Apparatus for manufacturing dry ice block

Abstract

To provide an apparatus for manufacturing dry ice blocks capable of manufacturing dry ice having a high pressure density and suitable as dry ice to be stored in cooling clothes for working in a hot place and used.SOLUTION: An apparatus 1 for manufacturing dry ice blocks comprises a press chamber 10, a supply section 50 for supplying a mixed fluid having carbon dioxide gas and particulate dry ice to the press chamber 10, a discharge section for sorting carbon dioxide gas from the supplied mixed fluid and discharging the sorted carbon dioxide gas to the outside through an outlet, and a press section for molding dry ice blocks by applying pressure to particulate dry ice remaining in the press chamber 10. The discharge section has a sintered metal filter 40. The sintered metal filter 40 is interposed between the press chamber 10 and the outlet and separates carbon dioxide gas from the mixed fluid.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to an apparatus for producing dry ice blocks. [Background technology]

[0002] The cooling suit for working in hot places described in Patent Document 1 is provided with pockets capable of accommodating dry ice blocks as a measure against heatstroke in workers working in hot places, and uses the heat of sublimation of the stored dry ice blocks to give the worker a feeling of coolness and lower his / her body temperature. The dry ice blocks stored in the cooling suit are formed, for example, as in the dry ice block manufacturing device described in Patent Document 2, by collecting granular dry ice generated from liquefied carbon dioxide gas, and compressing the collected granular dry ice with a press to consolidate it. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-53387 A [Patent Document 2] JP 2020-132481 A Summary of the Invention [Problem to be solved by the invention]

[0004] The dry ice block stored in the cooling suit for hot work as described in Patent Document 1 is desired to be thin from the viewpoint of the worker's workability and to have a long sublimation time from the viewpoint of reducing the frequency of the storage work. There is a trade-off between making the thickness of the dry ice block thin and making the sublimation time long, and in order to achieve both, it is necessary to increase the compaction degree of the dry ice block. However, the dry ice block manufacturing device described in Patent Document 2 does not disclose a means for increasing the compaction degree of the dry ice block.

[0005] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a dry ice block manufacturing device that can efficiently produce dry ice blocks with a high degree of compaction, which are suitable for use as dry ice blocks to be placed in cooling clothing for work in hot places. [Means for solving the problem]

[0006] According to one aspect of the present invention, a manufacturing apparatus for dry ice blocks includes a press chamber, a supply unit that supplies a mixed fluid having carbon dioxide gas and particulate dry ice to the press chamber, a discharge unit that separates carbon dioxide gas from the supplied mixed fluid and discharges the selected carbon dioxide gas to the outside through a discharge port, and a press unit that applies pressure to the particulate dry ice remaining in the press chamber to form a dry ice block. The discharge unit has a sintered metal filter. The sintered metal filter is interposed between the press chamber and the discharge port and separates the carbon dioxide gas from the mixed fluid. Effect of the Invention

[0007] According to the present invention, the dry ice block manufacturing device achieves both the collection of particulate dry ice by the sintered metal filter and the discharge of carbon dioxide gas by suppressing pressure loss, so that the particulate dry ice and the carbon dioxide gas can be separated with high efficiency and the particulate dry ice can be collected at a high density.Then, the particulate dry ice collected at a high density is compressed by the press unit, so that dry ice with a high compression density can be produced. [Brief description of the drawings]

[0008] [Figure 1] This is a view from the front of the wearer of an example of a cooling suit for working in a hot environment that can accommodate dry ice blocks produced by the dry ice block manufacturing apparatus of the present invention. [Diagram 2] FIG. 2 is a view of the example of cooling clothing for working in a heat-sensitive environment, as seen from behind the wearer. [Diagram 3] FIG. 1 is a diagram showing a dry ice block manufacturing apparatus according to a first embodiment of the present invention. [Figure 4]FIG. 2 is an external view of a press chamber in the dry ice block manufacturing apparatus. [Diagram 5] 5 is a three-dimensional view showing a cross-sectional structure taken along line AA in FIG. 4. [Figure 6] 5 is an enlarged cross-sectional view of a main part taken along line AA in FIG. 4. [Figure 7] FIG. 4 is a perspective view showing a sintered metal filter provided in the press chamber. [Figure 8] 8 is an enlarged side view of a main part showing the configuration of the sintered metal filter, taken along the line indicated by the arrow B in FIG. 7. [Figure 9] 4 is a vertical cross-sectional view showing a raw material supplying step in the manufacturing process by the dry ice block manufacturing apparatus of FIG. [Figure 10] 4 is a vertical cross-sectional view showing a pressing process of the dry ice block by the dry ice block manufacturing apparatus according to the embodiment of the present invention. FIG. [Figure 11] 4 is a vertical cross-sectional view showing a dry ice block removal process in the manufacturing process using the dry ice block manufacturing apparatus. FIG. [Figure 12] 2 is a vertical cross-sectional view showing an example of an on-off valve in the dry ice block manufacturing apparatus of the present invention. FIG. [Figure 13] FIG. 4 is a vertical cross-sectional view showing a modified example of the on-off valve. [Figure 14] FIG. 11 is an exploded perspective view of a press chamber of a dry ice block manufacturing apparatus according to a second embodiment of the present invention. [Figure 15] FIG. [Figure 16] 16 is a longitudinal sectional view in which each cross section shown in FIG. 15 is developed (hereinafter, referred to as "the longitudinal sectional view"). [Figure 17] FIG. 17 is an enlarged longitudinal sectional view of a portion C in FIG. 16. [Figure 18A] FIG. 17 is an enlarged longitudinal sectional view of a portion D in FIG. 16, showing a state in which the exhaust path is in a closed state. [Figure 18B] FIG. 18B is a perspective view seen from the arrow F in FIG. 18A. [Figure 19A]FIG. 17 is an enlarged vertical cross-sectional view of part D in FIG. 16, showing the state in which the exhaust path is in an open state. [Figure 19B] 19B is a perspective view seen from the arrow F in FIG. 19A. [Figure 20] FIG. 17 is an enlarged longitudinal sectional view of a portion E in FIG. 16. [Figure 21] 4 is a vertical cross-sectional view showing a raw material supplying step in the manufacturing process by the dry ice block manufacturing apparatus of FIG. [Figure 22A] 22 is an enlarged longitudinal sectional view of a portion G in FIG. 21. [Figure 22B] 22 is an enlarged longitudinal sectional view of a portion G in FIG. 21, showing a case where no peripheral wall member is present. FIG. [Figure 22C] 22 is an enlarged longitudinal sectional view of a portion G in FIG. 21, illustrating a case where the peripheral wall member does not have a chamfered portion. FIG. [Diagram 23] FIG. 2 is a vertical cross-sectional view showing a pressing step of the dry ice block in the manufacturing process by the dry ice block manufacturing apparatus. [Figure 24] FIG. 2 is a vertical cross-sectional view showing a pressing step of the dry ice block in the manufacturing process by the dry ice block manufacturing apparatus. [Diagram 25] 4 is a vertical cross-sectional view showing a dry ice block removal step in the manufacturing process using the dry ice block manufacturing apparatus. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] <Embodiment 1> [Cooling clothes for working in hot places] Hereinafter, the dry ice block manufacturing apparatus 1 according to the first embodiment of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are given the same reference symbols and will not be described repeatedly. In the following description, terms that mean positions or directions such as "upper", "lower", "horizontal" and "vertical" may be used. These terms are used for convenience to facilitate understanding of the embodiment, and are not limited to positions or directions when actually implemented.

[0010] First, an example of a cooling suit W for work in hot places that can accommodate a dry ice block manufactured by the dry ice block manufacturing device of the present invention will be described with reference to Figures 1 and 2. Figure 1 shows the example of the cooling suit W for work in hot places as seen from the front of the wearer. Figure 2 shows the same cooling suit W for work in hot places as seen from the back of the wearer.

[0011] The cooling suit W for working in hot places shown in Figs. 1 and 2 has multiple dry ice pockets P capable of accommodating dry ice blocks D. An example of a specific size of the dry ice blocks D is 20 mm thick x 140 mm long x 75 mm wide. In the example shown, the dry ice pockets P are arranged in two locations near the worker's sides and four locations near the worker's back. The dry ice pockets P accommodate the dry ice blocks D, and the heat of sublimation of the dry ice blocks D gives the worker a feeling of coolness while working, and cools the worker's body, thereby preventing the onset of heat stroke due to an increase in body temperature.

[0012] [How to make dry ice blocks] Dry ice blocks are produced using liquefied carbon dioxide as a raw material. Dry ice for producing dry ice blocks is produced by changing the phase of carbon dioxide from liquid to solid and gas phases. The phase change from liquefied carbon dioxide is performed by releasing the pressurized liquefied carbon dioxide in a cylinder to the atmosphere through a nozzle. That is, by releasing the liquefied carbon dioxide to the atmosphere, the liquefied carbon dioxide moves from the saturated liquid line on the pressure-enthalpy diagram through the gas-liquid two-phase region to the solid-gas two-phase region in the process of being decompressed by adiabatic expansion, and particulate dry ice and gaseous carbon dioxide are produced. In the following, the particulate dry ice produced in this way is referred to as "particulate dry ice" and the gaseous carbon dioxide is referred to as "carbon dioxide gas".

