JP2017014591A - Bell type annealing furnace and method for remodeling the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bell type annealing furnace which can increase heat input to an inner cover portion at a position away from a burner and can efficiently and uniformly input heat to the inner cover.SOLUTION: A bell type annealing furnace 10 includes an inner cover 2 and an outer cover 3 and forms flame in a space 81 between the inner cover 2 and the outer cover 3 by burners 4 provided in lower parts of the outer cover 3 to anneal a material 6 to be treated placed inside the inner cover 2. Radiators 11 extending in the vertical direction are disposed at positions causing no interference with the burners 4 and facing the side surface of the inner cover 3, in the space 81 between the inner cover 2 and the outer cover 3.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a bell-type annealing furnace and a modification method thereof.

  Conventionally, as shown in Patent Documents 1 and 2, it has an inner cover and an outer cover, and a burner provided at the lower part of the outer cover forms a flame in the space between the inner cover and the outer cover, A bell-type annealing furnace is disclosed that anneals a plurality of coil materials stacked in the vertical direction in an inner cover.

Japanese Patent Laying-Open No. 2005-213581 JP 2004-269918 A

  Here, in the bell-type annealing furnace as shown in Patent Documents 1 and 2, the heat input to the upper part of the inner cover at a position away from the burner is reduced with respect to the heat input to the lower part of the inner cover in the vicinity of the burner, There is a problem that heat is not sufficiently transmitted to the coil material located in the portion facing the upper portion of the inner cover.

  Therefore, the present invention provides a bell-type annealing furnace that can increase the amount of heat input to the inner cover portion at a position away from the burner and efficiently and uniformly perform heat input to the inner cover. With the goal.

1st invention of this application has an inner cover and an outer cover,
A bell-type annealing furnace that forms a flame in a space between the inner cover and the outer cover by a burner provided at a lower portion of the outer cover, and anneals a treatment material disposed in the inner cover. And
In the space between the inner cover and the outer cover, a radiator extending in the vertical direction is disposed so as not to interfere with the burner and to face the side surface of the inner cover. .

  According to the said structure, it is a position which does not interfere with a burner, Comprising: By arrange | positioning the radiator extended in an up-down direction so as to oppose the side surface of an inner cover, the heat input with respect to the inner cover part in a position without a burner The heat input to the inner cover can be performed efficiently and uniformly.

The first invention preferably further comprises the following configuration.
(1) The radiator includes a vent hole penetrating in a vertical direction.
(2) The burner is controlled to be in a state of forming a flame or in a state of not forming a flame by ON / OFF control.
(3) In the configuration (2), the burner is controlled so as not to form a flame when the atmospheric gas temperature in the lower part of the inner cover is equal to or higher than a predetermined temperature.
Furthermore, the time during which the burner does not form a flame is set to a certain time.

  According to the configuration (1), since the radiator includes the vent hole penetrating in the vertical direction, the radiator can be effectively heated by the combustion gas passing through the vent hole.

  According to the configuration (2), the burner is ON / OFF controlled, and when the burner is ON, the radiator is heated by the combustion gas. When the burner is OFF, the inner cover is generated by the radiant heat from the radiator heated when the burner is ON. By heating the inside, the thermal efficiency (fuel consumption) can be improved.

  According to the configuration (3), the burner is controlled so as not to form a flame when the temperature at a predetermined position in the inner cover is equal to or higher than the predetermined temperature, and the time during which the burner does not form a flame is a fixed time. Therefore, ON / OFF control of the burner is facilitated, and temperature fluctuation can be reduced.

The second invention of the present application has an inner cover and an outer cover,
Remodeling of a bell-type annealing furnace that forms a flame in the space between the inner cover and the outer cover by a burner provided at the lower part of the outer cover, and anneals the treatment material disposed in the inner cover. A method,
In the space between the inner cover and the outer cover, a radiator extending in the vertical direction is disposed so as to face the side surface of the inner cover at a position that does not interfere with the burner.

