Vacuum dryer

Abstract

To provide a vacuum dryer whose productivity and maintainability can be improved.SOLUTION: The vacuum dryer comprises a container (1), a door (2), a rack (3), a nozzle (4), a nozzle seal mechanism (5), an exhaust mechanism (6), and a heat medium supply / discharge mechanism (7). The container (1) is of a box shape with an opening (1a) formed on the front. The door (2) opens / closes the opening (1a). The rack (3) includes a plurality of shelf plates (31) and a frame (32) supporting the shelf plates (31), and is fixed in the container (1). Each of the shelf plates (31) is arranged in a vertical direction and comprises an internal passage (311). The nozzle (4) is fixed to one end surface (31a) of the shelf plate (31) to communicate with the internal passage (311) of the shelf plate (31). The nozzle (4) penetrates through a side plate (13) of the container (1). A nozzle seal mechanism (5) seals a gap between the nozzle (4) and the side plate (13) from outside of the container (1).SELECTED DRAWING: Figure 2

Description

[Technical Field]

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

[0002] In vacuum drying, the material to be dried is placed in a vacuum (including a reduced pressure close to a vacuum) to lower the boiling point of the liquid contained in the material, thereby promoting evaporation of the liquid and drying the material in a short time without exposing it to high temperatures. In vacuum drying, the material to be dried may also be heated by thermal conduction or radiant heat to further promote evaporation of the liquid.

[0003] A conventional shelf-type box-type vacuum dryer is known, as disclosed in Japanese Patent Laid-Open No. 2014-119227 (Patent Document 1). The vacuum dryer of Patent Document 1 includes a box-shaped container, a door for opening and closing the front opening of the container, and multiple shelves. Each shelf is individually fixed to the innermost side panel of the container via a bracket (nozzle). Each shelf has an internal passage, which is connected to a heat transfer pipe via a bracket. In vacuum drying using the vacuum dryer of Patent Document 1, a tray containing the objects to be dried is placed on the shelf, and the container is depressurized. This places the objects in a vacuum atmosphere. In this state, a heat transfer medium is supplied from the heat transfer pipe through the bracket to the internal passages of each shelf. This heats the shelves, and the objects between the shelves are heated by thermal conduction and radiant heat. This promotes evaporation of the liquid contained in the objects, resulting in drying. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-119227 Summary of the Invention [Problem to be solved by the invention]

[0005] In the vacuum dryer of Patent Document 1, each shelf is separated within the container and fixed to the side panels at the innermost part of the container by brackets. Therefore, the orientation of each shelf and the spacing between shelves depend on the flatness of the container's side panels. However, since the flatness of the side panels does not affect vacuum drying, it is not strictly regulated in the design, and some distortion of the side panels does not pose a problem. However, if the side panels are excessively warped, the orientation of each shelf panel fixed to the side panels will vary, causing the spacing between the shelves to become unstable. In this case, it becomes difficult to automatically load and unload trays containing materials to be dried onto and from the shelves using a loader or the like. Therefore, the vacuum dryer of Patent Document 1 cannot be expected to improve productivity.

[0006] Furthermore, in the vacuum dryer of Patent Document 1, the sealing between the brackets of each shelf and the side plates of the container is ensured by a seal member provided between the bracket and the inner surface of the side plate. In this case, since the seal member is provided inside the container, the shelf must be removed from the container to perform maintenance work such as replacing the seal member. Therefore, it cannot be said that the maintainability is good.

[0007] An object of the present disclosure is to provide a vacuum dryer that can improve productivity and maintainability. [Means for solving the problem]

[0008] The vacuum dryer according to the present disclosure comprises a container, a door, a rack, a nozzle, a nozzle seal mechanism, an exhaust mechanism, and a heat medium supply / exhaust mechanism. The container has a box shape and an opening formed on the front. The door opens and closes the opening of the container. The rack is fixed inside the container. The rack includes a plurality of shelves and a frame supporting the shelves. The shelves are arranged vertically and each has an internal passage. The nozzle is fixed to one end surface of each shelf and communicates with the internal passage of each shelf. The nozzle penetrates a side plate of the container. The nozzle seal mechanism seals the gap between the nozzle and the side plate from the outside of the container. The exhaust mechanism exhausts the atmosphere inside the container. The heat medium supply / exhaust mechanism supplies or exhausts a heat medium to or from the nozzle. [Effects of the Invention]

