JP2006183925A - Method of operating automatic ice machine for deicing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To evenly heat an ice making part when an automatic ice machine is operated for deicing. <P>SOLUTION: As the automatic ice machine is operated for deicing, a first bypass valve 42 is opened to directly introduce hot gas discharged from the compressor 20 of a refrigerating circuit 30 into the entrance side of the evaporator 14 to heat the portion of the evaporator 14 near its entrance. When a temperature sensing means Th installed in the vicinity of the entrance side of the evaporator 14 senses a preset temperature, a second bypass valve HV2 is opened to directly introduce the hot gas discharged from the compressor 20 into the mid section of the evaporator 14 via a second bypass pipe 44 so as to heat the ice making part 10 entirely and remove chunks of ice. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a deicing operation method of an automatic ice maker that deices ice blocks generated in an ice making unit by supplying hot gas to an evaporator disposed in the ice making unit.

  An automatic ice maker that automatically manufactures a large amount of ice blocks has an evaporator connected to a refrigeration circuit including a compressor, a condenser, an expansion valve, and the like arranged in an ice making unit, and the condenser and the expansion valve are connected to the evaporator. Ice-making water is supplied to an ice-making section that is forcibly cooled by a refrigerant that is circulated and supplied under action to generate ice blocks, and the resulting ice blocks are peeled off and dropped and released. For example, an automatic ice making machine includes an ice making water tank for storing a required amount of ice making water below the ice making unit, and supplies ice making water in the ice making water tank with a circulation pump during ice making operation to supply it to the ice making unit. The ice making water that has not been frozen is collected in an ice making water tank and then sent out again toward the ice making unit. When the ice making operation is continued and a predetermined time elapses, it is determined that the ice making is completed, the ice making operation is shifted to the deicing operation, and the hot discharge discharged from the compressor by switching the bypass valve (pipe line opening / closing means). By supplying gas (high-temperature, high-pressure vaporized refrigerant) directly to the evaporator via a bypass pipe and heating and melting the icing surface with the ice block, the ice block is separated from the ice making unit.

  Here, the ice making section is not uniformly heated during the deicing operation, but gradually heated from the upstream side (inlet side) in the supply direction of the hot gas supplied to the evaporator. That is, when hot gas is supplied to the evaporator after switching to the deicing operation, first, heat exchange is preferentially performed with the ice making region corresponding to the inlet side of the evaporator. Circulates in the evaporator and returns to the compressor with little heat exchange with the area of the ice making section corresponding to the outlet side. Then, the area of the ice making section corresponding to the inlet side is heated by the hot gas circulating in the evaporator, and if the icing surface of the ice block generated in this area melts, the load on the inlet side of the evaporator decreases, The area of the ice making part corresponding to the middle part of the vessel is heated by the hot gas. For this reason, it is pointed out that the deicing time becomes longer because the timing at which the ice blocks separate differs between the inlet side and the outlet side of the evaporator in the ice making unit.

  In addition, in order to shorten the deicing time, when the ice block is generated in the ice making unit in a state where the ice blocks are connected to each other, the ice block located on the inlet side of the evaporator can be dropped by its own weight as the deicing operation proceeds. Even so, the ice mass located on the outlet side of the evaporator is still frozen in the ice making section, so the ice mass as a whole cannot be detached from the ice making section, and heat exchange between the hot gas and the ice making section entrance side Is still done, although the amount is reduced. That is, the amount of heat of the hot gas that heats the ice making part corresponding to the middle part of the evaporator becomes low, and it takes time to melt the ice formation between the ice making part and the ice block. Since the melting of the ice block further progresses, it is pointed out that the ice block becomes deformed ice or becomes thin and the dimensions are not uniform. Further, in the deicing operation, since the ice making part is heated unevenly, when all the ice blocks are detached from the ice making part, the area between the area corresponding to the inlet side of the evaporator and the area corresponding to the outlet side in the ice making part. The temperature difference is quite large. Therefore, since the ice making part is subjected to intense heat shock between the ice making operation and the deicing operation, if the material of the ice making part itself deteriorates or the ice making part is subjected to surface treatment such as plating, the surface treatment is peeled off. Etc. will be induced.