[0013] [Dry ice block manufacturing equipment] Next, the dry ice block manufacturing apparatus 1 according to the first embodiment of the present invention will be described with reference to Fig. 3. Fig. 3 is a diagram showing the dry ice block manufacturing apparatus 1 according to the first embodiment of the present invention.

[0014] As shown in FIG. 3, the dry ice block manufacturing apparatus 1 includes a press unit 100, a hydraulic unit 6, an air pressure unit 8, a liquefied carbon dioxide gas cylinder 9 for storing liquefied carbon dioxide gas, a control unit 2, and an input unit 4.

[0015] The press unit 100 has a supply section 50, a press chamber 10, a press cylinder section 60, and a slide cylinder section 70.

[0016] Supply section 50 has supply path 52 and on-off valve 51 provided in supply path 52. In the supply process in supply path 52 downstream of on-off valve 51, supply path 52 releases liquefied carbon dioxide gas from liquefied carbon dioxide gas cylinder 9 to the atmosphere, thereby causing a phase change of the liquefied carbon dioxide gas to a mixed fluid of particulate dry ice and carbon dioxide gas, and supplies the mixed fluid to press chamber 10 of press unit 100.

[0017] The pressing chamber 10 has a sintered metal filter 40, and carbon dioxide gas in the mixed fluid supplied to the pressing chamber 10 is discharged to the outside through the sintered metal filter 40 (details will be described later).

[0018] The press cylinder section 60 has a press block 61 and a press rod 62 connected to the press block 61, and the press block 61 is driven by the hydraulic unit 6 via the press rod 62. The slide cylinder section 70 has a slide plate 71 and a slide rod 72 connected to the slide plate 71, and the slide plate 71 is driven by the pneumatic unit 8 via the slide rod 72.

[0019] The control unit 2 controls each unit and device based on the dry ice production conditions (such as the number of pieces) input by the user to the input unit 4 (such as a touch panel). Specifically, the control unit 2 drives an on-off valve 51 (such as an electromagnetic valve) to supply liquefied carbon dioxide gas from the liquefied carbon dioxide gas cylinder 9 to a supply path 52.

[0020] The control unit 2 controls the hydraulic unit 6 to drive the press block 61 of the press cylinder unit 60. The control unit 2 applies pressure to the granular dry ice in the mixed fluid supplied into the press chamber 10 by the press block 61, thereby consolidating the granular dry ice inside the press chamber 10 and forming a dry ice block.

[0021] The control unit 2 controls the air pressure unit 8 to drive the slide plate 71 of the slide cylinder portion 70. The control unit 2 pushes out the formed dry ice block with the slide plate 71, thereby discharging the dry ice block outside the unit.

[0022] As described above, the dry ice block manufacturing apparatus 1 molds a dry ice block from the supplied liquefied carbon dioxide gas.

[0023] The following describes in detail the dry ice block manufacturing apparatus 1. After describing the configuration of the press chamber 10 and the configuration of the sintered metal filter 40, the specific dry ice manufacturing process will be described.

[0024] [Press Room Configuration] First, the press chamber 10 in the press unit 100 will be described with reference to Fig. 4 and Fig. 5. Fig. 4 is an external view of the press chamber 10 in the dry ice block manufacturing apparatus 1. Fig. 5 is a three-dimensional view showing a cross-sectional structure taken along line AA in Fig. 4. Fig. 4 shows the external view of the press chamber 10 according to this embodiment in detail, while Fig. 5 shows the cross-sectional structure of a main part of the press chamber 10 with some of the configuration simplified.

[0025] 4, the press chamber 10 is box-shaped, and the press chamber 10, press block 61, and slide plate 71 form a box-like body with an internal space. The press chamber 10 has a bottom plate 20 and a peripheral wall portion 30 arranged to extend upward from the bottom plate 20. The peripheral wall portion 30 has a supply hole 31 continuing from a supply path 52 of a supply portion 50, and a discharge hole 32.

[0026] 4, the peripheral wall portion 30 is specifically configured by combining peripheral wall portions 30a1, 30a2 arranged at both ends of the press chamber 10 in the longitudinal direction and peripheral wall portions 30b1, 30b2 arranged at both ends of the press chamber 10 in the width direction. The peripheral wall portions 30a1, 30a2, 30b1, 30b2 are connected by bolts 36. (In the following figures, the peripheral wall portions 30a1, 30a2, 30b1, 30b2 and the bolts 36 are omitted from illustration.)

[0027] Supply hole 31 is provided penetrating in the thickness direction through one peripheral wall portion 30a2 located in the longitudinal direction of press chamber 10. Supply hole 31 and supply path 52 are screw-connected. At this time, supply path 52 is exposed to the inside of press chamber 10 through supply hole 31.

[0028] The discharge holes 32 are provided in the peripheral wall portions 30b1, 30b2 on both sides located in the width direction of the press chamber 10 in the shape of elongated holes extending in the longitudinal direction of the press chamber 10 and penetrating the peripheral wall portions 30b1, 30b2 in the thickness direction.

[0029] The discharge hole 32 according to this embodiment is divided into upper and lower portions by a partition wall 32c connected to the inner surface of the discharge hole, and has an upper discharge hole 32a and a lower discharge hole 32b. (The partition wall 32c is not shown in FIG. 5 and FIG. 7 and subsequent figures.)

[0030] The exhaust hole 32 functions as an exhaust path for exhausting the carbon dioxide gas. The outer end of the exhaust hole 32 functions as an exhaust port for exhausting the carbon dioxide gas to the outside of the unit.

[0031] As shown in Figure 5, the press chamber 10 further has a filter accommodating section 33 arranged at the inner end of the discharge hole 32, a sintered metal filter 40 provided in the filter accommodating section 33, a press area 34 (an example of the "inside of the press chamber"), and a guide section 35.

[0032] The filter accommodating portion 33 is a circumferential recess provided on the inner surface of the peripheral wall portion 30 around the inner end portion of the discharge hole 32 so as to be recessed in a direction from the inside to the outside of the press chamber 10 .

[0033] The sintered metal filter 40 is a plate-shaped filter material, and its periphery is housed in the filter housing portion 33 (details will be described later).

[0034] The pressing area 34 is a space surrounded by the upper surface 71a of the slide plate 71, the inner surface 30c of the peripheral wall portion 30, the lower surface 61a of the press block 61, and the surface 41a of the sintered metal filter 40 accommodated in the filter accommodating portion 33 that faces inward within the press chamber 10.

[0035] The guide portions 35 are openings provided at the lower ends of the peripheral wall portions 30 on both sides in the width direction of the press chamber 10 so as to open in a penetrating state toward the bottom plate 20. The slide plate 71 is supported between the opening faces of the guide portions 35 and the upper surface of the bottom plate 20 so as to be able to slide thereon.

[0036] In other words, when the dry ice block is molded, the slide plate 71 is partially contained inside the guide portion 35, and when the dry ice block is removed, the friction of the outer peripheral surface is guided by the opening surface of the guide portion 35 and the upper surface of the bottom plate 20.

[0037] Among the components of the press chamber 10 described above, the exhaust hole 32, the filter housing 33, and the sintered metal filter 40 function as an exhaust section that exhausts carbon dioxide gas to the outside. The press area 34, the press block 61, and the slide plate 71 function as a press section that presses the granular dry ice. The slide plate 71 functions as an extraction section that extracts the dry ice block.

[0038] [Configuration of sintered metal filter] Next, the sintered metal filter 40 will be described in detail with reference to Fig. 6 and Fig. 7. Fig. 6 is an enlarged cross-sectional view of a main part taken along line AA in Fig. 4. Fig. 7 is a perspective view showing the sintered metal filter 40 provided in the press chamber 10.

[0039] 6 and 7, the sintered metal filter 40 has a laminated sorting filter material 41 and a reinforcing material 42. In the sintered metal filter 40, the sorting filter material 41 and the reinforcing material 42 are laminated, and a front surface 41a of the sorting filter material 41 and a front surface 42a of the reinforcing material 42 are exposed on the surface.

[0040] 6, the filter accommodating section 33 has an accommodating bottom surface 33a and an accommodating side surface 33b that is continuous with the outer periphery of the accommodating bottom surface 33a. The sintered metal filter 40 is accommodated and fixed in the filter accommodating section 33 by the accommodating bottom surface 33a and the exposed surface 42a of the reinforcing material 42 being in contact with each other and the accommodating side surface 33b and the outer periphery of the sintered metal filter 40 being fitted together with a gap therebetween. In other words, the exposed surface 41a of the sorting filter material 41 of the sintered metal filter 40 faces the inside of the press chamber 10. The sintered metal filter 40 is fixed to the filter accommodating section 33 by screw connection or the like (not shown).

[0041] 6, the partition wall 32c of the discharge hole 32 according to the present embodiment shown in FIG. 4 is disposed so that the end of the partition wall 32c on the press chamber 10 side abuts against the exposed surface 42a of the reinforcing material 42 of the sintered metal filter 40 housed in the filter housing portion 33. As a result, the partition wall 32c functions as a rib that shares part of the pressing pressure applied from the inside of the press chamber 10 in the thickness direction of the sintered metal filter 40 material.

