WO2024053206A1

WO2024053206A1 - Defrosting device and defrosting method

Info

Publication number: WO2024053206A1
Application number: PCT/JP2023/023133
Authority: WO
Inventors: 直子仲村; 英博北山; 行一津幡; 瑞生工藤; 秀幸原
Original assignee: 株式会社前川製作所
Priority date: 2022-09-05
Filing date: 2023-06-22
Publication date: 2024-03-14

Abstract

[Problem] Provided are a defrosting device and a defrosting method with which it is possible to discharge frost attached to the defrosting device while the frost remains as frost. [Solution] This defrosting device includes: a suction port that suctions in air to which frost is attached; a filter unit to which the frost attaches, and that separates the frost from the air; a first flow path where the air from which the frost has been separated in the filter unit is transmitted to inside an ultra-low temperature freezer; and a discharge unit that discharges, to outside, the frost that has fallen down from the filter unit.

Description

Defrost device and defrosting method

The present invention relates to a defrost device and a defrosting method.

In recent years, in ultra-low temperature refrigerated warehouses, there has been a shift from binary refrigerators that use fluorocarbon refrigerants to air refrigerant refrigerators in order to reduce the amount of fluorocarbon refrigerants used as environmental measures and to save energy by reducing fan power (for example, in patent documents 1).

The air refrigerant refrigerator uses an air cycle that sucks in air from inside the warehouse, compresses it, and returns the cooled air to the inside of the warehouse through adiabatic expansion. Therefore, the moisture contained in the air turns into frost and accumulates inside the refrigerator and the warehouse, making it necessary to periodically defrost the inside of the refrigerator and the warehouse.

Japanese Patent Application Publication No. 2006-234275

In the defrost device of Patent Document 1 mentioned above, since the defrost device is installed outside the freezer, when the ambient temperature is relatively high, the frost melts and plate-shaped ice forms on the filter part. , there is a risk that the defrost device will become clogged and cannot be defrosted.

The present invention was invented in order to solve the above problems, and an object of the present invention is to provide a defrost device and a defrosting method that can discharge frost that has formed on the defrost device as it is. .

A defroster according to the present invention that achieves the above object includes: a suction port through which air with frost is sucked; a filter section to which the frost is attached and which separates the frost from the air; It has a first flow path through which the air from which the frost has been separated is sent into the ultra-low temperature freezer, and a discharge section through which the frost that has fallen from the filter section is discharged to the outside.

Further, the defrosting method according to the present invention that achieves the above object includes a suction step of sucking air with frost attached from a suction port, a separation step of making the frost adhere to a filter part and separating it from the air, and the above-mentioned steps. The method includes a step of sending the air from which the frost has been separated in the filter section into an ultra-low temperature freezer, and a discharging step of discharging the frost that has fallen from the filter section to the outside.

According to the above-described defrost device and defrosting method, fallen frost can be discharged outside as frost by the discharge section. Therefore, it is possible to suitably prevent frost from melting and plate-shaped ice forming on the filter portion, which would cause the defroster to become clogged and unable to defrost.

1 is a system diagram showing an ultra-low temperature refrigeration system including a defrost device according to an embodiment of the present invention. It is a figure showing a defrost concerning this embodiment, and is a figure showing a state where frost is attached to a filter part. It is a figure which shows the defrost device based on this embodiment, Comprising: It is a figure which shows how the frost adhering to a filter part fell by its own weight. 7 is a diagram showing a defrost device according to modification example 1. FIG. It is a figure showing a defrost concerning modification 2. It is a figure which shows the defrost concerning the modification 3, Comprising: It is a figure which shows a mode that a filter part is arrange|positioned in a defrost. It is a figure which shows the defrost concerning the modification 3, Comprising: It is a figure which shows a mode that a filter part is arrange|positioned outside the defrost. It is a figure which shows the defrost concerning the modification 4, Comprising: It is a figure which shows a mode that a filter part is arrange|positioned in a defrost. It is a figure which shows the defrost concerning the modification 4, Comprising: It is a figure which shows a mode that a filter part is arrange|positioned outside the defrost.