Therefore, as in the ice making machine disclosed in Patent Document 1, the first bypass pipe connected from the compressor to the inlet side of the evaporator via the first solenoid valve, bypassing the condenser and the pressure reducing means. And the structure provided with the 2nd side pipe connected via the 2nd solenoid valve in the middle of the entrance side and exit side of an evaporator is proposed. That is, in the deicing operation, the first solenoid valve is opened and hot gas is supplied from the inlet side of the evaporator via the first side pipe, and at the same time, the second solenoid valve is opened and the second solenoid valve is opened. By supplying hot gas also from the middle part of the evaporation pipe through the side pipe, melting of the ice block is started simultaneously from the inlet side and the middle part of the ice making part to shorten the deicing time.
Japanese Utility Model Publication No. 55-17200

  However, in the ice making machine disclosed in Patent Document 1, since hot gas is simultaneously supplied to the inlet side and the intermediate part in the deicing operation, hot gas is supplied from the second side pipe having low pipe resistance. Is preferentially supplied, and the disadvantage that the entire ice making unit cannot be heated uniformly is pointed out. Therefore, in the ice making machine, the diameter of the second side pipe is made narrower than that of the first side pipe so that the hot gas flows on the first side pipe and the second side pipe on average. However, depending on the size of the evaporator (the length from the inlet to the outlet of the pipe) and the position where the second side pipe is connected, the second pipe with a different pipe diameter is used. A side pipe is required, resulting in an increase in cost and inconvenience of complicated material management. Further, the averaging of the hot gas supply amount to the evaporator by the pipe diameter of the side pipe is difficult to adjust, and there is a drawback that the supply timing cannot be appropriately controlled according to the fluctuation of the external temperature or the like.

  That is, the present invention has been proposed in order to suitably solve these problems inherent in the deicing operation method of the automatic ice making machine according to the prior art, and supplies hot gas to the evaporator. It is an object of the present invention to provide a deicing operation method for an automatic ice maker that can uniformly heat the ice making unit when the ice block generated in the ice making unit is separated.

In order to overcome the above problems and achieve the intended purpose, the deicing operation method of the automatic ice maker according to the present invention is:
An evaporator disposed in the ice making unit and connected to the refrigeration circuit; and a first pipe opening / closing means interposed in a first bypass pipe for guiding hot gas from the compressor of the refrigeration circuit to the inlet side of the evaporator; And a second pipe opening / closing means interposed in a second bypass pipe for guiding hot gas from the compressor to the middle part of the evaporator, and both opening / closing means are opened during the deicing operation so that the inlet side of the evaporator and In the deicing operation method of the automatic ice maker, in which the ice block generated in the ice making part is released by supplying hot gas to the intermediate part,
The second pipe opening / closing means is opened after the first pipe opening / closing means is delayed by a required time after the first pipe opening / closing means is opened.

  According to the deicing operation method of the automatic ice maker according to the first aspect of the present invention, in the deicing operation, the first pipe opening / closing means is opened and hot gas is supplied to the inlet side of the evaporator, and the delay is a required time. Then, by opening the second pipe opening / closing means and supplying hot gas to the middle part of the evaporator, the temperature of the entire ice making part can be raised uniformly, and it is generated in any region in the ice making part. Since the ice blocks can be discharged at substantially the same timing, the generation of deformed ice and the like can be suppressed, and the ice making capacity can be improved by shortening the deicing time. In addition, the ice making part does not excessively increase the temperature in the area corresponding to the vicinity of the evaporator inlet side compared to the area corresponding to the vicinity of the outlet side of the evaporator. It is possible to improve the life of the ice making part by avoiding deterioration of the surface and peeling of the surface treatment such as plating applied to the surface of the ice making part. Furthermore, in the deicing operation, hot gas can be preferentially supplied from the second bypass pipe to the intermediate section by utilizing the pipe resistance between the inlet side of the evaporator and the intermediate section. Can be formed from a common tube. Furthermore, by changing the delay time, the time difference from the start of the deicing operation to the opening of the second pipe opening / closing means can be easily adjusted, so that it can cope with fluctuations in the external temperature, Even different models can be applied. According to the invention according to claim 2, by using the temperature of the evaporator detected by the temperature detecting means installed in the vicinity of the inlet side of the evaporator as an index for determining the opening timing of the second pipe opening / closing means. A good response can be obtained, timely supply of hot gas can be performed from the middle part of the evaporator via the second bypass pipe, and the ice making part can be heated more evenly in the deicing operation.