[0042] As shown in FIG. 6, the exposed surface 41 a of the selection filter material 41 of the sintered metal filter 40 is disposed so as to be flush with the inner circumferential surface 30 c of the peripheral wall portion 30 continuing to the filter housing portion 33 .

[0043] However, as shown in FIG. 6, the exposed surface 41a of the sorting filter material 41 may be configured to have a predetermined tolerance T (approximately 50 μm to 100 μm) so that it is positioned outside the press chamber 10 with respect to the inner circumferential surface 30c of the peripheral wall portion 30, taking into consideration manufacturing variations and the like.

[0044] Here, as shown in FIG. 6, the press area 34 specifically has a discharge press area 34E and a consolidation press area 34P. The discharge press area 34E is an area of ​​the press area 34 that is above the lower end of the filter accommodating section 33. The consolidation press area 34P is an area of ​​the press area 34 that is below the lower end of the filter accommodating section 33 and above the thickness t of the dry ice block that is finally formed. In the discharge press area 34E, the discharge of carbon dioxide gas and the consolidation of the granular dry ice proceed in parallel. In the consolidation press area 34P, the consolidation of the granular dry ice mainly proceeds.

[0045] Next, the sintered metal filter 40 will be further described with reference to Fig. 8. Fig. 8 is an enlarged side view of a main part showing the configuration of the sintered metal filter 40, taken along the line B in Fig. 7.

[0046] As shown in FIG. 8, the sintered metal filter 40 is specifically a sintered wire mesh filter, and the sorting filter material 41 and the reinforcing material 42 are each formed by stacking a plurality of wire meshes 41n, 41n, 42n, 42n, and further sintering the stacked layers.

[0047] Sintering is a process in which wires of the wire mesh are typically fused together by holding the wire mesh material at a temperature range close to its melting point to form an integral wire mesh structure. The sintered metal filter 40 can form fine and uniform filter holes by fusing the meshes of the wire mesh of each layer together, and the diameter of the filter filter holes, i.e., the opening size, can be adjusted by changing the mesh size of the wire mesh and the number of layers.

[0048] In this embodiment, the sorting filter material 41 is made by stacking multiple sheets of wire mesh 41n having a fine wire diameter and sintering the stacked layers, so that the diameter of the filter holes in the sorting filter material 41 is smaller than the particle diameter of the granular dry ice, but is set to a size that allows carbon dioxide, which is a gas, to pass through.

[0049] Specifically, the diameter of the filter pores of the sorting filter material 41 is set in the range of 60 to 140 μm. By setting the diameter in this range, it is possible to both capture particulate dry ice inside the pressing chamber 10 and efficiently exhaust carbon dioxide gas outside the pressing chamber 10, i.e., ensure air permeability.

[0050] The reinforcing material 42 is formed by stacking a plurality of wire meshes 42n, 42n, which have filter holes having a larger diameter than the sorting filter material 41 and a larger wire diameter than the wire mesh 41n of the sorting filter material 41, and therefore have a bending strength in the thickness direction greater than that of the sorting filter material 41.

[0051] Specifically, the wire diameter of the wire mesh 42n used in the reinforcing material 42 is about 7 to 13 times the wire diameter of the wire mesh 41n used in the sorting filter material. By setting the wire diameter of the wire mesh 42n of the reinforcing material 42 within this range, the reinforcing material 42 can increase the mechanical strength (particularly bending strength) of the sintered metal filter 40 as a whole while ensuring fusion with the sorting filter material 41. This makes it possible to prevent the sintered metal filter 40 from being plastically deformed by the pressure applied to the sintered metal filter 40 when the granular dry ice is pressed in the press chamber 10.

[0052] Furthermore, since the diameter of the filter holes of the reinforcing material 42 is larger than that of the sorting filter material 41, the sintered metal filter 40 can reinforce the mechanical strength of the sintered metal filter 40 while minimizing the decrease in air permeability of the sintered metal filter 40 as a whole (or suppressing the increase in pressure loss).

[0053] With the above-described configuration, the sintered metal filter 40 can reliably capture particulate dry ice within the press chamber 10 by setting an appropriate mesh size, and by having a multi-layer structure, it is possible to achieve both efficient exhaust of carbon dioxide gas by ensuring air permeability (or reducing pressure loss) and the necessary mechanical strength.

[0054] The sintered metal filter 40 may be composed of three or more wire meshes, and may be configured to have, for example, a second reinforcing material (not shown) separate from the reinforcing material 42, the mesh size of which is larger than that of the sorting filter material 41 and smaller than that of the reinforcing material 42, and the wire diameter of the wire mesh of the reinforcing material 42 and larger than that of the sorting filter material 41.

[0055] [Dry ice block manufacturing process] Next, the process for manufacturing a dry ice block from the above-mentioned configuration will be specifically described with reference to Figures 9 to 11. The process for manufacturing a dry ice block mainly includes three steps: a supply step for generating a mixed fluid of particulate dry ice and carbon dioxide gas from liquefied carbon dioxide gas and supplying the mixed fluid to the press unit 100, a pressing step for pressing the particulate dry ice, and a removal step for removing the formed dry ice block.

[0056] (Supply process) First, the supplying step will be described with reference to Fig. 9. Fig. 9 is a vertical cross-sectional view showing the supplying step of the dry ice block manufacturing apparatus 1.

[0057] To repeat, the supply path 52 releases the liquefied carbon dioxide gas to the atmosphere during the supply process, thereby causing a phase change of the liquefied carbon dioxide gas into a mixed fluid of particulate dry ice and carbon dioxide gas, and supplies the mixed fluid to the press chamber 10 of the press unit 100. Specifically, as shown in FIG. 9, the mixed fluid DP of particulate dry ice and carbon dioxide gas is supplied from the supply path 52 to the press chamber 10 through the supply hole 31. At this time, the diameter of the filter hole of the sorting filter material 41 facing the inside of the press chamber 10 among the sintered metal filter 40 provided in the press chamber 10 is smaller than the particle diameter of the particulate dry ice, so that the particulate dry ice is reliably captured within the press chamber 10 without being discharged from the discharge hole 32. On the other hand, the filter hole of the sorting filter material 41 allows carbon dioxide gas, which is a gas, to pass through, so that the carbon dioxide gas is discharged to the outside from the discharge hole 32 (arrow D1 in FIG. 9).

[0058] At this time, since the sintered metal filter 40 has high air permeability (or low pressure loss), the carbon dioxide gas is efficiently discharged to the outside of the press chamber 10. If the carbon dioxide gas discharge efficiency is poor, the mixture ratio of carbon dioxide gas in the mixed fluid DP becomes high. As a result, as the granular dry ice accumulates, the carbon dioxide gas accumulates inside the press chamber 10, and it becomes more likely that cavities will form inside the accumulated granular dry ice.

[0059] Cavities formed inside the dry ice lead to localized density deficiencies, which can lead to insufficient pressing pressure during pressing and cause cracks and chips in the formed dry ice block. In other words, poor carbon dioxide exhaust efficiency leads to a decrease in the molding quality of the dry ice block. Therefore, the dry ice block manufacturing device 1 can prevent cavities from forming inside the dry ice by reducing the pressure loss of the sintered metal filter 40, and by collecting granular dry ice at a high density in the press chamber 10, it is possible to improve the compaction density of the dry ice and the molding quality.

[0060] (Pressing process) Next, the pressing step will be described with reference to Fig. 10. Fig. 10 is a cross-sectional view showing the pressing step of the dry ice block manufacturing apparatus 1.

[0061] Again, press area 34 includes ejection press area 34E and consolidation press area 34P.

[0062] As shown in FIG. 10, the press cylinder unit 60 lowers the press block 61 within the press chamber 10 until the press block 61 passes through the discharge press area 34E and reaches the consolidation press area 34P, and finally a dry ice block DB is formed (arrow D2 in FIG. 10).

[0063] During this process, since a sintered metal filter 40 is arranged on the inner surface of the press chamber 10 in the discharge press area 34E, the press block 61 can apply pressure to the granular dry ice while also pushing out excess carbon dioxide gas to the outside through the sintered metal filter 40 and the discharge hole 32.

[0064] Therefore, the dry ice block manufacturing apparatus 1 can simultaneously compress the granular dry ice and discharge the carbon dioxide gas until just before the formation of the dry ice block DB is completed, and can compress the granular dry ice to a high density in the press area 34. Therefore, the dry ice block manufacturing apparatus 1 can improve the compression density of the dry ice block DB.

[0065] Furthermore, the surface of the sintered metal filter 40 housed in the filter housing 33 facing the inside of the press chamber 10 and the inner peripheral surface of the peripheral wall portion 30 connected to the filter housing 33 are configured to be flush with each other, so that the particulate dry ice close to the sintered metal filter 40 during molding can smoothly move from the discharge press area 34E to the consolidation press area 34P. This allows the dry ice block DB to be molded without causing uneven shapes, scratches, etc. on the side surface of the dry ice block DB. The uneven shapes, scratches, etc. on the side surface of the dry ice block DB can cause a decrease in strength of the dry ice block DB when an external force is applied to the dry ice block DB. Therefore, the dry ice block manufacturing device 1 can mold a dry ice block DB with a smooth surface without uneven shapes, scratches, etc., thereby improving the molding quality of the dry ice block DB.

