JP2007215446A - Apparatus for producing frozen dessert - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus for producing frozen dessert where a high-temperature refrigerant flows into a cooler while bypassing a condenser and a decompression device to eliminate temperature rise in a compressor when performing heat sterilization. <P>SOLUTION: The apparatus for producing frozen dessert is provided with a pressure-equalizing circuit 42 bypassing a compressor 18 and a condenser 20 to make the high-pressure side of a refrigerant circuit communicate with the low-pressure side of the refrigerant circuit, a pressure equalizing valve 43 set to the pressure equalizing circuit, and a hot gas circuit 40 bypassing the condenser and the decompression device. In the apparatus, the high-temperature refrigerant discharged out of the compressor is supplied to the cylinder cooler 11 via the hot gas circuit so that the refrigerant discharged from the cylinder cooler is sucked to the compressor to subject the mix to heat sterilization, and the pressure equalizing valve opens and closes in a temperature-raising process for the heat sterilization. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a frozen confection manufacturing apparatus for manufacturing a frozen confection such as soft ice cream.

  Conventionally, this kind of frozen confectionery manufacturing apparatus for producing frozen confectionery such as soft cream is equipped with a cooling device comprising a compressor, a condenser, a throttle (a pressure reducing device) and a cooling cylinder and a cooler equipped in a hopper (mix tank). The refrigeration cycle is reversible with a four-way valve, and during the production of frozen desserts, the liquefied refrigerant is decompressed and fed to each cooler to cool the cooling cylinder and hopper, and at the time of sterilizing the mix and equipment, the high-temperature refrigerant gas (hot gas) from the compressor Was conducted to each cooler to dissipate heat, and the cooler acted as a radiator to heat the cooling cylinder and hopper.

A beater driven by a beater motor is mounted in the cooling cylinder, and the mix supplied as appropriate from the hopper is agitated by the beater while cooling in the cooling cylinder to produce soft cream and the like. Further, a hopper stirrer called an impeller (also driven by a motor) is provided in the hopper, and the mix is stored by stirring the mix stored in the hopper by rotating the impeller. Uniformity was intended.
Japanese Utility Model Publication No. 63-20304

  Here, in order to reduce the cost and simplify the configuration in this seed frozen dessert manufacturing apparatus, the four-way valve is eliminated and a three-way valve is used, and a hot gas pipe bypassing the condenser and the decompression device is connected to the three-way valve, and heating is performed. At the time of sterilization, it is conceivable that the high-temperature refrigerant discharged from the compressor is caused to flow through this hot gas pipe and directly to the cooling cylinder or the hopper cooler.

  According to such a configuration, although the configuration can be simplified and the cost can be reduced, the relatively high temperature refrigerant from the cooling cylinder or the hopper cooler is sucked into the compressor without evaporating in the condenser as in the reverse circuit. Therefore, there arises a problem that the temperature of the compressor abnormally increases due to the temperature of the return refrigerant.

  On the other hand, during the busy season for selling frozen desserts, the compressor is frequently operated and stopped. If the pressure difference (high / low pressure difference) between the discharge side and the suction side is large when the compressor is started, the load becomes excessive. Therefore, conventionally, a pressure equalizing pipe that connects the high pressure side and the low pressure side of the refrigerant circuit is provided, and a pressure equalizing valve is provided in the pressure equalizing pipe, and when starting the compressor, the pressure equalizing valve is once opened, Control to start the compressor after closing was executed.

  The present invention has been made to solve the conventional technical problem, and eliminates the rise in the temperature of the compressor when heat sterilization is performed by bypassing the condenser and the pressure reducing device and flowing high-temperature refrigerant to the cooler. An apparatus for producing frozen desserts that can be provided is provided.

  The frozen dessert manufacturing apparatus of the present invention includes a cooling cylinder that manufactures frozen dessert by cooling the mix while stirring, a cylinder cooler for cooling the cooling cylinder, a compressor, a condenser, a decompression device, a cylinder cooler, and the like. A cooling device having a refrigerant circuit and a control device for controlling the operation of the cooling device are provided, bypassing the compressor and the condenser and communicating between the high pressure side and the low pressure side of the refrigerant circuit. A pressure circuit, a pressure equalizing valve provided in the pressure equalizing circuit, and a hot gas circuit that bypasses the condenser and the pressure reducing device, and the control device cools the high-temperature refrigerant discharged from the compressor through the hot gas circuit through cylinder cooling. The mixture is heated and sterilized by sucking the refrigerant from the cylinder cooler into the compressor. Both the Atsushi Nobori step of the heat sterilization, characterized by opening and closing the equalizing valve.

  According to a second aspect of the present invention, the control device opens and closes the pressure equalizing valve based on the temperature of the cylinder cooler.

  According to a third aspect of the present invention, the control device opens the pressure equalizing valve for a predetermined time each time the cylinder cooler rises by a predetermined temperature.

  According to the present invention, a cooling cylinder for producing a frozen dessert by cooling the mix while stirring, a cylinder cooler for cooling the cooling cylinder, a refrigerant circuit from a compressor, a condenser, a decompression device, a cylinder cooler and the like In a frozen confectionery manufacturing apparatus comprising a cooling device configured of the above and a control device for controlling the operation of the cooling device, a pressure equalizing circuit that bypasses the compressor and the condenser and communicates the high-pressure side and the low-pressure side of the refrigerant circuit And a pressure equalizing valve provided in the pressure equalizing circuit, and a hot gas circuit that bypasses the condenser and the pressure reducing device, and the control device supplies the high-temperature refrigerant discharged from the compressor to the cylinder cooler via the hot gas circuit. Supply and sterilize the mix by sucking the refrigerant from the cylinder cooler into the compressor In both cases, the pressure equalizing valve is opened and closed in the temperature raising step of the heat sterilization. Therefore, the pressure equalizing valve is turned on each time the cylinder cooler rises to a predetermined temperature based on the temperature of the cylinder cooler, for example, as in claims 2 and 3. By executing the control for releasing for a predetermined time, the refrigerant cooled in the condenser can be sucked from the pressure equalizing circuit, mixed with the high-temperature refrigerant from the cylinder cooler, and sucked into the compressor.

