JP7167292B1 - Continuous heating furnace - Google Patents

Abstract

An object of the present invention is to improve maintainability of a continuous heating furnace. A continuous heating furnace (10) disclosed herein includes a tunnel-shaped furnace body (11) provided with an inlet (11a) and an outlet (11b); and a cylindrical muffle 30 that forms a transfer space 30a for transferring to. The muffle 30 has a bottom portion 31 , a ceiling portion 32 facing the bottom portion 31 , and a pair of side portions 33 connecting the bottom portion 31 and the ceiling portion 32 . At least one side surface portion 33 is configured to be detachable. The furnace body 11 has a pair of side walls 11s, and the side walls 11s corresponding to the removable side portions 33 are detachable. [Selection drawing] Fig. 2

Description

The present disclosure relates to continuous heating furnaces.

WO2013/065556 discloses a continuous method for producing boron nitride powder. A pusher type tunnel furnace is disclosed as a continuous reactor used in such a manufacturing method. A pusher type tunnel furnace is equipped with a graphite heater and a graphite muffle in the furnace. The pusher type tunnel furnace is constructed so that a nitrogen stream flows. It is said that contamination of the heater with volatile substances can be prevented by using such a pusher type tunnel furnace.

Japanese Patent Publication No. 2-31305 discloses a high-temperature continuous reactor in which reaction vessels charged with raw materials are continuously connected in a pusher-type tunnel furnace to form a muffle. A high temperature continuous reactor is provided with a reactant gas inlet and a gas outlet. The reaction vessel has openings only in the direction of movement. According to such a high-temperature continuous reactor, the reaction between the raw materials and the reaction gas in the reaction vessel proceeds reliably, and the reaction raw materials, by-products, and reaction products do not scatter from the reaction vessel. It is said that the damage of

WO2013/065556 JP-A-2-31305

By the way, a continuous heating furnace needs to be maintained regularly. For example, a reaction gas can be generated by heat-treating an object to be processed in a continuous heating furnace. The generated reaction gas adheres to the furnace body and heaters and the like provided in the furnace body, which may deteriorate the equipment. Therefore, it is necessary to clean the equipment in the furnace such as the muffle and the heater. The present inventor wishes to provide a continuous heating furnace structure that facilitates maintenance work.

The continuous heating furnace disclosed here forms a tunnel-shaped furnace body provided with an inlet and an outlet, and a transfer space provided inside the furnace body in which the object to be processed is transferred in the transfer direction. It has a tubular muffle. The muffle has a bottom portion, a ceiling portion facing the bottom portion, and a pair of side portions connecting the bottom portion and the ceiling portion. At least one side portion is configured to be detachable. The furnace body has a pair of side walls, and the side walls corresponding to the removable side portions are detachable.
A continuous heating furnace having such a configuration is easy to maintain.

The muffle may be configured such that both side portions are detachable.
The bottom portion may be supported from the lower portion of the furnace body, and the ceiling portion may be held from the upper portion of the furnace body.
An exhaust stack may be connected to the muffle.
The stack may be connected to the ceiling of the muffle.
The muffle may have a ventilation structure that communicates the space inside the furnace body with the transfer space.
The ventilation structure may be formed on at least one of the boundary between the bottom portion and the side portion and the boundary between the ceiling portion and the side portion.
The muffle may include a bottom portion, a ceiling portion, and a side portion, and may be composed of a plurality of units adjacent to each other in the transport direction. A ventilation structure may be formed between adjacent units.
The muffle may have a shield that shields the inflow of gas from the ventilation structure.

FIG. 1 is a side view schematically showing a continuous heating furnace 10. FIG. FIG. 2 is a sectional view taken along line II-II of FIG. FIG. 3 is a side view of the continuous heating furnace 10. FIG. FIG. 4 is a schematic diagram showing a connection structure between the bottom portion 31 and the ceiling portion 32 and the side portion 33. As shown in FIG. FIG. 5 is a schematic diagram showing the ventilation structure 34 formed between the units 30b. FIG. 6 is a schematic diagram of a muffle 30 according to another embodiment.

One typical embodiment of the present disclosure will be described in detail below with reference to the drawings. In the drawings below, members and portions having the same function are denoted by the same reference numerals. Also, the dimensional relationships (length, width, thickness, etc.) in each drawing do not reflect the actual dimensional relationships. Up, down, left, right, front, and rear directions are indicated by arrows U, D, L, R, F, and Rr, respectively. Here, the orientations of up, down, left, right, front, and rear are defined for convenience of explanation only, and do not limit the present invention unless otherwise specified. In this specification, the conveying direction of the object to be processed is set to be the same as the forward direction (direction F in the drawing).