[0066] In this case, the bending strength of the sintered metal filter 40 is reinforced by the reinforcing material 42, which has a greater bending strength than the sorting filter material 41, and therefore the sintered metal filter 40 can be prevented from being plastically deformed by the press pressure during the process of compressing the particulate dry ice and discharging the carbon dioxide gas in parallel. The plastic deformation of the sintered metal filter 40 can cause uneven shapes and scratches on the side of the dry ice, which reduces the strength of the dry ice and affects the molding quality of the dry ice block DB.

[0067] In the consolidation press area 34P, the granular dry ice is consolidated at high pressure (up to about 10 MPa) by the press block 61. The small amount of remaining carbon dioxide gas is discharged to the outside through the gap between the peripheral wall portion 30 and the press block 61.

[0068] At this time, since the filter housing portion 33 is not disposed on the inner peripheral surface of the press chamber 10 of the peripheral wall portion 30 within the range of the thickness of the dry ice block DB to be molded, the dry ice block manufacturing apparatus 1 can complete molding without being affected by various influences caused by the side surface of the dry ice block DB coming into contact with the sintered metal filter 40. This allows the dry ice block manufacturing apparatus 1 to improve the molding quality of the molded dry ice block DB.

[0069] After the formation of the dry ice block DB is completed, the press cylinder unit 60 slightly raises the press block 61 to release the pressure applied to the dry ice block DB.

[0070] (Removal process) Next, the removal step will be described with reference to Fig. 11. Fig. 11 is a vertical cross-sectional view showing the removal step of the dry ice block manufacturing apparatus 1.

[0071] 11, the slide cylinder unit 70 drives the slide plate 71 toward the outside of the press chamber 10 (arrow D3 in FIG. 11) and the press cylinder unit 60 lowers the press block 61 (arrow D2 in FIG. 11), thereby moving the dry ice block DB onto the bottom plate 20 of the press chamber 10. After that, the slide cylinder unit 70 drives the slide plate 71 toward the inside of the press chamber 10 (the opposite direction of arrow D3 in FIG. 11), thereby pushing the dry ice block DB on the bottom plate 20 out to the outside of the apparatus (phantom line in FIG. 11).

[0072] This series of operations is automated as a sequence by the control unit 2 shown in Figure 3, and the user can enter the production conditions in the input unit 4 in Figure 3 and then wait for a while before removing the dry ice block DB as shown by the virtual line in Figure 11.

[0073] [Configuration of opening and closing valve] Next, the configuration of the on-off valve 51 in the dry ice block manufacturing apparatus of the present invention will be described with reference to Fig. 12. Fig. 12 is a vertical cross-sectional view showing the on-off valve 51 in the dry ice block manufacturing apparatus of the present invention.

[0074] In the following explanation, the side from the on-off valve 51 that supplies liquefied carbon dioxide gas to the on-off valve 51 is referred to as the "upstream side", and the side from which the liquefied carbon dioxide gas that has passed through the on-off valve 51 is supplied to the press unit 100 is referred to as the "downstream side".

[0075] As shown in Figure 12, the on-off valve 51 has a valve box 53, a granulation section 56 connected to the downstream side of the valve box 53, a valve element 54 arranged to be movable inside the valve box 53, a valve element moving means 55 for moving the valve element 54, and an orifice 57 for regulating the flow path area of ​​the liquefied carbon dioxide gas.

[0076] To repeat, the on-off valve 51 is provided in the supply path 52. Specifically, the supply path 52 has, from the upstream side, an upstream supply path 52a, a valve seat 52b, and a downstream supply path 52c.

[0077] The valve seat 52b opens and closes the supply path 52 together with the valve body 54. The granulating section 56 is specifically provided downstream of the downstream supply path 52c.

[0078] When the on-off valve 51 is in a closed state, the valve body 54, together with the valve seat 52b, blocks the supply path 52 (phantom line in FIG. 12), and at this time, the liquefied carbon dioxide gas is not supplied downstream of the upstream supply path 52a.

[0079] On the other hand, the on-off valve 51 is opened when the valve element 54 is moved by the valve moving means, and a flow path for the liquefied carbon dioxide gas (hereinafter referred to as the valve seat path 52d) is formed between the valve element 54 and the valve seat 52b.

[0080] The orifice 57 is disposed in the granulation section 56 and upstream of the granulation section 56. The flow path area of ​​the liquefied carbon dioxide gas regulated by the orifice 57 is smaller than the flow path area of ​​a narrow passage section 52e where the flow path area is reduced in the flow path from the upstream supply path 52a to the valve seat path 52d.

[0081] As a result, the liquefied carbon dioxide gas is decompressed and changes phase due to adiabatic expansion in the granulation section 56 after passing through the orifice 57, where the flow passage area is the smallest in the supply flow passage. In other words, granular dry ice and carbon dioxide gas are produced in the granulation section 56.

[0082] Even after passing through the narrow passage portion 52e, the liquefied carbon dioxide gas does not change phase because the pressure reduction is suppressed while the liquefied carbon dioxide gas is located upstream of the orifice 57. In other words, the liquefied carbon dioxide gas does not change phase in the valve seat path 52d, and particulate dry ice and carbon dioxide gas are not generated in the valve seat path 52d.

[0083] Here, the conventional on-off valve does not have an orifice 57. At this time, when the liquefied carbon dioxide gas passes through the narrow passage portion 52e where the flow passage area is the smallest in the supply passage 52, the pressure is reduced by adiabatic expansion and the phase changes. That is, granular dry ice and carbon dioxide gas are generated in the valve seat passage 52d. As a result, in the conventional on-off valve, the granular dry ice generated adheres to the valve seat 52b, and when the valve is closed, the granular dry ice gets caught between the valve body 54 and the valve seat 52b, which can cause operational problems.

[0084] In contrast, in the on-off valve 51, the liquefied carbon dioxide gas does not undergo a phase change in the valve seat path 52d and remains in a liquid state, so that granular dry ice is not generated in the valve seat path 52d. Therefore, the on-off valve 51 does not cause operational problems due to the granular dry ice generated sticking to the valve seat 52b. Therefore, the dry ice block manufacturing device 1 can stably generate granular dry ice and carbon dioxide gas in the granulating section 56, improving the quality of the dry ice formed.

[0085] As shown in Fig. 13, the orifice 257 may be disposed and configured so as to be integrated with the configuration of the valve seat 52b in the valve box 53. Fig. 13 is a vertical cross-sectional view showing an on-off valve 251 according to a modified example of the present invention (one example of an "on-off valve with an orifice").

[0086] As with the orifice 57, the flow path area of ​​the liquefied carbon dioxide gas restricted by the orifice 257 is smaller than the flow path area of ​​the narrow passage portion 52e in the valve seat path 52d. This allows the on-off valve 251 to suppress a drop in the internal pressure of the liquefied carbon dioxide gas upstream of the orifice 257. In other words, the liquefied carbon dioxide gas is depressurized and undergoes a phase change due to adiabatic expansion in the granulation portion 56 past the orifice 257, so that particulate dry ice is not generated in the valve seat path 52d upstream of the orifice 257, and the dry ice does not adhere to the valve seat 52b. Therefore, the on-off valve 251 can prevent operational malfunctions similar to the on-off valve 51.

[0087] As described above, the dry ice block manufacturing apparatus 1 can separate the particulate dry ice from the carbon dioxide gas with high efficiency and collect the particulate dry ice at a high density by achieving both the collection of particulate dry ice by the sintered metal filter 40 and the discharge of carbon dioxide gas by suppressing pressure loss. Then, the particulate dry ice collected at a high density is compressed in the press section, producing dry ice with a high degree of compaction. Therefore, the dry ice block manufacturing apparatus 1 can improve the compaction degree of the dry ice.

[0088] Furthermore, by arranging the multi-layered sintered metal filter 40 at an optimal position in the press chamber 10, the dry ice block manufacturing apparatus 1 can reliably collect particulate dry ice in the press chamber 10, while ensuring air permeability (or reducing pressure loss) to efficiently discharge carbon dioxide gas and providing the necessary mechanical strength. This prevents the dry ice block from becoming uneven or scratched due to deformation of the sintered metal filter 40, and produces a dry ice block with a smooth surface free of unevenness or scratches. Therefore, the dry ice block manufacturing apparatus 1 can improve the compaction degree of the dry ice block and improve the molding quality of the dry ice block.

[0089] [Confirmation results of dry ice block quality rate] As a manufacturing test of the dry ice block, a dry ice block of a size that is easy to put into a cooling suit, about 20 mm thick x 140 mm long x 75 mm wide, was manufactured, and the yield rate of the manufactured dry ice block without cracks or chips was confirmed. The yield rate of the dry ice block manufactured by the conventional device, which is a press device without the sintered metal filter 40 of the present invention and a dry ice block manufacturing device equipped with an on-off valve without the orifice 57 of the present invention, was 72%. In contrast, the yield rate of the dry ice block molded by the press chamber 10 having the sintered metal filter 40 of the present invention and the dry ice block manufacturing device 1 equipped with the on-off valve 51 of the present invention was 98%. In other words, the yield rate of the dry ice block of a size that is easy to put into a cooling suit was significantly improved by improving the compaction degree of the dry ice block. <Embodiment 2>

[0090] Next, the press unit 200 of the dry ice block manufacturing apparatus 1 according to the second embodiment of the present invention will be described with reference to Fig. 14 onwards. The press unit 200 according to this embodiment is obtained by improving the "seal structure", "supply section" and "press section" of the press unit 100 according to the first embodiment, thereby improving the manufacturing efficiency and molding quality of the dry ice block manufacturing apparatus 1. The press unit 200 includes a press chamber 210, a supply section 250 and a slide cylinder section 70.

