JP2006090627A - Roller hearth kiln - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a roller hearth kiln facilitating the maintenance of a hearth in the roller hearth kiln constituted to install a roller above the hearth and to apply heat treatment while moving treated objects placed on the roller. <P>SOLUTION: The hearth 10 is formed as an independent body separated from a kiln wall 20, and the hearth 10 is formed to be movable and moved by a moving means 80. The total length of the hearth is formed longer than the length of a kiln 1, and a hearth region for the hearth that cannot be settled within the kiln is formed outside the kiln. The hearth within the kiln and the hearth in the hearth region are moved by the moving means and sequentially replaced. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a roller hearth kiln in which a plurality of rollers are installed above a hearth inside a furnace and heat treatment is performed while an object to be processed is placed on the rollers and moved.

  The roller hearth kiln is a tunnel-type furnace in which a furnace wall is erected on both sides of a fixed hearth and the top of the furnace wall is covered. A large number of rollers are installed on the furnace wall and the roller is installed. It heat-processes, putting a to-be-processed object on top and moving. This roller hearth kiln is used in a wide range of fields because it can be fired for a short time and has good fuel efficiency, but there is still room for improvement in terms of maintenance.

  In other words, the roller hearth kiln moves on the rollers lined up at a small pitch with slight vibration, so that the fallen or scattered matter from the object to be processed, or the gas or tar generated from the object to be processed The material is deposited on the top of the hearth. Such deposits are regularly removed because they can damage the hearth and affect the yield of the workpiece. The floor cleaning work (deposit removal work) is carried out by workers entering the furnace. Therefore, during maintenance, it is necessary to stop the operation of the furnace, lower the inside of the furnace to a workable temperature, and raise the temperature again after the work is completed, and the furnace cannot be used at all for about one week.

  In addition, in Roller Hearth Kiln, there is a problem that the workpieces fall on the upper surface of the hearth due to breakage of the rollers, etc., and then the subsequent workpieces fall one after another and become clogged in the furnace. In such a case, the operation is stopped in the same manner as described above to lower the temperature in the furnace, and an operator enters the furnace to remove the fallen objects. Of course, the outage period for that will be around one week.

Thus, a means for removing the deposits accumulated on the hearth of the roller hearth kiln has been devised conventionally. For example, in Patent Document 1, a coil conveyor is installed on the hearth so that deposits are sent out of the furnace.
JP 58-147512 A

  In the conventional case where the hearth is provided with a conveyor, the problem related to periodic removal of deposits can be solved, but for example, different types of refractory bricks covering the surface of the hearth are required. It is completely powerless with respect to maintenance, and has no meaning for troubles such as roller breakage. On the other hand, there is even a harmful effect that the conveyor in the hearth gets in the way and it is difficult to work in the furnace. In addition, since the maintenance of the installed conveyor itself is newly generated, the merit by introduction is extremely limited.

  The present invention has been made in view of the above, and an object thereof is to provide a roller hearth kiln that is easy to maintain.

  In the roller hearth kiln as set forth in claim 1, wherein a plurality of rollers are installed above the hearth inside the furnace, and the heat treatment is performed while the workpiece is placed on the rollers and moved. The floor is separated from the furnace wall and formed as a separate body, and the hearth is formed so that it can be moved by moving means, and the total length of the hearth is formed larger than the length of the furnace and fits in the furnace. There is provided a roller hearth kiln in which a hearth area for a hearth that cannot be cut is formed outside the furnace, and the hearth inside the furnace and the hearth in the hearth area are moved sequentially by the moving means.

  Further, as described in claim 2, the hearth of the roller hearth kiln according to claim 1, wherein the hearth is formed by arranging a plurality of hearth blocks which are individually independent in a moving direction of the workpiece. I will provide a.

  In addition, as described in claim 3, the hearth area is provided side by side or above or below the furnace, and the hearth block that goes out of the furnace from one of the furnace ports is opposed through the hearth area. The roller hearth kiln according to claim 2, wherein the roller hearth kiln is returned from the side mouth into the furnace.

  Further, as described in claim 4, the roller hearth kiln according to claim 3, wherein the moving direction of the hearth block in the furnace in the normal use state is opposite to the moving direction of the workpiece. To do.