  Next, the deicing operation method of the automatic ice making machine according to the present invention will be described below with reference to the accompanying drawings by giving a preferred embodiment. In addition, as an ice making mechanism for generating ice blocks in an automatic ice making machine, the deicing operation method of the present application can be applied to any of so-called open cell type, closed cell type, flow-down type, and the like.

  FIG. 1 is a schematic diagram illustrating a refrigeration circuit that can suitably perform the deicing operation of the automatic ice maker according to the embodiment. In the automatic ice making machine of the embodiment, an evaporator 14 composed of an evaporation pipe 14a led out of a refrigeration circuit 30 and formed in a meandering manner is closely fixed to the back surface of an ice making unit 10 disposed in an ice making chamber (not shown), and a refrigerant is used during ice making operation. The ice making unit 10 is forcibly cooled by circulating the air. In addition, during ice making operation, ice making water is supplied by a circulation pump (not shown) to an ice making chamber (not shown) defined in the ice making section 10 cooled by the evaporator 14, so that each ice making chamber has a predetermined value. Each shape ice block is generated. The evaporator 14 has an inlet side connected to a refrigerant pipe 34 communicating with a discharge side of an expansion valve (decompression means) 24 described later, and an outlet side connected to a refrigerant pipe 34 connected with a suction side of a compressor 20 described later. Has been. The evaporator tubes 14a constituting the evaporator 14 are meandering so as to extend corresponding to the ice making chambers of the ice making unit 10, and the refrigerant (hot gas) flowing through the evaporator tubes 14a, the ice making unit 10 and the like. Is arranged so that heat can be exchanged evenly.

The refrigeration circuit 30 for cooling the ice making unit 10 is disposed on the back surface of the ice making unit 10, such as a compressor 20, a condenser 22, a fan motor FM and an expansion valve 24, which are disposed in a machine room (not shown). The main circuit 32 is basically composed of the evaporator 14. In the main circuit 32, devices are arranged so that the refrigerant circulates in the order of the compressor 20, the condenser 22, the expansion valve 24, and the evaporator 14, and the devices are connected in communication by a refrigerant pipe 34. That is, the vaporized refrigerant compressed by the compressor 20 is condensed and liquefied by the condenser 22 through the refrigerant pipe 34, then depressurized by the expansion valve 24, flows into the evaporator 14 and expands at once. Then, it evaporates and exchanges heat with the ice making unit 10 to forcibly cool the ice making unit 10 to below the freezing point. The vaporized refrigerant evaporated and heat-exchanged in the evaporator 14 is configured to repeat a cycle of returning to the compressor 20 via the refrigerant pipe 34. The fan motor FM functions to cool the condenser 22. In the embodiment, the expansion valve 24 is used as the pressure reducing means, but other appropriate means such as a capillary tube may be used.

  In the main circuit 32 of the embodiment, a receiver R that temporarily stores the liquefied refrigerant condensed in the condenser 22 is disposed between the discharge side of the condenser 22 and the suction side of the expansion valve 24. In addition, a dryer D for removing excess water from the liquefied refrigerant is disposed between the discharge side of the receiver R and the suction side of the expansion valve 24. Reference numeral 26 inserted between the receiver R and the dryer D denotes an ice making valve, which controls the flow of refrigerant flowing through the main circuit 32 and is opened during ice making operation. At the end, it is closed and the supply of the refrigerant to the evaporator 14 is stopped.