[0091] [Press Room 210 Configuration] First, the configuration of the press chamber 210 of the press unit 200 will be described with reference to Figures 14, 15, and 16. Figure 14 is an exploded perspective view of the press chamber 210. Figure 15 is a vertical cross-sectional perspective view of the press chamber 210. Figure 16 is a vertical cross-sectional view in which the cross sections shown in Figure 15 are developed.

[0092] The press chamber 210 has a press cylinder portion 260 and a peripheral wall portion 230 instead of the press cylinder portion 60 and the peripheral wall portion 30 described in the first embodiment above.

[0093] The press cylinder section 260 has a press block 261, a first seal plate 63 (an example of a first metal member), a damper 64 (an example of an elastic member), a press plate 80 (an example of a press plate), and a first bolt B1. The press block 261 is connected to a press rod 262. In the following, the configuration above the press rod 262 in the press cylinder section 260 is similar to the configuration in the first embodiment described above, and therefore illustrations and descriptions thereof will be omitted by referring to the above.

[0094] The press plate 80 is configured by stacking a first press plate 81 (an example of a first press plate) made of metal arranged above and a second press plate 82 (an example of a second press plate) made of, for example, PTFE (Poly Tetra Fluoro Ethylene) arranged below. The second press plate 82 is screwed to the first press plate 81 from above.

[0095] The damper 64 is an elastic member arranged in an annular shape on the upper surface along the outer circumferential edge of the first press plate 81. The damper 64 is made of, for example, NBR (Nitril-Butadiene Rubber). The first seal plate 63 is, for example, a metal member laminated in an annular shape above the damper 64 so as to cover the upper surface of the damper 64.

[0096] A recess 86 that is recessed annularly downward from the upper surface is provided at the outer circumferential edge of the upper surface of the first press plate 81. The damper 64 and the first seal plate 63 are fitted into the recess 86 and housed in a stacked state.

[0097] With the damper 64 and the first seal plate 63 housed in the recess 86, the press block 261 is fixed to the first press plate 81 by a first bolt B1. The first bolt B1 is screwed into a screw hole (reference number omitted) provided in the first press plate 81. At this time, the outer end of the lower surface of the press block 261 and the inner end of the upper surface of the first seal plate 63 overlap over the entire circumference when viewed from above, and in this overlapping portion, the lower surface of the press block 261 is configured to be able to come into contact with the upper surface of the first seal plate 63 in the up-down direction.

[0098] The peripheral wall portion 230 has a second seal plate 37 (an example of a second metal member), a gasket 38, and a second bolt B2.

[0099] The second seal plate 37 is an annular member, for example a metal member, and is fixed to the upper end of the peripheral wall portion 230 by a second bolt B2 via a gasket 38. The second bolt B2 is screwed into a screw hole (reference number omitted) provided in the upper end of the peripheral wall portion 230. At this time, the inner end of the lower surface of the second seal plate 37 and the outer end of the upper surface of the first seal plate 63 overlap over the entire circumference when viewed from above, and the lower surface of the second seal plate 37 is configured to be able to come into contact with the upper surface of the first seal plate 63 in the up-down direction in this overlapping portion.

[0100] The inner surface of the second seal plate 37 and the outer surface of the press block 261 are disposed to face each other with a predetermined gap therebetween.

[0101] In the following, the configurations of the portion indicated by the symbol C (seal structure), the portion indicated by the symbol D (supply section 250), and the portion indicated by the symbol E (press section: press plate 80) in FIG. 16 will be described in order.

[0102] (Seal structure configuration) First, the configuration of the seal structure in the press chamber 210 will be described with reference to Fig. 17. Fig. 17 is an enlarged vertical cross-sectional view of part C in Fig. 16.

[0103] To repeat, in the dry ice block manufacturing apparatus 1, liquefied carbon dioxide gas is phase-changed into a mixed fluid of particulate dry ice and carbon dioxide gas, and the mixed fluid is supplied to the press chamber 210 to manufacture dry ice blocks. Here, in the dry ice block manufacturing apparatus 1, the challenge is to improve the manufacturing efficiency (conversion efficiency) of the dry ice block with respect to the liquefied carbon dioxide gas per unit amount supplied. Specifically, the challenge is to ensure the sealing property in the press chamber 210 when the mixed fluid is supplied. In the press chamber 210, a certain gap is required for the press section to drive, but if this gap is not properly sealed when the mixed fluid is supplied, the amount of leakage of the mixed fluid (particulate dry ice in particular) from the gap increases, and the conversion efficiency deteriorates. In addition, in a dry ice manufacturing apparatus that is premised on operating in a low-temperature environment, the challenges are the deterioration of the sealing property due to the shrinkage of the sealing material at low temperatures and the decrease in the durability strength of the sealing material due to the tendency of the physical properties to become brittle at low temperatures. The seal structure of this embodiment provides a seal structure that can sufficiently ensure the sealing property in the press chamber 210 even in a low-temperature environment.

[0104] In this embodiment, the first seal plate 63, the second seal plate 37, the damper 64, the first press plate 81, and the press block 261 described above form a seal structure that seals the inside of the press chamber 210.

[0105] As described above, the first press plate 81 is fixed from above by fastening the press block 261 to the first press plate 81 with the first bolt B1 (see FIG. 16) in a state in which the damper 64 and the first seal plate 63 are stacked and fitted into the recessed portion 86. At this time, the press block 261 is fixed in a state in which the outer end 261b of the lower surface of the press block 261 and the inner end 63b of the upper surface of the first seal plate 63 are in contact over the entire circumference as shown in the figure.

[0106] In the process of fixing the press block 261 to the first press plate 81, the damper 64 is compressed by Δ1 as shown in the figure from the initial state (see the imaginary line in FIG. 17). In other words, the damper 64 is assembled to the first press plate 81 in a state in which it has been compressed by Δ1 in advance and is pressurized.

[0107] A peripheral wall member 87 extending upward along the outer periphery is provided in the recess 86. The damper 64 and the first seal plate 63 are housed inside the peripheral wall member 87 in a stacked state while fitting into the recess 86.

[0108] A chamfered portion 87c is formed along the inner edge of the upper end of the peripheral wall member 87. The height H1 of the peripheral wall member 87 is set to be smaller than the height H2 of the compressed damper 64. In other words, the damper 64 can be further compressed by the difference between these heights (H2-H1).

[0109] A predetermined gap is provided between the inner surface 87b of the peripheral wall member 87 and the outer surface of the damper 64. The damper 64 is capable of elastic deformation within the range of this gap.

[0110] In the following, the position where the first press plate 81 (press plate 80) is located at the top within the press chamber 210 and the first seal plate 63 and the second seal plate 37 are not in contact with each other, as shown in Figures 16 and 17, is referred to as the "origin position" with respect to the vertical position of the press plate 80.

[0111] (Configuration of Supply Unit 250) Next, the configuration of the supply unit 250 will be described with reference to Figures 18A, 18B, 19A, and 19B. Figures 18A and 19A are enlarged longitudinal sectional views of part D in Figure 16. Figures 18B and 19B are perspective views of Figures 18A and 19A, respectively, as viewed from the inside of the press chamber 210 (as viewed from the arrow F).

[0112] Although details will be described later, in the dry ice block manufacturing apparatus 1, for example, due to malfunction of the on-off valve 51 (see FIG. 1), liquefied carbon dioxide gas may be unintentionally supplied into the press chamber 210. In this case, the molding quality of the dry ice block may be affected. The supply unit 250 of the present embodiment provides a supply unit 250 that can ensure the molding quality of the dry ice block even when a mixed fluid or a liquefied carbon dioxide mixed fluid is unintentionally supplied from the supply path 52 into the press chamber 210 without being phase-changed. The following describes, as an example, a case where liquefied carbon dioxide gas is unintentionally supplied from the supply path 52 into the press chamber 210.

[0113] As shown in the figure, the supply unit 250 has a supply path 52. To repeat, the supply path 52 changes the phase of the liquefied carbon dioxide gas into a mixed fluid of particulate dry ice and carbon dioxide gas, and supplies the mixed fluid to the pressing region 34 of the pressing chamber 210 (arrow D6).

[0114] The supply section 250 further has an exhaust path 58. The exhaust path 58 is provided above the supply path 52 within the press chamber 210. Specifically, the exhaust path 58 is configured as a recess that is recessed outward on the inner surface of the peripheral wall section 230. The exhaust path 58 is provided such that one end 58b opens into the press chamber 210 and the lower end of the other end 58c opens into the supply path 52. In this embodiment, the one end 58b is formed to extend in the circumferential direction of the peripheral wall section 230, and the other end 58c is formed to extend in the up-down direction.

