JP2009210228A - Sterilization method for chiller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sterilization method extensively improving a sterilization function with respect to a heat exchanger for cooling in a cooling chamber, in regard to a chiller provided with a cold air cooling function. <P>SOLUTION: The composite chiller 1 is equipped with the cooling chamber 5 housing a cooling reception object, a cold air cooling part 10 carrying out the cold air cooling of the cooling reception object, a vacuum cooling part 20 carrying out the vacuum cooling of the cooling reception object, a hot water jetting part 30 jetting out hot water for sterilizing the heat exchanger 11 for cooling the cold air cooling part 10 by high temperature treatment, and a control part 50 carrying out the control of the whole of the composite chiller 1. During sterilization treatment, after carrying out pump down operation (S11), hot water is jetted on the heat exchanger 11 for cooling from the hot water jetting part 30 (S12) to carry out the sterilization treatment by high temperature treatment. During hot water jetting, it is monitored that pressure in the heat exchanger 11 for cooling does not reach predetermined pressure or higher (S13), and the reaches the predetermined pressure or higher, the pump-down operation is carried out again (S14). <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a cooler provided with a cold air cooling device, and more particularly, to a sterilization method for sterilizing a heat exchanger for cooling cold air installed in a cooling chamber of the cooler.

  Conventionally, a cold air cooler that cools food by directly blowing cold air on the food in the cabinet has been widely provided. In addition to the cold air cooling function, the inside of the refrigerator is depressurized with a vacuum pump to evaporate the moisture contained in the food, etc., and to cool with the heat of vaporization at that time. A cooler is also provided.

For example, Patent Document 1 below discloses a composite cooling device that can cool an object to be cooled by cold air cooling and vacuum cooling.
JP 2007-240137 A

  By the way, since dirt adheres to the cooling heat exchanger in the cabinet required for cold air cooling, regular cleaning is indispensable. The composite cooling device disclosed in Patent Document 1 is configured so that the cooling heat exchanger can be exposed during cleaning, and cleaning is performed by spraying the cleaning liquid directly onto the cooling heat exchanger with a cleaning gun. Yes.

  On the other hand, since microorganisms such as filamentous fungi, bacteria, and viruses may adhere to the cooling heat exchanger, it is necessary to remove or kill them for hygiene purposes. However, conventionally, much consideration has not been given to sterilization of the heat exchanger for cooling, and ordinary cleaning has only been performed manually.

  The present invention has been made to solve the above-described problems, and provides a sterilization method in which a sterilization function for a cooling heat exchanger in a cooling chamber is significantly improved in a cooler having a cold air cooling function. With the goal.

  In order to solve the above-described problems, a sterilization method for a cooler according to the present invention is the sterilization method for a cooler for sterilizing a cooling heat exchanger installed in a cooling chamber of a cooler having a cold air cooling function. It is provided with the heating process which heats the surface of the said heat exchanger for cooling installed indoors.

  Further, the cooler according to the present invention is a cooler that cools the cooling chamber with a cold air cooling function, a cooling heat exchanger installed in the cooling chamber, a condensing device installed outside the cooling chamber, and the cooling heat. A cold air cooling unit having a refrigerant pipe connecting the exchanger and the condenser, a heating device for heating the surface of the cooling heat exchanger, and a control for controlling the cold air cooling unit and the heating device Means for controlling the heating device to operate in order to sterilize the surface of the cooling heat exchanger.

  According to the cooler sterilization method of the present invention, the sterilization function of the cooling heat exchanger installed in the cooling chamber can be greatly improved.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a diagram schematically showing the configuration of the composite cooler according to the present embodiment. The composite cooler 1 according to the present embodiment is a composite cooler having a cold air cooling function and a vacuum cooling function, and as shown in FIG. 1, a cooling chamber 5 for storing an object to be cooled, and an object to be cooled by cold air Cold air cooling unit 10 for cooling, vacuum cooling unit 20 for cooling the object to be cooled in vacuum, and hot water injection for injecting hot water for sterilizing the cooling heat exchanger 11 of the cold air cooling unit 10 by high-temperature treatment The unit 30, the pressure returning unit 40 that returns the pressure in the cooling chamber 5, and the control unit 50 that controls the entire composite cooler 1 are provided.

