Firing furnace

Abstract

To suppress adhesion of a volatile substance(s) generated from an object to be treated to a door of a firing furnace.SOLUTION: A firing furnace 1 comprises: a furnace body 10 having a tunnel-shaped firing space; and a bottom plate 20 provided at the firing space 10a so as to cover a bottom wall of the furnace body. The furnace body 10 comprises: a carry-in port 11 where an object to be treated is carried in; a carry-out port 12 where the object to be treated is carried out; and a heating chamber 70 for heat-treating the object to be treated. The carry-in port 11 is provided with a first shutter 41a. The carry-out port 12 is provided with a second shutter 41b. The bottom wall 10b of the furnace body 10 includes an air intake port 50 at at least one end part of an end part 11a on the side of the carry-in port 11 and an end part 12b on the side of the carry-out port 12, and a flow passage from the air intake port 50 to the end part of the bottom plate 20 is provided at a space with the bottom face 20b of the bottom plate 20.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present disclosure relates to a kiln. [Background technology]

[0002] Japanese Patent Application Laid-Open Publication No. 2023-148905 discloses a tunnel-shaped muffle furnace that isolates a transport space through which materials to be processed are transported. Because this muffle furnace is a pusher furnace, the materials to be processed are pushed forward. The muffle furnace has an inlet section, a transport section, a transport pusher, and an outlet pusher. The transport pusher pushes the materials to be processed in the transport section of the muffle furnace forward. The outlet pusher pushes the materials to be processed in the transport section of the muffle furnace toward the outlet section. A muffle furnace typically has an air supply device connected to the bottom or side of the muffle for introducing atmospheric gas.

[0003] Japanese Patent Laid-Open Publication No. 10-267544 discloses a continuous heat treatment furnace equipped with a gas supply means. The gas supply means comprises a first gas supply means that supplies gas along the surface of the ceiling or sidewall of the muffle, and a second gas supply means that supplies gas toward the workpiece to be heat treated at a slower speed than the first gas supply means. In this continuous heat treatment furnace, gas is supplied to the ceiling and sidewall at a high speed, preventing volatile substances generated from the workpiece from adhering to the ceiling and sidewall of the furnace body.

[0004] Japanese Patent Application Laid-Open Publication No. 2011-64423 discloses a heat treatment device having a first zone (preparatory zone) and a second zone (heat treatment zone) inside the furnace body. In the preparatory zone, a gas suction port, a cooler that cools the reaction gas generated from the workpiece to below the dew point temperature, and a drainage mechanism that discharges the liquefied evaporated gas are located below the transport path. The preparatory zone is a section through which the workpiece passes immediately after passing through the inlet of the heat treatment device. In this heat treatment device, the reaction gas is attracted below the transport path, preventing condensation of the evaporated gas above the workpiece and dripping onto the workpiece. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2023-148905 [Patent Document 2] Japanese Patent Application Publication No. 10-267544 [Patent Document 3] Japanese Patent Application Laid-Open No. 2011-64423 Summary of the Invention [Problem to be solved by the invention]

[0006] When the material is heated to a high temperature, its components vaporize or sublimate, resulting in reaction gases that remain in the muffle. Some of the reaction gases (e.g., binders, tar, etc.) generated from the material, as well as molten or semi-molten fly ash particles, tend to solidify in areas where the temperature is likely to drop, such as near the entrance and exit of the kiln. If the solidified material adheres to the door of the kiln, it may impair its opening and closing function.

[0007] The present disclosure has been made in consideration of these points, and its purpose is to reduce adhesion of components derived from the workpiece contained in the reaction gas to the entrance / exit door of the firing furnace and its surrounding area.

[0008] One aspect of the firing furnace disclosed herein has a furnace body including a heating chamber having a tunnel-shaped firing space for heat-treating a workpiece, an inlet provided on a first side of the heating chamber, and an outlet provided on a second side of the heating chamber. The bottom wall of the furnace body is provided with a bottom plate that covers the bottom wall. The inlet of the furnace body has a first shutter. The outlet has a second shutter. The bottom wall of the furnace body has an air inlet at at least one end of the inlet side and the outlet side, and a flow path from the air inlet to the end of the bottom plate is provided in the gap between the bottom surface of the bottom plate and the bottom wall of the furnace body.

[0009] In this firing furnace, a gas fluidized layer is formed on the surface of the opening and closing mechanism. Therefore, the gas fluidized layer formed on the surface of the opening and closing mechanism can prevent the reaction gas from approaching the opening and closing mechanism. This effect can reduce adhesion of components derived from the workpiece contained in the reaction gas to the opening and closing mechanism. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic plan view of a firing furnace 1. As shown in FIG. [Figure 2] FIG. 2 is a vertical cross-sectional side view of the heating chamber 70. As shown in FIG. [Figure 3] FIG. 3 is a vertical cross-sectional side view of the loading chamber 80. As shown in FIG. [Figure 4] FIG. 4 is a schematic diagram of the bottom surface 20b of the bottom plate 20 as viewed from below. [Figure 5] FIG. 5 is a diagram showing a schematic view of the flow of the ambient gas when the first shutter 41a is closed. [Figure 6] FIG. 6 is a vertical cross-sectional side view of the first replacement chamber 60a. DETAILED DESCRIPTION OF THE INVENTION

[0011] <Terminology> One embodiment of the present disclosure will be described in detail below with reference to the drawings. In the following drawings, components and parts that perform the same function are denoted by the same reference numerals. Furthermore, the dimensional relationships (length, width, thickness, etc.) in each drawing do not reflect the actual dimensional relationships. The directions of up, down, left, right, front, and rear are represented by arrows U, D, L, R, F, and Rr, respectively, in the drawings. Here, the directions of up, down, left, right, front, and rear are defined merely for the convenience of explanation and do not limit the present invention unless otherwise specified.