[0009] According to the vacuum dryer according to the present disclosure, productivity and maintainability can be improved. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic diagram of a vacuum dryer according to this embodiment as viewed from the front. [Figure 2] FIG. 2 is a schematic diagram of the vacuum dryer according to this embodiment as viewed from the side. [Figure 3] FIG. 3 is a schematic diagram of a rack in the vacuum dryer according to this embodiment, viewed from the front. [Figure 4] FIG. 4 is a schematic diagram of the rack in the vacuum dryer according to this embodiment as viewed from the side. [Figure 5] FIG. 5 is a schematic diagram showing an example of a nozzle sealing mechanism in the vacuum dryer according to this embodiment. [Figure 6] FIG. 6 is a schematic diagram of the nozzle seal mechanism shown in FIG. 5 as viewed from the rear side of the container. [Figure 7] FIG. 7 is a schematic diagram showing an example of a rack height adjustment mechanism in the vacuum dryer according to this embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] A vacuum dryer according to an embodiment of the present disclosure includes a container, a door, a rack, a nozzle, a nozzle seal mechanism, an exhaust mechanism, and a heat medium supply / exhaust mechanism. The container is box-shaped and has an opening formed on the front. The door opens and closes the opening of the container. The rack is fixed inside the container. The rack includes a plurality of shelves and a frame supporting the shelves. The shelves are arranged vertically and each has an internal passage. The nozzle is fixed to one end surface of each shelf and communicates with the internal passage of each shelf. The nozzle penetrates a side plate of the container. The nozzle seal mechanism seals the gap between the nozzle and the side plate from the outside of the container. The exhaust mechanism exhausts the atmosphere inside the container. The heat medium supply / exhaust mechanism supplies or exhausts a heat medium to or from the nozzle (first configuration).

[0012] In vacuum drying using the vacuum dryer according to the first configuration, a tray containing the material to be dried is placed on the shelf and the door is closed. The exhaust mechanism is then activated to evacuate the atmosphere inside the container and reduce the pressure inside the container. This places the material to be dried in a vacuum atmosphere. In this state, the heat medium supply / exhaust mechanism is activated to supply a heat medium through the nozzles to the internal passages of each shelf. This heats the shelf, and the material to be dried between the shelves is heated by the heat conduction and radiant heat. This promotes evaporation of the liquid contained in the material to be dried, resulting in drying of the material.

[0013] In particular, in the vacuum dryer of the first configuration, each shelf plate forms a rack together with the frame. In the rack, each shelf plate is supported by the frame, and the position of each shelf plate and the spacing between the shelves are stable. This rack is fixed inside the container. In this case, since the position of each shelf plate and the spacing between the shelves are stable, trays containing materials to be dried can be automatically loaded and unloaded onto and from the shelves by a loader or the like. This can improve productivity.

[0014] Furthermore, in the vacuum dryer of the first configuration, the nozzle seal mechanism ensures sealing between the nozzle of each shelf and the side plate of the container. Because the nozzle seal mechanism seals the gap between the nozzle and the side plate from the outside of the container, maintenance of the nozzle seal mechanism can be easily performed from the outside of the container. Moreover, maintenance can be performed without removing the shelf from the container. This improves maintainability.

[0015] In the vacuum dryer according to the first configuration, the nozzle sealing mechanism preferably includes a first plate, a second plate, a first annular sealing member, a second annular sealing member, and a fastening mechanism. The first plate has a first through hole into which the nozzle is inserted and is stacked on the outer surface of the side plate. The second plate has a second through hole into which the nozzle is inserted and is stacked on the outer surface of the first plate. The first annular sealing member is provided coaxially with the first through hole between the outer surface of the side plate and the first plate. The second annular sealing member is provided between the first plate and the second plate in a gap between the first through hole and the nozzle. The fastening mechanism fastens the second plate and the first plate to the side plate (second configuration).

[0016] In the vacuum dryer according to the second configuration, the sealing between the nozzles of each shelf plate and the side plate of the container is ensured by the first and second annular seal members. During maintenance work, for example, the first and second plates can be separated from the side plate by removing the bolts that make up the fastening mechanism, and the first and second annular seal members can be cleaned or replaced.

[0017] The vacuum dryer preferably further includes a rack height adjustment mechanism for adjusting the installation height of the rack (third configuration).

[0018] In the vacuum dryer according to the third configuration, when the rack is fixed in the container, the rack can be adjusted to an appropriate height by the rack height adjustment mechanism. The rack height adjustment mechanism is, for example, a type that supports the rack from below. The rack height adjustment mechanism may also be a type that suspends the rack.

[0019] In the vacuum dryer according to the third configuration, the rack height adjustment mechanism preferably includes at least three pedestals and a pedestal sealing mechanism. The pedestals penetrate the bottom plate of the container and are movable up and down relative to the floor. The pedestals support the rack from below. The pedestal sealing mechanism seals the gap between the pedestals and the bottom plate from the outside of the container (fourth configuration).