[0115] The exhaust path 58 is switched between a closed state and an open state by the movement of the press plate 80 (first press plate 81, second press plate 82). Here, as shown in Fig. 18A, the press plate 80 is configured so that a gap CL1 between the outer surface of the first press plate 81 and the inner surface of the peripheral wall portion 230 is larger than a gap CL2 between the outer surface of the second press plate 82 and the inner surface of the peripheral wall portion 230. Note that CL1 is set as a dimension that allows the particulate dry ice described above to easily pass through continuously. Also, CL2 is set as a dimension that allows the particulate dry ice to have difficulty passing through continuously.

[0116] 18A and 18B, when the press plate 80 rises from the origin position indicated by the imaginary line (see FIG. 18A) (arrow D4 in the figure), one end 58b of the exhaust path 58 faces the outer surface of the second press plate 82. Since CL2 is set to a dimension that makes it difficult for particulate dry ice to pass through, the exhaust path 58 is closed. At this time, the liquefied carbon dioxide gas from the supply path 52 is not exhausted above the press plate 80 (dotted arrow in the figure).

[0117] 19A and 19B, when the press plate 80 is lowered from the state shown in FIGS. 18A and 18B (arrow D5 in FIG. 19A), one end 58b of the exhaust path 58 does not face the outer surface of the second press plate 82, but faces the outer surface of the first press plate 81. At this time, the exhaust path 58 is in an open state because CL1 is set to a dimension that allows particulate dry ice to easily pass through. Specifically, at this time, the liquefied carbon dioxide gas from the supply path 52 passes through the other end 58c, one end 58b, and the gap CL1 between the inner surface of the peripheral wall portion 230 and the first press plate 81 in this order, and can be exhausted above the press plate 80 in the press chamber 210 (arrow D7).

[0118] (Configuration of press plate 80) Next, the configuration of the press plate 80 in the press chamber 210 will be described with reference to Fig. 20. Fig. 20 is an enlarged vertical cross-sectional view of a portion E in Fig. 16.

[0119] Although details will be described later, an issue to be addressed in the dry ice block manufacturing apparatus 1 is how to improve the molding quality of the dry ice blocks. The press plate 80 of the present embodiment provides a press plate 80 that can improve the molding quality of the dry ice blocks by effectively using the second press plate 82 (PTFE plate).

[0120] As described above, the second press plate 82 (a PTFE plate) is disposed below the first press plate 81, and the second press plate 82 is screwed from above to the first press plate 81. Specifically, the first press plate 81 is provided with a plurality of through holes 84 (see FIG. 1), and the upper end of each through hole 84 is formed with a countersunk portion 84b, and the lower end of each screw hole is formed with a chamfered portion 84c.

[0121] Further, the second press plate 82 is provided with a plurality of tapping holes 85 at positions corresponding to the plurality of through holes 84 (see FIG. 1). Then, a plurality of tapping screws 83 (one example of a screw) are passed through the through holes 84 and screwed into the tapping holes 85 of the second press plate 82. At this time, as illustrated in the upper blowing section, the height of the head of the tapping screw 83 is configured to be slightly greater than the height of the countersunk portion 84b of the screw hole. As a result, the head of the tapping screw 83 protrudes by Δ2 from the upper surface of the first press plate 81.

[0122] In this state, the press block 261 (connecting member) is fixed to the first press plate 81 by the first bolt B1 (see FIG. 16). As a result, as shown in FIG. 20, the lower surface of the press block 261 presses the head of the tapping screw 83 from above with a predetermined acting force F1.

[0123] Generally, the PTFE member (second press plate 82) has a low coefficient of friction, which makes it difficult to screw in. This is because sufficient friction is not generated on the contact surface between the thread and the PTFE member, resulting in insufficient axial force of the screw and making the screw prone to loosening.

[0124] In this embodiment, with the above-described configuration, the head of the tapping screw 83 is pressed from above, thereby compensating for any insufficient axial force of the screw, and a certain frictional force is obtained at the contact surface between the seat surface of the head of the tapping screw 83 and the first press plate 81. This suppresses rotation of the tapping screw 83, thereby suppressing loosening of the tapping screw 83. In other words, the tapping screw 83 can be screwed into the PTFE member (second press plate 82) without requiring any new parts such as a washer, and is prevented from loosening by only the components of the press cylinder portion 260.

[0125] Furthermore, when the PTFE member is screwed in, the hole of the tapping screw 83 is forced open while being screwed in, which causes the second press plate 82 to deform, and as shown by the imaginary line, the deformation flows into the boundary between the first press plate 81 and the second press plate 82, which may cause a gap CL to form between the first press plate 81 and the second press plate 82. This may prevent the second press plate 82 from being stably fixed to the first plate 81.

[0126] In this embodiment, a chamfered portion 84c is formed at the lower end of the through hole 84 of the first press plate 81, and as shown in the lower blow-out portion, a predetermined space is formed between the chamfered portion 84c and the second press plate 82. This makes it possible to accommodate the deformed amount of the PTFE member expanded by being screwed into the second press plate 82 in this space. This suppresses the occurrence of a gap CL at the boundary between the first press plate 81 and the second press plate 82, and thus the second press plate 82 is tightly attached to the first press plate 81 and stably fixed.

[0127] [Dry ice block manufacturing process] Next, the process of manufacturing a dry ice block in the above configuration will be described with reference to Figures 21 to 25. To repeat, the process of manufacturing a dry ice block mainly includes three steps: a supply step of supplying a mixed fluid of particulate dry ice and carbon dioxide gas to the press unit 200, a pressing step of pressing the particulate dry ice to form a dry ice block, and a removal step of removing the formed dry ice block.

[0128] (Supply process) First, the supplying step will be described with reference to Fig. 21. Fig. 21 is a vertical cross-sectional view showing the supplying step of the dry ice block manufacturing apparatus 1 using the press unit 200.

[0129] As shown in FIG. 21, the press cylinder portion 260 raises the press plate 80 (arrow D4 in FIG. 21) from the state in which the press plate 80 is in the original position shown in FIG. 16 and FIG. 17 (a state in which the first seal plate 63 and the second seal plate 37 are not in contact).

[0130] 21 and 22A, the first seal plate 63 comes into contact with the second seal plate 37. Fig. 22A is an enlarged vertical cross-sectional view of portion G in Fig. 21. As shown in the figure, the outer end 63b of the upper surface of the first seal plate 63 and the inner end 37b of the lower surface of the second seal plate 37 come into contact with each other and are pressed against each other in the vertical direction, so that the damper 64 at the bottom of the first seal plate 63 receives a compressive force F2 from the state of the imaginary line shown in the figure and elastically deforms (Δ3 in FIG. 22). As a reaction force, a force F3 is applied from the first seal plate 63 to the second seal plate 37, sealing the gap between the first seal plate 63 and the second seal plate 37. Note that the gap between the second seal plate 37 and the peripheral wall portion 230 is appropriately sealed by disposing the gasket 38. Therefore, in the gap between the inner surface of the peripheral wall portion 230 and the outer surface of the first press plate 81, particularly the particulate dry ice DP (arrow D9 in the figure) of the mixed fluid flowing from below is blocked at the top (broken line arrow in the figure) and does not leak to the outside. That is, the sealing property in the press chamber 210 during the supply process is ensured.

[0131] Here, as described above, since the damper 64 is assembled to the first press plate 81 in a state in which it is previously contracted by Δ1 (see FIG. 17), at the time shown in FIG. 22A, the damper 64 is in a state compressed by Δ1+Δ3 from the initial state. In the seal structure of this embodiment, the compression allowances Δ1 and Δ3 of the damper 64 can be set so as to be sufficiently secured. This makes it possible to configure the damper 64 so as to secure a desired acting force F3 even when considering the low-temperature contraction of the damper 64 (and manufacturing variations, etc.). The compression allowances Δ1 and Δ3 of the damper 64 are set using parameters such as the height H1 of the peripheral wall member 87, the height H2 of the damper 64 (see FIG. 17), the rise amount of the press cylinder portion 260, and the recess depth of the recess portion 86, for example.

[0132] For example, if the damper 64 is disposed in the gap between the inner surface of the peripheral wall portion 230 and the first press plate 81, if the compression allowance of the damper 64 is made too large out of concern for deterioration of sealing performance due to shrinkage at low temperatures, excessive stress will be generated in the damper 64 material during operation at room temperature, which is a trade-off. However, in the seal structure of this embodiment, even if a sufficient compression allowance is provided, the above-mentioned trade-off does not occur during operation at room temperature.

[0133] At this time, only a compressive force is applied to the damper 64, and no shear force, friction force, or the like is applied, so that the mechanical load on the damper 64 can be stabilized. Furthermore, the damper 64 is pressed against the second seal plate 37 via the first seal plate 63, and is not pressed directly against the second seal plate 37. Therefore, for example, the occurrence of stress concentration in the damper 64 due to localized strong contact with the end of the second seal plate 37 is suppressed.