  The cooling chamber 5 is provided with a temperature sensor 6 for measuring the temperature in the room and a pressure sensor 7 for measuring the pressure in the room, and these outputs are sent to the control unit 50.

  The cold air cooling unit 10 includes a cooling heat exchanger 11, a fan 12, a drive motor 13, a condensing unit (condensing device) 15, pressure sensors 16 and 17, and on-off valves 18 and 19. The installed cooling heat exchanger 11 and the condensing unit 15 installed outside the room are connected by a refrigerant pipe 14. The fan 12 is installed on the side wall near the cooling heat exchanger 11 in the cooling chamber 5 and is rotated by a drive motor 13 installed outside the room.

  In such a configuration, the refrigerant compressed and cooled in the condensing unit 15 that is a condenser is sent to the cooling heat exchanger 11 through the refrigerant pipe 14, and the pressure is reduced in the cooling heat exchanger 11. Cooling is performed by the heat of vaporization of the refrigerant. Since the fins for expanding the contact area are installed on the surface of the cooling heat exchanger 11, the cooling heat generated in the cooling heat exchanger 11 by the rotation of the fan 12 is circulated in the cooling chamber 5. It is possible to cool the inside of the cooling chamber 5 well.

  The vacuum cooling unit 20 includes a vacuum pump 21, a check valve 22, and an on-off valve 23, and is connected to the cooling chamber 5 by a decompression pipe 25. When the vacuum pump 21 is operated, the pressure in the cooling chamber 5 decreases, so that moisture contained in the object to be cooled such as food is evaporated, and the object to be cooled is cooled by the heat of evaporation.

  The hot water injection unit 30 includes a hot water supply unit 31 connected to a water supply line and a steam line, and an on-off valve 32, and is connected to the cooling chamber 5 by a hot water pipe 35. Under the control of the control unit 50, the hot water supply unit 31 generates hot water by mixing the water supplied from the water supply line with the steam from the steam line, and generates heat from the injection port at the tip of the hot water pipe 35. Inject hot water into the head.

  The injection port of the hot water pipe 35 is installed toward the upper part of the side surface of the cooling heat exchanger 11. When hot water is injected from the injection port, the hot water first reaches the upper part of the side surface of the cooling heat exchanger 11. Then, it travels down the side and falls down. In addition, since the side surface of the cooling heat exchanger 11 is formed of a metal having high thermal conductivity, the entire heat exchange surface of the cooling heat exchanger 11 can be warmed by the hot water jetted from the jet port. it can.

  The return pressure unit 40 includes an air filter 41 and an on-off valve 42 and is connected to the cooling chamber 5 by a return pressure pipe 45. When the inside of the cooling chamber 5 that has become negative pressure by the operation of the vacuum pump 21 is returned to the external pressure, the on-off valve 42 is opened by the control of the control unit 50, and the outside air that has passed through the air filter 41 enters the cooling chamber 5. It is introduced and the inside of the cooling chamber 5 is decompressed.

  The control unit 50 includes a calculation unit 51 for performing various calculations, a storage unit 52 for storing various types of information, and a timer unit 53 for measuring time. As shown by a dotted line in FIG. In order to receive a measured value or transmit a control signal, it is communicably connected to each member constituting the composite cooler 1.

  As mentioned above, although the structure of the composite chiller 1 which concerns on this embodiment was demonstrated in detail, in the composite chiller 1 of the said structure, the flow of the process at the time of disinfecting the heat exchanger 11 for cooling is shown in drawing. The description will be given with reference. FIG. 2 is a flowchart showing a flow of processing when the cooling heat exchanger 11 is sterilized. Note that the following processing is automatically performed under the control of the control unit 50 when the operator commands the sterilization processing by pressing a switch or the like.

  When the sterilization process is started, first, in S11, the control unit 50 controls the condensing unit 15 and the on-off valves 18 and 19 to perform the pump-down operation. As a result, the chlorofluorocarbon (R404a), which is a refrigerant gas, is extracted from the cooling heat exchanger 11 and collected in the condensing unit 15. This pump-down operation is performed until the refrigerant pressure in the cooling heat exchanger 11 measured by the pressure sensor 17 in the condensing unit 15 becomes 0 MPa.

