JP2018071835A - Ice machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ice machine with high safety and cooling efficiency by cooling frazil plate using secondary refrigerant cooled with primary refrigerant.SOLUTION: An ice machine comprises a metal frazil plate 2 that each frazil side (one face and another face) is arranged for a vertical direction, and a nozzle spraying water on each frazil face of the frazil plate 2. The frazil plate 2 has a secondary refrigerant circulation pass for circulating carbon dioxide or antifreeze (secondary refrigerant) cooled to a temperature at least lower than a melting point of ice with low temperature ammonia (primary refrigerant) cooled in a primary refrigerating cycle, and a heat medium circulation pass for circulating ice-separating water or antifreeze (heat medium) with temperature at least higher than the melting point of ice.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an ice making machine that obtains plate-like ice by spraying water on one and other surfaces of an ice plate.

  As this type of ice making machine, a refrigerant cooled below the freezing point through a refrigeration cycle of compression → condensation (heat dissipation) → evaporation (cooling) → compression is passed directly into the freezing plate, and the resulting freezing is below the freezing point. By spreading ice on one and the other side of the plate, ice of a predetermined thickness is grown on each side, and then a heating medium with a temperature exceeding the melting point of the ice is passed through the ice plate, It is known to obtain plate-shaped ice crushed to a predetermined size by dropping ice that has grown to a predetermined size from each surface of the freezing plate (for example, Patent Document 1).

  As for the above refrigerant, chlorofluorocarbon having low toxicity has been widely used in the past, but it has become clear that it is the cause of ozone layer destruction, so now it is a natural refrigerant and has high cooling efficiency. Has been. However, since ammonia has a strong toxicity and bad odor, when it is used as a refrigerant for directly cooling an ice plate, a safety problem occurs.

  Therefore, as a result of extensive research, the inventor has limited the use of a natural refrigerant that has high cooling efficiency but has a safety problem as a primary refrigerant to a minimum extent, and that has been cooled by the primary refrigerant. By indirect cooling of the ice plate using a low secondary refrigerant, an ice making machine with high safety and cooling efficiency has been developed.

JP 2004-003734 A

  The present invention has been made in view of the above circumstances, and provides an ice making machine with high safety and cooling efficiency by indirectly cooling an ice plate using a secondary refrigerant cooled by a primary refrigerant. It is an issue.

  In order to solve the above-mentioned problem, the invention according to claim 1 is characterized in that a metal ice plate provided with one and the other surfaces facing up and down, and water is applied to one and other surfaces of the ice plate. The ice plate has a secondary refrigerant flow path through which a secondary refrigerant cooled to a temperature lower than the melting point of ice by at least a low-temperature primary refrigerant cooled in the primary refrigeration cycle flows. And a heat medium circulation channel through which a heat medium having a temperature higher than at least the melting point of ice circulates.

  The invention according to claim 2 is the invention according to claim 1, wherein the secondary refrigerant flow channel and the heat medium flow channel are formed entirely from the lower part to the upper part of the ice plate, The secondary refrigerant is supplied from the lower part of the ice plate to the upper part through the secondary refrigerant flow path, and the heat medium is supplied from the upper part to the lower part of the ice plate through the heat medium flow path. It is characterized by being adapted.

  The invention according to claim 3 is the invention according to claim 1 or 2, wherein the primary refrigerant is ammonia, the secondary refrigerant is carbon dioxide or antifreeze, and the heat medium is water or antifreeze. It is characterized by.

  The invention according to claim 4 is the invention according to any one of claims 1 to 3, wherein the inflow channel of the secondary refrigerant communicated with the upstream end portion of the secondary refrigerant circulation channel. An inflow passage opening / closing valve for opening / closing the inflow passage is provided, and an inflow passage control circuit for controlling opening / closing of the inflow passage opening / closing valve is provided.

  The invention according to claim 5 is the invention according to any one of claims 1 to 4, wherein the secondary refrigerant inflow channel communicates with the upstream end of the secondary refrigerant flow channel, and the secondary refrigerant. A bypass flow path is provided so as to connect the secondary refrigerant outflow flow path leading to the downstream end of the flow flow path, and a bypass on-off valve that opens and closes the bypass flow path is provided in the bypass flow path. A bypass control circuit for controlling opening and closing of the on-off valve is provided.

  The invention according to claim 6 is the invention according to any one of claims 1 to 5, wherein the pressure of these flow paths is added to the secondary refrigerant flow path or the flow path leading to the secondary refrigerant flow path. It is characterized by providing a safety valve that prevents abnormal rises.

  The invention according to claim 7 is the invention according to any one of claims 1 to 6, wherein the secondary refrigerant circulation channel or a channel communicating with the secondary refrigerant circulation channel is expanded in these channels. The present invention is characterized in that an accumulator is provided that absorbs the secondary refrigerant and suppresses an increase in pressure.

  The invention according to claim 8 is the invention according to any one of claims 1 to 7, wherein the heat medium is heated by using at least the exhaust heat of the primary refrigeration cycle. It is characterized by being supplied to the road.

