Drum type ice maker

Abstract

To provide a drum type ice maker capable of preventing generation of abnormalities such as freezing caused by ice pieces remaining on a cutter or around the cutter.SOLUTION: An ice making drum 12 is supported rotatably inside an ice making water tank 11 with a part of the ice making drum immersed in ice making water. During ice making operation, the ice making drum 12 is cooled, and ices produced on an external surface of the drum by rotating ice making drum 12 are peeled off by a cutter 23. A first heater 26 is provided to heat the cutter 23 and the periphery of the cutter 23. The first heater 26 is controlled so that a temperature of a heating unit is higher when the ice making operation is stopped than during the ice making operation.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] This invention relates to a drum-type ice maker in which an ice-making drum is partially immersed in ice-making water stored in an ice-making water tank and rotated, and ice formed on the outer surface of the ice-making drum is peeled off with a cutter to obtain ice pieces. [Background technology]

[0002] As an automatic ice making machine, a drum type ice making machine is known in which a cylindrical ice making drum cooled by a refrigerant is rotated in an ice making water tank in which ice making water is stored, forming layers of ice on the surface of the ice making drum, and the formed ice is peeled off by a cutter to continuously make ice pieces (see, for example, Patent Document 1). The drum type ice making machine of Patent Document 1 includes an ice making water tank that stores a predetermined amount of ice making water, and an ice making drum that is arranged inside the ice making water tank and is rotatable about a horizontal axis with a part of it immersed in the ice making water. The drum type ice making machine also includes a cutter that scrapes off the ice formed on the outer surface of the ice making drum. The cutter is provided along the axial direction of the ice making drum with its blade pointing toward the outer surface of the part of the ice making drum that is exposed from the ice making water. The ice pieces scraped off by the cutter are then discharged into an ice storage room via a chute. In addition, a heater is provided below the cutter to heat the cutter and its surroundings, and the heater is configured to melt and remove fine pieces of ice (chips) that have been scraped off by the cutter. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5329384 Summary of the Invention [Problem to be solved by the invention]

[0004] In the drum type ice maker of Patent Document 1, the heater provided for the cutter is ON-OFF controlled according to the temperature detected by the temperature detection means during ice making operation of the ice maker. In addition, in the drum type ice maker, when the ice making operation is stopped, the heating control of the heater is stopped and the ice making water in the ice making water tank is discharged. Therefore, if the peeled ice pieces remaining on the cutter immediately after the ice making operation is stopped or the ice pieces that have fallen from the cutter and remain in the ice making water tank remain without melting by the time the next ice making operation starts, the ice pieces may cause abnormalities such as freezing, which may hinder normal ice making operation.

[0005] The present invention has been proposed in consideration of the problems inherent in the conventional technology described above, and aims to provide a drum-type ice maker that can prevent abnormalities such as freezing caused by ice pieces remaining on the cutter and its surroundings. [Means for solving the problem]

[0006] In order to overcome the above problems and achieve the intended purpose, the drum type ice maker according to the invention of claim 1 comprises: A drum-type ice making machine is provided with an ice making drum (12) that rotates while being partially immersed in ice making water stored in an ice making water tank (11), and a cutter (23) that scrapes off ice formed on the outer surface of the ice making drum (12), and is configured to cool the ice making drum (12) during ice making operation and to form ice on the drum outer surface by rotating the ice making drum (12), a heater (26) for heating the cutter (23) and the periphery of the cutter (23); The heater (26) is controlled so that the temperature of the heating section heated by the heater (26) is higher during the stoppage of the ice-making operation than during the ice-making operation. According to the invention of claim 1, the cutter and its surrounding areas are heated by the heater while the ice-making operation is stopped, so that ice pieces remaining on the cutter just before the ice-making operation is stopped and ice pieces that have fallen into the ice-making water tank after the ice-making water has been discharged can be melted, and abnormalities such as freezing caused by ice pieces can be prevented. Moreover, the temperature of the heating part heated by the heater is set higher while the ice-making operation is stopped than during the ice-making operation, so that ice pieces that have fallen into the ice-making water tank can be effectively melted.