  In addition, as described in claim 5, when a roller or an object to be processed falls on the upper surface of the hearth block in the furnace, the hearth block is moved in the same direction as the object to be processed so that the roller or the like is moved into the furnace. The roller hearth kiln according to claim 3 or 4, wherein the roller hearth kiln is discharged outside.

The hearth inside the furnace can be taken out of the furnace to remove deposits in the hearth area, or damaged refractory bricks can be replaced. On the other hand, in order to place the hearth that was in the hearth area until then, instead of the hearth pushed out of the furnace, the hearth always exists in the furnace without interruption, so it is necessary to stop the operation of the furnace There is no. Therefore, since periodic maintenance of the furnace can be carried out in the operating state, the cost required for maintenance can be greatly reduced, and at the same time, the physical and mental burden of the worker required for maintenance can be reduced.
In addition, the hearth itself functions as a cart that carries out the clogged workpieces, etc., due to clogging of the workpieces caused by breakage of the rollers, etc. It is possible to remove processed materials. Therefore, since several days and fuel for raising and lowering the temperature of the furnace are not required, the recovery operation when trouble occurs can be performed in a very short time and at a low cost.

  In addition, as described in claim 2, if a hearth is formed by arranging a plurality of hearth blocks that are individually independent, the hearth block can be freely moved off the extension line of the furnace. This increases the degree of freedom with respect to the placement of the hearth area.

  In addition, as described in claim 3, if the hearth area is arranged side by side next to the furnace and the hearth block is circulated in an annular shape, the area occupied by the roller hearth kiln including the hearth area is reduced. be able to.

  Furthermore, as described in claim 4, by making the moving direction of the hearth block in the furnace in the normal use state opposite to the object to be processed, the hearth block entering the furnace is heated by unnecessary heat on the outlet side. Since it goes to the entrance side of the furnace while being heated, the loss of fuel consumption accompanying the movement of the hearth block can be minimized. That is, the entrance side of the furnace is a heating area for heating the object to be processed, and if a cooled hearth block is put in the heating area, the temperature is lowered, so that extra fuel is spent to make up for it. On the other hand, the exit side of the furnace is a cooling region for cooling the workpiece, and there is no effect even if the cooled hearth block is put therein and the temperature is lowered. In addition, since the hearth block is heated by the unnecessary heat on the outlet side of the furnace and reaches the heating area on the furnace inlet side in a warm state, the loss of fuel consumption due to the movement of the hearth block is minimized. It is.

  In addition, if the hearth block is moved in the same direction as the object to be processed at the time of abnormality when the object to be processed or the like falls on the hearth block as in claim 5, the cooling area on the outlet side of the furnace is used. Since the fallen object to be processed can be cooled, removal work outside the furnace can be performed quickly.

  Embodiments of the present invention will be described below with reference to the drawings. 1 is a longitudinal sectional view of the roller hearth kiln, FIG. 2 is a cross sectional view of the roller hearth kiln with the middle omitted, and FIG. 3 is a plan view of the roller hearth kiln with the middle omitted.

  As shown in FIG. 3, the roller hearth kiln of the present invention includes a furnace 1 and a hearth area 2 provided next to the furnace 1.

  As shown in FIG. 1, the furnace 1 is in the form of a tunnel in which furnace walls 20 and 20 are arranged on both sides of the hearth 10 and the top of the furnace wall 20 is covered. Rollers 30, 30 ... and burners 40, 40 ... are provided. The rollers 30, 30... Are arranged horizontally at a constant pitch, and both ends protruding outside the furnace walls 20, 20 are rotatably supported by bearings 21, 21 attached to the furnace walls 20, 20. Each roller 30 has a sprocket 31 at one end, and is connected to a driving motor (not shown) via a chain (not shown) that spans the sprocket 31. The upper surface of the rollers 30, 30... Is a transfer surface for the workpiece W, and the rollers 30, 30... Are driven by the rotation of the motor to move the workpiece W thereon in a predetermined direction. Note that the moving direction of the workpiece W in this embodiment is from left to right as indicated by arrows in FIG. 3, and therefore the left side in FIGS. 2 and 3 is the inlet of the furnace 1 and the right side is the furnace. 1 exit.