<Continuous heating furnace 10>
The continuous heating furnace 10 is a so-called pusher type continuous heating furnace. Although not particularly limited, the pusher-type continuous heating furnace 10 includes, for example, nitride-based ceramic powders such as silicon nitride, boron nitride, and aluminum nitride, which are heat dissipating materials, and carbon-based and silicon-based materials, which are negative electrode materials for lithium ion batteries. It can be used for heat treatment of system powders and the like. These powders can be heat-treated and fired at a temperature of 1500° C. to 2800° C. under an inert atmosphere such as nitrogen or argon.

FIG. 1 is a side view schematically showing a continuous heating furnace 10. FIG. FIG. 2 is a sectional view taken along line II-II of FIG. FIG. 3 is a side view of the continuous heating furnace 10. FIG. FIG. 3 shows the interior of the furnace body 11 with the side wall 11s and the side wall 33 removed. The continuous heating furnace 10 is a heating furnace for continuously heating an object to be processed while conveying it in the conveying direction. In this embodiment, the object to be processed is conveyed through the continuous heating furnace 10 while being accommodated in the heating container A. As shown in FIG. The heating container A is made of, for example, a material with excellent heat resistance. The material of the heating container A can be appropriately selected according to the heating temperature, the type of the object to be treated, and the like. In this embodiment, a heating container A made of carbon is used.

As shown in FIG. 2, the continuous heating furnace 10 includes a furnace body 11 and a muffle 30. As shown in FIG. The continuous heating furnace 10 further includes a conveying path 20 and heaters 15 . The object to be processed is transported along the transport path 20 in the furnace body 11 inside the continuous heating furnace 10 . The object to be processed is indirectly heated by the heater 15 via the muffle 30 .

<Furnace 11>
The furnace body 11 surrounds a furnace space 10a in which a heater 15 and a muffle 30 for heat-treating an object to be processed are provided. The furnace body 11 surrounds a muffle 30 in which a linear transfer space 30a is formed. The furnace body 11 is formed in a tunnel shape. The furnace body 11 is provided with a carry-in port 11a and a carry-out port 11b (see FIG. 1).

The furnace body 11 is composed of a heat insulating material 12 and an outer wall 13 . The heat insulating material 12 surrounds the entire circumference of the muffle 30 in the conveying direction. The heat insulating material 12 is surrounded by an outer wall 13 on the outside. The thickness of the heat insulating material 12 is set to a required thickness that sufficiently insulates the heat inside the furnace body 11 . As the heat insulating material 12, for example, ceramic fiber boards molded into a predetermined shape stacked in the thickness direction, or carbon fiber laminated layers can be used. In this embodiment, a heat insulating material made of carbon fiber is used as the heat insulating material 12 . The outer wall 13 is made of a metallic material having excellent rigidity and heat resistance. For example, stainless steel or the like can be used for the outer wall 13 .

As shown in FIG. 1, the inlet 11a is formed at one end of the furnace body 11. As shown in FIG. A carry-out port 11 b is formed at the other end of the furnace body 11 . An object to be processed is carried in from the carry-in port 11a, heat-treated in the continuous heating furnace 10, and carried out from the carry-out port 11b.

A carry-in line 42 is connected to the carry-in port 11a, through which an object to be processed before heat treatment is carried. The carry-in line 42 is provided with a carry-in rail (not shown). The height of the carry-in rail is set so as to be the same height as the transport path 20 (see FIG. 2). A base plate 46 is placed on the carry-in rail, and the heating container A containing the object to be processed is placed on the base plate 46 . The carry-in port 11a is configured to be openable and closable by an opening/closing mechanism (not shown). Although not particularly limited, the opening/closing mechanism may be a lid, a shutter, or the like. The opening/closing mechanism may be provided with a sealing member for keeping the inside of the furnace body 11 airtight when the inlet 11a and the outlet 11b are closed. Further, the opening/closing mechanism may be provided with a sealing member that closes an opening of a cylindrical muffle 30 (see FIG. 2), which will be described later, when the inlet 11a and the outlet 11b are closed.