  Thereby, the temperature of the refrigerant sucked into the compressor is lowered in the temperature raising step, the temperature rise of the compressor is suppressed, and the occurrence of damage can be avoided in advance.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing the internal configuration of a soft ice cream manufacturing apparatus SM as an embodiment of the frozen dessert manufacturing apparatus of the present invention, FIG. 2 is a refrigerant circuit diagram of the soft ice cream manufacturing apparatus SM, and FIG. 3 is the soft ice cream manufacturing apparatus 2 shows a block diagram of the SM control device C. FIG. The soft cream manufacturing apparatus SM of an Example is an apparatus which manufactures and sells one kind of soft cream among the soft cream which added vanilla soft cream, chocolate soft cream, or other syrup (additive), for example.

  In each figure, 1 is a main body, 2 is a hopper for storing a mix which is a raw material of frozen confectionery (soft cream), and has a hopper cover 3 as a cover to be removed when the mix is replenished, and is wound around the hopper 2 The mix is stored and kept in a hopper cooler (cooling coil) 4. The periphery of the hopper 2 is insulated with a heat insulating material. Reference numeral 5 denotes an impeller as a hopper stirrer provided on the bottom surface in the hopper 2. The impeller 5 basically stores a predetermined amount or more of the mix in the hopper 2, and the hopper cooler 4 stores the reduced-pressure refrigerant. Is rotated by the stirring motor 6 and rotated based on an instruction from the stirring switch 61 described later when the hot gas which is a high-temperature refrigerant gas is supplied and is sterilized by heating. Driven.

  7 is a mix detection device that detects whether or not the hopper 2 has a predetermined amount or more of the mix. The mix detection device 7 includes a pair of conductive electrodes. The hot gas circulation is stopped and the impeller 5 is not rotated so as not to perform the heat sterilization described later.

  Reference numeral 8 denotes a cooling cylinder for producing a frozen dessert by rotating and stirring the mix appropriately supplied from the hopper 2 by the mix feeder 9 with the beater 10, and a cylinder cooler 11 is arranged around the cooling cylinder. It is insulated. The beater 10 is rotated via a beater motor 12, a drive transmission belt, a speed reducer 13, and a rotating shaft. The manufactured frozen confectionery (soft cream) is taken out by operating the take-out lever 15 disposed on the freezer door 14 so that the plunger 16 moves up and down to open an extraction path (not shown).

  Next, a cooling device for cooling the hopper 2 and the cooling cylinder 8 will be described using the refrigerant circuit diagram of FIG. 18 is a rotary type compressor (rotary compressor), 19 is connected to the discharge side of the compressor 18, and the refrigerant discharged from the compressor 18 is cooled during the cooling cycle (indicated by solid arrows in FIG. 2) and during the heating cycle (FIG. 2). And a water-cooled condenser 20 that is cooled by tap water that is constantly circulated through a water-saving valve (not shown). The high-pressure refrigerant gas is cooled to condense and liquefy to form a liquefied refrigerant.

  The compressor 18 and the condenser 20 are installed in the machine room MR. Reference numeral 41 denotes an intermediate cooling circuit that is drawn into the compressor 18 from the middle of the piping of the condenser 20, and has an effect of cooling the compressor 18 with the coolant cooled by the condenser 20.

  During the cooling operation in which the three-way valve 19 is used as a cooling cycle, the refrigerant liquefied by the condenser 20 enters the high-pressure side pipe 21 connected to the outlet side of the condenser 20, and the dehydrator (dryer) 23 interposed there After passing, it is divided into two at the branch point P1, one of which passes through a cylinder cooling valve 24 and enters a capillary tube 25 (inner diameter 1.2 mm) for a cooling cylinder as a pressure reducing device. It flows into the vessel 11 and evaporates to cool the cooling cylinder 8. Then, the other enters the hopper capillary tube 27 (inner diameter 1.2 mm) as the preceding decompression device through the hopper cooling valve 26, and after being decompressed there, flows into the hopper cooler 4 and similarly evaporates. After the hopper 2 is cooled, the hopper 2 exits through a capillary tube 28 (inner diameter 1.2 mm) as a subsequent decompression device.

  Then, the refrigerant exiting the cooling cylinder 8 and the hopper 2 joins at the joining point P2, and then enters the accumulator 30 through the low-pressure side pipe 22. The low pressure side pipe 22 is provided with a muffler 33 having a predetermined capacity, and the refrigerant having passed through the junction P2 passes through the muffler 33 and reaches the accumulator 30. And the circulation which the refrigerant | coolant which left this accumulator 30 is suck | inhaled by the suction side of the compressor 18 is repeated (solid line arrow of FIG. 2).

  By the way, in this cooling operation, it is necessary to keep the cooling cylinder 8 and the hopper 2 cooled to a predetermined temperature in order to obtain a high-quality frozen dessert. Therefore, a cylinder sensor 31 (FIG. 3) for detecting the temperature of the mix in the cooling cylinder 8 from the temperature of the cooling cylinder 8 is provided, and the cylinder cooling valve 24 is controlled by equilibrium temperature control as will be described later. ON (open), the compressor 18 is turned ON to perform cooling, and when the cylinder cooling valve 24 is OFF (closed), the hopper cooling valve 26 is opened / closed and the compressor 18 is turned ON / OFF. That is, the cooling of the cooling cylinder 8 is prioritized and the hopper cooling valve 26 is turned on under the condition that the cylinder cooling valve 24 is turned off.