[0007] The invention according to claim 2 is characterized in that a heater (30) is provided on a shaft support (29) that rotatably supports the ice making drum (12) in the ice making water tank (11). According to the invention of claim 2, a heater is disposed on the shaft support section that supports the ice-making drum so that it can rotate freely, thereby enabling the surrounding area to be heated. Therefore, the heater disposed on the shaft support section can maintain the area of ​​the ice-making water tank that is separated from the position of the heater that heats the cutter, etc. at a constant temperature or higher that is nearly uniform with the area heated by the heater that heats the cutter, etc., thereby melting the ice pieces remaining inside the ice-making water tank after the ice-making water has been discharged, thereby preventing freezing. Effect of the Invention

[0008] According to the drum-type ice-making machine of the present invention, when the ice-making operation is stopped, ice pieces remaining on the cutter and its surrounding area can be melted, thereby preventing abnormalities such as freezing caused by the ice pieces. [Brief description of the drawings]

[0009] [Figure 1] 1 is a schematic vertical sectional front view showing a drum type ice making machine of an embodiment. FIG. [Diagram 2] FIG. 2 is a schematic side view showing a vertical section of the ice making water tank of the embodiment. [Diagram 3] FIG. 1 is a schematic diagram showing a refrigeration circuit of an embodiment. [Figure 4] FIG. 4 is a timing chart of the first heater in the embodiment. [Diagram 5]FIG. 1 is a schematic vertical sectional front view showing a drum type ice making machine according to a first alternative embodiment. [Figure 6] FIG. 11 is a schematic vertical sectional front view showing a drum type ice making machine of a second alternative embodiment. [Figure 7] FIG. 11 is a schematic diagram showing a refrigeration circuit according to a third alternative embodiment. [Figure 8] FIG. 11 is a schematic diagram showing a refrigeration circuit according to a fourth alternative embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Next, a drum type ice maker according to the present invention will be described below by way of a preferred embodiment with reference to the accompanying drawings. In the following description, the terms "upper", "lower", "left" and "right" refer to the positions shown in FIG. 1. EXAMPLES

[0011] 1 and 2, a drum type ice maker 10 of the embodiment includes an ice-making water tank 11 in which ice-making water is stored, and a cylindrical ice-making drum 12 arranged inside the ice-making water tank 11 so as to be rotatable about a horizontal axis with a portion of the drum 12 immersed in the ice-making water. The ice-making water tank 11 is formed in a box shape with an open top and made up of front, rear, left and right walls (front wall 13, rear wall 14, left wall 15, right wall 16) and a bottom wall 17, and the top opening is covered by a lid member 18 that can be opened and closed. A water supply port 19 that is connected to a water supply pipe (not shown) extending from an external water system is provided on the rear wall 14 of the ice-making water tank 11, and ice-making water (tap water) is supplied from the water supply port 19 to the inside of the ice-making water tank 11 via the water supply pipe. In addition, a water level sensor 20 such as a float switch for detecting the amount of ice-making water stored (water level) is arranged inside the ice-making water tank 11, and the water level in the ice-making water tank 11 is maintained constant by controlling the amount of ice-making water supplied according to the water level detection status by the sensor 20.

[0012] Drum type ice making machine 10 is equipped with a control means (not shown) that controls devices such as compressor CM and valves such as water supply valves that constitute refrigeration circuit 21 described later, and other devices. Drum type ice making machine 10 is configured such that each device is controlled by the control means based on information obtained from various switches, temperature detection means 27 (described later), etc., and during ice making operation, refrigerant is supplied from refrigeration circuit 21 to the inside of ice making drum 12, and ice making drum 12 cooled by the refrigerant rotates in ice making water tank 11 to grow layered ice (ice layer I) on its surface (outer surface). In the embodiment, drum type ice making machine 10 starts ice making operation by turning on an operation switch connected to the control means, and stops ice making operation by turning off the operation switch. In addition, when ice making operation is stopped, a drain valve connected to ice making water tank 11 is opened to drain ice making water stored in ice making water tank 11.