  According to the first aspect of the present invention, by passing the secondary refrigerant cooled to a temperature lower than the melting point of ice at least through the secondary refrigerant circulation passage of the ice plate, one and the other surfaces of the ice plate are Cooling to a temperature below the freezing point, and then spraying water from the nozzle onto the one and other surfaces, the water is gradually solidified, and transparent ice of a predetermined thickness is applied to the one and the other surface. Can be grown.

  In addition, after ice having a predetermined thickness grows on one and other surfaces of the ice plate, the ice plate is passed through a heat medium having a temperature higher than the melting point of the ice through the heat medium flow passage of the ice plate. By making one and the other side of the plate have a temperature exceeding the melting point of ice, the plate-like ice is detached from the ice plate and dropped, thereby obtaining the plate-like ice.

  Since the secondary refrigerant is cooled by the low-temperature primary refrigerant cooled in the primary refrigeration cycle, for example, it has extremely low toxicity such as carbon dioxide liquid and antifreeze, and has excellent fluidity and heat transfer. Liquids having different characteristics can be used. For this reason, safety and cooling efficiency can be improved even when a large number of ice plates are installed to produce a large amount of plate ice.

  On the other hand, since the primary refrigerant is cooled by the primary refrigeration cycle, it needs to be a substance that can be easily liquefied and vaporized and can efficiently discharge heat to the atmosphere, and is It is preferable to use a natural refrigerant such as ammonia that does not cause serious environmental destruction.

  However, for example, ammonia has advantages such as high cooling efficiency, but has strong toxicity and bad odor, so that it has a safety problem when used as a refrigerant in a wide range. However, a natural refrigerant such as ammonia can be suppressed to a very small amount by using it as a primary refrigerant for cooling the secondary refrigerant. For this reason, the primary refrigeration cycle using the primary refrigerant can be a small device, and the entire device can be easily stored in a safe and rigid unit. Therefore, it is possible to improve the cooling efficiency and safety in the primary refrigeration cycle using the primary refrigerant.

  Therefore, it is possible to provide an ice making machine with high safety and cooling efficiency.

  According to the second aspect of the present invention, the secondary refrigerant is supplied from the lower part of the ice plate to the upper part of the secondary refrigerant flow path, so that the secondary refrigerant is moved upward in the ice plate. The temperature gradually increases as you go. That is, as the secondary refrigerant moves upward in the ice plate, the specific gravity of the secondary refrigerant gradually decreases, so that the resistance of the secondary refrigerant flowing through the secondary refrigerant flow path can be reduced.

  On the other hand, since the heat medium is supplied from the upper part to the lower part of the ice plate through the heat medium flow path, the temperature of the heat medium gradually decreases as it goes downward in the ice plate. That is, since the specific gravity of the heat medium gradually increases as the heat medium moves downward in the ice plate, the resistance of the heat medium flowing in the heat medium flow path can be reduced.

  Therefore, plate ice can be produced more efficiently.

  According to the invention described in claim 3, since ammonia is used as the primary refrigerant, the cooling efficiency can be improved. In this case, although ammonia is toxic, it can be suppressed to a very small amount as a primary refrigerant. Moreover, since the primary refrigeration cycle using the primary refrigerant can be configured with a small device, the entire device can be easily stored in a safe and robust unit. That is, safety against ammonia can be ensured.

  In addition, since carbon dioxide or antifreeze is used as the secondary refrigerant, it is possible to solve the problem of the toxicity of the refrigerant that cools the freezing plate, and even in a large-scale plate-like ice production facility equipped with many freezing plates. Safety can be easily secured.

  Therefore, a large amount of plate ice can be produced efficiently and safely.

  According to the fourth aspect of the present invention, the inflow channel opening / closing valve that opens and closes the inflow channel is provided in the inflow channel of the secondary refrigerant that communicates with the upstream end of the secondary refrigerant circulation channel, and the inflow channel Since the inflow channel control circuit for controlling the opening and closing of the on-off valve is provided, the flow rate of the secondary refrigerant flowing through the secondary refrigerant circulation channel in the ice plate can be adjusted.

  Therefore, since the temperature of one and the other surfaces of the icing plate can be adjusted based on the inflow channel control circuit, the thickness of the ice icing on each surface and the speed of icing can be controlled.

  According to the fifth aspect of the present invention, the secondary refrigerant inflow passage leading to the upstream end portion of the secondary refrigerant circulation passage and the secondary refrigerant outflow flow leading to the downstream end portion of the secondary refrigerant circulation passage. Since a bypass flow path is provided so as to connect the road, a bypass open / close valve that opens and closes the bypass flow path is provided in the bypass flow path, and a bypass control circuit that controls opening and closing of the bypass open / close valve is provided. By controlling the opening and closing of the bypass on-off valve based on the bypass control circuit, the flow rate of the secondary refrigerant flowing through the secondary refrigerant flow path can be controlled.

  In this case, since the flow of the secondary refrigerant flowing through the secondary refrigerant circulation channel does not stop completely, the temperature of one surface and the other surface of the ice plate can be more finely adjusted. Therefore, it is possible to finely adjust the thickness of ice forming on one and the other surfaces of the ice plate.