  After the sale is made under the above-described cooling operation, the mix is sterilized by the heating method when the store is closed. In this case, the cooling device is switched from the cooling cycle to the heating cycle operation. That is, the three-way valve 19 is operated to cause the refrigerant to flow as indicated by the broken line arrow. As a result, the high-temperature and high-pressure refrigerant gas discharged from the compressor 18, that is, hot gas enters the hot gas pipe 40 through the three-way valve 19. The hot gas pipe 40 bypasses the high-pressure side pipe 21 from the capacitor 20 to both capillary tubes 25 and 27, and the refrigerant gas that has entered the hot gas pipe 40 is split into two at the branch point P3. It flows into the cylinder cooler 11 from the junction P4 on the downstream side of the capillary tube 25 through the cylinder throttle pipe 36 and the cylinder hot gas valve 34, and the other passes through the hopper throttle pipe 37 and the hopper hot gas valve 35. And flows into the hopper cooler 4 from the junction P5 on the downstream side of the capillary tube 27, generates a heat radiation action in each, and heats the cooling cylinder 8 and the hopper 2 at a specified sterilization temperature for a predetermined time (the broken line in FIG. 2). Indicated by an arrow).

  The inner diameters of the throttle tubes 36, 37 are larger than the capillary tubes 25, 27, 28, and smaller (narrower) than the inner diameters of the pipes in the other refrigerant circuits, for example, 2 mm.

  After radiating heat from the cylinder cooler 11, the liquefied refrigerant exiting from the cylinder cooler 11 and the liquefied refrigerant passing through the capillary tube 28 after radiating heat from the hopper cooler 4 are merged at the junction P2 as described above. It enters the low-pressure side pipe 22 and returns to the compressor 18 through the muffler 33 and the accumulator 30. 38 is a sterilization / cooling sensor (FIG. 3) for detecting the heating temperature of the cooling cylinder 8, and the cylinder is set at a predetermined upper limit and lower limit set temperature values so as to maintain a predetermined sterilization temperature for the mix. The hot gas valve 34 and the compressor 18 are ON / OFF controlled.

  The hopper 2 is heated by a hopper sensor 32 for detecting the mix temperature in the hopper 2 from the hopper 2 temperature. The hopper hot gas valve 35 and the hopper hot gas valve 35 are set at the same set temperature value set in the cooling cylinder 8. The compressor 18 is configured to be turned on and off. The sterilization / cooling sensor 38 described above shifts to cooling after heat sterilization and turns on the compressor 18 so as to maintain a certain low temperature state until the point of sale on the next day, that is, the cool temperature (about + 8 ° C. to + 10 ° C.). OFF control and ON / OFF control of the cylinder cooling valve 24 and the hopper cooling valve 26 are performed.

  44 is an electrical box, and 45 is a front drain receptacle. Furthermore, 55 is a water tap, which is used to supply water to the hopper 2 and the cooling cylinder 8 during the mix cleaning. Furthermore, 42 communicates between the low-pressure side pipe 22 (the inlet side of the accumulator 30) between the accumulator 30 and the muffler 33 and the high-pressure side pipe 21 (the outlet side of the capacitor 20) between the capacitor 20 and the dehydrator 23. Thus, a pressure equalizing pipe that constitutes a pressure equalizing circuit that bypasses the compressor 18 and the capacitor 20, and a pressure equalizing valve 43 that is mainly used for preventing overload of the compressor 18 is interposed in the pressure equalizing pipe 42. Yes.

  In FIG. 3, the control device C is configured on a substrate housed in the electrical box 44 and is designed around a general-purpose microcomputer 46. The microcomputer 46 includes the cylinder sensor 31 and the hopper sensor 32. The output of the sterilization / cooling sensor 38 is input, and the output of the microcomputer 46 includes the compressor motor 18M of the compressor 18, the beater motor 12, the stirring motor 6, the cylinder cooling valve 24, the cylinder hot gas valve 34, and the hopper cooling valve 26. The hopper hot gas valve 35, the three-way valve 19, and the pressure equalizing valve 43 are connected.

  In this figure, 47 is a current sensor (current transformer) for detecting the energizing current of the compressor motor 18M, 48 is a current sensor (current transformer) for detecting the energizing current of the beater motor 12, and each output is a microcomputer. 46 is input. An extraction switch 51 is opened and closed by operating the take-out lever 15, and its contact output is input to the microcomputer 46. Reference numeral 56 denotes a CT sensor that detects the temperature of the capacitor 20, and its output is also input to the microcomputer 46.

  Similarly, reference numeral 53 denotes a control start temperature setting volume for changing the control start temperature for permitting the start of the equilibrium temperature control in the equilibrium temperature control, and any output is input to the microcomputer 46. Further, 52 is a key input circuit including a cooling operation switch for instructing the microcomputer 46 to perform a cooling operation. The key input circuit 52 includes various switches for instructing various other operations.

  The key input circuit 52 is disposed on an operation panel (not shown) of the soft ice cream manufacturing apparatus SM, and the control start temperature setting volume 53 is attached to the substrate of the control apparatus C. Furthermore, an LED display 54 for performing various display operations such as an alarm is connected to the output of the microcomputer 46.

  With the above configuration, the operation of the soft ice cream manufacturing apparatus SM will be described with reference to FIGS. When the operation of the soft cream manufacturing apparatus SM of the embodiment is started, each of the cooling operation (cooling process, defrost process), heat sterilization / cooling operation (sterilization heating process, sterilization holding process, cold holding pull-down process, cold holding process) Run the operation. The timing chart of FIG. 4 shows the temperature of the cooling cylinder 8 and the hopper 2 during the cooling operation after the pull-down is completed and the operation of each device, and FIG. 5 shows the timing chart regarding the equilibrium temperature control described later.

(1) Cooling operation First, the cooling operation will be described. When the cooling operation switch provided in the key input circuit 52 is operated, the microcomputer 46 starts the cooling process of the cooling operation.

(1-1) Cooling Step In this cooling step, the microcomputer 46 operates the compressor 18 (compressor motor 18M), and the three-way valve 19 is in the cooling cycle. Then, the cylinder cooling valve 24 is turned on (opened), the hopper cooling valve 26 is turned off (closed), and the cylinder hot gas valve 34 and the hopper hot gas valve are turned off. Further, the beater 10 is rotated by the beater motor 12.