[0134] Here, the first press plate 81 is provided with a peripheral wall member 87 and a chamfered portion 87c on the peripheral wall member 87. As shown in FIG. 22B, if the peripheral wall member 87 is not provided, for example, when the damper 64 elastically deforms and moves outward, the damper 64 may come into strong contact with the outer periphery of the recessed portion 86 as indicated by reference symbol C1. In addition, at this time, the damper 64 may come into contact with the inner surface of the peripheral wall portion 230 as indicated by reference symbol C2, and shear force, friction force, and the like may be applied. In addition, as shown in FIG. 22C, if the chamfered portion 87c of the peripheral wall member 87 is not provided, the damper 64 may come into strong contact with the upper end of the peripheral wall portion 230 as indicated by reference symbol C3 when the damper 64 elastically deforms. As described above, by providing the peripheral wall member 87 and the chamfered portion 87c on the peripheral wall member 87, the occurrence of stress concentration and the occurrence of shear force and friction force in the damper 64 is suppressed, and as a result, the durability strength of the damper 64 can be improved. In particular, when the damper 64 is used in a low-temperature environment, the physical properties tend to become brittle and the influence of stress concentration becomes greater, but by configuring as described above, the generated stress is alleviated even in a low-temperature environment, and a predetermined durability strength can be ensured. Note that in this embodiment, the chamfered portion 87c is configured as a C-chamfer, but the chamfered portion 87c may be configured as, for example, an R-chamfer.

[0135] Thereafter, similarly to the first embodiment, the mixed fluid is supplied to the pressing chamber 210 (arrow D6 in FIG. 21). The carbon dioxide gas in the mixed fluid is discharged to the outside from the discharge hole 32 (arrow D8 in FIG. 21), and the particulate dry ice DP is reliably collected in the pressing chamber 210 by maintaining the sealing performance within the pressing chamber 210 as described above. In other words, the dry ice block manufacturing apparatus 1 can stably ensure the sealing performance within the pressing chamber 210 for a long period of time.

[0136] (Pressing process) Next, the pressing process will be described with reference to Fig. 23 and Fig. 24. Fig. 23 and Fig. 24 are vertical cross-sectional views showing the pressing process of the dry ice block manufacturing apparatus 1 using the press unit 200. Fig. 23 shows the state immediately after the pressing process starts, and Fig. 24 shows the state after the pressing process is completed.

[0137] The pressing process is started after the supply of liquefied carbon dioxide gas into the press chamber 210 is completed and the supply of liquefied carbon dioxide gas is stopped in the supply process described above. The supply of liquefied carbon dioxide gas is stopped by the operation of the on-off valve 51 (see FIG. 1) described above. However, there is a possibility that liquefied carbon dioxide gas may be unintentionally supplied into the press chamber 210 even after the pressing process is started due to, for example, a malfunction of the on-off valve 51. In this case, if the pressure in the press chamber 210 becomes excessively high due to an excessive supply of liquefied carbon dioxide gas in the press chamber 210, the liquefied carbon dioxide gas may remain in the press chamber 210 as liquefied carbon dioxide gas without changing into a mixed fluid and may coexist with the dry ice block. In that case, when the press chamber 210 is opened to the outside and released to the atmosphere in the subsequent removal process, the pressure in the press chamber 210 is suddenly reduced, and the liquefied carbon dioxide gas changes into a gas phase and expands rapidly, which may cause cracks in the dry ice block and reduce the molding quality of the dry ice block.

[0138] In this embodiment, as shown in FIG. 23, in the early stage when the press cylinder portion 260 starts to descend (arrow D5 in FIG. 23), the exhaust path 58 is opened as described above, and the supply path 52 communicates with the upper part of the press plate 80 (arrow D7 in FIG. 23). Therefore, even if liquefied carbon dioxide gas is unintentionally supplied from the supply path 52 during the pressing process (arrow D6 in FIG. 23), the excessively supplied liquefied carbon dioxide gas can be exhausted above the press plate 80 from the open exhaust path 58. As a result, even if there is an excessive supply of liquefied carbon dioxide gas, the pressure in the press chamber 210 is vented, thereby preventing a sudden pressure increase in the press chamber 210. As a result, even if liquefied carbon dioxide gas is unintentionally supplied into the press chamber 210, the molding quality of the dry ice block is ensured.

[0139] More specifically, when a pilot type on-off valve 51 is used as the on-off valve 51, the opening and closing of the valve is controlled based on the pressure difference between the primary side and secondary side of the on-off valve 51. In this case, if there is an excessive supply of liquefied carbon dioxide gas as described above and the pressure on the secondary side (inside the press chamber 210) becomes high, there is a risk of the on-off valve 51 malfunctioning. In this embodiment, even when a pilot type on-off valve 51 is used, it is possible to avoid malfunction of the on-off valve 51 by exhausting the excessively supplied liquefied carbon dioxide gas as described above and venting the secondary side pressure.

[0140] Then, as shown in FIG. 24, the press cylinder portion 260 further lowers the press block 261 (arrow D5 in FIG. 24), whereby a dry ice block DB is formed in the press area .

[0141] (Removal process) Next, the removal step will be described with reference to Fig. 25. Fig. 25 is a vertical cross-sectional view showing the removal step of the dry ice block manufacturing apparatus 1 using the press unit 200.

[0142] As shown in Figure 25, the slide cylinder unit 70 drives the slide plate 71 toward the outside of the press chamber 210 (arrow D10 in Figure 25) and the press cylinder unit 260 lowers the press block 261 (arrow D5 in Figure 25), thereby moving the dry ice block DB onto the bottom plate 20 of the press chamber 210.

[0143] In this case, the manufacturing apparatus 1 for the dry ice block has the following issues: ensuring the detachability of the dry ice block DB from the press plate 80, ensuring the smoothness of the surface of the dry ice as the molding quality of the dry ice block DB, and ensuring the heat insulation by the press plate 80. For example, if a metal surface with low detachability is exposed on the surface of the press plate 80 and the dry ice block DB is not detached from the press plate 80, the dry ice block DB will not be taken out of the press unit 200 and will remain and accumulate in the press unit 200, which may make it difficult to continue the manufacturing sequence. In addition, since the unevenness of the surface of the dry ice block DB can be the starting point of stress concentration, ensuring the smoothness of the surface is also important from the viewpoint of ensuring the strength of the dry ice block DB. In addition, when the press chamber 210 is at room temperature when the apparatus is started, if the press plate 80 is made of a material with high thermal conductivity, if significant heat is input from the press plate 80 to the surface of the dry ice block DB during the pressing process, intense sublimation occurs on the surface of the dry ice block DB, and high-pressure gas is generated on the surface of the dry ice block DB. Then, when the load on the dry ice block is removed in the removal process, this gas expands, and there is a risk of cracks occurring in the dry ice block DB. Therefore, from the viewpoint of the molding quality of the dry ice block DB, it is important that the press plate 80 has high thermal insulation properties.

[0144] In this embodiment, the press plate 80 contacts the dry ice block DB via the second press plate 82 (a PTFE plate) that has high releasability, so that the dry ice block DB is easily peeled off from the press plate 80. Also, because the second press plate 82 is screwed from above, the screw surfaces are not exposed on the underside of the second press plate 82. Therefore, the dry ice block DB does not enter, for example, the uneven portion that accommodates the screw head, which causes an anchor effect that deteriorates the releasability from the second press plate 82, so that the dry ice block DB is easily peeled off from the press plate 80.

[0145] Also, because the second press plate 82 is screwed from above, the lower surface of the second press plate 82 is kept smooth since the screw surfaces are not exposed. Furthermore, because the through holes 84 are provided with chamfered portions 84c (see FIG. 20), the second press plate 82 is stably fixed to the first press plate 81. Therefore, the dry ice block DB that comes into contact with the lower surface of the second press plate 82 stably maintains its surface smoothness, improving the molding quality.

[0146] In addition, the heads of the tapping screws 83 that screw the second press plate 82 are pressed from above (see FIG. 20), thereby preventing the tapping screws 83 from turning. Therefore, the dry ice block manufacturing device 1 can stably manufacture the dry ice blocks DB with the above-mentioned quality assured for a long period of time.

[0147] In addition, the second press plate 82 (PTFE plate) has low thermal conductivity, i.e., high thermal insulation, compared to, for example, metal materials. Therefore, the heat input from the first press plate 81 connected above to this is almost completely blocked by the second press plate 82. This suppresses the generation of gas due to sublimation on the surface of the dry ice block DB as described above, and the generation of cracks in the dry ice block DB due to gas generation.

[0148] Although not shown in the figure, the dry ice block DB is then pushed out of the device by the slide cylinder section 70. Finally, the press cylinder section 260 moves the press block 261 until the press plate 80 is located at the origin position (see Figures 16 and 17), and the process ends. As a result, the production of the dry ice block DB is completed, and the press plate 80 is located at the origin position while waiting for the next dry ice block DB to be produced in the production sequence. In other words, during this time, the damper 64 is not compressed and deformed. Therefore, the damper 64 is prevented from generating permanent compression set due to the application of a compressive force for a long period of time.