  In addition, when the pressure in the secondary refrigerant flow passage of the icing plate increases, the pressure on the upstream side of the icing plate is released to the downstream side by opening the bypass on-off valve, thereby reducing the pressure. There is also an advantage that can be.

  According to the sixth aspect of the present invention, the secondary refrigerant flow path or the flow path leading to the secondary refrigerant flow path is provided with a safety valve that prevents the pressure of these flow paths from rising abnormally. Therefore, even when the secondary refrigerant is warmed while passing through the secondary refrigerant flow path of the ice plate and, for example, a part thereof is vaporized, the pressure increase due to the vaporization can be suppressed to a predetermined pressure or less by the safety valve. it can. In this case, a part of the secondary refrigerant flows out from the safety valve to the atmosphere side. However, it is preferable that the outflowed secondary refrigerant is collected in a container or the like and reused.

  According to the seventh aspect of the present invention, the secondary refrigerant flow path or the flow path leading to the secondary refrigerant flow path absorbs the secondary refrigerant expanded in these flow paths and suppresses an increase in pressure. Since the accumulator is provided, the pressure in the icing plate or the like can be suppressed to a predetermined safe pressure without causing the secondary refrigerant to flow out to the atmosphere.

  In addition, when a safety valve is used in combination, the safety valve is activated even when a large pressure rise cannot be absorbed by the accumulator. Can be suppressed.

  According to the invention described in claim 8, heat is discharged to the atmosphere side in order to cool the primary refrigerant to a temperature lower than the melting point of ice in the primary refrigeration cycle. Since the obtained heat medium is supplied to the heat medium flow passage, it is possible to improve the energy efficiency required for producing the plate ice.

It is explanatory drawing which shows the refrigerating cycle of the ice making machine shown as one Embodiment of this invention. It is explanatory drawing of the ice making machine (thing using warm water as a heat medium supplied to the heating medium circulation channel of an ice plate), (a) is an explanatory view of a position corresponding to the front of the ice making machine, (B) is explanatory drawing of the position corresponding to B arrow view of (a), (c) is explanatory drawing of the position corresponding to C arrow view of (a). It is a figure which shows the ice plate in the ice making machine, Comprising: (a) is a top view of the ice plate, (b) is a front view of the ice plate, (c) is C arrow view of (b) (D) is sectional drawing which follows the DD line | wire of (b), (e) is E arrow line view of (b). It is explanatory drawing which shows the other example at the time of using an antifreeze liquid as a heat medium in the said ice making machine, Comprising: (a) is explanatory drawing of the position corresponding to the front of the ice making machine, (b) is (a). It is explanatory drawing of the position corresponding to B arrow view of (a), (c) is explanatory drawing of the position corresponding to C arrow view of (a). It is explanatory drawing which shows the other example of each said ice maker, (a) is explanatory drawing which shows the example which provided the safety valve in the outflow flow path connected to a secondary refrigerant | coolant circulation flow path, (b) is a secondary refrigerant | coolant. It is explanatory drawing which shows the example which provided the accumulator and the safety valve in the outflow channel which leads to a circulation channel.

  The form for implementing this invention is demonstrated in detail based on embodiment.

  As shown in FIGS. 1 to 3, an ice making machine 1 shown as one embodiment of the present invention is made of aluminum (metal) installed in a state where each icing surface 2 a as one and the other surface is directed in the vertical direction. And a watering header 3 having nozzles 3a for spraying ice-making water, i.e., ice-making water, on each ice surface 2a of the ice plate 2.

  The freezing plate 2 is a secondary refrigerant flow path through which carbon dioxide (secondary refrigerant) cooled to a temperature lower than the melting point of ice by low-temperature ammonia (primary refrigerant) cooled in the primary refrigeration cycle in the refrigerator 4 flows. 21 and a heat medium flow passage 22 through which deiced water (heat medium) set to a temperature higher than the melting point of ice flows.

  As shown in FIG. 1, the refrigerator 4 has a configuration including a compressor 4a, a condenser 4b, and an evaporator 4c. The refrigerator 4 compresses the ammonia vaporized by the evaporator 4c by the compressor 4a to high pressure and high temperature, and then releases the heat to the atmosphere (exhaust heat) by the condenser 4b to lower the temperature. The liquefied ammonia is reduced in pressure by the evaporator 4c and vaporized to lower the ammonia to, for example, about −45 ° C.

  In addition, as shown in FIG. 3 (b), the icing plate 2 is formed in a rectangular plate shape that is long in the horizontal direction when viewed from the front by joining three pieces formed in a predetermined width in the width direction. Each icing surface 2a is formed in a rectangular planar shape.

  The secondary refrigerant circulation channel 21 and the heat medium circulation channel 22 are formed so as to exist from the lower part to the upper part in the ice plate 2.

That is, the secondary refrigerant circulation channel 21 is formed so that two sets of upper and lower adjacent channels are set as one set, and 14 sets extend in the horizontal direction. Is formed so as to communicate with the two flow paths immediately above it at the horizontal end of the ice plate 2 so as to continuously extend from the lower part to the upper part of the ice plate 2. . Further, carbon dioxide (shown as “CO ₂ ” in FIG. 3) in different directions flows through two adjacent lower and upper two.