  As a result, the mix in the cooling cylinder 8 is cooled by the cylinder cooler 11 and stirred by the beater 10 as described above. Next, the microcomputer 46 determines based on the output of the cylinder sensor 31 whether or not the current mix temperature in the cooling cylinder 8 is equal to or higher than the control start temperature (for example, -1 ° C. by default, FIG. 5). If the mix temperature is still equal to or higher than the control start temperature, the cooling operation is continued.

(1-1-1) Equilibrium temperature control When the temperature of the mix in the cooling cylinder 8 is lowered to the control start temperature described above by the cooling operation, the microcomputer 46 determines the equilibrium temperature described below based on the output of the cylinder sensor 31. Control is started (FIG. 5). With this equilibrium temperature control, the microcomputer 46 allows the temperature drop of the mix to elapse for T seconds (for example, set at a time between 20 seconds to 40 seconds), at T ° C (for example, 0.1 ° C to 0.2 ° C). It is determined whether the value is within the range of That is, it is determined whether or not the temperature drop rate of the mix in the cooling cylinder 8 is within a predetermined value.

  When the temperature drop rate is larger than a predetermined value, the cooling operation is continued, and the mix in the cooling cylinder 8 is cooled while stirring. Here, the temperature of the mix decreases with the progress of cooling, and the temperature drop gradually slows as it approaches the transformation point (freezing point) unique to the mix. When the temperature drop during the t seconds (difference between the current mix temperature and the temperature before t seconds) falls within the T ° C., the microcomputer 46 determines that the conduction current of the beater motor 12 is predetermined based on the output of the current sensor 48. It is determined whether or not the threshold is exceeded.

  The mix cooled while being stirred in the cooling cylinder 8 has a predetermined hardness when it becomes a frozen confection for sale. And since the load of the beater 10 which is stirring it increases with the hardness of this frozen dessert (soft cream), the energization current of the beater motor 12 will rise.

  If the energization current of the beater motor 12 exceeds the threshold value, the microcomputer 46 sets the current mix temperature to the cooling end temperature (OFF point temperature) and stops cooling. That is, in this cooling stop, the microcomputer 46 turns off the cylinder cooling valve 24 and turns on the hopper cooling valve 26 instead. As a result, the cooling of the cooling cylinder 8 is stopped, and the hopper 2 is now cooled by turning on the hopper cooling valve 26 (FIG. 4). This ends the pull-down.

  Based on the output of the cylinder sensor 31, the microcomputer 46 determines whether or not the current mix temperature has risen to the cooling end temperature (OFF point temperature) + 0.5 ° C. or higher. If it has not risen, the cooling control of the hopper 2 is continued. That is, based on the output of the hopper sensor 32, the microcomputer 46 turns off the hopper cooling valve 26 and stops the compressor 18 in this case when the temperature of the hopper 2 is also cooled below a predetermined temperature. . In the embodiment, the hopper cooling valve 26 is turned on at 10 ° C. and turned off at 8 ° C.

  When the temperature of the mix (frozen dessert) rises to the cooling end temperature (OFF point temperature) + 0.5 ° C. or higher, the microcomputer 46 starts cooling the cooling cylinder 8 as described above.

(1-1-2) Change in Control Start Temperature of Equilibrium Temperature Control Here, the control start temperature permitting the start of the above-described equilibrium temperature control is the cooling cylinder 8 just after installing the soft ice cream manufacturing apparatus SM. It is provided in order to avoid starting the equilibrium temperature control in a state where the temperature drop rate is slow when the temperature of the mix is high. That is, it is set for the purpose of starting the equilibrium temperature control from the stage where the temperature of the mix in the cooling cylinder 8 is lowered to some extent (usually 0 ° C. or less).

  However, depending on the mix (for example, when a plurality of types of mixes are mixed), two or more transformation points may occur. For example, in the case of a mix having two transformation points at −2 ° C. and −5 ° C., the temperature drop of the mix is as shown by a one-dot chain line in FIG. Is fixed, equilibrium temperature control is started after passing through -1 ° C, and cooling is stopped at the transformation point of the higher -2 ° C. In this case, since some components in the mix start to solidify at the higher transformation point, the energization current of the beater motor 12 also exceeds the threshold value, but as a whole does not reach the hardness available for sale.

  Therefore, a control start temperature setting volume 53 as shown in FIG. 3 is provided. When using a mix having a transformation point as described above, this control start temperature setting volume 53 is operated, and control is started from the default −1 ° C. to, for example, −3 ° C. as indicated by an arrow in FIG. Reduce temperature. Based on this change, the microcomputer 46 does not execute the equilibrium temperature control at the above-described transformation point of −2 ° C., and stops cooling by the equilibrium temperature control at the transformation point of −5 ° C. lower than −3 ° C. that has passed through this. It becomes like this. This allows the mix to cool to the final transformation point and create a good hardness that can be sold.

  In the above-described example, the case where the control start temperature is lowered has been described, but it may be raised. For example, when the transformation point is higher than the default or close to that, the equilibrium temperature control is not performed even after the transformation point, and cooling is continued. In this case, the control start temperature setting volume 53 is operated to increase the control start temperature (for example, 0 ° C.).

(1-1-3) Equilibrium temperature control fail-safe time 1
Here, since the equilibrium temperature control is achieved based on the temperature drop rate of the mix in the cooling cylinder 8 as described above, when the measurement or calculation of the temperature drop in the t seconds fails due to some factor, Alternatively, when the detection of the energization current of the beater motor 12 fails, the cooling is not stopped and the cylinder cooler 11 of the cooling device is continuously cooled. In such a case, the mix in the cooling cylinder 8 is naturally frozen.

  For this reason, the microcomputer 46 operates a cooling operation switch provided in the key input circuit 52 to start the compressor 18 and starts cooling the cooling cylinder 8 by the cylinder cooler 11. 15 minutes have elapsed), and the program is programmed to forcibly stop cooling when the fail-safe time has elapsed. This is based on an empirical rule that a frozen dessert can be produced in 15 minutes.