[0020] In the vacuum dryer according to the fourth configuration, the rack height adjustment mechanism uses pedestals to support the rack from below. The height and parallelism of the rack relative to the container can be adjusted by moving each pedestal up and down. Furthermore, in the vacuum dryer according to the fourth configuration, the sealing between each pedestal and the bottom plate of the container is ensured by a pedestal sealing mechanism. The pedestal sealing mechanism seals the gap between the pedestal and the bottom plate from the outside (bottom) of the container, making it easy to secure the rack inside the container from outside the container.

[0021] In the vacuum dryer according to the fourth configuration, the base seal mechanism preferably includes a tubular member, a flexible tube, a ring body, a flange, a third annular seal member, a fourth annular seal member, and a fifth annular seal member. The tubular member has the base inserted therein and protrudes outward from the bottom plate. The flexible tube has the base inserted therein and is stacked on the outer end surface of the tubular member. The ring body has the base inserted therein and is stacked on the outer end surface of the flexible tube. The flange protrudes from the lower end of the base and is stacked on the outer surface of the ring body. The third annular seal member is provided coaxially with the base between the outer end surface of the tubular member and the inner end surface of the flexible tube. The fourth annular seal member is provided coaxially with the base between the outer end surface of the flexible tube and the ring body. The fifth annular seal member is provided coaxially with the base between the inner surface of the flange and the ring body (fifth configuration).

[0022] In the case of the vacuum dryer according to the fifth configuration, the sealing between each pedestal and the bottom plate of the container is ensured by the third, fourth and fifth annular sealing members.

[0023] In the vacuum dryer according to the fifth configuration, the ring body preferably has a drain connecting its inner circumferential surface with its outer circumferential surface (sixth configuration).

[0024] When the pressure inside the container returns to normal pressure after vacuum drying, some of the vapor inside the container liquefies. The liquid produced by the liquefaction accumulates at the bottom of the container. This liquid then passes through the gap between the base and the tubing and the gap between the base and the flexible tube, and tends to accumulate in the gap between the base and the ring body. In the vacuum dryer according to the sixth configuration, a drain is provided on the ring body. In this case, the liquid that accumulates in the gap between the base and the ring body can be discharged through the drain on the ring body.

[0025] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In each drawing, the same or equivalent components are designated by the same reference numerals, and redundant description will not be repeated.

[0026] [Vacuum dryer configuration] A vacuum dryer 100 according to this embodiment will be described with reference to Figures 1 to 7. Figures 1 and 2 are schematic diagrams showing the overall configuration of the vacuum dryer 100. Figure 1 is a diagram of the vacuum dryer 100 as seen from the front, and Figure 2 is a diagram of the vacuum dryer 100 as seen from the side. Figure 2 shows a see-through view of the interior of the vacuum dryer 100.

[0027] As shown in FIGS. 1 and 2, the vacuum dryer 100 includes a container 1, a door 2 (FIG. 2), a rack 3, a nozzle 4, a nozzle seal mechanism 5 (FIG. 2), an exhaust mechanism 6 (FIG. 2), and a heat medium supply / exhaust mechanism 7 (FIG. 2). The container 1 has a box shape. Specifically, the container 1 has a substantially rectangular parallelepiped shape. The container 1 has left and right side panels 11 and 12, an innermost side panel 13, a ceiling panel 14, and a bottom panel 15, and an opening 1a is formed in the front. The container 1 is placed on a floor G with its bottom raised. In this embodiment, the container 1 has legs 1b extending downward from the bottom panel 15, i.e., toward the outside of the container 1, and the legs 1b are fixed to the floor G.

[0028] The door 2 opens and closes the opening 1a of the container 1. The door 2 is attached to the container 1 so that the opening 1a can be opened and closed. For example, the door 2 is attached to the container 1 by a hinge. The container 1 is sealed in a state in which the door 2 closes the opening 1a of the container 1.

[0029] The rack 3 is fixed inside the container 1. Figures 3 and 4 are schematic diagrams showing the overall configuration of the rack 3. Figure 3 is a diagram of the rack 3 as seen from the front, and Figure 4 is a diagram of the rack 3 as seen from the side. Figure 4 shows a see-through view of the inside of the rack 3.

[0030] As shown in FIGS. 3 and 4, the rack 3 includes a plurality of shelves 31 and a frame 32 that supports the shelves 31. Each shelf 31 has a substantially rectangular shape. The shelves 31 are arranged in the vertical direction. The number of shelves 31 is not particularly limited. In the example shown in FIGS. 3 and 4, there are 12 shelves 31. The shelves 31 are made of metal. For example, the material of the shelves 31 is stainless steel or alloy steel.