By opening the carry-in port 11a and pushing the base plate 46 against the pusher 42a, the object to be processed stored in the heating vessel A is carried into the continuous heating furnace 10 through the carry-in port 11a. Inside the continuous heating furnace 10 , the bed plate 46 is arranged on the transport path 20 . When the base plate 46 is carried in, the carry-in port 11a is closed.

After a certain period of time has elapsed, the next base plate 46 on which the heating container A is placed is conveyed from the carry-in line 42 . The base plate 46 is pushed by the pusher 42a and hits the rearmost base plate 46 (the closest base plate 46 from the carry-in port 11a) in the continuous heating furnace 10. As shown in FIG. The bed plate 46 is pushed forward in the carrying direction by the length of the bed plate 46 by being pushed from the upstream side in the carrying direction by the bed plate 46 to be carried in next. In this manner, the base plates 46 are sequentially carried in from the carry-in line 42 and the last base plate 46 is pushed forward, thereby intermittently conveying the plurality of base plates 46 within the continuous heating furnace 10 .

A carry-out line 44 is connected to the carry-out port 11b for carrying out the heat-treated object. The carry-out line 44 is provided with a carry-out rail (not shown). The height of the carry-out rail is set so as to be the same height as the transport path 20 in the same manner as the carry-in rail. The base plate 46 conveyed through the continuous heating furnace 10 is carried out to the carry-out line 44 from the carry-out port 11b. The carry-out port 11b is configured to be openable and closable by an opening/closing mechanism (not shown). The carry-out port 11b is opened when the base plate 46 is carried out. After the base plate 46 has been unloaded, the unloading port 11b is closed. As described above, since the base plate 46 in the continuous heating furnace 10 is pushed and conveyed sequentially, the loading and unloading of the base plate 46 are performed at the same timing. Therefore, opening and closing of the carry-in port 11a and the carry-out port 11b are performed at the same timing. In addition, the continuous heating furnace 10 is not limited to the form in which the opening-and-closing mechanism was provided in the carrying-in port 11a and the carrying-out port 11b which were mentioned above. The continuous heating furnace 10 may be, for example, a so-called atmospheric furnace in which the inlet 11a and the outlet 11b are open without opening/closing mechanisms.

Loading and unloading of the base plate 46 can be performed at predetermined constant time intervals. By performing loading and unloading of the base plate 46 at regular intervals, it is possible to make the time for heat treatment of the workpiece in the continuous heating furnace 10 constant regardless of the timing of loading and unloading. The interval between loading and unloading of the base plate 46 is appropriately set according to the processing conditions of the object to be processed. The bed plate 46 is conveyed on the conveying path 20 inside the furnace body 11 . Also, the loading and unloading of the base plate 46 may be performed continuously at a predetermined speed. For example, the base plate 46 may be conveyed on the conveying path 20 by being pushed by the pusher 42a at a predetermined speed.

<Conveyance path 20>
The transport path 20 extends linearly from the carry-in port 11a toward the carry-out port 11b. As shown in FIG. 2, the objects to be processed are placed on a base plate 46 while being accommodated in a plurality of heating containers A and conveyed on the conveying path 20 . The transport path 20 is inserted through a transport space 30a formed inside a muffle 30, which will be described later. In this embodiment, the transport path 20 is arranged on the inner bottom surface of the muffle 30 . The transport path 20 is a prismatic rail. A base plate 46 is placed on the upper portion of the transport path 20 . The surface of the base plate 46 that contacts the transport path 20 may be formed with a groove for positioning the position to be placed on the transport path 20 . The transport path 20 can be made of, for example, metal, ceramic, or carbon materials. In this embodiment, the transport path 20 is made of carbon.

In addition, the structure of the conveyance path 20 is not limited to the form mentioned above. The transport path 20 may be supported from the outside of the muffle 30 so as to be spaced from the bottom surface of the muffle 30 by a predetermined distance without being arranged on the muffle 30 . For example, the transport path 20 may be supported by the furnace body 11 or the like on the upstream and downstream sides of the end of the muffle 30 in the transport direction, and may be inserted through the muffle 30 . Further, the conveying path 20 is not limited to being on rails, and may have rollers on the surface that contacts the base plate 46, for example. The transport path 20 may be fixed to the muffle 30 or may be detachably arranged. The object to be processed is continuously heated while being conveyed on the conveying path 20 .