  However, for example, after the heat sterilization described later is performed, when the operation of the soft cream manufacturing apparatus SM is temporarily stopped and the cooling operation switch is operated again, the temperature of the mix in the cooling cylinder 8 is extremely high. The cooling operation is started from the beginning. Even in such a case, if the cooling is stopped after the above-described 15-minute fail-safe time has elapsed, there is a problem that in 15 minutes, the temperature of the mix is not sufficiently lowered and the frozen dessert cannot be manufactured.

  Therefore, the microcomputer 46 is based on the temperature of the mix in the cooling cylinder 8 at the time when the cooling operation switch is operated (at the time of starting the cooling operation) based on the output of the cylinder sensor 31 (which may be the sterilization / cooling sensor 38). Change the fail-safe time. That is, as shown in the graph of FIG. 6, the microcomputer 46 changes the fail-safe time to be longer as the temperature of the mix in the cooling cylinder 8 (cylinder temperature (temperature of the cooling cylinder 8)) is higher. As a result, when the cooling operation is started under the condition where the temperature of the mix is high as described above, for example, the fail-safe time is extended to 20 minutes or more, and the mix is cooled further. Therefore, it is possible to reliably manufacture a frozen dessert having a hardness for sale while avoiding freezing due to unnecessary cooling of the cooling cylinder 8.

(1-1-4) Equilibrium temperature control fail-safe time 2
In addition to the case where the fail safe time is changed by the temperature of the mix in the cooling cylinder 8 at the time when the cooling operation switch is operated as described above, the fail safe time is fixed and the temperature at which the count starts is specified. You may do it. That is, in this case, as shown in FIG. 5, the microcomputer 46 has a cylinder sensor 31 (or a sterilization / cooling sensor 38) up to a predetermined count start temperature set at, for example, any one of 10 ° C. to 20 ° C. From the point in time when the temperature of the mix in the cooling cylinder 8 based on the output of the above has decreased, counting of the fail-safe time of 15 minutes is started.

  According to such a configuration, the count of the fail safe time is not started in a state where the mix temperature immediately after the heat sterilization is high, and the count of the fail safe time is always started at one count start temperature. Therefore, the fail safe time can be functioned without being influenced by the temperature of the mix in the cooling cylinder 8 at the start of the cooling operation. As a result, similarly, it is possible to realize reliable frozen dessert production while avoiding freezing due to unnecessary cooling of the cooling cylinder 8.

(1-2) Defrost Process Next, the above-described defrost process will be described. When a defrost switch (not shown) provided in the key input circuit 52 is operated during the cooling operation, the microcomputer 46 switches the three-way valve 19 to the heating cycle, performs ON / OFF control of the cylinder hot gas valve 34, and performs hot gas The cooling cylinder 8 is heated to increase the temperature of the mix to a predetermined temperature (5 ° C.). Thereafter, the microcomputer 46 returns the three-way valve 19 to the cooling cycle, continues the cooling operation, and again performs the cooling process of the mix.

(1-3) Impeller control 1
The microcomputer 46 opens the hopper cooling valve 26 and drives the agitation motor 6 during the period when the refrigerant is flowing through the capillary tube 27 to the hopper cooler 4 (while the hopper 2 is cooled) The impeller 5 is rotated. This prevents a non-uniform temperature distribution from occurring in the mix stored in the hopper 2, and this is the basic drive control of the impeller 5 by the microcomputer 46 (FIG. 4).

  In addition, when an additive such as syrup is introduced into the hopper 2 and mixed with the mix to produce and sell the soft cream, after opening the hopper cover 3 and introducing the syrup into the hopper 2 The stirring switch 61 is operated. When the agitation switch 61 is operated, the microcomputer 46 drives the agitation motor 6 for a predetermined time (for example, 60 seconds) from that time to rotate the impeller 5. This is forcibly executed regardless of whether or not the refrigerant is supplied to the hopper cooler 4 as described above. Thereby, the syrup and mix thrown in in the hopper 2 are mixed smoothly.

  That is, the impeller 5 can be arbitrarily driven to rotate by operating the stirring switch 61 and instructing the microcomputer 46. Thereby, in addition to the time when the syrup is introduced, the impeller 5 does not rotate because the refrigerant is not supplied to the hopper cooler 4 for a relatively long time due to the influence of the outside temperature or the like, and the stirring state of the mix in the hopper 2 is changed. Even when the user notices that it has deteriorated, the stirring switch 61 forcibly rotates the impeller 5 to stir the mix in the hopper 2 to make the temperature distribution uniform. It is possible to improve convenience and improve the cold storage performance of the mix.

  Further, since the impeller 5 is driven to rotate for a predetermined time based on an instruction operation by the agitation switch 61, the impeller 5 is stopped after being rotated for a predetermined time, so that the rotation of the impeller 5 started by the agitation switch 61 is automatically ended after the predetermined time. The operation for stopping the impeller 5 is not necessary.

(1-4) Impeller control 2
In the above description, the impeller 5 is rotated by the user operating the agitation switch 61. However, a hopper cover switch for detecting the opening and closing of the hopper cover 3 is provided at the opening edge of the hopper 2, and this hopper cover switch is provided. May detect that the impeller 5 is driven to rotate when the hopper cover 3 is closed.

  In that case, after opening the hopper cover 3 and adding an additive such as syrup into the hopper 2, if the hopper 2 is closed again with the hopper cover 3, the hopper cover switch detects it and automatically Since the impeller 5 is driven to rotate to mix the additive and the mix, the operability is remarkably improved.

(1-5) Impeller control 3
Further, as described above, when the outside air temperature is low, the refrigerant does not flow into the hopper cooler 4 for a long time. In such a situation, unless the user notices, the impeller 5 is basically not rotated, so that the hopper 2 is not stirred for a long time, resulting in a non-uniform temperature distribution in the mix in the hopper 2 and the mix. There is also a risk of causing separation.