  According to the said structure, it is a position which does not interfere with a burner, Comprising: By arrange | positioning the radiator extended in an up-down direction so as to oppose the side surface of an inner cover, the heat input with respect to the inner cover part in a position without a burner Can be modified to a bell-type annealing furnace capable of efficiently and uniformly performing heat input to the inner cover.

  In short, according to the present invention, there is provided a bell-type annealing furnace capable of increasing heat input to the inner cover portion at a position away from the burner and efficiently and uniformly performing heat input to the inner cover. be able to.

It is the schematic of the bell-type annealing furnace which concerns on embodiment of this invention. It is the schematic of a spacer. It is a conceptual diagram of a bell type annealing furnace showing an example of arrangement of radiators 11. It is the schematic of the radiator 11 part. It is a schematic top view of a coil material part. 1 is a schematic perspective view of a radiator 12. It is the schematic which shows the opposing state of a coil member and an inner cover.

  FIG. 1 is a schematic view of a bell-type annealing furnace 10 according to an embodiment of the present invention. As shown in FIG. 1, the bell-type annealing furnace 10 includes a hearth 1, an inner cover 2, an outer cover 3, a burner 4 provided at a lower portion of the outer cover 3, and an upper wall of the outer cover 3. And an exhaust port 5 provided.

  Examples of the treatment material for the bell-type annealing furnace 10 include a coil material 6 obtained by winding a metal strip (steel strip) that is thinly elongated in the process of manufacturing a steel plate into a donut shape. Usually, the coil material 6 is stacked in the vertical direction on the mounting plate 19 positioned at the upper part of the hearth 1 in the inner cover 2 via the spacer 7 shown in FIG. The spacer 7 connects the disk-shaped upper plate 71, the disk-shaped lower plate 72, the upper plate 71 and the lower plate 72, and a plurality of spacers 7 are arranged in the circumferential direction of the upper plate 71 and the lower plate 72. And a connecting member 73, which has a donut shape as a whole, and is configured to allow the atmospheric gas in the inner cover 2 to flow in the radial direction of the coil material 6. The bell-shaped inner cover 2 is disposed so as to cover the coil material 6, and the bell-shaped outer cover 3 is disposed so as to cover the inner cover 2.

  The burners 4 are provided as a pair at symmetrical positions on the lower side surface of the outer cover 3. The burner 4 forms a flame in the space 81 between the inner cover 2 and the outer cover 3, and heats the gas in the space 81 and the inner cover 2 in the vicinity of the burner 4. The burner 4 is controlled so as to form a flame or not to form a flame by ON / OFF control. The gas in the space 81 heated by the burner 4 is discharged from the exhaust port 5 while transferring heat to the inner cover 2 and the outer cover 3.

  A circulation fan 9 is provided at the lower part in the inner cover 2, and the circulation fan 9 circulates the atmospheric gas in the inner cover 2. The circulation fan 9 is connected to a motor 91 provided below the hearth 1 and is rotated by the rotation of the motor 91. The atmospheric gas in the inner cover 2 moves from the lower side to the upper side in the space 82 between the inner cover 2 and the outer side surface 6b of the coil material 6, and from the upper side in the space 83 formed by the inner side surface 6a of the coil material 6. By moving downward, the inner cover 2 is circulated.

  In the vicinity of the circulation fan 9 in the inner cover 2, a temperature sensor 92 for detecting the gas temperature of the portion is provided. Further, the inner cover 2 is movable upward with respect to the hearth 1 for loading and unloading the coil material 6.

  In the space 81, a radiator 11 extending in the vertical direction is disposed so as not to interfere with the burner 4 and to face the side surface of the inner cover 2. The radiator 11 is provided as a pair above the burner 4 so as to correspond to the burner 4. Radiator 11 is made of silicon carbide (silicon carbide) or refractory bricks, and has a surface emissivity of 0.9 or more. The inner cover 2 and the outer cover 3 are made of carbon steel, and the surface emissivity is about 0.7 to 0.8. The radiator 11 has a heat capacity greater than or equal to a predetermined value.