  In this way, the refrigerant is removed before the hot water is applied to the cooling heat exchanger 11 if the refrigerant remains in the cooling heat exchanger 11 as it is, when the hot water is applied, the refrigerant is warmed. This is to prevent the pressure from rising and the cooling heat exchanger 11 and the refrigerant pipe 14 from being damaged or failing.

  Subsequently, in S <b> 12, the injection of 80 ° C. hot water from the injection port of the hot water injection unit 30 toward the upper side portions on both sides of the cooling heat exchanger 11 is started. Specifically, under the control of the control unit 50, the on-off valve 32 is opened, and 80 ° C. hot water supplied from the hot water supply unit 31 is injected from the injection port. Here, most of the bacteria and the like generated in the cooling chamber 5 are killed when the temperature reaches 60 ° C. or higher. And if hot water of 80 ° C is jetted, fins are installed on the surface, and even on the surface of the heat exchanger 11 for cooling where hot water does not reach directly to the back, the entire surface is heated by heat conduction. Can exhibit a sterilizing function.

  Next, in S13, the pressure sensor 16 installed in the refrigerant pipe 14 of the cold air cooling unit 10 monitors whether the refrigerant pressure has increased to 0.5 MPa or more. This is because the pressure may increase due to warming of the refrigerant gas remaining in the cooling heat exchanger 11.

  In S13, when the refrigerant pressure becomes 0.5 MPa or more, the process proceeds to S14, where the pump down operation is performed again, and the refrigerant gas is extracted from the cooling heat exchanger 11. Also at this time, the pump-down operation is performed until the refrigerant pressure in the cooling heat exchanger 11 measured by the pressure sensor 17 becomes 0 MPa. Thus, by controlling the pressure in the cooling chamber 5 to be within 0 to 0.5 MPa, it is possible to reliably prevent damage due to an excessive increase in the refrigerant pressure.

  In S13, when the refrigerant pressure is less than 0.5 MPa, and when the pump-down operation in S14 is completed, the process proceeds to S15, and the timer function of the timer unit 53 determines whether a predetermined time has elapsed since the injection of hot water in S12. Monitor whether or not. In this embodiment, it is monitored whether 30 minutes have passed. The reason for setting the time to 30 minutes is that, generally, when the temperature reaches 60 ° C. or higher, bacteria attached to the cooling heat exchanger 11 in the cooling chamber 5 can be almost killed. Then, after warm water of 80 ° C. is applied to the cooling heat exchanger 11, it takes 10 minutes as a time for the entire surface of the cooling heat exchanger 11 to be heated to 60 ° C. by heat conduction, and then 20 minutes as a time for sufficient sterilization. This is to ensure

  Of course, the time for injecting the hot water can be changed, and is appropriately changed according to the temperature and amount of the hot water injected from the hot water injection unit 30, the size of the cooling heat exchanger 11, and the like.

  If it is determined in S15 that the predetermined time has elapsed, the process proceeds to S16. If it is determined that the predetermined time has not elapsed, the process returns to S13, and the processes in and after S13 are repeated.

  If it progresses to S16, the on-off valve 32 will be closed by control of the control part 50, and the injection of warm water will be stopped. Then, it progresses to S17, water is injected from the warm water injection part 30 to the heat exchanger 11 for cooling, and the temperature of the warmed heat exchanger 11 for cooling is lowered | hung. Specifically, steam is not mixed in the hot water supply unit 30 and the on-off valve 32 is opened, and water supplied from the water supply line is directly injected from the injection port to the cooling heat exchanger 11.

  If the cooling heat exchanger 11 is kept warm after the sterilization process, when the combined cooler 1 is restarted immediately, the refrigerant gas sent into the cooling heat exchanger 11 expands and the refrigerant pressure is increased. However, if the cooling heat exchanger 11 warmed in the sterilization treatment is cooled immediately as in the present embodiment, the combined chiller 1 is immediately removed after sterilization. Can be restarted.