  Therefore, when the microcomputer 46 continues to drive the stirring motor 6 that rotates the impeller 5 for a predetermined time (for example, 5 minutes) (stop time shown in FIG. 4), the refrigerant to the hopper cooler 4 Regardless of the supply, the agitation motor 6 is driven for a predetermined time (for example, 60 seconds) to forcibly rotate the impeller 5. As a result, inconveniences such as the occurrence of a non-uniform temperature distribution due to the situation where the impeller 5 does not rotate for a long time are avoided. Moreover, since it rotates only for predetermined time (60 second), the problem which makes the mix in the hopper 2 foam by the stirring more than necessary also does not arise by making this time the value in which the mix in the hopper 2 does not foam.

(2) Heat sterilization / cooling operation Next, the heat sterilization / cooling operation (sterilization temperature rising process, sterilization holding process, cold holding pull-down process, cold holding process) will be described. When a sterilization switch (not shown) of the key input circuit 52 is operated, the microcomputer 46 starts a heat sterilization / cooling operation under a condition that there is no running out of the mix.

(2-1) Sterilization Temperature Raising Step That is, the microcomputer 46 switches the refrigerant circuit from the cooling cycle to the heating cycle by the three-way valve 19. Thereby, the high-temperature and high-pressure refrigerant gas (hot gas) discharged from the compressor 18 is supplied to the cylinder cooler 11 and the hopper cooler 4 through the cylinder hot gas valve 34 and the hopper hot gas valve 35 of the hot gas pipe 40. The mix in the cooling cylinder 8 and the hopper 2 is heated and the temperature rises.

  The refrigerant radiated by the cylinder cooler 11 reaches the junction P2. The refrigerant radiated by the hopper cooler 4 is decompressed by the capillary tube 28 and then merged with the refrigerant from the cylinder cooler 11 at the junction P2. Thereafter, the refrigerant enters the low pressure side pipe 22 and is sucked into the compressor 18 through the muffler 33 and the accumulator 30 in order.

(2-2) Sterilization and holding step When the above-described sterilization temperature raising step is completed, the microcomputer 46, on the basis of the outputs of the sterilization / cooling sensor 38 and the hopper sensor 32, now has the compressor 18, the cylinder hot gas valve 34, the hopper hot The gas valve 35 is controlled to be turned on and off, and both the cooling cylinder 8 and the hopper 2 are held in the heating temperature range of + 69 ° C. to + 72 ° C. for about 40 minutes. At this time, the microcomputer 46 operates to operate the compressor 18 when one of the hot gas valves 34 and 35 is opened, and to stop the compressor 18 when both the hot gas valves 34 and 35 are closed. To do.

(2-3) Control of Hot Gas Valve Here, since the refrigerant circuit is a reverse cycle in the conventional general frozen dessert manufacturing apparatus, the cylinder cooler 11 and the hopper cooler are used in the sterilization temperature rise and sterilization holding processes described above. The refrigerant that has exited 4 is depressurized and evaporated by the condenser and then returned to the compressor. However, in the cooling device of FIG. 2, the relatively high-temperature refrigerant that exits the cylinder cooler 11 and the hopper cooler 4 remains as it is (that is, , Without being evaporated by the condenser). Therefore, the compressor 18 is likely to be overloaded as it is, and the current flowing through the compressor motor 18M abnormally increases.

  In order to solve this problem, the microcomputer 46 controls the cylinder hot gas valve 36 of the hot gas circuit 40 as shown in FIG. That is, the initial microcomputer 46 in the above-described sterilization temperature raising process opens (ON) the cylinder hot gas valve 36 and the hopper hot gas valve 35, and causes the hot gas to flow through both the coolers 11 and 4. Here, the length of the cylinder cooler 11 is set longer than that of the hopper cooler 4 because the cooling cylinder 8 must be cooled strongly. Therefore, the temperature of the cooling cylinder 8 (shown by a solid line in FIG. 7) rises faster than the temperature of the hopper 2 (shown by a broken line in FIG. 7).

  Based on the output of the current sensor 47, the microcomputer 46 determines that the value of the current flowing through the compressor motor 18M is a predetermined set value (upper) (the upper limit value in this case. When the value rises to a value lower than (value), the cylinder hot gas valve 34 is closed (OFF), and the supply of hot gas to the cylinder cooler 11 is stopped. As a result, the load on the compressor 18 is reduced, and the current flowing through the compressor motor 18M decreases. Further, the temperature rise of the cooling cylinder 8 stops (around + 60 ° C.), and the temperature rise of the hopper 2 becomes steep. When the pressure drops to a predetermined set value (lower) (lower limit value in this case), the cylinder hot gas valve 34 is opened again (ON), and supply of hot gas to the cylinder cooler 11 is resumed (at this time, the hopper The temperature of 2 has reached + 72 ° C). Therefore, the temperature of the cooling cylinder 8 rises again, and the cooling cylinder 8 eventually reaches + 72 ° C. (FIG. 7).

  Thus, when the energization current to the compressor motor 18M rises to a predetermined set value (up), the supply of hot gas to the cylinder cooler 11 of the cooling cylinder 8 whose temperature rises faster than the hopper 2 is stopped. As a result, the cooling cylinder 8 and the hopper 2 are heated almost equally and the sterilization heating process during the heat sterilization operation is performed without hindrance, and an excessive current flows through the compressor motor 18M to cause winding burnout. The occurrence of inconvenience can be avoided in advance.

(2-4) Compressor temperature rise suppression control by pressure equalization valve In addition, as described above, in the cooling device of FIG. 2, the relatively high temperature refrigerant exiting the cylinder cooler 11 and the hopper cooler 4 is not evaporated by the condenser. Since the air is sucked into the compressor 18, the temperature of the compressor 18 rises abnormally as it is due to the effect of the temperature of the return refrigerant.