  In addition to the main circuit 32 described above, the refrigeration circuit 30 includes a first bypass pipe 42 and a second bypass pipe 44 branched from the first bypass pipe 42 with respect to the evaporator 14 during the deicing operation. A bypass circuit 40 for supplying hot gas (high-temperature, high-pressure vaporized refrigerant) is provided. The first bypass pipe 42 has a start end connected to the refrigerant pipe 34 between the discharge side of the compressor 20 and the suction side of the condenser 22, and a terminal end connected to the inlet side of the evaporator 14. Connected to the discharge side of the expansion valve 24. That is, the first bypass pipe 42 is configured to be able to directly supply the hot gas discharged from the compressor 20 to the inlet side of the evaporator 14 without passing through the refrigeration action by the condenser 22 and the expansion valve 24. . In the middle of the first bypass pipe 42, a first bypass valve (first pipe opening / closing means) HV1 for closing the pipe is opened and closed. The first bypass valve HV1 is controlled by a control unit (not shown) to be closed during the ice making operation, opened along with the start of the deicing operation, and closed again when the deicing operation is completed.

  The second bypass pipe 44 is branched from the downstream side of the first bypass valve HV1 in the first bypass pipe 42 and is connected to the intermediate portion of the evaporator 14. Here, the intermediate portion of the evaporator 14 connected to the second bypass pipe 44 is connected to the compressor 20 and the inlet side communicating with the expansion valve 24 in the evaporation pipe 14 a extending in a meandering manner with respect to the ice making section 10. In the entire route between the outlet side and the communicating side, the size of the ice making unit 10 and the length of the evaporator 14 are appropriately set in consideration of the size of the ice making unit 10, the length of the evaporator 14, and the like. A tube 44 is connected. That is, the hot gas is configured to be supplied not only from the inlet side to the evaporator 14 but also from the middle of the evaporation pipe 14 a meanderingly arranged in the ice making unit 10. In the middle of the second bypass pipe 44, a second bypass valve (second pipe opening / closing means) HV2 for closing and opening the pipe is freely inserted. The second bypass valve HV2 is closed during the ice making operation, and is configured to open in conjunction with temperature detecting means Th that is a delay means described later in the deicing operation. After the valve HV1 is opened, the valve is opened when the temperature detecting means Th detects a preset temperature (required condition) set in advance. Therefore, the opening of the second bypass valve HV2 is controlled independently of the opening of the first bypass valve HV1 by the temperature detecting means Th, whereas the opening of the first bypass valve HV1 and the second bypass valve HV2 is closed. Are set to be executed at the same timing. Here, the first bypass valve HV1 and the second bypass valve HV2 are preferably electromagnetic valves, electric valves, etc., but can be arbitrarily operated (inserted) by control means (not shown) or other control by equipment. The pipes of the first bypass pipe 42 and the second bypass pipe 44 are closed during ice making operation to block the circulation of hot gas, and controlled during deicing operation. The supply of hot gas may be permitted by opening the pipelines of the first bypass pipe 42 and the second bypass pipe 44 based on the control of the means and the like.

  The temperature detecting means Th is disposed in the vicinity of the inlet side of the evaporator 14, and controls the opening timing of the second bypass valve HV2 by detecting the temperature in the vicinity of the inlet side of the evaporator 14. Then, after shifting from the ice making operation to the deicing operation and opening the first bypass valve HV1, the second bypass valve HV is opened directly or through control means so as to be delayed by a required timing (required time). Indirect control. That is, even if heating progresses by hot gas supplied from the inlet side of the evaporator 14 with the opening of the first hot gas valve HV1 after starting the deicing operation, the evaporator 14 detected by the temperature detecting means Th. When the temperature of the second bypass valve HV2 is lower than a preset temperature, the closed state of the second bypass valve HV2 is maintained. When the heating further proceeds by the hot gas supplied from the inlet side of the evaporator 14 and the temperature of the evaporator 14 detected by the temperature detecting means Th becomes equal to or higher than a preset temperature, the second bypass The valve HV2 is opened and hot gas is supplied to the middle part of the evaporator 14 via the second bypass pipe 44. For example, the set temperature is heated by the hot gas supplied from the inlet side of the evaporator 14, and ice blocks that have frozen in the ice making unit 10 corresponding to the vicinity of the inlet side of the evaporator 14 have progressed to a certain extent, and the ice making chamber has progressed to some extent. It is set to a temperature at which it can be released soon.