[0031] The frame 32 is composed of a plurality of support posts 321, a base 322, crosspieces 323, etc. Receiving seats 321a for the shelves 31 are formed on each support post 321 at regular intervals in the vertical direction. The frame 32 is made of metal. For example, the material of the frame 32 is stainless steel or alloy steel. The support posts 321, base 322, and crosspieces 323 are joined by, for example, welding, to form the frame 32 with high dimensional accuracy.

[0032] The shelf board 31 is fixed to the frame 32. For example, the shelf board 31 is fastened to the frame 32 with bolts, with its edge supported by the receiving seat 321a of the support 321. The shelf board 31 may also be fixed to the frame 32 (receiving seat 321a) by other methods (welding, etc.).

[0033] Each shelf 31 has an internal passage 311. The internal passage 311 is formed in most of the interior of the shelf 31. The inlet and outlet of the internal passage 311 are spaced apart and open at one end surface 31a (FIG. 4) of the shelf 31. In this embodiment, the end surface 31a of each shelf 31, where the inlet and outlet of the internal passage 311 open, is the rear end surface, and is disposed so as to face the side panel 13 on the innermost side of the container 1 (FIG. 2).

[0034] The nozzles 4 are fixed to one end surface 31a of each shelf plate 31. For example, the nozzles 4 are fixed to the shelf plate 31 by welding. As a result, the nozzles 4 are connected to the inlet and outlet of the internal passage 311 that opens to one end surface 31a of the shelf plate 31, and communicate with the internal passage 311 of the shelf plate 31. The nozzles 4 are tubular and have a circular cross section.

[0035] 1 and 2, the description of the configuration of the vacuum dryer 100 will continue. As described above, the rack 3 is composed of a plurality of shelves 31 and a frame, and this rack 3 is fixed inside the container 1. In this embodiment, the vacuum dryer 100 is equipped with a rack height adjustment mechanism 8, the details of which will be described later. The height of the rack 3 inside the container 1 is adjusted by the rack height adjustment mechanism 8, and the rack 3 is fixed in that state. As shown in FIG. 2, when the rack 3 is fixed inside the container 1, the nozzle 4 penetrates a side plate of the container 1, i.e., a side plate 13 on the innermost side of the container 1, and the gap between the nozzle 4 and the side plate 13 is sealed by a nozzle seal mechanism 5.

[0036] 5 and 6 are enlarged schematic views of a portion of the vacuum dryer 100, showing an example of the nozzle sealing mechanism 5. Fig. 5 corresponds to a cross-sectional view taken along line VV in Fig. 2. Fig. 6 is a view showing the nozzle sealing mechanism 5 as viewed from the rear side of the container 1, and corresponds to a view of the nozzle sealing mechanism 5 shown in Fig. 5 as viewed from top to bottom on the paper.

[0037] As shown in FIG. 5 , the nozzle seal mechanism 5 is configured to seal the gap between the nozzle 4 and the side plate 13 from the outside of the container 1. In this embodiment, the side plate 13 on the innermost side of the container 1 has nozzle holding portions 131 at positions corresponding to each nozzle 4. The nozzle holding portions 131 are part of the side plate 13 and protrude toward the outside of the container 1, i.e., toward the rear of the container 1. The nozzle holding portions 131 include a cylindrical portion 131a and a plate portion 131b. One end of the cylindrical portion 131a opens into the interior of the container 1. The plate portion 131b protrudes radially outward from the other end of the cylindrical portion 131a. The nozzle 4 is inserted into the nozzle holding portion 131 of the side plate 13.

[0038] The nozzle sealing mechanism 5 includes a first plate 51, a second plate 52, a first annular sealing member 53, a second annular sealing member 54, and a fastening mechanism 55. The first and second plates 51, 52 and the first and second annular sealing members 53, 54 are disposed outside the nozzle holding portion 131 of the side plate 13.

[0039] The first plate 51 has a first through hole 511 into which the nozzle 4 is inserted. The first through hole 511 is a circular hole. This first plate 51 is stacked on the side plate 13, i.e., the outer surface of the plate portion 131b of the nozzle holding portion 131. The second plate 52 has a second through hole 521 into which the nozzle 4 is inserted. The second through hole 521 is a circular hole. This second plate 52 is stacked on the outer surface of the first plate 51. In short, the first plate 51 and the second plate 52 are stacked in this order on the plate portion 131b of the nozzle holding portion 131.