[0012] FIG. 1 is a schematic plan view of the firing furnace 1. FIG. 2 is a longitudinal side view of the heating chamber 70. FIG. 1 shows a schematic plan view seen from above with the interior of the furnace body 10 exposed, so as to show the general configuration of the firing furnace 1 of one embodiment disclosed herein. FIG. 2 shows a schematic cross-sectional view (see FIG. 1) of the heating chamber 70 taken along the II-II line along the conveying direction Y, so as to show the conveying state of the workpiece A within the heating chamber 70. In FIGS. 1 and 2, hatching other than that of the sealing member is omitted as appropriate. In addition, in FIG. 1, a portion of the bottom plate 20 is transparent so that the air inlets 50a, 50b, 50c, and 50d can be seen.

[0013] <Firing furnace 1> The firing furnace 1 continuously heats the workpieces (hereinafter also referred to as workpieces A) placed in a heating container B while transporting them along a transport direction. In this embodiment, the firing furnace 1 has a furnace body 10, a pusher 30, and a replacement chamber 60. The workpieces A are transported by being pushed sequentially by the pusher 30 on a bottom plate 20. The firing furnace 1 can be a pusher furnace.

[0014] <Processing object A> The workpiece A is a material to be treated in the firing furnace 1. The workpiece A may be, for example, a nitride ceramic powder, which is a heat dissipation material, a powder used as a positive or negative electrode material for a secondary battery, or a paste to be applied to a glass substrate such as a touch panel. Examples of nitride ceramic powder include silicon nitride, boron nitride, and aluminum nitride. Examples of powders used as positive electrode materials for secondary batteries include nickel composite metal oxides, lithium composite metal oxides, oxide-based solid electrolytes, and sulfide-based solid electrolytes. Examples of powders used as negative electrode materials for secondary batteries include carbon-based powders and silicon-based powders. Examples of pastes include those obtained by dissolving metals such as silver and copper, polyurethane resins, polyimide resins, or binder resins in any organic solvent. However, the workpiece A is not limited to these.

[0015] In this embodiment, the workpiece A is transported through the firing furnace 1 while being housed in a heating container B. The heating container B is made of, for example, a material with excellent heat resistance. The material and shape of the heating container B can be selected appropriately depending on the heating temperature, the type of workpiece, etc. The material of the heating container B is, for example, carbon or ceramic. In this embodiment, the shape of the heating container B is approximately rectangular with a flat bottom and side walls. The heating container B is also called a "sheath." A lid B1 may be attached to the heating container B. The heating container B may also be transported while placed on a base plate B2. The lid B1 and the base plate B2 may be made of the same material as the heating container B.

[0016] <Furnace body 10> 1, the furnace body 10 has a heating chamber 70, an inlet 11, and an outlet 12. The heating chamber 70 has a tunnel-shaped firing space 10a for heat-treating the workpiece A.

[0017] In this embodiment, as shown in Figures 1 and 2, the furnace body 10 has a bottom wall 10d, a pair of side walls 10c1 and 10c2, and an upper wall 10b facing the bottom wall 10d, which surround the heating chamber 70. The bottom wall 10d, the pair of side walls 10c1 and 10c2, and the upper wall 10b are each made of a thermal insulating material. In the embodiment shown in Figure 1, the heating chamber 70 has a linear, tunnel-shaped firing space.

[0018] <Heating chamber 70> The heating chamber 70 is a path for heat-treating the workpiece A while transporting it along the transport direction Y. The heating chamber 70 is formed in a straight tunnel (or cylindrical) shape so as to surround the baking space 10a in which the workpiece A is baked. The baking space 10a has an inlet on a first side of the heating chamber 70 and an outlet on a second side opposite the first side. The material of the heating chamber 70 is not particularly limited. The heating chamber 70 can be made of metal, ceramic, or carbon. As will be described later, the furnace body 10 is provided with an air inlet 50 for supplying atmospheric gas into the furnace body 10.

[0019] A heater (not shown) is disposed in the heating chamber 70. The heater (not shown) is a device for heat-treating the workpiece A. The type, material, shape, etc. of the heater are not particularly limited. The type of heater can be appropriately selected depending on the heating conditions, such as the target heating temperature and heating atmosphere. The heater for heating the workpiece A may be provided in the heating chamber 70. Examples of the heater include far-infrared, electric, and hot air heating types. The heater may be made of, for example, ceramic, carbon, or metal. The heater may be cylindrical or may be a plate-shaped panel heater. A temperature sensor may be installed in the heating chamber 70. In this case, the temperature conditions can be adjusted based on the temperature detected by the temperature sensor.