[0013] As shown in Fig. 1, a cutter 23 is disposed on the right wall 16 of the ice making water tank 11 via a cutter mount 22. The cutter 23 is disposed with its cutting edge 23a close to the outer surface of the ice making drum 12 and inclined downward as it moves away from the ice making water tank 11. The upper surface of the cutter 23 is formed with a flat slope 25 that slopes downward as it moves away from the ice making water tank 11, and the lower end of the slope 25 faces the receiving port 24a of the chute 24 that communicates with an ice storage bin (not shown). That is, the cutter 23 is configured to scrape off the ice layer I formed on the outer surface of the ice making drum 12 with the cutting edge 23a of the cutter 23, slide the scraped ice pieces down the slope 25 of the cutter 23, and release the ice pieces from the receiving port 24a to the chute 24. The ice pieces discharged into the chute 24 fall down the chute 24 and are discharged into the ice storage bin, where they are stored.

[0014] A first heater 26 for heating the cutter 23 and the periphery of the cutter 23 is disposed on the cutter mount 22. A temperature detection means 27 such as a thermistor for detecting the temperature of the heating portion (the cutter 23 and its periphery) heated by the first heater 26 is disposed on the cutter mount 22, and the first heater 26 and the temperature detection means 27 are electrically connected to the control means. The control means is configured to control the first heater 26 to turn ON / OFF in response to the temperature detected by the temperature detection means 27, so as to maintain the temperature of the heating portion heated by the first heater 26 constant. The control means is configured to control the first heater 26 to turn OFF when the temperature detection means 27 detects a preset upper limit temperature, and to control the first heater 26 to turn ON when the temperature detection means 27 detects a preset lower limit temperature, so as to maintain the temperature of the heating portion between the upper limit temperature and the lower limit temperature. In the embodiment, the first upper limit temperature and the first lower limit temperature for controlling the ON-OFF of the first heater 26 during the ice-making operation of the ice maker are set lower than the second upper limit temperature and the second lower limit temperature for controlling the ON-OFF of the first heater 26 during the stop of the ice-making operation. That is, the first heater 26 is controlled so that the temperature of the heating part heated by the first heater 26 is set to a higher temperature during the stop of the ice-making operation than during the ice-making operation. Specifically, for example, the first upper limit temperature during the ice-making operation is set to 3°C and the first lower limit temperature is set to 1°C, and the second upper limit temperature during the stop of the ice-making operation is set to 10°C and the second lower limit temperature is set to 5°C (see FIG. 4). The above upper limit temperature and lower limit temperature are merely examples, and can be set appropriately according to the specifications.

[0015] As shown in Fig. 2, the ice making drum 12 has rotating shafts 28a, 28b extending outward from the center of each end face in the axial direction, and each rotating shaft 28a, 28b is rotatably supported by shaft support parts (bearings) 29, 29 provided on the front and rear walls 13, 14 of the ice making water tank 11. One rotating shaft 28a is connected to a driving means (not shown), and is configured to rotate the ice making drum 12 by the driving means during ice making operation. The other rotating shaft 28b is configured as a double pipe that constitutes the inlet and outlet of the refrigerant flow path formed inside the ice making drum 12, and is configured to guide the refrigerant from the refrigeration circuit 21 into the inside of the ice making drum 12 through the rotating shaft 28b, and to return the refrigerant that has exchanged heat with the ice making drum 12 to the refrigeration circuit 21. In other words, the ice making drum 12 functions as an evaporator that constitutes the refrigeration circuit 21. The double-tube rotating shaft 28b is hereinafter referred to as the refrigerant inlet / outlet portion 28b. A second heater 30 is provided in each shaft support portion 29, and the second heater 30 is configured to be able to heat the shaft support portion 29 and the front and rear walls 13, 14 on which the shaft support portion 29 is provided. As the second heater 30, for example, a belt heater is used, and the second heater 30 is configured to be ON / OFF controlled according to the detected temperature (first upper limit temperature, first lower limit temperature, second upper limit temperature, and second lower limit temperature) by the temperature detection means 27 during ice-making operation and when the ice-making operation is stopped, in the same manner as the first heater 26, to heat the shaft support portion 29 and the front and rear walls 13, 14.