  The furnace floor 10 and the furnace walls 20 and 20 are installed on a frame-like base 50 installed on the ground as a common base. The hearth 10 and the furnace walls 20, 20 are separated and separated, and the furnace walls 20, 20 are integrally fixed on the frame 51 of the base 50. On the other hand, the hearth 10 includes rotatable wheels 11, 11... On the lower surface, and the wheels 11, 11. Seal portions 60, 60 are formed on both side surfaces of the hearth 10 and the inner side surfaces of the furnace walls 20, 20 so as to fit loosely with an appropriate gap C as shown in FIG. Heat in the furnace 1 is prevented from leaking to the outside by the seal portions 60, 60. If the sealing effect is insufficient with only the illustrated seal portions 60, 60, the base 50 and the hearth 10 as shown in FIG. 1 or between the furnace walls 20, 20 and the hearth 10 although not shown. Another sealing portion 61, 61 may be interposed to further enhance the sealing effect. The second seal portion 61 shown in FIG. 1 is a combination of a bowl-shaped sand receiver 62 installed on the rail 52 of the base 50 and a seal plate 63 suspended from the hearth 10. This is a known sand seal in which the tip of the plate 63 is inserted into the sand 64 of the sand receiver 62.

In the embodiment, as described above, the hearth 10 and the furnace walls 20, 20 are installed on the base 50 which is a common base, but the purpose is to ensure free movement of the hearth 10. is there.
That is, as described above, the hearth 10 and the furnace walls 20 and 20 are loosely fitted with an appropriate gap C. This gap C is essential for ensuring the free movement of the hearth 10. It is. However, if there is no gap C between the hearth 10 and the furnace walls 20, 20, the hearth 10 cannot move due to a large frictional resistance.
If the hearth 10 is installed directly on the ground instead of the base 50, only the furnace walls 20 and 20 supported by the base 50 are greatly raised due to the difference in thermal expansion. C disappears and the hearth 10 and the furnace walls 20 and 20 come into contact with each other.
On the other hand, if the hearth 10 and the furnace walls 20, 20 are installed on the base 50 which is a common base, the hearth 10 and the furnace walls 20, 20 are displaced almost together due to the thermal expansion of the base 50. The fluctuation of the gap C is minimized, and as a result, free movement of the hearth 10 can be ensured.

  The hearth 10 of the embodiment has a collective structure in which a plurality of hearth blocks 12, 12... That are individually independent are arranged in a line on the rail 52 of the base 50. In this case, if the number of hearth blocks 12, 12... Constituting the hearth 10 satisfies the condition that at least one hearth block 12 protrudes outside the furnace, the total length of the hearth 10 is equal to the length of the furnace 1. Beyond that. Base plates 70 and 70 having a size on which one hearth block 12 is placed are provided outside the furnace on the exit side and the entrance side of the furnace 1, respectively, and the base plates 70 and 70 are accommodated in the furnace 1. A hearth block 12 that cannot be removed is placed.

  The furnace 1 is provided with moving means 80 for moving the movable hearth 10. The moving means 80 of the embodiment is a fluid pressure cylinder 82 that expands and contracts the rod 81 using air pressure, hydraulic pressure, or the like as a power source, and the tip of the rod 81 faces the mounting base 83 fixed on the outlet side of the furnace 1 in the furnace 1. It is mounted in a horizontal state.

  The hearth area 2 is provided beside the furnace 1 as shown in the plan view of FIG. In the hearth area 2, a rail (not shown) having the same standard and the same length as the rail 52 in the furnace 1 is laid. The floor plate 70 and 70 at the entrance and exit of the furnace floor 2 are connected by a lateral conveyor 71, and the movement of the hearth block 12 to the rail 52 of the furnace 1 and the rail of the hearth area 2 This can be done freely by the going conveyor 71. The hearth area 2 may be provided with moving means for moving the hearth block 12 on the rail (for example, a hook is provided on the chain and the hook is hooked on the hearth block 12 and pulled). You may make it move the hearth block 12 manually without providing such a moving means.