[0040] 6, the second plate 52 is rectangular. The first plate 51 is also rectangular, like the second plate 52. However, the shapes of the first and second plates 51 and 52 are not limited to rectangular, and may be, for example, elliptical or circular.

[0041] 5, the first annular sealing member 53 is provided coaxially with the first through-hole 511 between the outer surface of the plate portion 131b (side plate 13) of the nozzle holding portion 131 and the first plate 51. Specifically, the first annular sealing member 53 is sandwiched between the plate portion 131b and the first plate 51. The first annular sealing member 53 is, for example, a sheet packing.

[0042] The second annular sealing member 54 is provided in the gap between the first through-hole 511 and the nozzle 4, between the first plate 51 and the second plate 52. Specifically, the portion of the first plate 51 facing the second plate 52 of the first through-hole 511 is chamfered. The second annular sealing member 54 is inserted into this chamfered portion, and is sandwiched between the chamfered surface of the first plate 51, the inner surface of the second plate 52, and the outer peripheral surface of the nozzle 4. The second annular sealing member 54 is, for example, an O-ring.

[0043] 5 and 6, the fastening mechanism 55 is configured to fasten the second plate 52 and the first plate 51 to the side plate 13, i.e., the plate portion 131b of the nozzle holding portion 131. Specifically, the fastening mechanism 55 includes a presser plate 551 and a bolt 552. In this embodiment, two presser plates 551 are stacked on the second plate 52. The two presser plates 551 are arranged on opposite sides of the nozzle 4. Each presser plate 551 has two bolt holes 551a, and a bolt 552 is inserted into each of the bolt holes 551a.

[0044] The second plate 52 is provided with a through hole 522 through which the bolt 552 passes. Similarly, the first plate 51 is provided with a through hole 512 through which the bolt 552 passes. The first annular seal member 53 is also provided with a through hole 531 through which the bolt 552 passes. The plate portion 131b (side plate 13) of the nozzle holding portion 131 is provided with a threaded hole 131c that engages with the bolt 552.

[0045] Bolt 552 is inserted into bolt hole 551a of presser plate 551, through hole 522 of second plate 52, through hole 512 of first plate 51, and through hole 531 of first annular seal member 53, and is screwed into threaded hole 131c of plate portion 131b (side plate 13) of nozzle holder 131. This fastens second plate 52 and first plate 51 to plate portion 131b of nozzle holder 131. As a result, the first and second annular seal members 53 and 54 seal the gap between nozzle 4 and side plate 13 from the outside of container 1. That is, nozzle seal mechanism 5 seals the gap between nozzle 4 and side plate 13 from the outside of container 1.

[0046] Returning to FIG. 2 again, the exhaust mechanism 6 is configured to exhaust the atmosphere inside the container 1. Specifically, the exhaust mechanism 6 includes an exhaust pipe 61. The exhaust pipe 61 is connected to the side panel 13 on the innermost side of the container 1 and opens into the interior of the container 1. A vacuum pump (not shown) is connected to the exhaust pipe 61. By operating the vacuum pump, the atmosphere inside the container 1 is exhausted, making it possible to reduce the pressure inside the container 1 and create a vacuum.

[0047] The heat medium supply / discharge mechanism 7 is configured to supply or discharge a heat medium to or from the nozzle 4. Specifically, as described above, the nozzle 4 is connected to the inlet and outlet of the internal passage 311, which opens on one end surface 31a of the shelf 31. For each shelf 31, the heat medium supply / discharge mechanism 7 includes a supply pipe 71 and a discharge pipe 72. The supply pipe 71 is connected to a nozzle 4 connected to the inlet of the internal passage 311 of the shelf 31. The discharge pipe 72 is connected to a nozzle 4 connected to the outlet of the internal passage 311 of the shelf 31. The supply pipe 71 is connected to a heat medium generator (not shown), a heat medium tank (not shown), a pump (not shown), and the like. The heat medium tank stores the heat medium generated by the heat medium generator. The heat medium is, for example, hot water, steam, or oil. When the pump is operated, the heat medium is supplied to the internal passage 311 of the shelf 31 through the supply pipe 71 and the nozzle 4. The heat medium supplied to the internal passage 311 flows through the internal passage 311 and is then discharged through the discharge pipe 72. At this time, the heat medium flows through the internal passage 311, so that the shelf board 31 can be heated.

[0048] In this embodiment, the vacuum dryer 100 includes a rack height adjustment mechanism 8. The rack height adjustment mechanism 8 is configured to enable adjustment of the installation height and horizontality of the rack 3 when fixing the rack 3 in the container 1.

