to which the exhaust gas is injected correspond to each other with the lower portion of the accommodating part 7. It is composed of

In addition, the horizontal and vertical circulation pipe (112a) (112b), the pressure value of the pressure gauge (8) installed to measure the internal pressure formed in the inner passage (3) of the furnace body (2) during the firing operation of the ceramic product The gas supply control valves 113a and 113b are respectively provided to appropriately adjust the gas supply amount injected into the inner passage 3 on the basis of the above.

In addition, each of the air supply pipes 5a of the air supply port 5 is provided with a gas supply control valve 5b so as to appropriately adjust the gas supply amount injected into the inner passage 3 based on the pressure value of the pressure gauge 8. (5b) is provided.

Here, the horizontal circulation pipe (112a) is preferably arranged every vertical line that the air supply pipe (5a) of the air supply line 5 is aligned, which is the front end of the horizontal circulation pipe (112a) and the air supply pipe (5a) By concentrating the injection pressure of the atmospheric gas supplied from the air into the ceramic product loaded in the receiving part, it is possible to facilitate the external discharge of the debinder gas generated at the time of debinder and to improve the gas flow rate so that the gas stagnation zone is not generated. It can be.

On the other hand, the heat exchanger 120 is branched from the exhaust port (6) in the middle of the length of the gas branch line 111 to exchange heat with the exhaust gas flowing in one direction toward the inner passage (3) of the furnace body (2) It is provided.

The heat exchanger 120, as shown in Figure 6 (a) (b), the jacket 121 surrounding the outer surface of the middle length of the gas branch line 111, and the heat exchange heat exchanged in contact with the exhaust gas It is composed of a medium supply pipe 122 connected to the jacket 121 so that the medium flows in one direction inside the jacket 121.

Here, the gas branch line 111 wrapped in the jacket 121 may be composed of a plurality of tubules 123 having a small inner diameter so as to widen the contact area with the heat exchange medium.

In addition, the heat exchange medium supplied to the heat exchanger 120 should selectively use a fluid for raising or cooling the branched exhaust gas in accordance with the working conditions of the region for firing the ceramic product.

That is, in the binder removal area A for gradually removing the binder included in the molding by gradually providing a heat source having a predetermined temperature or more to the ceramic product proceeding in one direction in the inner passage of the furnace body 2, it is supplied into the heat exchanger 120. The heat exchange medium heat-exchanged with the exhaust gas may raise the exhaust gas resupply to the inner passage 3 corresponding to the debinding zone A according to the high temperature condition of the debinding zone A to a firing temperature of 1300 ° C. It must be a hot fluid that provides a possible heat source.

Accordingly, in the debinder region A, the exhaust gas branched from the gas branch line 111 is heat-exchanged with a heat-exchange medium, which is a high-temperature fluid, so as to pass through the heat exchanger 120 to be heated up to a temperature higher than the exhaust temperature. By re-supplying into the inner passage 3 in which the debinding process is performed, the thermal efficiency of the firing furnace can be prevented from being lowered.

In addition, the circulation pipe 112 installed in the binder removal area A provides a heat source when the power is applied so that the exhaust gas can be heated up before being branched from the exhaust port 6 and resupplied to the inner passage 3. The thermocouple to be wound may be wound up.

In this case, since the exhaust gas heated up while passing through the heat exchanger 120 provided in the debinder region A is heated up again by the thermocouple just before being re-supplied into the inner passage of the furnace body, the debinder The time for raising the temperature of the exhaust gas in the region A can be shortened.

On the other hand, in the cooling zone (C) for cooling the ceramic product which has undergone the binder and baking process at room temperature while proceeding in one direction in the inner passage of the furnace body (2), it is supplied into the heat exchanger (120) to exchange heat with the exhaust gas. The heat exchange medium must be a fluid absorbing a heat source of a gas capable of cooling the exhaust gas supplied back to the inner passage 3 corresponding to the cooling zone C to room temperature according to the low temperature condition of the cooling zone C. do.

Accordingly, in the cooling region C, the exhaust gas branched from the gas branch line 111 is heat-exchanged with the medium for heat exchange, which is a low-temperature fluid, so as to pass through the heat exchanger 120 and be heated up to a temperature lower than the exhaust temperature. By re-supplying into the inner passage 3 where the cooling process is performed, the amount of the atmosphere gas used in the cooling process may be reduced by the supply amount of the exhaust gas to be supplied again, thereby reducing the maintenance cost of the kiln.

On the other hand, in the gas branch line 111 of the rear end side of the heat exchanger 120 to remove foreign substances contained in the exhaust gas branched from the exhaust port 6, and at the same time to remove the tar component generated in the exhaust gas during cooling clean atmosphere The filter member 125 is provided to supply only the gas component into the inner passage 3 of the furnace body 2.

In addition, the gas branch line 111 of the rear end side of the filter member 125 is heat-exchanged while passing through the gas branch line 111 so that the amount of exhaust gas supplied back into the inner passage 3 can be measured. A flow meter 126 is provided.