  FIG. 3 is a conceptual diagram of the bell-type annealing furnace 10 showing an arrangement example of the radiator 11. As shown in FIGS. 3A and 3B, the radiator 11 has a cylindrical shape or a prismatic shape, and has a ventilation hole 11a penetrating the center of the radiator 11 in the vertical direction. I have. FIG. 4 is a schematic view of the radiator 11 portion. 4A and 4B are schematic side views, and FIG. 4C is a schematic top view. As shown in FIG. 4, the number of ventilation holes 11 a may be one, and the air holes 11 a may be suspended by being suspended by a suspension device 31 having a recess so as to hold the radiator 11. Further, as shown in FIG. 3, the air holes 11 may be formed in a honeycomb shape and provided with a large number of holes. Further, as shown in FIGS. 3A and 3B, a plurality of radiators 11 may be provided, and as shown in FIG. , Having a predetermined circumferential distance, and having a predetermined interval, may be provided over the entire circumference.

  The radiator 11 is suspended from the upper wall of the outer cover 3 by a suspension device 31. The outer cover 3 is movable upward with respect to the hearth 1 for loading and unloading the coil material 6. When the outer cover 3 moves upward, a predetermined gap D <b> 1 is provided between the radiator 11 and the inner cover 2 so that the radiator 11 suspended from the outer cover 3 does not interfere with the inner cover 2. Is provided. A predetermined gap D <b> 2 is also provided between the radiator 11 and the outer cover 3. The vertical position of the radiator 11 in the space 81 can be changed by the suspension device 31 of the radiator 11.

  Within the inner cover 2 and in a space 83 formed by the inner side surface 6 a of the coil material 6, a radiator 12 extending in the vertical direction is disposed so as to face the inner side surface 6 a of the coil material 6. The radiator 12 is placed on the placement plate 19. Radiator 12 is made of silicon carbide (silicon carbide) or refractory bricks, and has a surface emissivity of 0.9 or more. The radiator 12 has a predetermined heat capacity.

  FIG. 5 is a schematic top view of the coil material 6 portion, and FIG. 6 is a schematic perspective view of the radiator 12. As shown in FIGS. 5 and 6, the radiator 12 is configured by arranging a plurality of cylindrical members 121 (three in this embodiment). The cylindrical member 121 is made of a radiation material as described above, and has a vent hole 121a extending in the vertical direction. The plurality of cylindrical members 121 are accommodated in the steel bucket 13. The bucket 13 includes a bottom plate 131 and a ring-shaped support 132 that is attached to the bottom plate 131 and supports the bottom portion of each cylindrical member 121. Further, the bucket 13 has a plurality of bands 133 in the vertical direction so as to hold the cylindrical member 121 together. And the hook 134 for suspending the bucket 13 with a crane is provided in the uppermost band 133a so that the bucket 13 which accommodated the cylindrical member 121 can be arrange | positioned and taken out.

  As shown in FIG. 1, the upper end portion of the radiator 12 is located between the first coil material 61 located at the top and the second coil material 62 located second from the top. More specifically, the upper end portion of the radiator 12 coincides with the upper end portion of the second coil material 62. For this reason, the radiator 12 is positioned below the lower end portion of the spacer 7 provided between the first coil material 61 and the second coil material 62.

  The bell-type annealing furnace 10 processes the coil material 6 as follows.

  The coil material 6 to be processed in the bell-type annealing furnace 10 is stacked on the mounting plate 19 via the spacer 7 in the vertical direction.

  The radiator 12 suspended by the crane is lowered in the space 83 formed by the inner side surface 6 a of the coil material 6 and is disposed on the placement plate 19. The upper end portion of the radiator 12 is made to coincide with the upper end portion of the second coil material 62.