  The location of the temperature detecting means Th is not limited to the vicinity of the inlet side of the evaporator 14, but is disposed in the ice making unit 10 corresponding to the vicinity of the inlet side of the evaporator 14, so that the temperature change of the ice making unit 10 is changed. It is also possible to adopt a configuration for detecting the above. That is, an aspect in which the temperature in the vicinity of the inlet side of the evaporator 14 is not directly detected but may be indirectly detected. Further, when a temperature detecting means such as a thermistor is used as an operation switching means for judging the transition from the ice making operation to the deicing operation and the transition from the deicing operation to the ice making operation, it is also used as the temperature detecting means Th. Alternatively, it is possible to determine whether the ice making operation and the deicing operation are completed based on the temperature detection result of the temperature detecting means Th, and to determine whether the second bypass valve HV is opened.

(Effects of Example)
Next, the operation of the deicing operation method of the automatic ice maker according to the embodiment will be described. First, in the ice making operation, the first bypass valve HV1 and the second bypass valve HV2 are closed, the refrigerant flow to the bypass circuit 40 is shut off, and the ice making valve 26 is opened. When the motor 20 and the fan motor FM are driven, the refrigerant circulates through the main circuit 32 of the refrigeration circuit 30, and the ice making unit 10 is forcibly cooled by the vaporized refrigerant supplied to the evaporator 14 (solid arrow in FIG. 1). ). The circulation pump is driven to supply ice making water to the ice making unit 10, and the ice making water gradually freezes in layers to generate ice blocks in each ice making chamber. The ice making operation is terminated when a predetermined time elapses, and the operation moves to the deicing operation.

  When the deicing operation is started, the first bypass valve HV1 is opened under the control of the control means, so that the hot gas discharged from the compressor 20 is on the inlet side of the evaporator 14 connected to the expansion valve 24. Directly through the first bypass pipe 42 (dotted arrow in FIG. 1). The ice making unit 10 that has been cooled to below the freezing point in the ice making operation preferentially has a region corresponding to the vicinity of the inlet side of the evaporator 14 by the hot gas supplied from the inlet side of the evaporator 14 at the start of the deicing operation. Heated. At this time, since the temperature detecting means Th has not reached the set temperature, the second bypass valve HV2 is maintained in a closed state, and hot gas is supplied to the intermediate portion of the evaporator 14 via the second bypass pipe 44. It is never supplied.