[0020] In this embodiment, the heating chamber 70 is configured by a metal muffle. The atmosphere inside the heating chamber 70 can be maintained by the muffle. The muffle is a tunnel-shaped member interposed between the workpiece A and the heater. The workpiece A is indirectly heated via the muffle. The heating chamber 70 (here, the muffle) is surrounded by an outer wall (not shown) via a heater (not shown) and a heat insulating material (not shown).

[0021] <Exhaust port 55> In this embodiment, as shown in Fig. 2, the furnace body 10 is provided with an exhaust port 55 that connects to the heating chamber 70. The exhaust port 55 is a hole for exhausting gas (reaction gas generated from the workpiece A) inside the furnace body 10. The exhaust port 55 is connected to an exhaust pipe 56. The exhaust pipe 56 is connected to an exhaust device (not shown) such as an exhaust pump outside the furnace body 10. When the exhaust pump starts suction, the gas inside the furnace body 10 is sucked through the exhaust port 55.

[0022] The shape, arrangement, and number of the exhaust ports 55 are not particularly limited. In this embodiment, as shown in FIG. 2, multiple exhaust ports 55 are provided in the upper wall 10b of the heating chamber 70. The reactive gas generated by heating the workpiece A is typically lighter than the atmospheric gas and tends to flow upward. Therefore, by providing the exhaust ports 55 in the upper wall 10b, the reactive gas can be efficiently exhausted. The exhaust ports 55 are also provided in the center of the firing space 10a of the furnace body 10. This allows the reactive gas in the furnace body 10 to be exhausted in a balanced manner. The reactive gas is discharged to the outside of the furnace body 10 through the exhaust ports 55. This prevents deterioration of the furnace body 10. The reactive gas in the furnace body 10 can also be appropriately collected. The exhaust ports 55 may be connected to the side walls 10c1 and 10c2 of the furnace body 10.

[0023] <Inlet 11, Outlet 12> The inlet 11 is an entrance to the baking space 10a. The outlet 12 is an exit from the baking space 10a. In this embodiment, the inlet 11 is provided on a first side of the heating chamber 70. The outlet 12 is provided on a second side of the heating chamber 70.

[0024] In this embodiment, the furnace body 10 is provided with a carry-in chamber 80 on a first side of the heating chamber 70 so as to be connected to the heating chamber 70 and to be perpendicular thereto. A carry-in entrance 11 is provided at one end of the carry-in chamber 80. Furthermore, a carry-out chamber 90 is provided on a second side of the heating chamber 70 so as to be connected to the heating chamber 70 and to be perpendicular thereto. A carry-out exit 12 is provided at one end of the carry-out chamber 90.

[0025] 1, front and rear are defined along the conveying direction Y of the heating chamber 70. That is, with respect to the furnace body 10, the upstream side is defined as the rear (Rr) and the downstream side is defined as the front (F) along the direction in which the workpiece A is conveyed. Also, left and right (L, R) are defined toward the front along the direction in which the workpiece A is conveyed. Furthermore, in the carry-in chamber 80, a carry-in direction X is set in the direction from the carry-in entrance 11 toward the heating chamber 70. Furthermore, in the carry-out chamber 90, a carry-in direction Y is set in the direction from the heating chamber 70 toward the carry-out exit 12.

[0026] <Bottom plate 20> The furnace body 10 is provided with a bottom plate 20 covering the bottom wall 10d of the furnace body 10. The bottom plate 20 is disposed on the bottom wall 10d (or floor) of the furnace body 10. The bottom plate 20 is a plate-shaped member having a predetermined thickness. The bottom plate 20 has an upper surface 20a and a bottom surface 20b opposite the upper surface 20a. The bottom plate 20 extends from the loading entrance 11 to the unloading exit 12 of the furnace body 10. The bottom plate 20 has an end 20c on the loading chamber 11 side of the furnace body 10 and an end 20d on the unloading chamber 12 side. The top surface 20a of the bottom plate 20 can support the workpiece A (or the heating vessel B or the base plate B2) from below. The bottom wall 20b of the bottom plate 20 abuts against the bottom wall 10d of the furnace body 10. The bottom plate 20 can regulate the flow path of the atmospheric gas by covering with its bottom surface 20b the air inlet 50 provided in the bottom wall 10d of the furnace body 10. In this embodiment, the bottom plate 20 is laid in a substantially C-shape along the carry-in chamber 80, the heating chamber 70, and the carry-out chamber 90, as shown in FIG. 1 . In this embodiment, a recess 21 and a guide portion 22 for guiding the workpiece A are provided on the upper surface of the bottom plate 20. The guide portion 22 guides the workpiece A by the bottom plate 20 when it is transported along the carry-in chamber 80, the heating chamber 70, and the carry-out chamber 90.

[0027] The material of the bottom plate 20 is not particularly limited. The material of the bottom plate 20 preferably has low thermal expansion. The material of the bottom plate 20 is preferably, for example, carbon or ceramic. The thickness of the bottom plate 20 is not particularly limited as long as it does not significantly impair the technology of the present disclosure. In this embodiment, a detachable carbon bottom plate 20 is provided on the bottom wall 10d of the furnace body 10.