  The freezing plate 2 is provided with a refrigerant upstream end joint 21a communicating with the upstream end portion at a position corresponding to the upstream end portion of the secondary refrigerant circulation channel 21, and the secondary refrigerant circulation channel. A refrigerant downstream end joint 21 b communicating with the downstream end portion is provided at a position corresponding to the downstream end portion in 21. In this case, the refrigerant upstream end joint 21 a is disposed at the lower end portion of the ice plate 2, and the refrigerant downstream end joint 21 b is disposed at the upper end portion of the ice plate 2.

  That is, carbon dioxide flows from the refrigerant upstream end joint 21a into the secondary refrigerant circulation channel 21, flows through the secondary refrigerant circulation channel 21 from the bottom to the top of the icing plate 2, and flows out from the refrigerant downstream end coupling 21b. Will do. At this time, carbon dioxide moves from the bottom to the top in the ice plate 2 while gradually raising the temperature.

  On the other hand, the heat medium circulation channel 22 is arranged to extend horizontally with a predetermined interval so as to sandwich the adjacent four secondary refrigerant circulation channels 21, and It is also arranged at a position along the upper edge and the lower edge. Further, the heat medium flow path 22 located on the upper side and the heat medium flow path 22 below the heat medium flow path 22 are provided by an external pipe 22c provided at the horizontal end of one icing surface 2a of the icing plate 2. It is in a state of communication. Thereby, the heat medium flow path 22 is formed so as to continuously extend from the upper part to the lower part of the ice plate 2.

  The ice plate 2 is provided with a heat medium upstream end joint 22 a communicating with the upstream end portion at a position corresponding to the upstream end portion of the heat medium circulation channel 22, and the heat medium circulation channel 22. A heat medium downstream end joint 22b communicating with the downstream end is provided at a position corresponding to the downstream end. In this case, the heat medium upstream end joint 22 a is disposed at the upper end portion of the ice plate 2, and the heat medium downstream end joint 22 b is disposed at the lower end portion of the ice plate 2.

  That is, the deicing water flows from the heat medium upstream end joint 22a into the heat medium flow path 22, flows through the heat medium flow path 22 from the top to the bottom, and flows out from the heat medium downstream end joint 22b. Will do. At this time, the deicing water moves from the top to the bottom in the ice plate 2 while gradually lowering the temperature.

  Further, as shown in FIG. 2, a plurality (three in this example) of the icing plates 2 are provided in parallel (in this example, in parallel at a constant interval at the same height position).

  A branch pipe 51 a branched from the carbon dioxide inflow passage 51 is connected to the refrigerant upstream end joint 21 a of each ice plate 2. As a result, the upstream end of the secondary refrigerant circulation channel 21 is in communication with the inflow channel 51. The inflow channel 51 is provided with an inflow channel on / off valve 51b for opening and closing the inflow channel 51. The opening and closing of the inflow channel opening / closing valve 51b is controlled by an inflow channel control circuit (not shown).

  The inflow channel control circuit controls the flow rate of carbon dioxide flowing through the secondary refrigerant circulation channel 21 by controlling the opening and closing of the inflow channel on / off valve 51b, and is generated on each icing surface 2a in each icing plate 2. It is possible to adjust the thickness of the ice.

  Further, a branch pipe 52 a branched from the carbon dioxide outflow passage 52 is connected to the refrigerant downstream end joint 21 b of each ice plate 2. As a result, the downstream end of the secondary refrigerant circulation channel 21 is in communication with the outflow channel 52.

  As shown in FIG. 1, the inflow channel 51 is a channel configured to supply carbon dioxide cooled to −20 to −10 ° C. in the evaporator 4 c to the icing plate 2. Carbon dioxide has a pressure of about 6 MPa and is in a liquefied state. The outflow channel 52 is a channel configured to return the carbon dioxide whose temperature has risen by passing through the secondary refrigerant circulation channel 21 of the ice plate 2 to the evaporator 4c and to recool it. Carbon dioxide is in a liquid state in a temperature range of about −55 ° C. to about + 20 ° C. when the pressure is about 6 MPa.

  The inflow channel 51 and the outflow channel 52 are connected by a bypass channel 53 as shown in FIGS. 1 and 2. The bypass channel 53 is provided with a bypass on-off valve 53 a that opens and closes the bypass channel 53. The opening / closing of the bypass opening / closing valve 53a is controlled by a bypass control circuit (not shown).

  The bypass control circuit controls the flow rate of carbon dioxide flowing from the inflow channel 51 to the secondary refrigerant circulation channel 21 by controlling the opening and closing of the bypass on-off valve 53a, and is applied to each icing surface 2a of each icing plate 2. It is possible to adjust the thickness of the ice produced. However, in this case, the inflow channel opening / closing valve 51b needs to be opened. When the ice thickness is controlled by the bypass opening / closing valve 53a, the ice thickness can be adjusted more finely than when the ice thickness is controlled by the inflow channel opening / closing valve 51b. .