  Therefore, in the present invention, the pressure equalizing valve 43 provided in the pressure equalizing pipe 42 is opened and closed in the sterilization temperature rising process during the heat sterilization operation. The specific opening / closing control of the pressure equalizing valve 43 by the microcomputer 46 in this case is shown at the bottom of FIG. That is, in the microcomputer 46, the temperature rises to some extent as described above in the sterilization temperature raising step, and then the cylinder hot gas valve 34 is first closed by the increase in the current value of the compressor motor 18M, and only the hopper 2 is heated. When the temperature of the hopper 2 is increased, for example, every time the temperature of the hopper 2 rises by a predetermined temperature, that is, in the embodiment, + 45 ° C., + 48 ° C., + 51 ° C., + 54 ° C., + 57 ° C., + 60 ° C., Control is performed to open and close the pressure equalizing valve 43 for a predetermined time (for example, 5 seconds) every time the temperature rises by + 63 ° C., + 66 ° C., + 69 ° C., + 72 ° C. and 3 ° C. (deg).

  Further, when the hopper hot gas valve 35 is closed and only the cooling cylinder 8 is heated as described above, for example, every time the temperature of the cooling cylinder 8 rises by a predetermined temperature based on the output of the sterilization / cooling sensor 38, That is, in the embodiment, every time the temperature rises by + 63 ° C., + 66 ° C., + 69 ° C. and 3 ° C. (deg), the pressure equalizing valve 43 is opened and closed for a predetermined time (for example, 5 seconds). During this heat sterilization operation, the cylinder cooling valve 24 and the hopper cooling valve 26 are closed after opening for 30 seconds at the start (FIG. 7).

  When the pressure equalizing valve 43 is thus opened, the high-pressure side pipe 21 on the outlet side of the capacitor 20 and the low-pressure side pipe 22 on the inlet side of the accumulator 30 communicate with each other. The low refrigerant is sucked by the compressor 18 through the pressure equalizing pipe 42 and flows into the accumulator 30. This low-temperature refrigerant joins with the high-temperature refrigerant from each cooler 11, 4 in the accumulator 30 and is then sucked into the compressor 18, so that the temperature of the refrigerant sucked into the compressor 18 is lowered. Alternatively, the temperature rise can be suppressed. Thereby, the temperature rise of the compressor 18 in the sterilization temperature rising step can be suppressed, and inconveniences such as the occurrence of winding damage and the operation of the protection device can be avoided in advance.

(2-5) Muffler of throttle pipe and low-pressure side pipe of hot gas circuit Also, the relatively high-temperature refrigerant that has left the cylinder cooler 11 and the hopper cooler 4 is sucked into the compressor 18 without evaporating in the condenser. In order to suppress the temperature rise of the compressor 18 due to this, the hot gas circuit 40 is provided with throttle pipes 36 and 37. That is, although the inner diameters of the throttle tubes 36 and 37 are larger than the capillary tubes 25, 27 and 28 as described above, they are smaller than the inner diameters of the pipes in other refrigerant circuits (for example, an inner diameter of 2 mm). The circulation amount of the refrigerant flowing through the refrigerant circuit during the cycle is reduced as compared with the cooling cycle. Thereby, the abnormal temperature rise of the compressor 18 is prevented or suppressed.

  Further, as described above, the pipe length of the hopper cooler 4 is shorter than that of the cylinder cooler 11. Accordingly, the flow rate of the high-temperature refrigerant flowing through the hopper cooler 4 is smaller and faster because the pipe length is shorter than the flow rate of the high-temperature refrigerant flowing through the cylinder cooler 11. Therefore, in particular, when the cylinder hot gas valve 34 is closed as described above and the hot gas is allowed to flow only to the hopper cooler 4, the flow rate is high when the refrigerant discharged from the hopper cooler 4 enters the accumulator 30. Inflates and generates noise.

  Therefore, the muffler 33 is provided in the low pressure side pipe 22 to attenuate the pulsation pressure of the hot gas flow. That is, in the process of passing through the muffler 33, the pulsation pressure of the refrigerant discharged from the hopper cooler 4 (and the cylinder cooler 11) is lowered, so that no noise is generated even if the accumulator 30 is subsequently entered or becomes extremely small. .

Such a sterilization temperature rising and sterilization holding process is displayed by the sterilization LED of the LED display 54. When the sterilization holding process is completed, the microcomputer 46 proceeds to a cold insulation pull-down process. This cold transfer is also displayed on the LED display 54.
(2-6) Cooling pull-down process

  In the cold holding pull-down process that follows the sterilization holding process, the refrigerant circuit is switched to the cooling cycle by the three-way valve 19, and the temperature of the cooling cylinder 8 and the hopper 2 is set to + 8 ° C. or less under the condition that the temperature is not higher than the predetermined temperature within a predetermined time. Cool to + 10 ° C temperature range. Then, the process proceeds to a cold insulation process. In the cold insulation process, based on the outputs of the sterilization / cold insulation sensor 38 and the hopper sensor 32, the microcomputer 46 compresses the compressor motor 18M, the cylinder cooling valve 24, and the hopper cooling valve 26. ON / OFF control.

(3) Start-up load reduction control by pressure equalizing valve In the operation state described above, the compressor 18 is frequently operated (ON) -stopped (OFF) during the busy season of selling frozen desserts. If the pressure difference (high / low pressure difference) between the discharge side and the suction side is large when the compressor 18 is started, the load becomes excessive. Therefore, as shown in FIG. 4, when starting the compressor 18, the microcomputer 46 opens (ON) the pressure equalizing valve 43 for a predetermined time (for example, 2 seconds) and then closes (OFF) and then turns it on to the compressor motor 18 </ b> M. Control for energizing and starting the compressor 18 is executed. Thus, by opening the pressure equalizing valve 43 before the compressor 18 is started, the high pressure side pipe 21 (high pressure side) and the low pressure side pipe 22 (low pressure side) of the refrigerant circuit are communicated, and the pressure difference is eliminated or reduced. Therefore, the pressure difference between the discharge side and the suction side of the compressor 18 is also eliminated or reduced, and the load at the time of startup is reduced.

  However, depending on the operating state and the environment in which the soft ice cream manufacturing apparatus SM is installed, even if the pressure equalizing valve 43 is opened before the start-up, the load on the compressor 18 at the time of start-up increases, and the current value supplied to the compressor motor 18M increases. It may rise abnormally.