[0016] As shown in Fig. 3, the refrigeration circuit 21 is configured such that the compressor CM is connected to the condenser CD via a discharge pipe 31, and the refrigerant pipe 32 extending from the condenser CD is connected to the inlet 28c of the refrigerant inlet / outlet portion 28b of the ice making drum 12 via an expansion valve EV. Also, a suction pipe 33 connected to the outlet 28d of the refrigerant inlet / outlet portion 28b is connected to the suction side of the compressor CM. That is, during ice making operation, the vaporized refrigerant compressed by the compressor CM is liquefied in the condenser CD, then decompressed by the expansion valve EV, and heat exchange is performed in the process of evaporation in the ice making drum 12 as an evaporator, thereby cooling the ice making drum 12 to below freezing. The vaporized refrigerant evaporated in the ice making drum 12 is returned to the compressor CM via the suction pipe 33. Further, the refrigeration circuit 21 is provided with a heat exchanger 34 that brings the refrigerant pipe 32 between the condenser CD and the expansion valve EV and the suction pipe 33 into close proximity, and is configured so that the low-temperature, high-pressure liquefied refrigerant that flows out of the condenser CD and flows through the refrigerant pipe 32 is heat-exchanged in the heat exchanger 34 with the high-temperature, low-pressure refrigerant that flows out of the ice making drum 12 and flows through the suction pipe 33, thereby raising the temperature. A temperature sensing tube 35 is provided in the suction pipe 33 near the connection portion of the refrigerant inlet / outlet portion 28b, and the opening degree of the expansion valve EV is controlled according to the temperature of the refrigerant flowing through the suction pipe 33 detected by the temperature sensing tube 35.

[0017] [Function of the embodiment] Next, the operation of the drum type ice making machine according to the embodiment will be described.

[0018] During ice-making operation of drum type ice maker 10, first heater 26 is ON-OFF controlled in response to temperature detection means 27 detecting a first upper limit temperature and a first lower limit temperature set in advance, as shown in FIG. 4, to heat cutter 23 and its surrounding area. This allows ice pieces that are peeled off by cutter 23 and remain on the cutter, and ice pieces that have fallen into ice-making water tank 11 to melt. Even when ice-making operation of drum type ice maker 10 is stopped, first heater 26 is ON-OFF controlled in response to temperature detection means 27 detecting a second upper limit temperature and a second lower limit temperature set in advance, and cutter 23 and its surrounding area are heated to a predetermined temperature. Therefore, ice pieces that remain on cutter 23 immediately before stopping ice-making operation and ice pieces that have fallen into the ice-making water tank from which ice-making water has been discharged can be melted, and abnormalities such as freezing caused by the ice pieces can be prevented. In addition, since the temperature of the heating section heated by first heater 26 is set higher while ice-making operation is stopped than during ice-making operation, it is possible to effectively melt ice pieces that have fallen into ice-making water tank 11. Furthermore, since a second upper limit temperature for controlling first heater 26 to be OFF is set while ice-making operation is stopped, it is possible to prevent a situation in which the temperature of cutter 23 or the area around the cutter becomes too high when ice-making operation is restarted, causing normal ice pieces peeled off by cutter 23 to melt.

[0019] In drum type ice maker 10 of the embodiment, second heater 30 is provided on shaft support parts 29, 29 that support ice making drum 12 for rotation, and is configured to heat shaft support part 29 and front and rear walls 13, 14 of ice making water tank 11 during ice making operation and when ice making operation is stopped. This makes it possible to maintain the temperature of the part of ice making water tank 11 opposite the position of cutter 23, i.e., the position of first heater 26, across ice making drum 12 at a constant temperature or higher that is nearly uniform with the position of first heater 26, and melts ice pieces remaining in the part of ice making water tank 11 away from the position of first heater 26 after ice making water has been discharged, and prevents ice making water tank 11 from freezing over as a whole.

[0020] (About another embodiment) Next, the first to fourth alternative embodiments will be described. Note that for the first to fourth alternative embodiments, differences from the embodiment will be mainly described, and members having the same or similar functions as the embodiment will be given the same reference numerals and detailed descriptions will be omitted.