[0028] <Pusher 30> The pusher 30 is a device that pushes the workpiece A a predetermined distance along the conveying direction at predetermined time intervals. As shown in FIG. 1 , the pusher 30a is provided on the rear (Rr) side of the heating chamber 70. The pusher 30b is provided on the left (L) side of the discharge port 90. Since the pushers 30a and 30b can have the same configuration, the pusher 30a will be described as an example. In this embodiment, the pusher 30a can push the workpiece A supplied from the loading chamber 80 into the heating chamber 70 in the conveying direction Y. The pusher 30a includes a pusher head 31, a pusher rod 32, a pusher seal 33, and an actuator 34. The pusher rod 32 is inserted into the firing space 10a from the outside of the furnace body 10 via the pusher seal 33. The pusher seal 33 supports the sliding of the pusher rod 32 while ensuring airtightness within the furnace body 10. The pusher head 31 is attached to the tip of a pusher rod 32 that extends into the transfer space 10a.

[0029] When the actuator 34 is operated, the pusher rod 32 of the pusher 30a moves forward, pushing the workpiece A in the heating chamber 70 in the forward direction F. After the pusher 30a pushes out the workpiece A, the pusher head 31 and the pusher rod 32 move backward to wait. This ensures space for new workpieces A to be supplied from the carry-in chamber 80 to the heating chamber 70. In this embodiment, a servo motor is used as the actuator 34. However, this is not a limitation, and the actuator 34 may also be a cylinder mechanism. Because the actuator 34 is provided outside the muffle 10, the pusher rod 32 can be moved with little effect from the temperature inside the furnace body 10.

[0030] <Replacement room 60> In the embodiment shown in FIG. 1, the firing furnace 1 is provided with replacement chambers 60a and 60b. The replacement chambers 60a and 60b are spaces that can separate the atmosphere inside the furnace body 10 from the outside. In this embodiment, the first replacement chamber 60a is provided adjacent to the loading opening 11 of the loading chamber 80. The second replacement chamber 60b is provided adjacent to the unloading opening 12 of the unloading opening 12. The replacement chambers 60a and 60b each have the function of adjusting the atmosphere inside the furnace body 10. In the first replacement chamber 60a, the workpiece A is loaded into the loading chamber 80 after the atmosphere is adjusted to be approximately the same as inside the furnace body 10. In the second replacement chamber 60b, when the workpiece A is loaded into the replacement chamber 60b from the unloading chamber 90, the atmosphere inside the furnace body 10 is replaced before the workpiece A is unloaded. Although not shown, a pusher for pushing the workpiece A toward the first replacement chamber 60a and the carry-in chamber 80 is provided on the first replacement chamber 60a side.

[0031] By this pusher, the workpiece A is transported from the carry-in chamber 80 along the transport direction X and carried into the heating chamber 70. Next, the workpiece A is pushed sequentially through the heating chamber 70 in the transport direction Y by the pusher 30a. As a result, the workpiece A is intermittently transported through the heating chamber 70 and heat-treated. Thereafter, the workpiece A is carried out from the heating chamber 70 along the carry-out direction Z to the carry-out chamber 90 by the pusher 30b, and then carried out to the second replacement chamber 60b.

[0032] <First shutter 41a, second shutter 41b> The furnace body 10 has an opening / closing structure for creating an airtight space inside the furnace body 10. The opening / closing structure can be composed of a shutter, a lid, or the like. In this embodiment, a first shutter 41a and a first opening / closing mechanism 46a that opens and closes the first shutter 41a are provided between the loading entrance 11 of the furnace body 10 and the first replacement chamber 60a. Furthermore, a second shutter 41b and a second opening / closing mechanism 46b that opens and closes the second shutter 41b are provided between the unloading exit 12 of the furnace body 10 and the second replacement chamber 60b. The first shutter 41a is a member that opens and closes the loading entrance 11 of the furnace body 10. The second shutter 41b is a member that opens and closes the unloading exit 12 of the furnace body 10.

[0033] Here, we will explain the first shutter 41a provided at the carry-in entrance 11. The second shutter 41b provided at the carry-out exit 12 is configured in the same manner as the first shutter 41a. Here, the explanation of the second shutter 41b will be omitted as appropriate.

[0034] FIG. 3 is a longitudinal side view of the loading chamber 80. FIG. 3 schematically illustrates the configuration of the first shutter 41a. In this embodiment, the first shutter 41a is a substantially rectangular plate-like member of a predetermined size that closes the loading entrance 11. The first shutter 41a is made of a metal material. A seal 44 is provided on the surface of the first shutter 41a facing the loading entrance 11. In this embodiment, the seal 44 is composed of a rectangular frame 44a that abuts on the edge of the loading entrance 11 and an O-ring 44b attached to the frame 44a. On the other hand, a rectangular receiving opening 45 that abuts on the rectangular frame 44a is provided on the edge of the loading entrance 11. The rectangular receiving opening 45 is provided on the edge of the loading entrance 11. A refrigerant flow path 45a through which a refrigerant passes is formed so as to face the portion where the O-ring 44b abuts. By supplying a refrigerant to the refrigerant flow path 45a, the temperature of the portion where the O-ring 44b abuts is maintained low. This prevents the O-ring 44b from deteriorating.