  Further, the bypass control circuit detects this pressure when the pressure in the secondary refrigerant flow passage 21 of the ice plate 2 increases, and opens the bypass opening / closing valve 53a, so that the upstream side of the ice plate 2 is opened. The pressure is allowed to escape to the downstream side, so that the pressure can be reduced. Note that illustration of a sensor for detecting the pressure of carbon dioxide in the ice plate 2 is omitted.

  On the other hand, a branch pipe 61 a branched from the inflow channel 61 of the deicing water is connected to the heat medium upstream end joint 22 a of each ice plate 2. As a result, the upstream end of the heat medium flow passage 22 is in communication with the inflow passage 61. The inflow channel 61 is provided with an inflow channel opening / closing valve 61b for opening and closing the inflow channel 61. The opening and closing of the inflow channel opening / closing valve 61b is controlled by an inflow channel control circuit (not shown).

  The inflow channel control circuit controls the flow rate of deiced water flowing in the heat medium flow channel 22 of the icing plate 2 by controlling the opening and closing of the inflow channel on / off valve 61b, and each icing surface 2a of each icing plate 2 is controlled. The ice that has grown to a predetermined thickness is controlled to be detached from the ice surfaces 2a.

  Further, a branch pipe 62 a branched from the deicing water outflow passage 62 is connected to the heat medium downstream end joint 22 b of each ice plate 2. As a result, the downstream end of the heat medium flow passage 22 is in communication with the outflow passage 62.

  The deicing water uses predetermined water selected for ice making (the above-mentioned ice making water) and uses at least the heat (ie, exhaust heat) discharged from the condenser 4b of the refrigerator 4 (necessary). The heat medium flowing in each ice plate 2 is heated to 15 to 30 ° C. via the inflow passage 61, the branch pipe 61a, and the heat medium upstream end joint 22a. It is supplied to the upstream end of the passage 22 and flows through the heat medium flow passage 22 to the downstream end.

  Further, the deicing water flows out from the downstream end portion of the heat medium circulation channel 22 of each ice plate 2 to the outflow channel 62 through the heat medium downstream end joint 22b and the branch pipe 62a, and the raw material from the outflow channel 62 It flows into the water tank 71.

  The raw water tank 71 is supplied with ice-making water from a water supply pipe 72 having an automatic water supply valve 72a. The opening and closing of the automatic water supply valve 72a is controlled by a level control circuit (not shown). The level control circuit controls the opening and closing of the automatic water supply valve 72a so that the water level in the raw water tank 71 falls within a predetermined range. In addition, illustration is abbreviate | omitted about the sensor (water level meter) which detects a water surface level.

  Further, the raw water tank 71 is provided with a drain pipe 73 having an automatic drain valve 73a and an overflow prevention pipe 74. When the automatic drain valve 73a is opened when the ice-making water in the raw water tank 71 is replaced with a new one, the ice-making water can be reliably removed from the raw water tank 71. It has become. The automatic drain valve 73a is controlled to be opened and closed by a drain control circuit (not shown).

  Even when the water surface level in the raw material water tank 71 reaches a predetermined control level or higher due to the ice making water supplied from the outflow passage 62 or the like, the overflow prevention pipe 74 is used for the ice making water before overflowing from the raw material water tank 71. Can be discharged.

  On the other hand, the watering header 3 is disposed above each ice plate 2. A plurality of nozzles 3 a connected to the water spray header 3 are provided so that ice making water can be sprayed on the upper end portions of one and the other icing surface 2 a of each icing plate 2. Each nozzle 3a is formed in a tube-like shape extending long along the upper side portion of the icing surface 2a, and has a plurality of fountain holes at predetermined intervals in the longitudinal direction. The ice making water is uniformly distributed from each fountain hole to the upper end of each icing surface 2a.

  The ice making water sprayed from the nozzle 3 a is supplied from the raw water tank 71 to the watering header 3 through the watering supply pump 31 and the watering supply channel 32.

  The sprinkling supply pump 31 is installed at a predetermined water depth position in the raw water tank 71, draws up ice making water in the raw water tank 71, and sprinkles the header 3 through the sprinkling supply passage 32. It is comprised with what has the discharge pressure which can be supplied to.

  A deicing and collecting plate 8 is provided below the plurality of ice plates 2. The deicing / recovering plate 8 is made of a corrosion-resistant metal (for example, stainless steel) plate. The deicing and collecting plate 8 has a configuration including an inclined flat surface portion 8a positioned at a lower portion of each ice plate 2, a groove portion 8b positioned obliquely below, and an inclined portion 8c positioned obliquely below. ing.

  The inclined flat surface portion 8a receives the ice falling from each ice plate 2 and has a predetermined slope so that a portion having a predetermined extension extends obliquely downward so that the ice can be smoothly moved downward. It is provided with. The groove 8b is formed so as to have a part of a cylinder that curves downward. The inclined portion 8c is formed so as to extend downward from the groove portion 8b with the same gradient as the inclined flat surface portion 8a.

