Freezing device

Abstract

To provide a liquid freezing type refrigerator which can accurately detect a level of a coolant with a level sensor.SOLUTION: A refrigerator 1 places an object to be cooled (a cooled object) in contact with a coolant to freeze the cooled object and includes: an isolating structure 20 forming a detection space 21 isolated from the outside in an area above the coolant stored in a cooling tank 3; a vent hole 25 formed at the isolation structure 20; and a level sensor 30 configured to detect a level of the coolant in the detection space 21. The vent hole 25 is formed below an upper end 3B of the cooling tank 3 or an over-flow pipe 3D.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to an improvement in a liquid freezing type freezing apparatus in which food or other objects to be cooled are immersed in a cooling liquid to rapidly freeze them. [Background technology]

[0002] Known refrigeration systems for rapidly freezing food and other objects include air-cooled systems (air freezing systems) that cool the objects by blowing cold air into a cooling chamber in which the objects are placed, and liquid freezing systems that cool the objects by immersing them in a low-temperature liquid. While air-cooled systems have traditionally been the norm, liquid freezing systems, which can achieve higher quality freezing more quickly, have recently been attracting attention. For example, Patent Document 1 proposes an invention in which the cooling efficiency of a liquid freezing system is improved by moving the objects up and down in the cooling liquid. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6668563 Summary of the Invention [Problem to be solved by the invention]

[0004] In such liquid-freezing refrigeration systems, the amount of liquid coolant (a heat transfer medium (brine) that removes heat from the object being cooled) stored in the cooling tank constantly changes for various reasons. For example, when the frozen object (the object being frozen) is removed from the refrigeration system, the amount of liquid coolant may decrease if the liquid coolant adhering to the object is carried out of the system. Conversely, the amount of liquid coolant may increase if vapor in the air condenses in the cooling tank. Such changes in the amount of liquid coolant can adversely affect the function of the refrigeration system. For example, if the amount of liquid coolant becomes too high, it can damage the equipment due to overflow or increase manufacturing costs due to increased waste. Furthermore, if the amount of liquid coolant becomes too low, the object to be frozen may not be fully immersed in the liquid coolant, resulting in insufficient freezing. For this reason, regular maintenance and management of the liquid coolant level is necessary to maintain an appropriate amount of liquid coolant.

[0005] Traditionally, the main method for managing the coolant level has been through manual visual adjustment. However, this manual adjustment is time-consuming and places a heavy burden on the operator who adds and removes the coolant. For this reason, it has been considered to use a liquid level sensor to detect the liquid level and automatically adjust it, but because refrigeration systems use low-temperature coolant that is below the freezing point, freezing occurs, which creates a problem that prevents accurate detection by the liquid level sensor.

[0006] For example, in the case of a non-contact type liquid level sensor 101 as shown in Fig. 4(A), ice 103 formed on the wall surface 102 of the cooling tank can cause false detection by the sensor and a deterioration in detection accuracy. Even when a non-contact type liquid level sensor is used, ice 105 adhering to the float 104 in the case of a float type liquid level sensor as shown in Fig. 4(B), and ice 107 adhering to the probe portion 106 in the case of a guide rope type liquid level sensor as shown in Fig. 4(C), can cause false detection and a deterioration in detection accuracy.

[0007] The present invention has been made in response to these problems, and aims to provide a liquid freezing type refrigeration system that can accurately detect the cooling water level using a liquid level sensor. [Means for solving the problem]

[0008] The present invention relates to a refrigeration device that freezes an object to be cooled by bringing it into contact with a cooling liquid, and includes a cooling tank in which the cooling liquid is stored, an isolation structure that forms a detection space isolated from the outside above the cooling liquid stored in the cooling tank, an air vent formed in the isolation structure, and a water level detection device that detects the water level of the cooling liquid in the cooling tank within the detection space.

[0009] The vent may be formed at an upper end of the cooling tank or below an overflow pipe provided in the cooling tank.

[0010] The isolation structure may include a wall portion that covers the top and sides of the detection space.