  Note that the step of cooling the cooling heat exchanger 11 in S17 may be performed by a vacuum cooling function. That is, the vacuum cooling unit 20 may be operated instead of injecting water supply without mixing steam from the hot water control unit 30. When the vacuum cooling unit 20 is operated, the pressure in the cooling chamber 5 decreases, and the water adhering to the wall surface of the cooling heat exchanger 11 evaporates. Therefore, the cooling heat exchanger 11 is cooled by the heat of vaporization. Can do.

  As described above, the sterilization treatment described in detail is desirably performed periodically in order to maintain hygiene in the cooling chamber 5, and is desirably performed once a day if possible. According to this embodiment, the wall surface of the heat exchanger 11 for cooling is provided with a sterilization function by high-temperature treatment at 60 ° C. or higher, and the sanitary function has been significantly improved as compared with a conventional cooler. A cooler can be provided.

  Further, in the present embodiment, the cooling heat exchanger 11 is warmed by the hot water, so that the refrigerant pressure is extracted by performing a pump-down operation before and during the sterilization process so that the refrigerant pressure does not increase excessively. As a result, it is possible to prevent damage to the equipment due to an increase in refrigerant pressure.

  As mentioned above, although this embodiment including a modification was described in detail, embodiment of this invention is not limited to the said embodiment or its modification, In the range which does not deviate from the main point of this invention. Various modifications are possible.

  For example, in the present embodiment, a combined cooler having a cold air cooling function and a vacuum cooling function, but the present invention is an invention for sterilizing a cooling heat exchanger used in the cold air cooling function, The present invention is applicable to any cooler having a cold air cooling function. For example, the present invention can be applied to a cold air cooling type blast chiller.

  In this embodiment, hot water in which steam is mixed with feed water is used as the heat medium for heating the cooling heat exchanger. However, steam capable of high-temperature sterilization may be used as the heat medium. . Furthermore, as a means for heating the cooling heat exchanger, not only a heating device using a heat medium such as hot water or steam, but also other heating devices can be used as appropriate. For example, a heating means such as a heating wire may be used. In this case, it is necessary to arrange a hot wire on the surface of the cooling heat exchanger.

FIG. 1 is a diagram schematically showing the configuration of the composite cooler according to the present embodiment. FIG. 2 is a flowchart showing a processing flow when the cooling heat exchanger according to the present embodiment is sterilized.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Combined chiller 5 Cooling chamber 10 Cold air cooling part 11 Cooling heat exchanger 14 Refrigerant piping 15 Condensing unit 16, 17 Pressure sensor 20 Vacuum cooling part 21 Vacuum pump 30 Hot water injection part 31 Hot water supply part 40 Recompression part 50 Control Part

Claims (5)

In the sterilization method of the cooler for sterilizing the heat exchanger for cooling installed in the cooling chamber of the cooler having a cold air cooling function,
A cooling device sterilization method comprising a heating step of heating the surface of the cooling heat exchanger installed in the cooling chamber.   The sterilization method for a cooler according to claim 1, further comprising a pre-heating pump-down step of performing a pump-down operation and extracting the refrigerant in the cooling heat exchanger before the heating step.   During the heating step, when the pressure in the cooling heat exchanger becomes equal to or higher than a predetermined value, a pumping down step during heating is performed in which a pump down operation is performed and the refrigerant in the cooling heat exchanger is removed. The cooling machine sterilization method according to claim 1 or 2, further comprising:   The sterilization method for a cooler according to any one of claims 1 to 3, further comprising a cooling step of cooling the cooling heat exchanger after the heating step. In the cooler that cools the cooling chamber with the cold air cooling function,
A cooling air exchanger having a cooling heat exchanger installed in the cooling chamber, a condensing device installed outside the cooling chamber, and a refrigerant pipe connecting the cooling heat exchanger and the condensing device;
A heating device for heating the surface of the cooling heat exchanger;
Control means for controlling the cold air cooling unit and the heating device, the control means for controlling the heating device to operate in order to sterilize the surface of the cooling heat exchanger;
A cooling machine comprising:

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