[0035] The first opening / closing mechanism 46a, which opens and closes the first shutter 41a, is configured as a mechanism for pressing the first shutter 41a against the carry-in entrance 11. In this embodiment, the first opening / closing mechanism 46a is configured as a four-bar link 46a1, a stopper 46a2, and an actuator 46a3. The four-bar link 46a1 is provided at each end of the first shutter 41a. Joints for the four-bar link 46a1 are provided at the upper and lower ends of both ends of the first shutter 41a, and the first shutter 41a includes a link 41a1 facing the first shutter 41a and links 41a2 and 41a3 that form a parallelogram via the joint. The stopper 46a2 restricts the descent of the lower end of the first shutter 41a. The actuator 46a3 is a lifting device that raises and lowers the link 41a1 facing the first shutter 41a. The actuator 46a3 is configured as, for example, a cylinder mechanism.

[0036] In the embodiment shown in FIG. 3, when link 41a1 of four-bar link 46a1 is lowered by actuator 46a3, stopper 46a2 restricts the lower end of first shutter 41a from moving downward, and first shutter 41a is pushed toward rectangular receptacle 45 provided on the edge of inlet 11. Then, rectangular frame 44a of first shutter 41a is pressed against rectangular receptacle 45, which activates O-ring 44b and hermetically closes inlet 11. When inlet 11 is opened, link 41a1 of four-bar link 46a1 is pulled up by actuator 46a3, and the mechanism of four-bar link 46a1 moves first shutter 41a away from inlet 11. In this embodiment, actuator 46a3 is configured to further raise first shutter 41a to a position where it does not interfere with the movement of workpiece A relative to inlet 11. By raising the first shutter 41a to a position where it does not hinder the movement of the workpiece A relative to the carry-in port 11, the workpiece A can be moved from the first replacement chamber 60a to the carry-in port 11.

[0037] By closing the first shutter 41a and the second shutter 41b, the interior of the furnace body 10 can be sealed and the atmosphere can be maintained. Furthermore, by opening the first shutter 41a at the inlet 11, the workpiece A can be supplied into the furnace body 10. Furthermore, by opening the second shutter 41b at the outlet 12, the workpiece A can be discharged from the furnace body 10. In this embodiment, as shown in FIG. 1, the inlet 11 of the furnace body 10 is provided with the first shutter 41a. Furthermore, the outlet 12 of the furnace body 10 is provided with the second shutter 41b. By having the shutters 41a and 41b, the furnace body 10 can separate the atmosphere inside and outside the furnace body 10.

[0038] The firing furnace 1 is a device for heat-treating the workpiece A at a high temperature. The workpiece A is typically treated while controlling the atmosphere inside the furnace body 10. For this reason, an opening and closing structure is provided at the entrance and exit of the furnace body 10 to separate the atmosphere inside and outside the furnace body. High-temperature heating causes components in the workpiece A (e.g., binder, tar, etc.) to vaporize or sublimate and remain inside the furnace body 10 as reactive gas. The temperature tends to drop near the entrance and exit of the furnace body 10. The reactive gas remaining inside the furnace body 10 tends to cool and solidify near the inlet 11 and outlet 12 of the furnace body 10. In particular, if the reactive gas adheres to and sticks to the sealing portions of the first shutter 41a and the second shutter 41b provided at the inlet 11 and outlet 12 of the furnace body 10, the first shutter 41a and the second shutter 41b may not close properly, resulting in gas leakage. In the firing furnace 1 disclosed herein, the arrangement of the air inlet 50 and the configuration of the bottom plate 20 are devised as a measure to prevent such gas leakage.

[0039] <Air supply port 50> The air inlet 50 is a hole for supplying atmospheric gas (e.g., nitrogen, argon, etc.) into the furnace body 10. The air inlet 50 is provided on at least one of the end 11a on the inlet 11 side and the end 12a on the outlet 12 side of the bottom wall 10d of the furnace body 10. The air inlet 50 may be provided on both the end 11a on the inlet 11 side and the end 12a on the outlet 12 side. Alternatively, multiple air inlets 50 may be provided on the bottom wall 10d of the furnace body 10. In this embodiment, as shown in FIG. 1, two air inlets 50a, 50b are provided on the bottom wall 10d of the loading chamber 80. The air inlets 50a, 50b are provided at positions slightly away from the end 11a of the loading chamber 11. Two air inlets 50c, 50d are also provided on the bottom wall 10d of the unloading chamber 90. The air supply ports 50a and 50b are provided at a position slightly away from the end 12a of the discharge port 12.

[0040] The air inlet 50 is connected to an air inlet pipe 51. The air inlet pipe 51 is connected to a gas supply device (not shown) outside the furnace body 10. The air inlet pipe 51 is an atmospheric gas flow path connecting the gas supply device (not shown) to the air inlet 50. The gas supply device is an atmospheric gas supply source that supplies atmospheric gas from the outside of the furnace body 10 to the inside. The air inlet 50, the air inlet pipe 51, and the gas supply device also form a gas supply mechanism. The gas supply mechanism may be equipped with a heat-resistant filter. The filter can further purify the atmospheric gas supplied into the furnace body 10.