<Heater 15>
The heater 15 heats the object through the muffle 30 . A heater 15 is provided between the furnace body 11 and the muffle 30 . Although the shape and material of the heater 15 are not particularly limited, a cylindrical carbon heater is used as the heater 15 in this embodiment. Although the arrangement of the heaters 15 is not particularly limited, the heaters 15 are arranged above and below the muffle 30 at predetermined intervals along the transport direction. The heater 15 is supported by columns 15 a attached to the upper and lower surfaces of the outer wall 13 of the furnace body 11 . The pillars 15a may be provided with electrodes that apply current to the heater 15 . In this embodiment, the muffle 30 is wider in the width direction than in the height direction. In such a case, the heaters 15 are preferably provided above and below the furnace body 11 so as to sandwich the muffle 30 from the viewpoint of heat uniformity.

By the way, from the viewpoint of heat uniformity, it is preferable that the length of the heater 15 is at least equal to or greater than the width of the muffle 30 . In this embodiment, two heaters 15 are connected by a joint 15b. Therefore, even when the furnace body 11 and the muffle 30 are enlarged to heat-treat a large amount of objects to be treated, the objects to be treated are easily heated uniformly.

<Muffle 30>
The muffle 30 is provided inside the furnace body 11 . The muffle 30 forms therein a transfer space 30a in which the object to be processed is transferred in the transfer direction. The muffle 30 has a cylindrical shape and is open at both ends in the transport direction. An object to be processed is carried in and out through the opening. The muffle 30 is provided from the vicinity of the carry-in port 11a to the vicinity of the carry-out port 11b. The muffle 30 is arranged with a required space between it and the furnace body 11 . The muffle 30 has a bottom portion 31 , a ceiling portion 32 and side portions 33 . The muffle 30 includes a bottom portion 31, a ceiling portion 32, and a side portion 33, and is composed of a plurality of units 30b adjacent to each other in the transport direction. The unit 30b of the muffle 30 is composed of one bottom surface portion 31, one ceiling portion 32, and one side surface portion 33 on each side in the width direction. The muffle 30 has a square tubular shape with a rectangular cross section perpendicular to the transport direction. It should be noted that the shape of the muffle 30 is not limited to a rectangular tubular shape. For example, the muffle 30 may be provided with a curved portion having an arc-shaped cross section perpendicular to the conveying direction. As the muffle 30, one made of metal, ceramic, or carbon can be used. In this embodiment, muffle 30 is made of carbon.

The muffle 30 forms the transfer space 30a inside, as described above. From the viewpoint of heat-treating as many objects to be processed as possible, the transfer space 30a is set to have such a size that the heating containers A stacked in a plurality of stages can be arranged in a plurality of rows and transferred. In the embodiment shown in FIG. 2, the transfer space 30a is set to have such a size that the heating containers A stacked in three stages can be arranged in four rows and transferred. The width of the transfer space 30 a is set by the dimensions of the bottom portion 31 , the ceiling portion 32 and the side portions 33 of the muffle 30 . Here, the muffle 30 is configured to be wider in the width direction than in the height direction.

The bottom portion 31 is supported from the lower portion of the furnace body 11 by supports 31a. The struts 31a are attached to the bottom surface of the outer wall 13 and extend from below through the heat insulating material 12 below. The bottom surface portion 31 may be fixed to the support 31a, or may be arranged so as to be detachable from the support 31a. A groove for positioning the transport path 20 may be formed in the bottom surface portion 31 .

The ceiling portion 32 faces the bottom portion 31 . The ceiling part 32 is held from above the furnace body 11 . In this embodiment, the ceiling portion 32 is held by a holding member 32a attached to the upper surface of the outer wall 13 of the furnace body 11. As shown in FIG. The holding member 32a has an upper end attached to the upper surface of the outer wall 13, and a lower end expanding in diameter like a flange. The ceiling portion 32 is formed with an insertion hole through which the holding member 32a is inserted. The holding member 32a is inserted through the insertion hole, and the ceiling portion 32 is supported by the flange-like portion of the holding member 32a from the inner surface. The flange-like portion of the holding member 32a is set to have dimensions sufficiently larger than the insertion hole so that the ceiling portion 32 can be supported. The ceiling part 32 can be lifted upward by being suspended by a holding member 32a having a holding structure provided inside.