  The hot gas supplied through the first hot gas pipe 42 heats the region corresponding to the vicinity of the inlet side of the evaporator 14 in the ice making unit 10, and the temperature of the evaporator 14 reaches the set temperature. When the temperature detecting means Th detects this, the second bypass valve HV2 is opened, and hot gas is directly supplied to the intermediate portion of the evaporator 14 via the second bypass pipe 44 (dotted line arrow in FIG. 1). ). That is, the area corresponding to the intermediate part of the evaporator 14 in the ice making unit 10 is preferentially heated by the hot gas supplied to the intermediate part of the evaporator 14. At this time, even if the second bypass valve HV2 is opened, the hot gas is supplied to the inlet side of the evaporator 14, but in the evaporator 14, the path of the evaporation pipe 14a from the inlet side to the outlet side is from the intermediate portion. Since it is naturally longer than the path of the evaporation pipe 14 a to the outlet side, hot gas is preferentially supplied to the middle part of the evaporator 14 via the second bypass pipe 44 in terms of pipe resistance. That is, the melting of the icing surface has not progressed much compared to the melting state of the icing surface of the ice block generated in the region of the ice making unit 10 corresponding to the vicinity of the inlet side of the evaporator 14 to which the hot gas has been previously supplied. It is possible to preferentially heat the region corresponding to the intermediate portion of the evaporator 14 in the ice making unit 10 and the melting of the frozen surface. As the second bypass valve HV2 is opened, the region after the intermediate portion of the evaporator 14 is preferentially heated by hot gas, and a small amount of hot gas is supplied to the inlet side region of the evaporator 14 gradually. Since it is heated, the ice block corresponding to the vicinity of the inlet side of the evaporator 14 where the melting of the icing surface has been progressed to some extent by heating first, and the melting of the icing surface proceeds rapidly by preferential heating later. As a result, the timing at which the ice blocks corresponding to the regions after the intermediate portion of the evaporator 14 are separated from the ice making unit 10 is substantially the same.

  The deicing operation is completed when the ice block is completely discharged from the ice making unit 10 and a predetermined time has elapsed, and the operation is shifted to the ice making operation again. That is, by simultaneously closing the first bypass valve HV1 and the second bypass valve HV2, the supply of hot gas to the evaporator 14 is stopped, and the refrigerant discharged from the compressor 20 evaporates via the main circuit 32. Is supplied to the container 14.

  As described above, in the deicing operation, the hot gas can be supplied from both the inlet side and the intermediate portion of the evaporator 14, so that it is difficult to raise the temperature only by supplying the hot gas from the inlet side of the evaporator 14. Also in the region after the intermediate portion, the temperature can be raised by supplying hot gas directly. In addition, the automatic ice making machine of the embodiment supplies hot gas to the entire evaporator at the same time via the first bypass pipe 42 connected to the inlet side of the evaporator 14 and the second bypass pipe 44 connected to the intermediate portion. Instead of supplying the hot gas to the intermediate portion with a delay from the supply of the hot gas to the inlet side of the evaporator 14 by a required timing, the evaporators are respectively connected to the first bypass pipe 42 and the second bypass pipe 44. Hot gas can be supplied intensively with a time difference for each of the 14 regions. That is, when the deicing operation is started, the vicinity of the inlet side of the evaporator 14 is preferentially heated first, and the region corresponding to the vicinity of the inlet side of the evaporator 14 in the ice making unit 10 rapidly increases in temperature. As the bypass valve HV2 is opened, the temperature of the region corresponding to the middle portion of the evaporator 14 increases rapidly, and the temperature increase of the region corresponding to the vicinity of the inlet side becomes moderate. At that time, the temperature of the entire ice making unit can be raised uniformly. By thus heating the ice making unit 10 evenly, ice blocks generated in any region of the ice making unit 10 can be released at substantially the same timing, so that deformed ice resulting from excessive melting of the ice blocks And the like, and the ice making ability can be improved by shortening the deicing time. Moreover, the ice making unit 10 does not excessively increase in temperature in the region corresponding to the vicinity of the inlet side of the evaporator 14 as compared with the region corresponding to the vicinity of the outlet side of the evaporator 14, so the difference from the cooling temperature in the ice making operation. (Heat shock) can be reduced, and the life of the ice making unit 10 can be improved by avoiding deterioration of the material of the ice making unit 10 itself and peeling of surface treatment such as plating applied to the surface of the ice making unit 10.