[0041] The temperature and flow rate of the supplied atmospheric gas can be adjusted, for example, by a gas supply device. The temperature of the atmospheric gas is not particularly limited as long as it does not significantly impair the effects of the technology of the present disclosure. The temperature of the atmospheric gas is typically preferably equal to or higher than the freezing point of the volatilized components derived from the workpiece. The upper limit of the atmospheric gas temperature is preferably 100°C or higher, more preferably 150°C or higher, and even more preferably 200°C or higher, from the viewpoint of suppressing solidification of the vaporized workpiece. Furthermore, the upper limit of the atmospheric gas temperature is preferably 300°C or lower, more preferably 250°C or lower, and even more preferably 230°C or lower, from the viewpoint of preventing deterioration of the sealing material and maintaining hermeticity. The flow rate of the atmospheric gas is not particularly limited as long as it does not significantly impair the effects of the technology of the present disclosure. The flow rate of the atmospheric gas is, for example, 0.3 m / s or lower. This creates a positive pressure inside the furnace body 10, reducing the inflow of outside air into the furnace body 10 when the shutters 41a and 41b are opened.

[0042] In this embodiment, a flow path 23 extending from the air inlet 50 to the ends 20c and 20d of the bottom plate 20 is provided in the gap between the bottom surface 20d of the bottom plate 20 and the bottom wall 10d of the furnace body 10. The gap between the bottom surface 20b of the bottom plate 20 and the bottom wall 10d of the furnace body 10 forms a flow path space P, which serves as the flow path 23 for the atmospheric gas. By forming the flow path space P in the gap between the bottom surface 20b of the bottom plate 20 and the bottom wall 10d of the furnace body 10, the atmospheric gas can be injected approximately vertically toward the lower end of the opening / closing mechanism 40 of the furnace body 10. The configuration of the end 20c of the bottom plate 20 on the loading chamber 11 side of the furnace body 10 will be described below as an example. Note that the end 20d on the unloading port 12 side of the furnace body 10 can be configured in a similar manner, and therefore will not be described here.

[0043] FIG. 4 is a schematic diagram of the bottom surface 20b of the bottom plate 20 as viewed from below. In this embodiment, a recess 23a is provided in the bottom surface 20b of the bottom plate 20 as a flow path 23 extending from the air inlet 50 to the end 20c of the bottom plate 20. As shown in FIGS. 1 and 2, the flow path 23 extends from a position on the bottom surface 20b of the bottom plate 20 opposite the air inlets 50a and 50b toward the end 20c of the bottom plate 20. By providing the flow path 23 in the bottom plate 20, a flow path space P is formed in the gap between the flow path 23 and the bottom wall 10d of the furnace body 10. The flow path space P allows the atmospheric gas supplied from the air inlets 50a and 50b to be ejected toward the first shutter 41a of the furnace body 10. The atmospheric gas supplied from the air inlet 50 passes through the flow path space P and is ejected from the end 20c of the bottom plate 20 toward the lower end of the heat insulating plate 42 of the first shutter 41a. The atmospheric gas injected into the lower end of the insulating plate 42 runs up from the lower end of the insulating plate 42 along the surface to the upper end. The injected atmospheric gas then diffuses toward the center of the firing space 10a of the furnace body 10. The flow path 23 may be provided in the bottom wall 10d of the furnace body 10.

[0044] The bottom plate 20 can have a function of restricting the transport of the workpiece A (or heating container B or base plate B2). For example, the workpiece A (or heating container B or base plate B2) can be placed on the upper surface 20a of the bottom plate 20 with almost no gaps. In this state, when the foremost workpiece A (or heating container B or base plate B2) is pushed by the pusher 30, the workpiece A (or heating container B or base plate B2) on the bottom plate 20 is pushed one by one and transported. In this embodiment, the heating container B is placed on the base plate B2 placed on the bottom plate 20. The base plate B2 is transported on the bottom plate 20 by being positioned by the recess 21 and the guide portion 22 formed on the upper surface of the bottom plate 20. As shown in FIG. 2, the heating container B is placed on the bottom plate 20 with almost no gaps. In this state, when the heating container B located at the rearmost Rr side in the conveying direction Y is pushed one by one by the pusher 30, the heating containers B on the bottom plate 20 are pushed and conveyed sequentially. By repeating this loading process, the heating containers B can be conveyed sequentially along the bottom plate 20. As described above, since the heating containers B in the furnace body 10 are conveyed sequentially, the loading and unloading of the heating containers B are performed at the same time. Therefore, the first shutter 41a and the second shutter 41b open and close at the same time.

[0045] As described above, the firing furnace disclosed herein includes a furnace body 10 and a bottom plate 20. The furnace body 10 has a first shutter 41a at the inlet 11 provided on the first side of the heating chamber 70. A second shutter 41b is provided at the outlet 12 provided on the second side of the heating chamber 70. An air inlet 50 is provided in the bottom wall 10d of the end portions 11a, 12a of the furnace body 10 on the inlet 11 and / or outlet 12 side. The air inlet 50 is covered by the bottom plate 20. A flow path 23 is provided in the gap between the bottom surface 20d of the bottom plate 20 and the furnace body 10, extending from the air inlet 50 to the end portions 20c, 20d of the bottom plate 20.

[0046] 5 is a diagram schematically illustrating the flow of the atmospheric gas when the first shutter 41a on the side of the carry-in entrance 11 is closed. Arrows in FIG. 5 (for example, arrow W) indicate the flow of the atmospheric gas ejected from the gap (here, flow path 23) between the bottom surface 20b of the bottom plate 20 and the bottom wall 10d of the furnace body 10.