  The inner cover 2 is lowered and placed on the hearth 1 so as to cover the coil material 6.

  The outer cover 3 is lowered and placed on the hearth 1 so as to cover the inner cover 2. A radiator 11 is suspended from the upper wall of the outer cover 3, and when the outer cover 3 is placed on the hearth 1, the radiator 11 has a space 81 between the inner cover 2 and the outer cover 3. In FIG. 2, the burner 4 is disposed so as to face the side surface of the inner cover 2 above the burner 4 so as not to interfere with the burner 4 provided at the lower portion of the outer cover 3.

  When all the devices are arranged, the burner 4 is turned on and a flame is formed in the space 81 by the burner 4.

  The flame of the burner 4 heats the gas near the burner 4 in the space 81 and the inner cover 2 near the burner 4. The heated gas moves upward in the space 81, heats the inner cover 2 and the outer cover 3, and passes through the periphery of the radiator 11 and the vent hole 11 a disposed in the space 81 to radiate. The body 11 is heated. The radiator 11 heated by the gas in the space 81 heats the inner cover 2 and the outer cover 3 by radiation. The gas that has moved to the upper part of the space 81 is dissipated to the outside from the exhaust port 5 provided in the upper wall of the outer cover 3.

  The heat applied to the inner cover 2 is transmitted to the atmospheric gas in the inner cover 2 and the coil material 6. The atmospheric gas in the inner cover 2 moves from the lower side to the upper side in the space 82 between the inner cover 2 and the outer side surface 6b of the coil material 6, and from the upper side in the space 83 formed by the inner side surface 6a of the coil material 6. By moving downward, the radiator 12 is circulated in the inner cover 2 and heated in the space 83 formed by the coil material 6 and the inner surface 6a of the coil material 6. The radiator 12 heated by the gas in the inner cover 2 heats the inner surface 6a of the coil material 6 by radiation.

  The burner 4 is ON / OFF control in which ON control for forming a flame and OFF control for not forming a flame are alternately performed. The burner 4 has an atmospheric gas temperature in the inner cover 2, specifically, an atmospheric gas temperature detected by the temperature sensor 92 when the atmospheric gas temperature in the vicinity of the circulation fan 9 in the inner cover 2 exceeds a predetermined temperature. When the temperature is equal to or higher than the predetermined temperature, the control is changed from the ON control for forming a flame to the OFF control for not forming a flame. The time until the burner 4 is changed from the OFF control to the ON control, that is, the OFF control continuation time of the burner 4 is set to be constant.

  While the burner 4 is OFF controlled, the inner cover 2 is heated by the radiant heat of the radiator 11 heated while the burner 4 is ON controlled. Moreover, the coil material 6 below the second coil material 62 is heated by the radiant heat of the radiator 12 heated while the burner 4 is ON-controlled.

  While the burner 4 is OFF controlled, the inner cover 2 is heated by the radiator 11 as described above, but the gas temperatures of the radiator 11, the outer cover 3, and the space 81 are lowered. When the OFF control duration time of the burner 4 elapses, the burner 4 becomes ON control, and the gas of the radiator 11, the outer cover 3, and the space 81 whose temperature has been lowered is heated by the flame of the burner 4.

  When the processing of the coil material 6 is completed, the burner 4 is turned off so that no flame is formed in the space 8.

  Thereafter, the outer cover 3 is raised. When the outer cover 3 is raised, the radiator 11 suspended from the upper wall of the outer cover 3 is also raised.

  Next, the inner cover 2 is raised. Thereafter, the radiator 12 located in the space formed by the inner surface 6a of the coil material 6 is lifted by a crane. Then, the coil members 6 stacked in the vertical direction are taken out in order from the top.

  According to the bell-shaped annealing furnace 10 having the above-described configuration, the following effects can be exhibited.

(1) By disposing the radiator 11 that extends in the vertical direction so as to face the side surface of the inner cover 2 at a position that does not interfere with the burner 4, The amount of heat input can be increased and heat input to the inner cover 2 can be performed efficiently and uniformly.