  In addition, the code | symbol 90 in FIG.2, 3 is the table conveyor which conveys the to-be-processed object W. FIG. In addition, the front and rear surfaces of the hearth blocks 12, 12... Have a stepped structure that exactly matches the shape, and the rear and front surfaces of the hearth blocks 12, 12 positioned at the front and rear coincide with each other. The sealing effect is enhanced.

  Next, a method for operating the roller hearth kiln of the present invention will be described. It should be noted that the number of hearth blocks 12, 12,... To be used is a minimum configuration in which one is added to the number that completely fills the inside of the furnace 1.

  During normal operation, the rollers 30, 30... Rotate clockwise in FIG. When the workpiece W is placed on the rollers 30, 30..., The workpiece W moves from left to right as indicated by arrows in FIGS. The entrance side of the furnace 1 is a heating region, and the workpiece W is heated there. On the other hand, the outlet side of the furnace 1 is a cooling region, and the workpiece W is cooled to some extent, and then discharged to the table conveyor 90 on the outlet side. In the furnace 1, falling objects and scattered objects generated in the process of moving the workpiece W, or gas and tar-like substances generated from the workpiece are deposited on the furnace floor 10.

  Periodic removal of this deposit is performed as follows. First, the rod 81 of the fluid pressure cylinder 82 is extended with the hearth block 12 set on the base plate 70 on the outlet side of the furnace 1, and the hearth block 12 on the base plate 70 is pushed into the furnace 1. As a result, one hearth block 12, 12... Arranged in the furnace 1 is displaced by one, and the hearth block 12 at the end on the inlet side is pushed out onto the base plate 70. In this state, the sideways conveyor 71 is operated to slide the extruded hearth block 12 together with the base plate 70, and the hearth block 12 on the base plate 70 is further transferred to the rail in the hearth region 2. Waiting for the hearth block 12 to cool down in this state, the deposit on the upper surface of the hearth block 12 is removed after the temperature drops to an appropriate temperature. Alternatively, if the refractory brick on the upper surface of the hearth block 12 is damaged, it is peeled off and replaced.

  The hearth block 12 which has been maintained in this manner is placed on the base plate 70 on the lateral conveyor 71 on the outlet side of the furnace 1 and set together with the base plate 70 at the standby position at the outlet of the furnace 1. Thereafter, the same operation as described above is repeated to perform maintenance such as cleaning of deposits on the hearth 10 and replacement of refractory bricks.

  The above description relates to an embodiment having a minimum configuration in which only one hearth block 12 is provided in the hearth region 2. For example, 1 is provided at an interval corresponding to the time required for maintenance of one hearth block 12. If the time required for maintenance of a single hearth block 12 is 5 hours, it is one per 5 hours, or if the time required for maintenance of one hearth block 12 is 24 hours, it is one per day. The hearth block 12 can be maintained at a rate of Needless to say, when the frequency of maintenance is increased, the number of hearth blocks 12 can be increased in any way. If the number of hearth blocks 12 is twice the number of hearth blocks that completely fill the inside of the furnace 1 (in this case, the total length of the hearth 10 is twice the length of the furnace 1), the furnace 1. .. And the hearth blocks 12, 12... In the hearth region 2 can be totally replaced in a short time.

  Next, the roller 30 is broken at an arbitrary position in the furnace 1, and the roller 30 falls on the upper surface of the hearth block 12. Subsequently, the workpiece W falls on the hearth block 12 from the missing portion of the roller 30. And the recovery method when the trouble which the to-be-processed workpiece W also falls one after another occurs is demonstrated.

  First, one hearth block 12 is pushed by the fluid pressure cylinder 82 in the above-described manner to push out the first hearth block 12 to the outside of the furnace, and the pushed hearth block 12 is moved from the hearth area 2 to the opposite side. The operation of moving and pushing it into the furnace 1 again is repeated. Then, since the target hearth block 12 on which the fallen object is placed comes out of the furnace, the fallen object in the hearth block 12 can be removed at that time or moved to the hearth area 2. In addition, since replacement | exchange of the broken roller 30 can be performed by a well-known method, while moving the hearth blocks 12, 12, ..., the operation | movement of the furnace 1 is restarted when removal of a fallen object is completed. it can.