  A crusher 81 that is rotationally driven with the center of curvature of the groove 8b as the center of rotation is provided at a portion corresponding to the groove 8b. The crusher 81 is composed of a cylindrical outer peripheral portion provided with a plurality of crushing blades 81a, and when the ice that has been roughly divided by falling on the inclined flat surface portion 8a passes through the groove portion 8b, the ice Is further crushed to obtain plate-shaped ice of a predetermined size, and the plate-shaped ice is sent to the inclined portion 8c.

  Further, the groove 8b has a plurality of holes for water permeation, and melted from the water discharged from the nozzles 3a and flowing downward without being frozen by the ice plates 2, or from the ice in the inclined flat surface 8a and the groove 8b. It is configured so that water and fine ice flow downward. The water and fine ice that have flowed out downward from the groove 8b are stored in the raw water tank 71 disposed below the groove 8b, and are used again as ice making water.

  In the ice making machine 1 configured as described above, by flowing carbon dioxide having a temperature lower than the melting point of ice through the secondary refrigerant flow path 21 of the ice plate 2, one and other ice surfaces of the ice plate 2. 2a can be cooled to a temperature below freezing. In this state, when water is sprayed from the nozzle 3a to each icing surface 2a of the icing plate 2, the water is gradually solidified, and transparent ice having a predetermined thickness can be grown on each icing surface 2a.

  In addition, after ice having a predetermined thickness grows on each icing surface 2a of the icing plate 2, the sprinkling supply pump 31 is stopped to stop the spraying of water from the nozzle 3a, and the inflow channel opening / closing valve for supplying carbon dioxide 51b is closed via the inflow channel control circuit, and the inflow channel on / off valve 61b for deicing water is opened via the inflow channel control circuit, so that the melting point of the ice in the heat medium circulation channel 22 of the ice plate 2 is reached. By supplying deicing water at a higher temperature, each icing surface 2a of the icing plate 2 is raised to a temperature exceeding the melting point of the ice, and the plate-like ice is detached from the icing plate 2 so that the deicing and collecting plate 8 It is made to fall on the inclined plane part 8a.

  The plate-like ice roughly divided to a certain size by this fall moves obliquely downward on the inclined flat surface portion 8a, and is crushed to a predetermined size by the crushing blade 81a of the crusher 81 in the groove portion 8b. It is sent out to the part 8c and becomes plate-shaped ice as a product.

  After the ice falls from the icing plate 2, the inflow channel opening / closing valve 61b is closed via the inflow channel control circuit to close the inflow channel 61 and the branch pipe 61a located downstream from the inflow channel opening / closing valve 61b. The deiced water accumulated in the heat medium upstream end joint 22 a, the heat medium flow path 22, the heat medium downstream end joint 22 b, the branch pipe 62 a, the outflow path 62, etc. is caused to flow out to the raw water tank 71. That is, when the ice plate 2 is cooled again, the deicing water accumulated in the flow path such as the heat medium flow path 22 is frozen, thereby preventing the flow path from being blocked.

  The secondary refrigerant uses a carbon dioxide liquid that is extremely less toxic than the primary refrigerant produced by ammonia used in the primary refrigeration cycle, and has excellent fluidity and heat transfer. Even when 2 is installed to produce a large amount of plate ice, safety and cooling efficiency can be improved.

  On the other hand, with regard to the primary refrigerant, ammonia is used as a natural refrigerant that can be easily liquefied and vaporized in the primary refrigeration cycle and can efficiently discharge heat to the atmosphere side, so that the cooling efficiency can be improved. In addition, it is possible to prevent discharge of substances that cause environmental destruction such as chlorofluorocarbon.

  However, ammonia has strong toxicity and bad odor and has a safety problem, but it can be suppressed to a very small amount used as a primary refrigerant for cooling the secondary refrigerant. For this reason, the refrigerator 4 as an apparatus constituting the primary refrigeration cycle can be reduced in size, and the entire refrigerator 4 can be easily accommodated in a safe and solid unit. Therefore, by using ammonia as the primary refrigerant, it is possible to improve the cooling efficiency and safety.

  Therefore, there is a remarkable effect that the ice making machine 1 with high safety and cooling efficiency can be provided.

  Further, since carbon dioxide as the secondary refrigerant is supplied from the lower part of the ice plate 2 toward the upper part of the secondary refrigerant flow path 21, the carbon dioxide gradually increases in temperature as it goes upward in the ice plate 2. Becomes higher. That is, since the specific gravity of the carbon dioxide gradually decreases as the carbon dioxide moves upward in the ice plate 2, it is possible to reduce the resistance when the carbon dioxide flows in the secondary refrigerant flow path 21.

  On the other hand, since the deicing water is supplied from the upper part of the ice plate 2 toward the lower part of the heat medium flow passage 22, the temperature of the deicing water gradually decreases as it goes downward in the ice plate 2. That is, the specific gravity of the deiced water gradually increases as the deiced water moves downward in the icing plate 2, so that the resistance when the deiced water flows through the heat medium flow passage 22 can also be reduced.

  Accordingly, the production efficiency of the plate ice can be improved also from the viewpoint of the flow path resistance.