According to the present invention as described above, the process of firing the ceramic product by supplying the atmosphere gas through the air supply port into the furnace main body and at the same time by branching a part of the exhaust gas exhausted through the exhaust port from the furnace main body left and right By re-supplying from both sides and the bottom to the center side, a strong gas vortex can be formed in the debinder area, thereby suppressing the formation of dead zones in which the gas is stagnant and at the same time preventing local unevenness of the atmosphere gas. The debinder gas generated during the process is smoothly exhausted to the upper side exhaust port, and the debinder gas is not retained in the ceramic product so that the ceramic product of good quality without cracking and peeling phenomenon can be fired.

In addition, in the cooling zone, the exhaust gas is cooled and re-supplied into the inner passage of the furnace body. Thus, the gas consumption amount used to cool the ceramics after the firing process is lowered compared to the conventional method, thereby reducing the equipment maintenance cost of the kiln. Lose.

While the invention has been shown and described with respect to specific embodiments thereof, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit or scope of the invention as set forth in the claims below. I would like to clarify that knowledge is easy to know.

Figure 1 (a) is a cross-sectional view showing the internal structure of a typical tunnel type continuous firing furnace.

1 (b) is a firing profile in a typical tunnel type continuous firing furnace.

2 is a configuration diagram of a typical tunnel type continuous firing furnace.

3 is a longitudinal sectional view of a tunnel type continuous firing furnace having an atmosphere gas circulation system according to the present invention.

 4 is a cross-sectional view in a height direction of a tunnel type continuous firing furnace having an atmospheric gas circulation system according to the present invention.

5 is a configuration diagram of a tunnel type continuous firing furnace having an atmosphere gas circulation system according to the present invention.

Figure 6 (a) is a block diagram showing a heat exchanger of a tunnel type continuous firing furnace having an atmosphere gas circulation system according to the present invention.

Figure 6 (b) is a perspective view showing a heat exchanger of a tunnel type continuous firing furnace having an atmosphere gas circulation system according to the present invention.

Explanation of symbols on main parts of drawing

2: main body 3: internal passage

4: heating element 5: air supply

6: exhaust port 7: storage part

110: circulation section 111: gas branch line

112: circulation pipe 112a: horizontal circulation pipe

112b: vertical circulation pipe 113a, 113b: gas supply control valve

120: heat exchanger 121: jacket

122: medium supply pipe 100: firing furnace

Claims (11)

A furnace body having an inner passage, a heating element for providing a heat source to the inner passage, an air supply for supplying an atmospheric gas from the side surface of the furnace body to the center portion, an exhaust port for discharging the gas of the furnace body to the upper portion and an unbaked state In the firing furnace for firing the ceramic product having a conveying section for transporting the receiving portion in which the ceramic product is loaded in one direction, A circulation part for branching a part of the exhaust gas discharged through the exhaust port and resupplying the internal passage; And a heat exchanger branched from the exhaust port and heat-exchanged with the exhaust gas flowing in one direction toward the inner passage. The circulation part is mounted to the furnace main body so that the front end is exposed to the gas branch line branched from the exhaust port and the exhaust gas is introduced, and the gas branch line and the rear end are connected to a plurality of branched exhaust gas supplied. The circulation pipe comprises a plurality of horizontal circulation pipes horizontally installed on both left and right sides of the furnace body such that the tip thereof corresponds to the side of the housing portion, and the furnace body so that the tip thereof corresponds to the lower portion of the housing portion. Tunnel type continuous firing furnace having an atmosphere gas circulation system, characterized in that composed of a plurality of vertical circulation pipe installed perpendicular to the bottom of the. delete delete The method of claim 1, The horizontal and vertical circulation pipes are each provided with a gas supply control valve so as to adjust the gas supply amount injected into the inner passage based on the pressure value of the pressure gauge for measuring the internal pressure of the furnace body. Tunnel type continuous firing furnace with circulation system. The method of claim 1, The horizontal circulating pipe is a tunnel type continuous firing furnace having an atmosphere gas circulation system, characterized in that arranged on a vertical line in which the air supply is aligned. The method of claim 1, The heat exchanger is composed of a jacket surrounding the outer surface of the gas branch line and the atmosphere gas, characterized in that the heat supply medium which is in contact with the exhaust gas is connected to the jacket so that the medium flows in one direction inside the jacket Tunnel type continuous firing furnace with circulation system. The method of claim 6, The heat exchange medium is a tunnel type continuous firing furnace having an atmosphere gas circulation system, characterized in that the fluid for raising the exhaust gas supplied back to the inner passage corresponding to the debinder zone to the firing temperature. The method of claim 1, And a thermocouple wound around the circulation pipe so as to heat up the exhaust gas before re-supplying from the exhaust port to the internal passage. The method of claim 6, The heat exchange medium is a tunnel type continuous firing furnace having an atmosphere gas circulation system, characterized in that the fluid for cooling the exhaust gas supplied back to the internal passage corresponding to the cooling zone to room temperature. The method of claim 1, And a filter member is provided at a rear end side of the heat exchanger to remove foreign substances contained in exhaust gas branched from the exhaust port. The method of claim 1, And a flow meter for measuring the flow rate of the exhaust gas passing through the gas branch line in the middle of the length of the gas branch line.