[0149] As described above, in the manufacturing apparatus 1 for dry ice blocks according to this embodiment, the sealing structure in the press chamber 210 is improved compared to the first embodiment, and the sealing performance of the press chamber 210 is ensured, thereby improving the conversion efficiency from liquefied carbon dioxide to dry ice blocks DB (the manufacturing efficiency of dry ice blocks DB from liquefied carbon dioxide per unit amount) and ensuring the durability of the seal material (damper 64). Furthermore, the improvement of the exhaust structure in the press chamber 210 ensures the molding quality in the manufacturing process of the dry ice blocks DB. Furthermore, the improvement of the press plate 80 in the press chamber 210 improves the molding quality of the dry ice blocks DB.

[0150] As a result, the dry ice block manufacturing apparatus 1 according to this embodiment can stably ensure improved manufacturing efficiency and molding quality of the dry ice blocks DB for a long period of time compared to the first embodiment.

[0151] The embodiments of the present invention have been described above with reference to the drawings. However, the present invention is not limited to the above embodiments, and can be implemented in various forms without departing from the spirit of the present invention. The drawings are mainly schematic illustrations of each component for ease of understanding, and the thickness, length, number, spacing, etc. of each component shown in the drawings are different from the actual ones due to the convenience of drawing. In addition, the material, shape, dimensions, etc. of each component shown in the above embodiments are merely examples and are not particularly limited, and various modifications are possible within a range that does not substantially deviate from the configuration of the present invention. [Industrial Applicability]

[0152] INDUSTRIAL APPLICABILITY The present invention provides a dry ice block manufacturing device 1 and has industrial applicability. [Explanation of symbols]

[0153] W Cooling clothing for hot work D. Dry ice block P Dry Ice Pocket 1. Dry ice block manufacturing equipment 2. Control section 4 Input section 6 Hydraulic Unit 8 Pneumatic Unit 9 Liquefied carbon dioxide gas cylinder 10 Press Room 20 Bottom plate 30 Peripheral wall part 31 Supply hole 32 Discharge hole 33 Filter housing 34 Press Area 35 Guide section 40 Sintered metal filter 41 Filter material for sorting 42 Reinforcement 50 Supply section 51 On-off valve 52 Supply Channel 56 Granulation Section 57 Orifice 60 Press cylinder section 61 Press Block 63 First seal plate 64 Damper 80 Press plate (press plate) 81 First press plate (first press plate) 82 Second press plate (Second press plate) 83 Tapping screw 84 Through hole 85 Tapping hole 86 Recess 87 Peripheral wall member 37 Second seal plate 38 Gasket 58 Exhaust route 70 Slide cylinder part 71 Slide plate 100 Press Units

Claims

1. The press room and a supply unit that supplies a mixed fluid containing carbon dioxide gas and particulate dry ice to the press chamber; an exhaust unit that selects carbon dioxide gas from the supplied mixed fluid and exhausts the selected carbon dioxide gas to the outside through an exhaust port; A press section that applies pressure to the granular dry ice remaining in the press chamber to form a dry ice block; Equipped with The discharge section has a sintered metal filter interposed between the inside of the press chamber and the discharge port, which separates carbon dioxide gas from the mixed fluid. A dry ice block manufacturing apparatus.

2. Sintered metal filters are The pressing chamber has a selection filter material arranged on the inside side and a reinforcing material arranged on the discharge outlet side in a laminated state, The sorting filter material has openings smaller than the particle size of the granular dry ice and allows carbon dioxide to pass through. The reinforcing material has a larger mesh size than the sorting filter material and a higher bending strength in the thickness direction than the sorting filter material.

2. The dry ice block manufacturing apparatus according to claim 1 .

3. The press chamber has a bottom plate and a peripheral wall portion disposed above the bottom plate and continuing therewith, Sintered metal filters are In the filter housing portion provided on the inner surface of the peripheral wall portion, the selection filter material is housed in a state of being disposed on the pressing chamber side, The sintered metal filter is disposed so that a surface of the sintered metal filter housed in the filter housing portion facing the inside of the press chamber is flush with an inner surface of the peripheral wall portion connected to the filter housing portion.

3. The dry ice block manufacturing apparatus according to claim 1 or 2.

4. The filter housing portion is not disposed on the inner surface of the peripheral wall portion within the range of the thickness of the dry ice block formed in the press chamber.

4. The dry ice block manufacturing apparatus according to claim 3 .

5. The sintered metal filter is a sintered wire mesh filter.

3. The dry ice block manufacturing apparatus according to claim 1 or 2.

6. The supply section is A granulating section that changes the phase of the liquefied carbon dioxide gas into carbon dioxide gas and granular dry ice; a liquefied carbon dioxide gas supply path for supplying liquefied carbon dioxide gas to the granulation section; having The liquefied carbon dioxide gas supply route is as follows: an on-off valve for opening and closing a part of the liquefied carbon dioxide gas supply path; An orifice that is arranged on the secondary side of the on-off valve and regulates the flow area of ​​the liquefied carbon dioxide gas. having The flow area of ​​the liquefied carbon dioxide gas regulated by the orifice is smaller than the flow area of ​​the liquefied carbon dioxide gas in the on-off valve when the on-off valve is in the open state.

3. The dry ice block manufacturing apparatus according to claim 1 or 2.

7. The orifice and the on-off valve are integrally configured as an on-off valve with an orifice.

7. The dry ice block manufacturing apparatus according to claim 6.

8. The press room and a supply unit that supplies a mixed fluid containing carbon dioxide gas and particulate dry ice to the press chamber; an exhaust unit that selects carbon dioxide gas from the supplied mixed fluid and exhausts the selected carbon dioxide gas to the outside through an exhaust port; A press section that applies pressure to the granular dry ice remaining in the press chamber to form a dry ice block; Equipped with The press chamber has a bottom plate and a peripheral wall portion disposed above the bottom plate and continuing therewith, The press portion has a press plate that moves up and down within the peripheral wall portion, The press plate is An annular elastic member is disposed on the upper surface of the press plate along the outer periphery of the press plate; a first annular metal member laminated above the elastic member; having An annular second metal member is provided on an upper end of the peripheral wall portion, A dry ice block manufacturing device in which, when a press plate rises, a first metal member and a second metal member come into contact with each other in the vertical direction and press against each other.

9. The press plate is The outer peripheral edge of the upper surface of the press plate has a recessed portion that is annularly recessed downward from the upper surface, a peripheral wall member extending upward along the outer periphery of the recess; and The elastic member and the first metal member are fitted into the recessed portion and accommodated inside the peripheral wall member, The apparatus for producing dry ice blocks according to claim 8 , wherein the height of the peripheral wall member is smaller than the height of the elastic member.

10. The dry ice block manufacturing apparatus according to claim 9 , wherein the peripheral wall member has a chamfered portion formed along an inner edge of an upper end thereof.

11. On the press plate, An origin position is provided for the vertical position of the press plate, The press plate is After the press unit forms the dry ice, the supply unit is placed at the origin position before supplying the mixed fluid for forming the next dry ice to the press chamber, The dry ice block manufacturing apparatus according to any one of claims 8 to 10, wherein the first metal member and the second metal member are not in contact with each other at the origin position.

12. The press room and a supply unit that supplies a mixed fluid containing carbon dioxide gas and particulate dry ice to the press chamber; an exhaust unit that selects carbon dioxide gas from the supplied mixed fluid and exhausts the selected carbon dioxide gas to the outside through an exhaust port; A press section that applies pressure to the granular dry ice remaining in the press chamber to form a dry ice block; Equipped with The press chamber has a bottom plate and a peripheral wall portion disposed above the bottom plate and continuing therewith, The press portion has a press plate that moves up and down within the peripheral wall portion, The supply section is a supply path that communicates with the press chamber and supplies the mixed fluid to a position below the press plate in the press chamber; an exhaust path provided above the supply path in the press chamber and exhausting the mixed fluid above the press plate in the press chamber; having The exhaust path is provided such that one end communicates with the inside of the press chamber and the other end communicates with the inside of the supply path, When the press plate rises, one end of the exhaust path faces the outer surface of the press plate, so that the exhaust path is closed. This is an apparatus for manufacturing dry ice blocks, in which, when the press plate is lowered, one end of the exhaust path does not face the outer surface of the press plate, so that the exhaust path is in an open state.

13. The exhaust path is The dry ice block manufacturing apparatus of claim 12, wherein the peripheral wall has an inner surface formed with a recess that is recessed outward, one end of the recess communicating with the inside of the press chamber and the other end of the recess communicating with the inside of the supply path.

14. The press room and a supply unit that supplies a mixed fluid containing carbon dioxide gas and particulate dry ice to the press chamber; an exhaust unit that selects carbon dioxide gas from the supplied mixed fluid and exhausts the selected carbon dioxide gas to the outside through an exhaust port; A press section that applies pressure to the granular dry ice remaining in the press chamber to form a dry ice block; Equipped with The press chamber has a bottom plate and a peripheral wall portion disposed above the bottom plate and continuing therewith, The press department A press plate that moves up and down within the peripheral wall portion; A press rod connected to the press plate having The press plate includes a first press plate and a second press plate, A second press plate made of PTFE is disposed below the first press plate. A connecting member is disposed above the first press plate to connect the press plate and the press rod, An apparatus for manufacturing dry ice blocks, in which a second press plate is screwed to a first press plate from above, and the lower surface of a connecting member presses against the heads of the screws from above the first press plate.

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