[0011] The lower end of the isolation structure may be located below a lower limit water level of the coolant in the cooling tank. [Effects of the Invention]

[0012] According to the present invention, in a refrigeration device (e.g., refrigeration device 1), the coolant level is detected by a water level detection device (e.g., liquid level sensor 30) in a detection space (e.g., detection space 21) isolated from the outside. This effectively prevents freezing due to the inflow of moist air into the detection space, thereby appropriately preventing freezing from adversely affecting water level detection. Furthermore, an isolation structure (e.g., isolation structure 20) that forms the detection space is provided with a vent (e.g., vent 25), so the coolant level in the detection space is kept the same as the water level in other parts of the cooling tank, allowing for accurate detection of the coolant level. Therefore, the amount of coolant can be appropriately adjusted based on the detection results from the water level detection device, allowing the object to be appropriately frozen.

[0013] If the vent is formed below the upper end of the cooling tank (e.g., upper end 3B) or the overflow pipe (e.g., overflow pipe 3D), only low-temperature air with a low water vapor content inside the cooling tank will circulate through the vent, effectively preventing freezing caused by air flowing into the detection space from the vent.

[0014] If the isolation structure is provided with walls (for example, upper wall 22 and side wall 23) that cover the top and sides of the detection space, it is possible to appropriately form a detection space that is isolated from the outside by the walls.

[0015] If the lower end of the isolation structure (e.g., the lower end 23A of the side wall portion 23) is positioned below the lower limit water level position of the coolant in the cooling tank (e.g., the lower limit water level position 31), a detection space surrounded by the isolation structure and the coolant can be formed, and the detection space can be properly isolated from the outside. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a front view showing a refrigeration device according to an embodiment of the present invention. [Figure 2] FIG. 10 is a front view of the refrigeration device, showing the storage unit immersed in the cooling liquid. [Figure 3] FIG. 10 is a schematic diagram showing a configuration related to detection of the coolant level in the refrigeration device. [Figure 4] 1 is a diagram for explaining a problem in detecting the coolant level in a conventional refrigeration device. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. Figures 1 and 2 show a refrigeration system 1 according to an embodiment of the present invention. Figure 3 is a schematic diagram showing a configuration related to detection of the coolant level in the refrigeration system 1.

[0018] As shown in the figure, the refrigeration device 1 comprises a base 2 which is a base for supporting various components of the refrigeration device 1, a cooling tank 3 provided within the base 2, a cooling pipe 4 arranged within the cooling tank 3, a refrigerant supply unit 5 which supplies a refrigerant (primary refrigerant) to the cooling pipe 4, a storage unit 6 capable of storing an object to be cooled, a vertical drive mechanism 7 which drives the storage unit 6 up and down, a lifting mechanism 8 which drives the vertical drive mechanism 7 up and down, a control device (control panel) 9 which controls the operation of each part of the refrigeration device 1, an isolation structure 20 provided on top of the cooling tank 3, and a liquid level sensor 30 which detects the level of the cooling liquid.

[0019] 1 shows the storage unit 6 waiting above the cooling tank 3, and FIG. 2 shows the storage unit 6 lowered into the cooling tank 3 and immersed in the cooling liquid L. In addition, in FIGS. 1 and 2, only the cooling tank 3 portion of the base 2 is shown in partial cross section.

[0020] The cooling tank 3 is a tank for cooling items to be cooled (items to be frozen) such as food, and includes a storage section 3A for storing cooling liquid L. An opening 3C for carrying in and out a storage unit 6 is formed at an upper end 3B of the cooling tank 3 (storage section 3A). As shown in FIG. 2, when a storage unit 6 is carried into the cooling tank 3, the opening 3C is closed by a lid 11 that descends along with the storage unit 6. This keeps the contents of the storage section 3A of the cooling tank 3 cold.

[0021] An overflow pipe 3D (see Figure 3) is provided near the upper end 3B of the cooling tank 3, so that if there is too much cooling liquid L in the storage section 3A, it will be discharged from the overflow pipe 3D.

[0022] The cooling liquid (brine) is a refrigerant (secondary refrigerant) in which the object to be cooled is immersed to cool it. The cooling liquid may be, for example, an aqueous alcohol solution (e.g., an aqueous ethanol solution) at a low temperature (e.g., about −35° C.) with an appropriately adjusted water-to-alcohol ratio. The cooling liquid in the present invention is not limited to an aqueous alcohol solution, as long as it is a liquid that does not freeze at the temperature required to cool the object to be cooled.