The side portion 33 connects the bottom portion 31 and the ceiling portion 32 . A pair of side portions 33 are provided on both sides in the width direction. The side part 33 is attached to the bottom part 31 supported from the lower part of the furnace body 11 and the ceiling part 32 supported from the upper part of the furnace body 11 . At least one side portion 33 of the pair of side portions 33 is detachable. In this embodiment, the muffle 30 is configured such that the side portions 33 on both sides are detachable. Note that the side portions 33 between the units 30b adjacent in the transport direction are not fixed. Therefore, the side surface portion 33 is configured to be individually attachable and detachable for each unit 30b.

FIG. 4 is a schematic diagram showing a connection structure between the bottom portion 31 and the ceiling portion 32 and the side portion 33. As shown in FIG. Although the connection structure of the side surface portion 33 is not particularly limited, in this embodiment, as shown in FIG. ing. A lower end of the side surface portion 33 is provided with a convex portion 33c1 corresponding to the concave portion 31c of the bottom surface portion 31 . A concave portion 32 c is provided at the end of the inner surface of the ceiling portion 32 . A convex portion 33 c 2 corresponding to the concave portion 32 c of the ceiling portion 32 is provided at the upper end of the side portion 33 . The projections 33c1 and 33c2 are set to have smaller dimensions than the recesses 31c and 32c, respectively. The concave portions 31c and 32c may be formed as grooves continuous in the transport direction, or may be intermittently formed holes. The attachment and detachment of the side surface portion 33 may be performed, for example, in a state in which the ceiling portion 32 is lifted slightly to widen the space between the ceiling portion 32 and the bottom surface portion 31 . Note that illustration of these connection structures is omitted in FIG.

By the way, as shown in FIG. 2, the above-described furnace body 11 has a pair of side walls 11s. The furnace body 11 is configured such that side walls 11s corresponding to the removable side portions 33 are detachable. In this embodiment, the furnace body 11 has a plurality of detachable side walls 11s along the transport direction (see FIG. 1).

The furnace body 11 is formed with openings 11o on both side surfaces perpendicular to the conveying direction. The opening 11 o is formed at a position facing the detachable side portion 33 . The opening 11o is composed of an opening formed in the heat insulating material 12 and an opening formed in the outer wall 13 at a position corresponding to the opening. The opening of the outer wall 13 is one size larger than the opening of the heat insulating material 12 .

11 s of side walls block|close the opening 11o formed in the furnace body 11 side surface. 11 s of side walls are provided with 13 s of cover plates one size larger than the opening of the outer wall 13, and the heat insulation part 12s attached inside 13 s of cover plates. The heat insulating portion 12 s is a portion that is fitted into the opening of the heat insulating material 12 . The lid plate 13 s has a portion that is fitted into the opening of the outer wall 13 and a portion that abuts against the periphery of the opening on the outer surface of the outer wall 13 . The heat insulating part 12 s can be made of the same material as the heat insulating material 12 . The lid plate 13 s can be made of the same material as the outer wall 13 . A surface of the cover plate 13s that contacts the outer wall 13 is provided with a sealing member (not shown) for keeping the furnace space 10a airtight so as to surround the opening 11o. The side wall 11s is configured to be detachable from the furnace body 11 . In this embodiment, the sidewall 11s is attached by bolts 14 to the periphery of the opening 11o.

In the embodiment described above, the muffle 30 has a bottom portion 31 , a ceiling portion 32 and a pair of side portions 33 . At least one side portion 33 of the pair of side portions 33 is detachable. Furthermore, the furnace body 11 has a pair of side walls 11s, and the side walls 11s corresponding to the removable side portions 33 are detachable. Since the corresponding positions of the muffle 30 and the furnace body 11 are detachable in this manner, the furnace body 11 can be removed from the side surface during maintenance, and the muffle 30 and the side surface portion 33 can be removed in this state. . Therefore, maintenance of the inside can be performed by opening only the side surface of the muffle 30 without removing the entire muffle 30, and maintainability is excellent.

Moreover, in this embodiment, the plurality of side walls 11s are provided at positions corresponding to the plurality of units 30b. It is configured such that one side wall 11s can be opened for maintenance of one unit 30b. When the furnace length of the continuous heating furnace 10 is long, maintenance can be performed for each unit 30b by providing a plurality of positions at which the muffle 30 and the furnace body 11 can be attached and detached at positions corresponding to the units 30b. , and the maintainability of the continuous heating furnace 10 can be improved.