  Therefore, the microcomputer 46 starts up the compressor 18 and, based on the output of the current sensor 47, the value of the current flowing through the compressor motor 18M as shown in FIG. 8 is a predetermined upper limit value (for example, an upper limit value in this case such as 8A). The compressor 18 is stopped when it rises to a value higher than the set value (upper) (upper limit value) related to the control of the cylinder hot gas valve 34 described above and continues for a predetermined time (for example, 3 seconds). To do. Then, the pressure equalizing valve 43 is opened (ON) for a predetermined time (for example, 30 seconds to 1 minute), then closed (OFF), and then the compressor 18 is started again.

  As described above, by opening the pressure equalizing valve 43, the high-pressure side pipe 21 (high-pressure side) and the low-pressure side pipe 22 (low-pressure side) of the refrigerant circuit are communicated to eliminate the pressure difference. The pressure difference on the suction side is also eliminated, and the load at startup is reduced.

  The reason why the compressor 18 is stopped when the state in which the value of the current flowing through the compressor motor 18M reaches the upper limit setting value continues for a predetermined time is that the compressor 18 is stopped due to an instantaneous peak current at the time of startup. This is to avoid it. In addition, after the restart, when the current value of the compressor motor 18M rises again to the upper limit set value and the state continues for a predetermined time (3 seconds), the compressor 18 is stopped again, and the pressure equalizing valve 43 is turned on for the predetermined time. (30 seconds) After opening, the operation of restarting the compressor 18 after closing is repeated.

  In this way, when the compressor 18 is started up, if the energization current to the compressor motor 18M rises to a predetermined upper limit set value, the compressor 18 is stopped, the pressure equalizing valve 43 is opened for a predetermined time and then closed, and the compressor 18 is turned on again. Since the start-up is performed, the start-up load of the compressor 18 due to the high-low pressure difference of the refrigerant circuit is surely eliminated, and the compressor 18 without any trouble while avoiding the disadvantage that excessive current flows to the compressor motor 18M and causes winding burnout. Can be activated.

  Here, when the stop and restart of the compressor 18 due to the increase of the energization current value described above are repeated many times, there may be a cause such as failure of the compressor 18 or other equipment of the refrigerant circuit, the current sensor 47, or the like. Therefore, when the number of stoppages of the compressor 18 due to the increase in the energizing current value reaches a predetermined number (for example, three times), the microcomputer 46 displays a predetermined alarm on the LED display 54 and causes the soft ice cream manufacturing apparatus SM to malfunction. To warn you that inspection is necessary. This makes it possible to prompt quick maintenance when such an abnormality occurs.

It is a perspective view which shows the internal structure of the soft ice cream manufacturing apparatus as an Example of the frozen dessert manufacturing apparatus of this invention. It is a refrigerant circuit figure of the soft cream manufacturing apparatus of FIG. It is a block diagram of the control apparatus of the soft ice cream manufacturing apparatus of FIG. It is a timing chart explaining the cooling operation of the soft ice cream manufacturing apparatus of FIG. It is a timing chart explaining the equilibrium temperature control of the soft ice cream manufacturing apparatus of FIG. It is a timing chart explaining the relationship between the fail safe time in the equilibrium temperature control of the soft cream manufacturing apparatus of FIG. 1, and the temperature of the cooling cylinder at the time of cooling operation start. It is a timing chart explaining the sterilization temperature rising process of the heat sterilization driving | operation of the soft cream manufacturing apparatus of FIG. It is a timing chart explaining the control of the compressor and the pressure equalizing valve at the time of the compressor starting of the soft cream manufacturing apparatus of FIG.

Explanation of symbols

SM soft ice cream manufacturing equipment (frozen dessert manufacturing equipment)
DESCRIPTION OF SYMBOLS 1 Main body 2 Hopper 4 Hopper cooler 5 Impeller 6 Stirrer motor 8 Cooling cylinder 10 Beater 11 Cylinder cooler 12 Beater motor 18 Compressor 18M Compressor motor 19 Three-way valve 20 Capacitor 21 High pressure side piping 22 Low pressure side piping 24 Cylinder cooling valves 25, 27 Capillary Tube 26 Hopper cooling valve 30 Accumulator 31 Cylinder sensor 32 Hopper sensor 33 Muffler 34 Cylinder hot gas valve 35 Hopper hot gas valve 36, 37 Throttle pipe 40 Hot gas pipe 42 Pressure equalizing pipe (equal pressure circuit)
43 Pressure equalizing valve 46 Microcomputer 47, 48 Current sensor 51 Key input circuit 53 Control start temperature setting volume 54 LED indicator (alarm means)
61 Stirring switch

Claims (3)

Cooling cylinder that manufactures frozen desserts by cooling the mix while stirring, a cylinder cooler for cooling the cooling cylinder, a compressor, a condenser, a decompression device, a cooling circuit in which a refrigerant circuit is configured, etc. In a frozen confectionery manufacturing apparatus comprising a device and a control device for controlling the operation of the cooling device,
A pressure equalizing circuit that bypasses the compressor and the condenser to communicate the high pressure side and the low pressure side of the refrigerant circuit;
A pressure equalizing valve provided in the pressure equalizing circuit;
A hot gas circuit that bypasses the condenser and the decompression device,
The control device supplies the high-temperature refrigerant discharged from the compressor to the cylinder cooler via the hot gas circuit, and causes the refrigerant discharged from the cylinder cooler to be sucked into the compressor to heat sterilize the mix. As well as
An apparatus for producing frozen dessert, wherein the pressure equalizing valve is opened and closed in the heating step of the heat sterilization.   The said control apparatus opens and closes the said pressure equalization valve based on the temperature of the said cylinder cooler, The frozen confectionery manufacturing apparatus of Claim 1 characterized by the above-mentioned.   The frozen confectionery manufacturing apparatus according to claim 2, wherein the control device opens the pressure equalizing valve for a predetermined time each time the cylinder cooler rises by a predetermined temperature.

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