[0023] The cooling pipe 4 is a heat exchanger for cooling the cooling liquid L in the cooling tank 3, and is made up of a pipe line (in this embodiment, a coil-shaped pipe line surrounding the storage unit 6) through which the refrigerant flows. The refrigerant supply unit 5 is configured to introduce the refrigerant (primary refrigerant) into the cooling pipe 4, and is equipped with refrigerant pipes (refrigerant gas pipe 5A and refrigerant liquid pipe 5B) and various valves (solenoid valves, not shown, etc.).

[0024] The storage unit 6 is a storage shelf for storing objects to be cooled, and includes a frame 6A that forms an outer frame, and a plurality of loading trays 6B arranged within the frame 6A. The objects to be cooled are placed on the loading trays 6B and immersed in the cooling liquid.

[0025] The vertical drive mechanism 7 includes a housing 12, a drive means (for example, an electromagnetic motor, not shown) disposed within the housing 12, and a support arm 13 linked to the drive means. The support arm 13 supports the frame 6A of the storage unit 6 from above. As a result, the drive means causes the support arm 13 to move up and down (extend and retract), thereby moving the storage unit 6 up and down. The stroke and speed of the vertical movement of the storage unit 6 are appropriately controlled by a control device 9.

[0026] Note that Figure 1 shows a state in which the support arm 13 does not extend from the housing 12 and the storage unit 6 is on the upper side of the vertical movement, and Figure 2 shows a state in which the support arm 13 extends downward from the housing 12 and the storage unit 6 is on the lower side of the vertical movement.

[0027] During the freezing process of the object to be cooled, the storage unit 6 repeatedly moves up and down at a stroke and speed appropriately controlled by the control device 9. As a result, the object to be cooled held in the storage unit 6 is not simply immersed in the cooling liquid, but is also moved up and down in the cooling liquid, which increases the fluidity of the cooling liquid around the object to be cooled, thereby accelerating the cooling speed of the object to be cooled.

[0028] The lifting mechanism 8 includes a vertically long housing 14 attached to the base 2, a lifting drive mechanism 8A (power cylinder) provided within the housing 14, and a support arm 15 linked to the lifting drive mechanism 8A. The support arm 15 is connected to the housing 12 of the vertical drive mechanism 7 and supports the housing 12 from the side. With this configuration, as the vertical drive mechanism 7 is driven by the lifting drive mechanism to rise and fall, the storage unit 6 rises and falls, allowing it to move from the upper standby position shown in FIG. 1 to the cooling position within the cooling tank 3 shown in FIG. 2.

[0029] In addition, the lid 11 of the cooling tank 3 is attached integrally to the underside of the support arm 15 (or the housing 12 of the up-down drive mechanism 7), and when the storage unit 6 moves into the cooling tank 3, the lid 11 also descends to close the opening 3C of the cooling tank 3.

[0030] The isolation structure 20 is a box-shaped structure provided near the top of the cooling tank 3, and defines a detection space 21 isolated from the outside inside the isolation structure 20. More specifically, the isolation structure 20 includes an upper wall portion 22 that covers the upper side of the detection space 21, and a side wall portion 23 that covers the sides of the detection space 21. In this embodiment, part of the side wall of the cooling tank 3 constitutes part of the side wall portion 23.

[0031] Meanwhile, the lower side of the isolation structure 20 is open, and the lower end 23A of the side wall 23 extends below the lower limit water level position 31 of the coolant in the cooling tank 3. This allows the cooling water in the cooling tank 3 to flow around to the lower part of the isolation structure 20. With this configuration, a detection space 21 is formed inside the isolation structure 20, surrounded by the upper wall 22, the side wall 23, and the liquid surface of the coolant.

[0032] The isolation structure 20 is formed with a vent 25 that communicates with the detection space 21. The vent 25 is a small hole (e.g., a circular hole) with a diameter of about 6 mm. The vent 25 is formed to be located below the position where air flows in from outside the cooling tank 3, specifically, below the upper end 3B or overflow pipe 3D of the cooling tank 3. This allows only cooled air with a small amount of water vapor inside the cooling tank 3 (in the upper space 3E above the coolant) to pass through the vent 25.

[0033] The vent 25 is formed so as to be positioned above the upper limit water level position 32 of the cooling tank 3. This appropriately prevents the vent 25 from being blocked by the cooling water.