[0021] (First Alternative Example) As shown in Fig. 5, drum type ice maker 36 of the first alternative embodiment is provided with fan motors 37, 38 for blowing air inside ice making water tank 11. In the first alternative embodiment, a first fan motor 37 for blowing air from the left side to the right side (from the side away from cutter 23 to the cutter side) on the upper side of ice making drum 12, and a second fan motor 38 for blowing air from the left side to the right side (from the side away from the position of first heater 26 to the side where first heater 26 is disposed) on the lower side of ice making drum 12 are provided. In drum type ice maker 36 of the first alternative embodiment, both fan motors 37, 38 are configured to operate when first heater 26 is ON after ice making water is discharged from ice making water tank 11 due to stopping of ice making operation. That is, by operating first fan motor 37, air flows from the left to the right above ice making drum 12, and the air passes above cutter 23 and is exhausted outside the ice making water tank. This air flow effectively melts the ice pieces remaining above cutter 23.

[0022] Furthermore, operation of second fan motor 38 causes air to flow from left to right below ice making drum 12, and this air is heated as it passes through the area where first heater 26 is disposed, effectively melting the remaining ice pieces that have fallen into ice making water tank 11. That is, drum type ice maker 36 of the first alternative embodiment can effectively melt the remaining ice pieces on cutter 23 and inside ice making water tank 11 by the air flow, in addition to heating by first and second heaters 26, 30, so that freezing due to the ice pieces can be effectively prevented.

[0023] (Second Alternative Example) Drum type ice maker 39 of the second alternative embodiment differs from the first alternative embodiment in that it uses heater-equipped fan motors 40, 41 instead of fan motors 37, 38. Heater-equipped fan motors 40, 41 are combinations of heaters 40a, 41a and fan motors 40b, 41b, and air heated by heaters 40a, 41a is blown by fan motors 40b, 41b. That is, in drum type ice maker 39 of the second alternative embodiment, air heated by heaters 40a, 41a flows inside ice-making water tank 11, so that the ice pieces can be melted more effectively.

[0024] (Third Alternative Example) Drum type ice maker 42 of the third alternative embodiment has a different configuration of refrigeration circuit 43 from that of the embodiment. That is, as shown in Fig. 7, refrigeration circuit 43 of the third alternative embodiment is provided with a first solenoid valve 44 between heat exchange section 34 and expansion valve EV in refrigerant piping 32 leading out from condenser CD. Also, a bypass pipe 45 connects the upstream side of heat exchange section 34 in refrigerant piping 32 to the downstream side of expansion valve EV, and a second solenoid valve 46 is provided in bypass pipe 45.

[0025] In the drum type ice maker 42 of the third embodiment, during ice making operation, the first solenoid valve 44 is opened and the second solenoid valve 46 is closed to circulate the refrigerant in the same manner as in the embodiment, whereas before pumping down to stop the compressor CM when stopping the ice making operation, the first solenoid valve 44 is closed and the second solenoid valve 46 is opened for a certain period of time (heating time) to supply the ice making drum 12 with a refrigerant at a higher temperature than that after passing through the expansion valve EV via the bypass pipe 45 to heat the ice making drum 12. The arrows in FIG. 7 indicate the flow of the refrigerant during the heating time. That is, in the drum type ice maker 42 of the third embodiment, in addition to heating by the first and second heaters 26, 30, the ice making drum 12 is heated, so that the inner surfaces of the cutter 23 and the ice making water tank 11 adjacent to the ice making drum 12 can also be heated, and the ice pieces remaining inside the cutter 23 and the ice making water tank 11 can be effectively melted. In addition, since the temperature of the refrigerant flowing out of the condenser CD is close to room temperature, even if the refrigerant is supplied to the ice making drum 12, damage caused by the temperature of the various components used can be minimized.

[0026] (Fourth Alternative Example) A drum type ice maker 47 of the fourth alternative embodiment has a different configuration of a refrigeration circuit 48 from that of the embodiment. That is, as shown in Fig. 8, in the refrigeration circuit 48 of the fourth alternative embodiment, a first solenoid valve 49 is provided between the heat exchange section 34 and the expansion valve EV in the refrigerant piping 32 leading out from the condenser CD, and a second solenoid valve 50 is provided between the heat exchange section 34 and the refrigerant inlet / outlet section 28b in the suction pipe 33. A first bypass pipe 51 connects the upstream side of the heat exchange section 34 in the refrigerant piping 32 leading out from the condenser CD to the second solenoid valve 50 and the refrigerant inlet / outlet section 28b in the suction pipe 33, and a third solenoid valve 52 is provided in the first bypass pipe 51. A second bypass pipe 53 connects the upstream side of the heat exchange section 34 in the refrigerant piping 32 leading out from the condenser CD to the downstream side of the heat exchange section 34 in the suction pipe 33, and a fourth solenoid valve 54 is provided in the second bypass pipe 53.