In the continuous heating furnace 10 described above, the muffle 30 is configured such that the side portions 33 on both sides are detachable. Correspondingly, detachable side walls 11s are provided on both sides of the furnace body 11 . This allows maintenance from both sides of the muffle 30 . By the way, from the viewpoint of improving productivity, it is preferable that the transfer space 30a is wide in order to increase the amount of heat-treated objects to be processed at one time. For example, a structure of the muffle 30 wide in the width direction of the furnace body 11 can be adopted. Even in such a case, maintenance can be further improved by opening both sides of the muffle 30 . Note that the muffle 30 is not limited to such a form, and the muffle 30 may be configured such that one of the pair of side portions 33 is detachable, and the corresponding side wall 11s is detachable.

In this embodiment, the bottom part 31 is supported from the lower part of the furnace body 11 and the ceiling part 32 is supported from the upper part of the furnace body 11 . This makes it easy to remove only the side portion 33 of the muffle 30 . Thereby, the inside of the muffle 30 can be maintained only by removing the side part 33. - 特許庁In addition, the muffle 30 does not require, for example, a structure for supporting the ceiling portion 32 from the bottom portion 31, so that the structure of the muffle 30 can be made simpler. As a result, maintainability in the muffle 30 can be further improved.

<Exhaust pipe 16>
As shown in FIG. 2, the exhaust stack 16 is connected to the muffle 30 . The exhaust tube 16 exhausts reaction gas and atmosphere gas that may be generated by heating the object to be processed. The exhaust stack 16 penetrates the furnace body 11 from the outside of the furnace body 11 and is connected to the muffle 30 . A hole 32b is formed in a portion of the muffle 30 to which the exhaust pipe 16 is connected. The exhaust stack 16 is connected to an exhaust pump (not shown) outside the furnace body 11 . When the exhaust pump starts suction, the pressure inside the muffle 30 becomes negative through the exhaust pipe 16 .
If the reaction gas generated by heating the object to be processed adheres to the equipment in the furnace body 11, the adhered portion may be corroded and deteriorated. Since the exhaust stack 16 is connected to the muffle 30, the reaction gas generated in the muffle 30 can be discharged outside the furnace body 11 without being discharged into the furnace space 10a outside the muffle 30. 11 can be suppressed from deteriorating.

In this embodiment, stack 16 is connected to ceiling 32 of muffle 30 . The reaction gas generated by heating the object to be processed is lighter than the atmospheric gas and can flow upward. Therefore, by connecting the exhaust pipe 16 to the ceiling portion 32, the reaction gas can be exhausted more efficiently. Further, the hole 32b is provided in the central portion of the ceiling portion 32 in the width direction. As a result, the reaction gas can be exhausted in a well-balanced manner in the width direction within the muffle 30 .

Note that the furnace body 11 may be connected to a feed cylinder (not shown) for introducing atmospheric gas into the furnace space 10a. An air supply device for introducing atmospheric gas such as nitrogen or argon is connected to the supply cylinder. The supply cylinder can be connected from the bottom surface of the outer wall 13, for example.

The muffle 30 has a ventilation structure 34 that communicates the space inside the furnace body 11 with the transfer space 30a. The ventilation structure 34 is a structure that allows gas to flow from the outside to the inside of the muffle 30 when the inside of the muffle 30 becomes negative pressure due to the exhaust pipe 16 . The ventilation structure 34 is not particularly limited as long as it is a structure that allows communication between the inside and the outside of the muffle 30 .

In this embodiment, as shown in FIG. 4, a ventilation structure 34 is formed at the boundary between the bottom portion 31 and the side portion 33 and the boundary between the ceiling portion 32 and the side portion 33 . The ventilation structure 34 may be, for example, holes provided in the muffle 30 or gaps formed between parts of the muffle 30 . In this embodiment, the convex portion 33c1 at the lower end of the side surface portion 33 is set to have a smaller dimension than the concave portion 31c of the bottom surface portion 31. As shown in FIG. The projection 33 c 2 at the upper end of the side surface 33 is set to have a size smaller than that of the recess 32 c of the ceiling 32 . Moreover, the side surface portion 33 is attached to the bottom surface portion 31 and the ceiling portion 32 without using an adhesive, a sealing member, or the like. For this reason, gaps are inevitably formed at these boundaries, and airtightness is low at the boundary portions. In other words, at the boundary between the face portion 31 and the side portion 33 and the boundary between the ceiling portion 32 and the side portion 33, a ventilation structure 34 with low airtightness is formed. Such ventilation structure 34 is preferably formed at least one of the boundary between the bottom portion 31 and the side portion 33 and the boundary between the ceiling portion 32 and the side portion 33 .