[0034] The liquid level sensor 30 is a sensor that detects the water level (height of the liquid surface) of the coolant in the detection space 21, and at least its detection unit is arranged in the detection space 21 (inside the isolation structure 20). Based on detection by the liquid level sensor 30, the water level of the coolant is controlled to be a water level (normal water level) between a lower limit water level position 31 and an upper limit water level position 32.

[0035] The above-described configuration effectively prevents freezing within detection space 21, and enables accurate detection of the coolant level by liquid level sensor 30. To explain in more detail, it is believed that freezing occurs in the upper part of cooling tank 3 when storage unit 6 moves up and down to take in and out cooled objects, or when a structure above cooling tank 3 is cooled for some reason, causing convection in which cold air (humid air) generated in the surrounding area descends into upper space 3E of cooling tank 3 (the space above the liquid level of the coolant in cooling tank 3), causing the water vapor in this moist air to condense.

[0036] In contrast, in the refrigeration device 1, the detection space 21 is a space isolated from the outside, so even if convection of moist air occurs from above the cooling tank 3, this convection (moist air) will not flow into the detection space 21. Therefore, no freezing occurs in the detection space 21, and detection by the liquid level sensor 30 is not hindered by freezing.

[0037] On the other hand, since isolation structure 20 is provided with ventilation holes 25, the air pressure in detection space 21 is kept the same as that outside isolation structure 20, and the level of the coolant below detection space 21 is the same as the level of the coolant in other parts of cooling tank 3. Therefore, the liquid level sensor 30 can accurately detect the coolant level.

[0038] Furthermore, vent 25 is provided below upper end 3B or overflow pipe 3D of cooling tank 3, and only air with a low water vapor content that has been cooled in upper space 3E of cooling tank 3 passes between detection space 21 and upper space 3E of cooling tank 3 through vent 25, so only air with a low water vapor content flows into detection space 21. Furthermore, vent 25 is sufficiently small in size, so that even if a current of humid air occurs from above cooling tank 3, a large amount of humid air will not flow into detection space 21. Therefore, even with vent 25 provided, freezing in detection space 21 is appropriately prevented.

[0039] Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments and can be modified as appropriate within the scope of the claims. For example, in this embodiment, an example is shown in which a non-contact type liquid level sensor 30 is used as the water level detection device, but the present invention is not limited to this form. For example, a contact type liquid level sensor (e.g., a float type or guide rope type liquid level sensor) can also be used as the water level detection device. [Industrial Applicability]

[0040] INDUSTRIAL APPLICABILITY The present invention can be used to appropriately manage the level (amount) of cooling liquid in a liquid freezing type refrigeration device for quickly freezing objects to be cooled, such as food. [Explanation of symbols]

[0041] 1 Refrigeration equipment 2 base 3 Cooling tank 3A Cooling tank reservoir 3B Upper end of cooling tank 3C Cooling tank opening 3D Overflow Pipe 3E Cooling tank headspace 4 Cooling pipe (heat exchanger) 5 Refrigerant supply section 6 Storage Units 6A Storage unit frame 6B Storage unit tray 7 Up / down drive mechanism 8 Lifting mechanism 8A Lifting drive mechanism 9 Control Device 11 Lid 12. Housing of vertical drive mechanism 13 Support arm for vertical drive mechanism 14 Lifting mechanism housing 15 Support arm of lifting mechanism 20 Isolation structure 21 Detection Space 22 Upper wall of isolation structure 23 Side wall of isolation structure 23A Lower end of side wall 30 Liquid level sensor 31 Lower limit water level position 32 Upper limit water level position

Claims

1. In a refrigeration device that freezes an object to be cooled by bringing it into contact with a cooling liquid, a cooling tank in which the cooling liquid is stored; an isolation structure that forms a detection space isolated from the outside above the cooling liquid stored in the cooling tank; a vent formed in the isolation structure; a water level detection device that detects the water level of the coolant in the cooling tank within the detection space; A refrigeration device comprising:

2. 2. The refrigeration system according to claim 1, wherein the vent is formed below an upper end of the cooling tank or below an overflow pipe provided in the cooling tank.

3. The refrigeration apparatus according to claim 1 , wherein the isolation structure includes a wall portion that covers the top and sides of the detection space.

4. 2. The refrigeration system according to claim 1, wherein a lower end of the isolation structure is located below a lower limit water level of the coolant in the cooling tank.

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