[0027] In the refrigeration circuit 48 of the fourth embodiment, during ice making operation, the first and second solenoid valves 49, 50 are opened and the third and fourth solenoid valves 52, 54 are closed to circulate the refrigerant in the same manner as in the embodiment, whereas before pump-down to stop the compressor CM when stopping the ice making operation, the first and second solenoid valves 49, 50 are closed and the third and fourth solenoid valves 52, 54 are opened for a certain period of time (heating time) to supply the refrigerant having a higher temperature than that after passing through the expansion valve EV through the first bypass pipe 51 to the ice making drum 12 from the outlet 28d of the refrigerant inlet / outlet portion 28b, to heat the ice making drum 12, and to return the refrigerant from the ice making drum 12 to the compressor CM through the second bypass pipe 53. The arrows in FIG. 8 indicate the flow of the refrigerant during the heating time. That is, in the drum type ice making machine 47 of the fourth embodiment, in addition to the same effects as the drum type ice making machine 42 of the third embodiment, the following effects are further obtained. Since outlet 28d of refrigerant inlet / outlet portion 28b is designed to have a larger diameter than inlet 28c, the refrigerant supplied from first bypass pipe 51 flows smoothly into ice making drum 12, and ice making drum 12 can be heated to a predetermined temperature in a short time. In addition, by adopting a configuration in which the diameter of a part of the refrigerant flow path formed in ice making drum 12 is made smaller and narrower, the effect of supplying the refrigerant from large-diameter outlet 28d and heating from the outlet side is improved.

[0028] [Example of change] The present application is not limited to the configurations of the above-mentioned examples, etc., and other configurations may be appropriately adopted. Furthermore, the configurations described in the examples, etc., are not limited to the following modified examples, and various embodiments may be adopted within the scope of the present invention. (1) The location of the temperature detection means for controlling the first heater is not limited to the cutter mount, but may be any location where the temperature of the heating portion heated by the first heater can be detected. (2) A dedicated temperature detection means may be provided for detecting the temperature of the heating portion heated by the second heater, and the second heater may be controlled to be turned on and off in response to the temperature detected by the temperature detection means. (3) The second heater may be provided as needed, for example, when the first heater alone is insufficient to melt the ice pieces in the entire ice-making water tank depending on the size of the ice-making water tank, etc. (4) In the first and second variant embodiments, the first and second fan motors and the first and second heater-equipped fan motors are configured to operate when the first heater is ON, but it is also possible to adopt a configuration in which they always operate when ice-making operation is stopped. (5) In the first and second alternative embodiments, two fan motors or fan motors with heaters are provided, but it is also possible to adopt a configuration in which only one of them, for example, the second fan motor or the second fan motor with heater, is provided. The second fan motor or the second fan motor with heater has the advantage that the air in the ice making water tank can be warmed by contacting it with the heating part of the first heater, thereby improving the efficiency of melting the ice pieces. (6) The configuration of the refrigeration circuit according to the third or fourth embodiment may be combined with the configuration of the first or second embodiment. [Explanation of symbols]

[0029] 11 ice making water tank, 12 ice making drum, 23 cutter, 26 first heater (heater) 29 shaft support portion, 30 second heater (heater)

Claims

1. A drum-type ice maker is provided with an ice making drum that rotates while being partially immersed in ice making water stored in an ice making water tank, and a cutter that scrapes off ice formed on the outer surface of the ice making drum, and is configured to cool the ice making drum during ice making operation and to form ice on the outer surface of the drum by rotating the ice making drum, a heater for heating the cutter and the periphery of the cutter; The heater is controlled so that the temperature of the heating section heated by the heater is higher during the stop of the ice-making operation than during the ice-making operation. The drum type ice maker is characterized by the following features.

2. 2. The drum type ice making machine according to claim 1, wherein a heater is provided on a shaft support portion that rotatably supports said ice making drum in said ice making water tank.

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