[0049] 7 is a schematic diagram showing an enlarged portion of the vacuum dryer 100, illustrating an example of the rack height adjustment mechanism 8. FIG. 7 illustrates the lower part of the rack 3 in FIGS. 1 and 2 and the vicinity thereof.

[0050] 1, 2, and 7, particularly FIG. 7, the rack height adjustment mechanism 8 includes at least three pedestals 81 and a pedestal sealing mechanism 82. The vacuum dryer 100 of this embodiment is provided with four pedestals 81. Each pedestal 81 penetrates the bottom plate 15 of the container 1 and is provided so as to be movable up and down relative to the floor G. The pedestal 81 has a rod shape extending up and down. The pedestal 81 is supported by a screw mechanism 83 provided directly below it. The pedestal 81 can be raised and lowered by rotating the screw that constitutes the screw mechanism 83. This allows the pedestal 81 to be moved up and down relative to the floor G.

[0051] The rack 3 is placed on the pedestal 81, and the rack 3 is supported from below by the pedestal 81. In other words, the pedestal 81 supports the rack 3 from below. Specifically, in the frame 32 that constitutes the rack 3, the base 322 includes legs 322a. The legs 322a are provided at positions corresponding to directly above the pedestal 81. The legs 322a have recesses 322aa that receive the upper ends of the pedestals 81. Each pedestal 81 fits into the recesses 322aa of the corresponding legs 322a. In this way, the rack 3 is supported from below by the pedestal 81.

[0052] The base sealing mechanism 82 is configured to seal the gap between the base 81 and the bottom plate 15 of the container 1 from the outside of the container 1. In this embodiment, the base sealing mechanism 82 includes a tubular member 821, a flexible tube 822, a ring body 823, a flange 824, a third annular sealing member 825, a fourth annular sealing member 826, and a fifth annular sealing member 827. Most of the tubular member 821, the flexible tube 822, the ring body 823, the flange 824, and the third, fourth, and fifth annular sealing members 825, 826, and 827 are disposed below the bottom plate 15, i.e., outside the container 1.

[0053] The base 81 is inserted into the pipe 821. The pipe 821 protrudes outward from the bottom plate 15. The lower end of the pipe 821 protrudes radially outward. In other words, the pipe 821 has a flange portion at its lower end, i.e., its outer end. The upper end, i.e., its inner end, protrudes into the container 1.

[0054] The base 81 is inserted into the flexible tube 822. The flexible tube 822 is, for example, a bellows tube, and is flexible and deformable. This flexible tube 822 is stacked on the outer end surface (lower end surface) of the tube material 821. Specifically, the upper end, i.e., the inner end, of the flexible tube 822 protrudes radially outward. In other words, the flexible tube 822 has a flange portion at the upper end. Furthermore, the lower end, i.e., the outer end, of the flexible tube 822 protrudes radially outward. In other words, the flexible tube 822 has a flange portion at the lower end.

[0055] The base 81 is inserted into the ring body 823. This ring body 823 is stacked on the outer end surface (lower end surface) of the flexible tube 822. The flange 824 is a portion of the base 81 that protrudes radially outward from the lower end of the base 81. This flange 824 is stacked on the outer surface (lower surface) of the ring body 823. In short, the flexible tube 822, ring body 823, and flange 824 are stacked in this order downward on the lower end surface of the tube material 821.

[0056] The third annular sealing member 825 is provided coaxially with the base 81 between the outer end surface (lower surface) of the pipe material 821 and the inner end surface (upper surface) of the flexible tube 822. Specifically, the third annular sealing member 825 is sandwiched between the lower end (flange portion) of the pipe material 821 and the upper end (flange portion) of the flexible tube 822. The third annular sealing member 825 is, for example, a sheet packing.

[0057] Here, a backup ring 828 that is coaxial with the flexible tube 822 may be disposed below the upper end (flange portion) of the flexible tube 822. The lower end (flange portion) of the pipe material 821 and the backup ring 828 are fastened together with bolts, whereby the third annular seal member 825 is tightly sandwiched between the lower end (flange portion) of the pipe material 821 and the upper end (flange portion) of the flexible tube 822.

[0058] The fourth annular sealing member 826 is provided coaxially with the base 81 between the outer end surface (lower surface) of the flexible tube 822 and the ring body 823. Specifically, the fourth annular sealing member 826 is sandwiched between the lower end portion (flange portion) of the flexible tube 822 and the ring body 823. The fourth annular sealing member 826 is, for example, a sheet packing.