Furthermore, in this embodiment, a ventilation structure 34 is formed between adjacent units 30b. FIG. 5 is a schematic diagram showing the ventilation structure 34 formed between the units 30b. FIG. 5 schematically shows the ventilation structure 34 formed between the ceiling portion 32 of one unit 30b and the ceiling portion 32 of another unit 30b. The ventilation structure 34 between the units 30b is not particularly limited, but in this embodiment, as shown in FIG. ing. The step 32d is formed from one end of the ceiling portion 32 in the width direction (the direction perpendicular to the transport direction) toward the other end. In adjacent ceiling portions 32 , steps 32 d are provided on different surfaces so that the steps 32 d of the opposing ceiling portions 32 face each other to form a gap as the ventilation structure 34 . The adjacent ceiling portions 32 are provided so that the steps 32d overlap each other in plan view in the thickness direction of the ceiling portions 32 . Incidentally, the ventilation structure 34 may also be formed between the adjacent units 30b on the bottom surface portion 31 and the side surface portion 33 as well. The ventilation structure 34 may also be formed on the bottom portion 31 and the side portion 33 by a structure similar to the step 32d of the ceiling portion 32, for example.

In the embodiment described above, the muffle 30 includes the ventilation structure 34 that communicates the space inside the furnace body 11 and the transfer space 30a. When the exhaust pump to which the exhaust pipe 16 is connected is operated, the air is sucked from the exhaust pipe 16 and the inside of the muffle 30 becomes negative pressure. Then, atmospheric gas can flow into the muffle 30 from the furnace space 10 a through the ventilation structure 34 . By forming a gas flow from the outside to the inside of the muffle 30 in this manner, the reaction gas generated from the object to be processed is less likely to flow out of the muffle 30 . As a result, equipment in the furnace body 11 such as the heater 15 can be less likely to deteriorate.

In the embodiment described above, the ventilation structure 34 is formed at the boundary between the bottom portion 31 and the side portion 33 and the boundary between the ceiling portion 32 and the side portion 33 . The side portion 33 is configured to be detachable from the bottom portion 31 and the ceiling portion 32 . The muffle 30 having such a configuration has both a ventilation structure 34 that suppresses deterioration in the furnace body 11 and a connection structure that facilitates maintenance.

In the embodiment described above, the muffle 30 includes a bottom portion 31, a ceiling portion 32, and a side portion 33, and is composed of a plurality of units 30b adjacent to each other in the transport direction. A ventilation structure 34 is formed between adjacent units 30b. With such a configuration, a gas flow can be formed from the outside to the inside of the muffle 30 also between the units 30b. In addition, since the gap is provided between the units 30b, the thermal expansion of the muffle 30 can be mitigated when the furnace space 10a is heated to a high temperature. Thereby, deformation of the muffle 30 can be suppressed.

In the above-described embodiment, the boundaries between the side surface portion 33, the bottom surface portion 31, and the ceiling portion 32 are provided with concave portions 31c and 32c and convex portions 33c1 and 33c2 corresponding to the concave portions 31c and 32c. Further, the ceiling portion 32 is provided with a step 32d, and the ceiling portions 32 adjacent to each other in the conveying direction are arranged such that the steps 32d overlap in plan view. These ventilation structures 34 form a curved gas flow path from the outside to the inside of the muffle 30 . Since the muffle 30 has a structure in which curved gas flow paths are formed, the momentum of the atmosphere gas flowing into the muffle 30 can be suppressed.

The configuration inside the continuous heating furnace 10 can be variously modified and changed. For example, the structure of the muffle 30 is not limited to the forms described above. FIG. 6 is a schematic diagram of a muffle 30 according to another embodiment. FIG. 6 shows the connection structure between the bottom portion 31 and the ceiling portion 32 and the side portion 33 . In the embodiment shown in FIG. 6, the side sections 33 are attached to the ceiling section 32 by bolts 35 . Mounting holes 35a to which bolts 35 are mounted are formed at the ends of the ceiling portion 32 in the width direction. A through hole 35 b through which the bolt 35 is inserted is formed in the upper portion of the side portion 33 . The side portion 33 is attached by bolts 35 in a state where the upper end is aligned with the ceiling portion 32 . The lower end of the side surface portion 33 is placed on the widthwise end portion of the bottom surface portion 31 . A ventilation structure 34 is formed between the ceiling portion 32 and the side portion 33 and between the side portion 33 and the bottom portion 31 .