(2) Since the radiator 11 includes the vent hole 11a penetrating in the vertical direction, the radiator 11 can be effectively heated by the combustion gas passing through the vent hole 11a.

(3) Since the predetermined gap D1 is provided between the radiator 11 and the inner cover 2, the outer cover 3 is moved when the coil material 6 is loaded, taken out, or the vertical position of the radiator 11 is changed. In some cases, interference between the radiator 11 and the inner cover 2 can be prevented.

(4) Since the predetermined gap D <b> 2 is provided between the radiator 11 and the outer cover 3, interference between the radiator 11 and the outer cover 3 is prevented when the vertical position of the radiator 11 is changed. be able to.

(5) The burner 4 is ON / OFF controlled. When the burner 4 is ON, the radiant is heated by the combustion gas. When the burner 4 is OFF, the inside of the inner cover 2 is heated by the radiant heat from the radiant 11 heated when the burner 4 is ON. By doing so, thermal efficiency (fuel consumption) can be improved.

(6) The burner 4 is controlled so as not to form a flame when the temperature in the vicinity of the circulation fan 9 in the inner cover 2 exceeds a predetermined temperature, and the time during which the burner 4 does not form a flame is a fixed time. Is set. If the setting is such that the burner is reburned when the temperature falls below the predetermined temperature as in the prior art, depending on the set predetermined temperature, the burner will frequently repeat ignition and extinguishing, and the amount of temperature fluctuation increases, It is possible that the temperature is not stable. However, by setting the burner as described above, ON / OFF control of the burner is facilitated, and temperature fluctuations can be reduced.

(7) With respect to the existing bell-type annealing furnace, there is no burner 4 by disposing the radiator 11 extending vertically so as not to interfere with the burner 4 and to face the side surface of the inner cover 2. The amount of heat input to the inner cover 2 at the position can be increased, and the bell-type annealing furnace 10 can be modified to efficiently and uniformly input heat to the inner cover 2.

(8) By using silicon carbide or refractory bricks as the radiator 11, a radiator with high emissivity can be obtained.

(9) Since the radiator 11 has a heat capacity higher than a predetermined value, the inner cover 2 is sufficiently heated by the radiant heat of the radiator 11 heated during the ON control of the burner 4 even when the burner 4 is OFF controlled. Compared with the case where the radiator 11 is not provided, it is possible to suppress a decrease in the furnace temperature during the OFF control of the burner 4. As a result, the OFF control duration time of the burner 4 can be lengthened, the exhaust gas loss of the burner 4 can be reduced, and the thermal efficiency of the bell-type annealing furnace 10 can be improved.

(10) By arranging the radiator 12 so as to oppose the inner surface 6a of the coil material 6, it is possible to transfer radiant heat from the radiator 12 to the inner surface 6a of the coil material 6, and to make the coil material 6 more uniform. Can be annealed. Moreover, the temperature increase rate of the coil material 6 can be increased by increasing the heat input from the inner side surface 6 a of the coil material 6.

(11) Since the radiation rate of the radiator 12 is higher than the radiation rate of the inner cover 2, the radiation efficiency from the radiator 12 to the inner surface 6 a of the coil material 6 can be improved.

(12) By setting the position of the upper end portion of the radiator 12 between the first coil material 61 and the second coil material 62, the radiant heat from the radiator 12 is transmitted to the second coil material 62 and below. Become. FIG. 7 is a schematic diagram showing a facing state of the coil member 6 and the inner cover 2. As shown in FIG. 7A, when the radiator 12 is not disposed, the first coil material 61 positioned at the uppermost position has two surfaces, the upper surface and the side surface, facing the inner cover 2. On the other hand, the second coil material 62 and the lower coil material positioned below it has only one side surface facing the inner cover 2 (indicated by the arrow in FIG. 7A). There is a difference in the amount of radiant heat from the inner cover 2 between the material 61 and the second coil material 62 or lower positioned below the material 61. On the other hand, when the radiator 12 is arranged, the radiant heat from the radiator 12 is transmitted to the second coil material 62 or less, so that the second coil material 62 or less is also shown in FIG. Since there are two surfaces that receive radiant heat, the coil material 6 can be annealed more uniformly.