[0059] The fifth annular sealing member 827 is provided coaxially with the base 81 between the inner surface (upper surface) of the flange 824 of the base 81 and the ring body 823. Specifically, the fifth annular sealing member 827 is sandwiched between the flange 824 and the ring body 823. The fifth annular sealing member 827 is, for example, a sheet packing.

[0060] Here, a backup ring 829 that is coaxial with the flexible tube 822 may be disposed on the lower end (flange portion) of the flexible tube 822. When the flange 824 of the base 81 and the backup ring 829 are fastened together with bolts, the fourth annular seal member 826 is tightly sandwiched between the lower end of the flexible tube 822 and the ring body 823, and the fifth annular seal member 827 is tightly sandwiched between the flange 824 and the ring body 823.

[0061] With this configuration, the third, fourth, and fifth annular sealing members 825, 826, and 827 seal the gap between the base 81 and the bottom plate 15 from the outside of the container 1. That is, the base sealing mechanism 82 seals the gap between the base 81 and the bottom plate 15 from the outside of the container 1.

[0062] In this embodiment, the ring body 823 has a drain 823a. The drain 823a connects the inner peripheral surface and the outer peripheral surface of the ring body 823. That is, one end of the drain 823a opens to the inner peripheral surface of the ring body 823, and the other end of the drain 823a opens to the outer peripheral surface of the ring body 823. A drain pipe 9 is connected to the drain 823a.

[0063] [Vacuum drying process using vacuum dryer 100] The vacuum dryer 100 of this embodiment can perform the following vacuum drying process. First, the door 2 is opened. A tray containing the material to be dried is inserted between the shelves 31 through the opening 1a of the container 1 and placed on the shelf 31. Further, trays are sequentially placed on the remaining shelves 31 except for the top shelf 31, and then the door 2 is closed. The vacuum pump of the exhaust mechanism 6 is then activated to evacuate the atmosphere inside the container 1 and reduce the pressure inside the container 1. This places the material to be dried in a vacuum atmosphere. In this state, the pump of the heat medium supply / exhaust mechanism 7 is activated to supply a heat medium through the nozzles 4 to the internal passages 311 of each shelf 31. This heats the shelf 31, and the material to be dried between the shelves 31 is heated by thermal conduction and radiant heat. This promotes evaporation of the liquid contained in the material to be dried, resulting in drying.

[0064] [effect] In the vacuum dryer 100 of this embodiment, each shelf 31, together with the frame 32, constitutes a rack 3, and all of the shelves 31 are integrated as part of the rack 3. In the rack 3, each shelf 31 is supported by the frame 32, and the orientation of each shelf 31 and the spacing between the shelves 31 are stable. This rack 3 is fixed within the container 1. In other words, the orientation of each shelf 31 and the spacing between the shelves 31 do not depend on the flatness of the side panel 13 of the container 1. In this case, because the orientation of each shelf 31 and the spacing between the shelves 31 are stable, trays containing materials to be dried can be automatically loaded and unloaded onto and from the shelves 31 using a loader or the like. This improves productivity. Furthermore, if the spacing between the shelves 31 is stable, it is possible to narrow the spacing between the shelves 31 in design and increase the number of shelves 31 relative to the volume of the container 1. This increases the amount of materials to be dried per run, thereby improving productivity.

[0065] Furthermore, in the vacuum dryer 100 of this embodiment, the sealing between the nozzle 4 of each shelf 31 and the side plate 13 of the container 1 is ensured by the nozzle seal mechanism 5. The nozzle seal mechanism 5 seals the gap between the nozzle 4 and the side plate 13 from the outside of the container 1. This makes it possible to easily perform maintenance work on the nozzle seal mechanism 5 from the outside of the container 1. Moreover, maintenance work can be performed without removing the shelf 31 from the container 1. This improves maintainability.

[0066] In this embodiment, the sealing between the nozzle 4 of each shelf plate 31 and the side plate 13 of the container 1 is ensured by the first and second annular sealing members 53, 54. During maintenance work, the first and second plates 51, 52 can be separated from the side plate 13 by removing the bolts 552 that make up the fastening mechanism 55, and the first and second annular sealing members 53, 54 can be cleaned or replaced.

[0067] Furthermore, in the case of this embodiment, when the rack 3 is fixed in the container 1, the rack 3 can be adjusted to an appropriate height by the rack height adjustment mechanism 8. The rack height adjustment mechanism 8 of this embodiment is of a type that supports the rack 3 from below.