  In addition, an inflow channel opening / closing valve 51b is provided in the inflow channel 51 leading to the upstream end portion of the secondary refrigerant circulation channel 21, and an inflow channel control circuit for controlling opening / closing of the inflow channel opening / closing valve 51b is provided. Therefore, the flow rate of carbon dioxide flowing through the secondary refrigerant circulation passage 21 in the ice plate 2 can be adjusted.

  Therefore, since the temperature of each icing surface 2a of the icing plate 2 can be adjusted based on the inflow channel control circuit, the thickness and the icing speed of ice forming on each icing surface 2a can be controlled. .

  Further, a bypass flow path 53 is provided so as to connect the inflow flow path 51 and the outflow flow path 52, a bypass on-off valve 53a is provided on the bypass flow path 53, and a bypass for controlling the on-off opening / closing valve 53a Since the control circuit is provided, the flow rate of the carbon dioxide flowing through the secondary refrigerant flow passage 21 can be controlled by controlling the opening / closing of the bypass on-off valve 53a based on the bypass control circuit.

  In this case, since the flow of carbon dioxide flowing through the secondary refrigerant circulation passage 21 does not stop completely, the temperature of one of the icing plates 2 and the other icing surface 2a can be adjusted more delicately. Therefore, the thickness of ice forming on each ice surface 2a of the ice plate 2 can be finely adjusted.

  Furthermore, in the refrigerator 4, heat is discharged from the condenser 4 b to the atmosphere side, but since the deiced water is warmed and supplied to the heat medium flow passage 22 using at least this exhaust heat. From this point as well, the production efficiency of the plate ice can be improved.

  Next, another example of the ice making machine 1 will be described with reference to FIG. The ice making machine 1 in this other example is different from the ice making machine 1 shown in FIGS. 1 to 3 in that the antifreezing liquid is mainly used as a heating medium and the antifreezing liquid is circulated. In addition, the same code | symbol is attached | subjected to the element which is common in the component shown in FIGS. 1-3, and description is simplified.

  That is, the antifreeze liquid is supplied from the defrost pump 64 to the heat medium flow path 22 of the icing plate 2 through the inflow path 61 and the branch pipe 61a while being stored in the defrost tank 63. In this case, the inflow channel 61 is configured to communicate the discharge port of the defrost pump 64 and each branch pipe 61a.

  On the other hand, the outflow passage 62 is configured to communicate from the branch pipe 62 a on the outflow side of the heat medium circulation passage 22 to the defrost tank 63. The defrost tank 63 stores the antifreeze liquid as described above, and heats the antifreeze liquid to 15 to 30 ° C. by the heat exchanger 63a provided inside. Note that at least exhaust heat from the condenser 4b is used as heat supplied to the heat exchanger 63a. However, the exhaust heat of the condenser 4b may be used for heating the antifreeze using another heat exchanger or the like different from the heat exchanger 63a.

  In the ice making machine 1 configured as described above, by starting the defrost pump 64, the supply of the antifreeze liquid to the heat medium flow path 22 of the ice plate 2 can be started, and the defrost pump 64 is stopped. Thus, the supply of the antifreeze liquid to the heat medium flow passage 22 can be stopped.

  In addition, since the antifreeze is used as the heat medium, there is an advantage that the heat medium can be prevented from solidifying in the heat medium flow passage 22.

  Next, another example in which a safety valve is provided with reference to FIG. 5 (a) and another example in which a safety valve and an accumulator are provided will be described with reference to FIG. 5 (b).

  That is, the safety valve 52 b shown in FIG. 5A is provided in the outflow channel 52. When the pressure in the outflow passage 52 reaches a predetermined pressure, the safety valve 52b opens a valve configured therein to discharge carbon dioxide out of the outflow passage 52, and the pressure in the outflow passage 52 Is prevented from rising above a predetermined pressure.

  That is, the safety valve 52b is configured to prevent the pressure in the outflow passage 52 from rising abnormally. In this example, since the outflow channel 52 communicates with the secondary refrigerant circulation channel 21, the inflow channel 51, the evaporator 4c (see FIG. 1) and the like of the ice plate 2, these channels and It is possible to prevent the pressure of the equipment from rising abnormally.

  The carbon dioxide discharged from the safety valve 52b can be used again as a secondary refrigerant by storing it in the reserve tank 52d and storing it in a compressed state. Note that carbon dioxide may be discharged from the safety valve 52b to the atmosphere without providing the spare tank 52d.

  In the ice making machine 1 provided with the safety valve 52b as described above, carbon dioxide is warmed in the secondary refrigerant flow path 21 of the ice plate 2 and, for example, part thereof is vaporized, thereby increasing the pressure. Even if this occurs, the safety valve 52b can suppress the pressure to a safe pressure below a predetermined pressure.

  The safety valve 52b may be provided in the secondary refrigerant flow path 21, the inflow flow path 51, the bypass flow path 53, etc., as long as it is a passage communicating with the secondary refrigerant flow path 21.

  Further, as shown in FIG. 5B, a safety valve 52 b and an accumulator 52 c may be provided in the outflow channel 52.