In the embodiment shown in FIG. 6, the muffle 30 has a shielding portion 36 that shields the inflow of gas from the vent structure 34 . The shielding part 36 is provided inside the muffle 30 . The shielding portion 36 is a portion that protrudes from the inner surface of the muffle 30 . During the exhaust from the exhaust tube 16 (see FIG. 2), gas flows downward from above between the ceiling portion 32 and the side portion 33 . Between the side surface portion 33 and the bottom surface portion 31, gas flows from the outside toward the inside. In this embodiment, the gas flow path is formed linearly. The shielding part 36 is provided on an extension line of the ventilation structure 34 into which the gas flows. As a result, the momentum of the ambient gas flowing into the muffle 30 can be suppressed.

Although detailed descriptions have been given above with reference to specific embodiments, these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the embodiments described above. It is also possible to employ some of the techniques exemplified in the above embodiments.

10 Continuous heating furnace 10a Furnace space 11 Furnace body 11a Carry-in port 11b Carry-out port 11o Opening 11s Side wall 12 Heat insulating material 13 Outer wall 14 Bolt 15 Heater 16 Exhaust tube 20 Transfer path 30 Muffle 30a Transfer space 30b Unit 31 Bottom part 32 Ceiling part 33 Side part 34 Ventilation structure 35 Bolt 36 Shielding part 42 Carry-in line 44 Carry-out line 46 Base plate

Claims (10)

a tunnel-shaped furnace body provided with a carry-in port and a carry-out port;
A cylindrical muffle that is provided inside the furnace body and forms a transfer space in which the object to be processed is transferred in the transfer direction,
The muffle is
a bottom portion supported from the lower portion of the furnace body ;
a ceiling portion held from above the furnace body and facing the bottom portion;
Having a pair of side portions connecting the bottom portion and the ceiling portion,
At least one of the pair of side surface portions is configured to be detachable from the bottom surface portion and the ceiling portion,
A continuous heating furnace, wherein the furnace body has a pair of side walls, and the side walls corresponding to the detachable side walls are detachable independently of the side walls. 2. The continuous heating furnace according to claim 1, wherein said muffle is configured such that said side portions on both sides thereof are detachable. 3. The continuous heating furnace according to claim 1, wherein said muffle is connected to an exhaust pipe. 4. The continuous heating furnace according to claim 3 , wherein said exhaust stack is connected to said ceiling of said muffle. 5. The continuous heating furnace according to claim 3 , wherein said muffle has a ventilation structure that communicates a space inside said furnace body and outside said muffle with said transfer space inside said muffle. a tunnel-shaped furnace body provided with a carry-in port and a carry-out port;
A cylindrical muffle that is provided inside the furnace body and forms a transfer space in which the object to be processed is transferred in the transfer direction,
The muffle is
a bottom portion;
a ceiling portion facing the bottom portion;
Having a pair of side portions connecting the bottom portion and the ceiling portion,
At least one of the side portions is detachable,
The furnace body has a pair of side walls, and the side walls corresponding to the removable side parts are detachable,
An exhaust pipe is connected to the muffle,
The muffle has a ventilation structure that communicates a space inside the furnace body and outside the muffle with the transfer space inside the muffle,
Continuous heating furnace. 7. The ventilation structure according to claim 5 or 6 , wherein the ventilation structure is formed on at least one of a boundary between the bottom portion and the side portion and a boundary between the ceiling portion and the side portion. Continuous heating furnace. The muffle includes the bottom portion, the ceiling portion, and the side portion, and is composed of a plurality of units adjacent to each other in the conveying direction, and the ventilation structure is formed between the adjacent units. Continuous heating furnace according to any one of claims 5 to 7 , characterized in that 9. The continuous heating furnace according to any one of claims 5 to 8 , wherein said muffle has a shielding portion that shields the inflow of gas from said ventilation structure. A convex portion is provided at the upper end and the lower end of the side surface portion,
The bottom surface portion and the ceiling portion are provided with recesses corresponding to the protrusions,
10. The continuous heating furnace according to any one of claims 1 to 9, wherein said side surface portion is connected via said convex portion and said concave portion.

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