(13) From the above (12), the upper end of the radiator 12 may be positioned below the first coil material 61, but preferably the upper end of the radiator 12 is the upper end of the second coil material 62. The radiator 12 is prevented from being positioned above the second coil material 62 by matching with the portion, and the radiator 12 inhibits the flow of the atmospheric gas that passes horizontally above the second coil material 62. It is preferable to prevent. Here, the temperature of the first coil material 61 and the second coil material 62 that are located away from the burner 4 among the coil materials stacked in multiple stages is lowered, so the first coil material 61 and the second coil material. By passing the atmosphere gas between the first coil member 61 and the second coil member 62, the temperature of the first coil member 61 and the second coil member 62 can be raised, and the temperature distribution of the entire coil member 6 can be made more uniform.

(14) Since the radiator 12 is constituted by the cylindrical member 121 having the vent hole 121a penetrating in the vertical direction, the ambient gas passes through the vent hole 121a, so that the radiator 12 is heated by the atmosphere gas. Can be promoted. And since the flow of the atmospheric gas in the radiator 12 is accelerated | stimulated because the radiator 12 is comprised by the some cylindrical member 121, the heating of the radiator 12 by atmospheric gas can further be accelerated | stimulated.

(15) Transmitting radiant heat from the radiator 12 to the inner surface 6a of the coil material 6 by arranging the radiator 12 so as to face the inner surface 6a of the coil material 6 with respect to the existing bell-type annealing furnace. The coil material 6 can be modified to a bell-type annealing furnace 10 that can anneal the coil material 6 more uniformly.

(16) By using silicon carbide or refractory bricks as the radiator 12, a radiator having a high emissivity can be obtained.

(17) Since the radiator 12 has a heat capacity higher than a predetermined value, the coil material 6 is sufficiently heated by the radiant heat of the radiator 12 heated during the ON control of the burner 4 even when the burner 4 is OFF controlled. As compared with the case where the radiator 12 is not provided, it is possible to suppress a decrease in the furnace temperature during the OFF control of the burner 4. As a result, the OFF control duration time of the burner 4 can be lengthened, the exhaust gas loss of the burner 4 can be reduced, and the thermal efficiency of the bell-type annealing furnace 10 can be improved.

  In the said embodiment, although the radiator 12 is comprised with the some cylindrical member 121, you may be comprised with one cylindrical member. By configuring the radiator 12 with one cylindrical member, it is not necessary to hold a plurality of cylindrical members with a bucket, and the radiator 12 can be easily handled.

  In the above embodiment, the radiator 12 is placed on the placement plate 19, but may be suspended from the upper wall of the inner cover 2.

  In the above embodiment, the coil material 6 is configured to be stacked in three stages. However, the number of coil material stacking stages is not limited to three, and may be two or four or more.

  In the said embodiment, although the radiator 11 is comprised by the member which has one column shape or prismatic shape, you may be comprised by the some cylindrical member or prismatic member. Since the radiator 11 is composed of a plurality of cylindrical members or prismatic members, the flow of the combustion gas in the radiator 11 is promoted, so that the heating of the radiator 11 by the combustion gas can be further promoted.

  In the above embodiment, the radiator 11 is suspended from the upper wall of the outer cover 3, but is held on the side wall of the outer cover 3 or the side wall of the inner cover 2 so as to be disposed in the space 81. Also good.