  The accumulator 52c uses the compressibility of a gas (for example, nitrogen gas) sealed in a pressure vessel through, for example, a diaphragm, and this pressure is increased when the pressure in the outflow passage 52 becomes higher than the pressure normally used. The pressure in the outflow passage 52 and in the passage communicating with the outflow passage 52 is suppressed.

  Further, the safety valve 52b cannot absorb pressure only by the accumulator 52c, and when the pressure in the outflow passage 52 reaches a predetermined pressure, carbon dioxide is supplied to the spare tank 52d outside the outflow passage 52. The outlet is configured to prevent the pressure in the outflow passage 52 and the passage communicating therewith from abnormally rising.

  In the ice making machine 1 provided with the accumulator 52c as described above, even if a part of carbon dioxide is vaporized and expanded in the secondary refrigerant flow passage 21 of the ice plate 2, the carbon dioxide accompanying the expansion. The pressure in the icing plate 2 and the like can be maintained at a predetermined safe pressure without absorbing the volume increase by the accumulator and discharging the carbon dioxide from the outflow passage 52.

  In addition, since the safety valve 52b is provided side by side, there is an advantage that a large pressure rise that cannot be absorbed by the accumulator 52c can be suppressed to a safe pressure below a predetermined pressure by the safety valve 52b.

  Note that the accumulator 52c and the safety valve 52b may be provided in the secondary refrigerant flow path 21, the inflow flow path 51, the bypass flow path 53, and the like as long as they are paths that communicate with the secondary refrigerant flow path 21. Needless to say.

  In the above embodiment, an example in which ammonia is used as the primary refrigerant has been shown, but other natural refrigerants may be used. Moreover, although the example which used the carbon dioxide as a secondary refrigerant | coolant was shown, you may use an antifreeze liquid (brine) etc. In this case, the pressure of the antifreeze liquid is preferably about 1 MPa in the flow path such as the secondary refrigerant flow path 21.

  The freezing plate 2 is composed of aluminum, but is composed of other metals with excellent corrosion resistance such as stainless steel or other metals with excellent thermal conductivity such as copper. It may be.

1 Ice machine 2 Ice plate 2
2a Each icing surface (one and the other)
3a Nozzle 21 Secondary refrigerant flow path 22 Heat medium flow path 21a Refrigerant upstream end joint 21b Refrigerant downstream end joint 22a Heat medium upstream end joint 22b Heat medium downstream end joint 51 Carbon dioxide (secondary refrigerant) inflow path 51b Inflow passage opening / closing valve 52 Outflow passage for carbon dioxide (secondary refrigerant) 52b Safety valve 52c Accumulator 53 Bypass passage 53a Bypass opening / closing valve 61 Inflow passage opening / closing valve 61b Inflow passage opening / closing valve 62 Outflow passage for deicing water

Claims (8)

A metal icing plate provided with one and the other side facing up and down;
A nozzle for spraying water on one and other surfaces of the ice plate,
The ice plate has a secondary refrigerant flow path through which a secondary refrigerant cooled to a temperature lower than the melting point of ice by at least a low-temperature primary refrigerant cooled in the primary refrigeration cycle flows, and at least ice. An ice making machine comprising a heat medium flow passage through which a heat medium having a temperature higher than the melting point flows. The secondary refrigerant circulation channel and the heat medium circulation channel are formed entirely from the lower part to the upper part of the ice plate,
The secondary refrigerant is supplied from the lower part of the ice plate toward the upper part of the secondary refrigerant circulation channel,
2. The ice making machine according to claim 1, wherein the heat medium is supplied from an upper part to a lower part of the ice plate in the heat medium flow path. The primary refrigerant is ammonia;
The secondary refrigerant is carbon dioxide or antifreeze,
The ice making machine according to claim 1 or 2, wherein the heat medium is water or antifreeze. An inflow passage opening / closing valve for opening and closing the inflow passage is provided in the inflow passage of the secondary refrigerant that communicates with the upstream end of the secondary refrigerant circulation passage;
The ice making machine according to any one of claims 1 to 3, further comprising an inflow channel control circuit that controls opening and closing of the inflow channel on / off valve. The secondary refrigerant inflow channel leading to the upstream end of the secondary refrigerant circulation channel and the secondary refrigerant outflow channel leading to the downstream end of the secondary refrigerant circulation channel are connected to each other. Provided a bypass channel,
In the bypass flow path, a bypass open / close valve for opening and closing the bypass flow path is provided,
The ice making machine according to any one of claims 1 to 4, further comprising a bypass control circuit that controls opening and closing of the bypass on-off valve.   6. The safety valve for preventing the pressure of these flow paths from increasing abnormally is provided in the secondary refrigerant flow path or the flow path leading to the secondary refrigerant flow path. An ice making machine according to any one of the above.   The accumulator which suppresses a rise in pressure by absorbing the secondary refrigerant expanded in these flow paths is provided in the flow path leading to the secondary refrigerant flow path or the secondary refrigerant flow path. Item 7. An ice making machine according to any one of Items 1 to 6.   8. The heating medium according to any one of claims 1 to 7, wherein the heating medium heated at least using the exhaust heat of the primary refrigeration cycle is supplied to the heating medium circulation channel. The ice making machine described in 1.

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