[0068] In particular, the rack height adjustment mechanism 8 of this embodiment is a type in which the rack 3 is supported from below by pedestals 81. The height and parallelism of the rack 3 relative to the container 1 can be adjusted by vertically advancing and retracting each pedestal 81. The number of pedestals 81 may be three or more, for example, four or six. Furthermore, in the vacuum dryer 100 of this embodiment, the sealing between each pedestal 81 and the bottom plate 15 of the container 1 is ensured by a pedestal sealing mechanism 82. The pedestal sealing mechanism 82 seals the gap between the pedestal 81 and the bottom plate 15 from the outside (below) of the container 1. Therefore, when fixing the rack 3 inside the container 1, the work can be easily performed from outside the container 1.

[0069] In this embodiment, the sealing between each seat 81 and the bottom plate 15 of the container 1 is ensured by third, fourth and fifth annular sealing members 825, 826, 827.

[0070] Furthermore, in this embodiment, a drain 823a is provided in the ring body 823 that constitutes the base seal mechanism 82. When the pressure inside the container 1 returns to normal pressure after vacuum drying, part of the vapor inside the container 1 liquefies. The liquid produced by the liquefaction accumulates at the bottom of the container 1. This liquid is likely to further accumulate in the gap between the base 81 and the ring body 823 through the gap between the base 81 and the tubular material 821 and the gap between the base 81 and the flexible tube 822. In this case, the liquid accumulated in the gap between the base 81 and the ring body 823 can be discharged through the drain 823a of the ring body 823.

[0071] Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above embodiments, and various modifications are possible without departing from the spirit of the present disclosure. For example, the rack height adjustment mechanism may be a type that suspends the rack 3 using a mechanism similar to a type that supports the rack 3 from below. [Explanation of symbols]

[0072] 100: Vacuum dryer 1: Container 1a: opening 13: Inner side panel 15: Bottom plate 2: Door 3: Rack 31: Shelf 31a: One end surface 311: Internal passage 32: Frame 4: Nozzle 5: Nozzle seal mechanism 51: First Plate 511: First through hole 52: Second Plate 521: Second through hole 53: First annular seal member 54: Second annular seal member 6: Exhaust mechanism 7: Heat medium supply and discharge mechanism 8: Rack height adjustment mechanism 81: Pedestal 82: Base seal mechanism 821: Piping material 822: Flexible tube 823: Ring body 823a:Drain 824: Flange 825: Third annular seal member 826: Fourth annular seal member 827: Fifth annular seal member G: Floor

Claims

1. A container having a box shape and an opening formed on the front surface; a door for opening and closing the opening of the container; a rack fixed within the container, the rack including a plurality of shelves arranged vertically, each having an internal passage, and a frame supporting the shelves; a nozzle fixed to one end surface of each of the shelf plates and communicating with the internal passage of each of the shelf plates, the nozzle penetrating a side plate of the container; a nozzle seal mechanism that seals the gap between the nozzle and the side plate from the outside of the container; an exhaust mechanism for exhausting the atmosphere inside the container; a heat medium supply / discharge mechanism that supplies or discharges a heat medium to or from the nozzle.

2. The vacuum dryer according to claim 1, The nozzle seal mechanism includes: a first plate having a first through hole into which the nozzle is inserted and stacked on an outer surface of the side plate; a second plate having a second through hole into which the nozzle is inserted and stacked on the outer surface of the first plate; a first annular seal member provided coaxially with the first through hole between the outer surface of the side plate and the first plate; a second annular seal member provided in a gap between the first through hole and the nozzle between the first plate and the second plate; a fastening mechanism that fastens the second plate and the first plate to the side plate.

3. The vacuum dryer according to claim 1 or 2, further comprising: A vacuum dryer comprising a rack height adjustment mechanism for adjusting the installation height of the rack.

4. The vacuum dryer according to claim 3, The rack height adjustment mechanism is At least three pedestals that penetrate the bottom plate of the container and are provided so as to be movable up and down relative to the floor, the pedestals supporting the rack from below; a base sealing mechanism that seals the gap between the base and the bottom plate from the outside of the container.

5. The vacuum dryer according to claim 4, The base sealing mechanism includes: a pipe member into which the base is inserted and which protrudes outward from the bottom plate; a flexible tube into which the seat is inserted and which overlaps the outer end surface of the tubing; a ring body into which the seat is inserted and which is stacked on the outer end surface of the flexible tube; a flange extending from the lower end of the base and stacked on the outer surface of the ring body; a third annular seal member disposed coaxially with the seat between the outer end surface of the tubular member and the inner end surface of the flexible tube; a fourth annular seal member provided coaxially with the seat between the outer end surface of the flexible tube and the ring body; a fifth annular seal member provided coaxially with the base between the inner surface of the flange and the ring body.

6. The vacuum dryer according to claim 5, The ring body has a drain connecting its inner peripheral surface and outer peripheral surface.

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