[0047] In the firing furnace 1, as shown in FIG. 6, gas (typically, atmospheric gas) supplied from the gas inlet 50 is ejected between the bottom surface 20d of the bottom plate 20 and the furnace body 10. The ejected gas flows through the formed flow path space P toward the bottom of the shutter 41a. The ejected gas then collides with the lower part of the shutter 41a and flows upward along the shutter 41a. This forms a gas fluidized layer on the surface of the shutter 41a. A portion of the gas also flows upward along the shutter 41a and toward the inside of the furnace body 10. This forms a fluidized layer of the gas supplied from the gas inlet 50 near the shutter 41a, making it difficult for the gas inside the furnace to approach the vicinity of the shutter 41a. This prevents components derived from the workpiece contained in the gas reacted in the furnace from adhering to the shutter 41a (or the O-ring 44b). As a result, solidification of components derived from the object to be treated on the shutter 41a (or O-ring 44b) can be suppressed, which makes it easier to maintain the airtightness of the furnace body 10. It is also possible to reduce the number of maintenance operations required inside the furnace body 10. The shutter 41b can be configured in a similar manner, so a description thereof will be omitted.

[0048] <Loading Room 80> The furnace body 10 may be provided with a carry-in chamber 80. The carry-in chamber 80 is a path for supplying the workpiece A to the heating chamber 70. The workpiece A is transported along the transport direction X (from R to L) and supplied to the heating chamber 70. The carry-in chamber 80 may be provided with a heater for preheating the workpiece A. In this embodiment, the carry-in chamber 80 is provided on the rear Rr side of the heating chamber 70. The carry-in chamber 80 is connected to the heating chamber 70 at a right angle. A pusher (not shown) is attached on an extension of the carry-in chamber 80.

[0049] <Export room 90> The furnace body 10 may be provided with a discharge chamber 90. The discharge chamber 90 is a path for discharging the workpiece A in the heating chamber 10 to the outside of the furnace body 10. The workpiece A is pushed by the pusher 30b along the conveying direction Z (from L to R) and discharged to the outside of the furnace body 10. The discharge chamber 90 may be provided with a heater for uniformly heating the workpiece A. In this embodiment, the discharge chamber 90 is provided on the front F side of the heating chamber 70. Furthermore, the discharge chamber 90 is connected to the heating chamber 70 at a right angle.

[0050] In this embodiment, the furnace body 10 has a loading chamber 80, a heating chamber 70, and an unloading chamber 90. The loading entrance 11 is provided in the loading entrance chamber 80. The unloading chamber 12 is provided in the unloading chamber 90. In the loading entrance chamber 80, pre-treatment and the like are performed for the workpiece A to be heated in the heating chamber 70. In the unloading chamber 90, heat dissipation and the like are performed for the workpiece A after it is heated in the heating chamber 70. Therefore, providing the loading entrance chamber 80 or the unloading chamber 90 in the furnace body 10 is preferable in terms of facilitating temperature adjustment during heat treatment and maintaining uniformity of the workpiece. In a firing furnace 1 having the loading entrance chamber 80 or the unloading chamber 90 as in this embodiment, the temperatures of the loading entrance chamber 80 and the unloading chamber 90 tend to be lower than those of the heating chamber 70. Therefore, the temperatures near the loading entrance 11 and the unloading chamber 12 are further reduced. Even in such a case, the atmospheric gas ejected from the gap (here, flow path 23) between the bottom wall 10d of the loading chamber 80 or the unloading chamber 90 and the bottom surface 20b of the bottom plate 20 can reduce the adhesion of components derived from the workpiece contained in the reaction gas to the shutters 41a, 41b.

[0051] The first replacement chamber 60a and the second replacement chamber 60b can have the same configuration, so the pusher 30a will be described as an example. FIG. 6 is a longitudinal side view of the first replacement chamber 60a. The first replacement chamber 60a is provided with a furnace body-side shutter 61 that separates the first replacement chamber 60a from the furnace body 10 and an external shutter 62 that separates the first replacement chamber 60a from the outside. The furnace body-side shutter 61 separates the first replacement chamber 60a from the inside of the furnace body 10. The external shutter 62 separates the first replacement chamber 60a from the outside of the calcination furnace 1. The first replacement chamber 60a may also include a guide unit 63 for transporting the workpiece A. In this embodiment, the furnace body-side shutter 61 is a plate-shaped insulating member. The furnace body-side shutter 61 is connected to the insulating plate 42 by a link arm 46. As a result, the furnace body side shutter 61 can be slid up and down together by the drive devices (not shown) of the opening and closing mechanisms 44a and 44b.

[0052] The first replacement chamber 60a is equipped with a mechanism for carrying the workpiece A into the calcination furnace 1. In this embodiment, first, the shutter 61 is opened with the shutter 62 closed. Next, the heating container B placed on the base plate B2 is introduced into the first replacement chamber 60a. Once the heating container B has been introduced into the first replacement chamber 60a, the external shutter 62 is closed. The atmosphere inside the first replacement chamber 60a is then adjusted. After the atmosphere inside the first replacement chamber 60a has been adjusted, the furnace body-side shutter 61 is opened. The carrying-in pusher 35 provided in the first replacement chamber 60a pushes out the heating container B, thereby carrying the heating container B into the calcination furnace 1. This separates the atmosphere inside and outside the calcination furnace 1, thereby suppressing the impact of outside air on the workpiece A inside the furnace body 10.