  By the way, in the above description, the hearth blocks 12, 12,... Are moved in the direction opposite to the moving direction of the workpiece W to remove the fallen objects as in the case of removing the deposits. When removing an object, the hearth blocks 12, 12... Are preferably moved in the same direction as the workpiece W. By doing so, it is possible to actively cool the object to be processed that has fallen using the cooling region on the outlet side of the furnace 1, so that it is possible to quickly remove the object to be processed that has come out of the furnace 1. Therefore, as shown by a two-dot chain line in FIG. 2, a fluid pressure cylinder 84 as a moving means of the hearth 10 may be installed on the inlet side of the furnace 1. Thus, it is ideal to provide both the hydraulic cylinders 82 and 84, but it goes without saying that the benefits of the present invention can be enjoyed with only one of them.

  As mentioned above, although embodiment of this invention was described, of course, this invention is not limited to the said embodiment. For example, in the embodiment, the hearth area 2 is provided beside the furnace 1, but may be provided above or below the furnace 1. When the hearth area 2 is provided above or below the furnace 1, the transverse conveyor 71 may be changed to a lift.

  In the embodiment, the hearth 10 is formed by an assembly of a large number of hearth blocks 12, 12,..., But one long hearth 10 is put into the furnace 1 and protrudes to the outside, and the protruding portion is the furnace 1. Maintenance may be performed on the portion that has been pushed in and moved out of the furnace, and vice versa. The hearth area 2 in this case is on the extension of the furnace 1 and is straight and elongated.

Moreover, the fluid pressure cylinder 82 shown in the embodiment is an example of the moving means 80, and includes any means that can move the hearth 10 such as a chain, a gear, and a screw.
Further, in the embodiment, the hearth 10 (furnace block 12) is provided with wheels 11 to be movable. However, the hearth 10 (furnace block 12) is changed to wheelless and the rail 52 of the base 50 is a roller. Instead of a conveyor, the hearth 10 (furnace block 12) may be placed on the roller conveyor and moved. Alternatively, the rail 52 may be changed to a flat floor laid with refractory bricks, and the floor surface and the abdominal surface of the hearth 10 without wheels may be in sliding contact with each other.

  Moreover, although the transverse conveyor 71 and the hearth area | region 2 were distinguished and demonstrated in embodiment, the sideways conveyor 71 can also be understood as a part of hearth area | region 2. FIG.

It is a longitudinal cross-sectional view of a roller hearth kiln. It is a cross-sectional view of a roller hearth kiln with the middle omitted. It is a top view of roller hearth kiln which omits the middle and shows.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Furnace 2 ... Hearth area | region 10 ... Hearth 12 ... Hearth block 20 ... Furnace wall 30 ... Roller 80 ... Moving means W ... Workpiece

Claims (5)

In the roller hearth kiln which installed a plurality of rollers above the hearth inside the furnace and heat-treated while moving the workpiece on the rollers,
The hearth is separated from the hearth wall and formed as a separate body so that the hearth can be moved and moved by moving means, and the total length of the hearth is formed larger than the length of the hearth, A roller characterized in that a hearth area for a hearth that cannot be accommodated in the furnace is formed outside the furnace, and the hearth inside the furnace and the hearth in the hearth area are moved sequentially by the moving means and are sequentially replaced. Herskin. The roller hearth kiln according to claim 1, wherein the hearth is formed by arranging a plurality of hearth blocks that are individually independent in a moving direction of an object to be processed. The hearth area is provided next to, above, or below the furnace, and the hearth block that goes out of the furnace from one of the furnace ports returns to the inside of the furnace from the other side through the hearth area. The roller hearth kiln according to claim 2. The roller hearth kiln according to claim 3, wherein a movement direction of the hearth block in the furnace in a normal use state is opposite to a movement direction of the workpiece. It is characterized in that when the roller or the object to be processed falls on the upper surface of the hearth block in the furnace, the hearth block is moved in the same direction as the object to be processed and the rollers and the like are discharged out of the furnace. The roller hearth kiln according to claim 3 or 4.

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