  The automatic ice maker is configured to preferentially supply hot gas from the second bypass pipe 44 to the intermediate part by utilizing the pipe resistance between the inlet side of the evaporator 14 and the intermediate part in the deicing operation. Therefore, the pipe resistance of the second bypass pipe 44 is adjusted to be different from that of the first bypass pipe 42 according to the difference in the pipe resistance of the evaporator 14 depending on the hot gas supply position. No measures are required, and the first bypass pipe 42 and the second bypass pipe 44 can be formed of a common pipe, and there is no cost in carrying out the deicing operation method of the embodiment. In the deicing operation method of the embodiment, the set temperature (required condition) of the temperature detecting means Th is changed to adjust the time difference from the start of the deicing operation to the opening of the second bypass valve HV2. Therefore, the timing of supplying hot gas to the intermediate portion of the evaporator 14 can be easily changed. Therefore, the size of the evaporator 14 (ice making unit 10) and the piping path of the evaporator 14 (for example, a meandering shape or a spiral shape) The set temperature can be arbitrarily set regardless of various conditions (such as a difference). Therefore, even different models can be commonly used without adding a separate configuration. Furthermore, the set temperature of the temperature detection means Th can be adjusted in advance to an appropriate value in response to changes in the installation environment of the automatic ice making machine (for example, temperature fluctuations depending on the season and the temperature of the installation location) The deicing time can be further shortened.

  Then, a temperature detection means Th is installed in the vicinity of the inlet side of the evaporator 14 as a delay means, and the temperature of the evaporator 14 is used as an index for judging the opening timing of the second bypass valve HV2. As a result, the hot gas can be supplied in a timely manner from the intermediate portion of the evaporator 14 via the second bypass pipe 44.

  In the embodiment, the temperature detecting means Th for directly or indirectly detecting the temperature of the evaporator 14 is adopted as the delay means, but the present invention is not limited to this, and it is necessary after opening the first bypass valve HV1 in the deicing operation. As long as the second bypass valve HV2 is opened after being delayed by a time, for example, a counting unit such as a timer or a counter that counts a predetermined time from the start of the deicing operation can be employed. This counting means starts timing after opening the first bypass valve HV1, and opens the second bypass valve HV2 when a preset time (predetermined condition) set in consideration of the external temperature or the like is counted up. It is set to be. In addition, a configuration in which a plurality of second bypass pipes 44 are branched from the first bypass pipe 42 and each second bypass pipe 44 is connected to an appropriate position in an intermediate portion of the evaporator 14 may be employed. At this time, in each of the plurality of second bypass pipes 44, the timing of opening of the corresponding valve HV2 is delayed by the delay means as the connection point goes to the outlet side of the evaporator 14, whereby each second bypass in the evaporator 14 is delayed. The vicinity where the pipe 44 is connected can be heated in order from the inlet side to the outlet side.

It is the schematic which shows the freezing circuit of the automatic ice maker which can implement suitably the deicing operation method of the automatic ice maker which concerns on the preferable Example of this invention.

Explanation of symbols

10 ice making unit, 14 evaporator, 20 compressor, 30 refrigeration circuit, 42 first bypass pipe,
44 second bypass pipe, HV1 first bypass valve (first pipe opening / closing means),
HV2 Second bypass valve (second pipe opening / closing means), Th temperature detection means (delay means)

Claims (2)

An evaporator (14) disposed in the ice making unit (10) and connected to the refrigeration circuit (30), and hot gas from the compressor (20) of the refrigeration circuit (30) is supplied to the inlet of the evaporator (14). The first bypass opening / closing means (HV1) inserted in the first bypass pipe (42) leading to the side and the second bypass pipe (hot gas from the compressor (20) leading to the middle part of the evaporator (14) ( 44) with a second pipe opening / closing means (HV2) inserted in the degassing operation. During deicing operation, both opening / closing means (HV1, HV2) are opened to supply hot gas to the inlet side and the middle of the evaporator (14). In the deicing operation method of the automatic ice maker that is designed to release the ice block generated in the ice making unit (10) by supplying,
A deicing operation method for an automatic ice making machine, wherein the second pipe opening / closing means (HV2) is opened after the first pipe opening / closing means (HV1) is delayed by a required time after being opened. The second pipe opening / closing means (HV2) is opened in a delayed manner on condition that the temperature detecting means (Th) installed in the vicinity of the inlet side of the evaporator (14) has detected a preset set temperature. Item 2. The deicing operation method of the automatic ice maker according to Item 1.

Images