  In the above embodiment, the radiator 11 is provided as a pair above the burner 4 corresponding to the burner 4, but does not correspond to the burner 4, and a plurality of radiators 11 are provided at predetermined intervals in the circumferential direction of the inner cover 2. It may be provided, and may be provided so as to cover the entire upper periphery of the side surface of the inner cover 2.

  In the above embodiment, the temperature in the inner cover 2 controlled so that the burner 4 does not form a flame is measured in the vicinity of the circulation fan 9, but the measurement location is not in the vicinity of the circulation fan 9. It can also be other representative locations. However, in the vicinity of the circulation fan 9, the atmospheric gas in the inner cover 2 is agitated by the circulation fan 9, and the temperature is likely to be constant.

  Various modifications and changes may be made to the above embodiments without departing from the spirit and scope of the invention as set forth in the claims.

  In the present invention, it is possible to provide a bell-type annealing furnace that increases the amount of heat input to the inner cover portion at a position away from the burner and can efficiently and uniformly perform heat input to the inner cover. The above utility value is great.

1 hearth 2 inner cover 3 outer cover 4 burner 5 exhaust port 6 coil material 61 first coil material 62 second coil material 7 spacer 71 upper plate 72 lower plate 73 connecting member 81 space (between inner cover and outer cover) 82 space (between the inner cover and the outer surface of the coil material) 83 space (formed by the inner surface of the coil material)
DESCRIPTION OF SYMBOLS 9 Circulation fan 91 Motor 92 Temperature sensor 10 Bell type annealing furnace 11 Radiator 11a Vent 12 Radiant 121 Cylindrical member 121a Vent 13 Bucket 131 Bottom plate 132 Support 133 Band 134 Hook 31 Suspension device

FIG. 3 is a conceptual diagram of the bell-type annealing furnace 10 showing an arrangement example of the radiator 11. As shown in FIGS. 3A and 3B, the radiator 11 has a cylindrical shape or a prismatic shape, and has a ventilation hole 11a penetrating the center of the radiator 11 in the vertical direction. I have. FIG. 4 is a schematic view of the radiator 11 portion. 4A and 4B are schematic side views, and FIG. 4C is a schematic top view. As shown in FIG. 4, the number of ventilation holes 11 a may be one, and the air holes 11 a may be suspended by being suspended by a suspension device 31 having a recess so as to hold the radiator 11. Further, as shown in FIG. 3, the air holes 11a may have a honeycomb shape and may be provided with a large number of holes. Further, as shown in FIGS. 3A and 3B, a plurality of radiators 11 may be provided, and as shown in FIG. , Having a predetermined circumferential distance, and having a predetermined interval, may be provided over the entire circumference.

Claims (5)

Having an inner cover and an outer cover,
A bell-type annealing furnace that forms a flame in a space between the inner cover and the outer cover by a burner provided at a lower portion of the outer cover, and anneals a treatment material disposed in the inner cover. And
In the space between the inner cover and the outer cover, a radiator extending in the vertical direction is disposed so as not to interfere with the burner and to face the side surface of the inner cover. , Bell-type annealing furnace.   The bell-type annealing furnace according to claim 1, wherein the radiator includes a vent hole penetrating in a vertical direction.   The bell-type annealing furnace according to claim 1 or 2, wherein the burner is controlled to be in a state of forming a flame or in a state of not forming a flame by ON / OFF control. The burner is adapted to be controlled so as not to form a flame when the atmospheric gas temperature in the lower part of the inner cover is equal to or higher than a predetermined temperature.
Furthermore, the time when the said burner does not form a flame is set to the fixed time, The bell-type annealing furnace of Claim 3. Having an inner cover and an outer cover,
Remodeling of a bell-type annealing furnace that forms a flame in the space between the inner cover and the outer cover by a burner provided at the lower part of the outer cover, and anneals the treatment material disposed in the inner cover. A method,
In the space between the inner cover and the outer cover, a bell extending in a vertical direction is arranged so as to face the side surface of the inner cover at a position that does not interfere with the burner. Remodeling method of mold annealing furnace.

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