[0053] In the embodiment described above, the firing furnace 1 has the replacement chamber 60. Since the internal temperature of the replacement chamber 60 is lower than that of the furnace body 10, components contained in the reaction gas are likely to solidify. In this embodiment, when the shutters 41a and 41b are open, the ambient gas ejected from the flow path space P passes through the opening of the furnace body 10 and gradually rises into the replacement chamber 60. Therefore, a gas curtain (gas barrier) is formed separating the furnace body 10 and the replacement chamber 60. This makes it possible to reduce the amount of reaction gas flowing from the furnace body 10 into the replacement chamber 60. In the replacement chamber 60, the amount of components contained in the reaction gas that adhere to the interior of the replacement chamber 60 can be reduced.

[0054] Although the invention disclosed herein has been described in detail above, it should be understood that these are merely examples and should not be construed as limiting the scope of the invention as claimed. The scope is not limited to the present invention. Furthermore, the disclosure herein may be modified in various ways, and no particular problems may arise. Unless otherwise specified, each component or each process described herein may be omitted or omitted as appropriate. They can be combined as desired.

[0055] This specification includes the following items 1 to 5. The following items 1 to 5 are not limited to the above-described embodiment.

[0056] Item 1: A firing furnace comprising: a heating chamber having a tunnel-shaped firing space for heat-treating an object to be treated; a furnace body having an inlet provided on a first side of the heating chamber; and an outlet provided on a second side of the heating chamber; a bottom plate provided in the firing space so as to cover the bottom wall of the furnace body; a first shutter for opening and closing the inlet; and a second shutter for opening and closing the outlet, wherein the bottom wall of the furnace body has an air inlet at at least one end of the inlet side and the outlet side, and a flow path from the air inlet to the end of the bottom plate in the gap between the bottom surface of the bottom plate and the bottom wall of the furnace body.

[0057] Item 2: The firing furnace according to Item 1, wherein a sealing material is provided on the outer periphery of the first shutter and / or the second shutter.

[0058] Item 3: The firing furnace according to Item 1 or 2, further comprising a cooling mechanism for cooling the sealing material of the first shutter and / or the second shutter.

[0059] Item 4: The firing furnace according to any one of Items 1 to 3, wherein the inlet is provided with a first replacement chamber, and the outlet is provided with a second replacement chamber.

[0060] Item 5: The firing furnace according to any one of Items 1 to 4, wherein the flow path from the air inlet to the end of the bottom plate is a recess provided in the bottom surface of the bottom plate. [Explanation of symbols]

[0061] 1. Kiln 10 Furnace body 10a Firing space 10b Upper wall 10c1 side wall 10c2 side wall 10d bottom wall 11 Loading entrance 11a End 12 Exit 12a end 20 Bottom plate 20a top surface 20b Bottom 20c Inlet side end 20d Exit side end 21 Recess 22 Guide section 23 Flow path 23a Depression 30 Pusher 30a Pusher 30b Pusher 31 Pusher Head 32 Pusher Rod 33 Pusher seal 34 Actuator 41a First shutter 41b Second shutter 44 Seal part 44a Outer frame 44b O-ring 44a First opening / closing mechanism 44b 2nd opening / closing mechanism 45 Underbite 45a Refrigerant flow path 46a 1st opening / closing mechanism 46b 2nd opening / closing mechanism 46a1 Four-section link 46a2 stopper 46a3 actuator 50 Air supply port 50a Air supply port 50b Air supply port 50c air supply port 50d air supply port 51 Air supply pipe 55 exhaust port 56 Exhaust pipe 60 Replacement room 60a First Replacement Room 60b 2nd exchange room 61 Furnace body side shutter 62 External shutter 63 Guide section 70 Heating chamber 80 Loading Room 90 Unloading room A. Processing object B Heating container B1 Lid B2 base plate P Flow path space W Arrow X conveying direction Y conveying direction Z conveying direction

Claims

1. a heating chamber having a tunnel-shaped baking space for heat-treating the object to be treated; an entrance provided on a first side of the heating chamber; an outlet provided on a second side of the heating chamber; a furnace body comprising: a bottom plate provided in the firing space so as to cover the bottom wall of the furnace body; a first shutter that opens and closes the carry-in entrance; a second shutter that opens and closes the carry-out port; and the bottom wall of the furnace body has an air inlet at at least one end of the inlet side and the outlet side, a passage extending from the air inlet to an end of the bottom plate in a gap between the bottom surface of the bottom plate and the bottom wall of the furnace body;

2. The firing furnace according to claim 2 , wherein a sealing material is provided on an outer peripheral edge of the first shutter and / or the second shutter.

3. The firing furnace according to claim 3 , further comprising a cooling mechanism for cooling the sealing material of the first shutter and / or the second shutter.

4. The inlet is provided with a first replacement chamber, The firing furnace according to claim 1 , wherein the discharge port is provided with a second replacement chamber.

5. The firing furnace according to claim 1 , wherein the flow path from the air inlet to the end of the bottom plate is a recess provided in the bottom surface of the bottom plate.

Images