Embodiments of the present invention will be described with reference to FIGS. 1 to 3. In addition, in the description of the drawings, the same elements are given the same reference numerals, and redundant description will be omitted. Dimensional proportions in the drawings are exaggerated for illustrative purposes and may differ from actual proportions.

FIG. 1 is a system diagram showing an ultra-low temperature refrigeration system 1 including a defrost device 40 according to an embodiment of the present invention. FIG. 2 is a diagram illustrating the defrost device 40 according to the present embodiment, and is a diagram illustrating how frost is attached to the filter section 42. As shown in FIG. FIG. 3 is a diagram illustrating the defrost device 40 according to the present embodiment, and is a diagram illustrating how frost attached to the filter section 42 falls under its own weight.

The ultra-low temperature refrigeration system 1 is used, for example, to cool a drug warehouse. Note that the object to be cooled is not limited to drug warehouses, but can also be used for cooling food warehouses and the like. As shown in FIG. 1, the ultra-low temperature refrigeration system 1 includes an ultra-low temperature freezer 10 that cools and stores objects to be cooled, a circulation path 20 that is connected to the ultra-low temperature freezer 10 and through which air circulates, and the air inside the ultra-low temperature freezer 10 as a refrigerant. , has an air refrigerant refrigerator 30 that supplies cooled air into the ultra-low temperature freezer 10, and a defroster 40 that removes frost from the air supplied from the air refrigerant refrigerator 30 into the ultra-low temperature freezer 10.

In the ultra-low temperature freezer 10, chemicals are cooled and stored as described above. In the ultra-low temperature freezer 10 where medicines are kept cooled, an automatic transport device is used to carry in and out the medicines unattended. If frost adheres to the automatic conveyance device, it may not function properly. Therefore, when using the air refrigerant refrigerator 30, the defrost device 40 removes the frost that adheres to the cooled air that returns to the ultra-low temperature freezer 10. must be removed.

Inside the ultra-low temperature freezer 10, an inlet (not shown) for air circulating through the circulation path 20 and an outlet (not shown) from which air cooled in the air refrigerant refrigerator 30 blows out are arranged. Although the internal temperature of the ultra-low temperature freezer 10 is not particularly limited, it is −50° C. or lower. In this way, since the temperature inside the ultra-low temperature freezer 10 is ultra-low, it is possible to prevent the frost from melting in the defrost device 40, and it is possible to suitably discharge the frost as it is. Further, when the internal temperature of the ultra-low temperature freezer 10 is -50° C. or lower, a certain amount of frost adhering to the filter section 42 will fall, so by removing the frost, continuous operation is possible.

When frost is formed in the air, the temperature of the air containing moisture decreases and moisture in excess of the saturated amount precipitates. Here, for example, when the temperature inside the refrigerator is higher than the temperature inside the ultra-low temperature freezer 10 according to the present embodiment, such as between -20°C and -30°C, the time when the droplets exist as supercooled droplets is long, and the liquid droplets freeze. It is easy to form large crystals by agglomeration and bonding before crystallization. On the other hand, since the internal temperature of the ultra-low temperature freezer 10 according to the present embodiment is between -60°C and -50°C, supercooling is easily released and the ice precipitates before the mass increases, so that the particle size can be reduced. Small frost forms. Furthermore, since the absolute humidity is lower as the internal temperature of the ultra-low temperature freezer 10 is lower, the amount of moisture that precipitates decreases even with the same temperature difference, and a relatively small amount of frost is generated. Therefore, the frost adhering to the filter portion 42, which will be described later, becomes powdery and can be easily discharged from the defrost device 40 by wind pressure, as described later.

As shown in FIG. 1, the air refrigerant refrigerator 30 includes a compressor 31, an expander 32, and a primary cooler 33. The compressor 31 and the expander 32 are integrated and connected to the same motor M. The air refrigerant refrigerator 30 constitutes a reverse Brayton cycle.

Hereinafter, the cycle in the air refrigerant refrigerator 30 will be explained. Note that the temperature described below is an example and is not particularly limited.

First, the air inside the ultra-low temperature freezer 10 (minus 60 degrees Celsius) that is sucked into the air refrigerant refrigerator 30 is compressed and heated in the compressor 31 to become high-temperature, high-pressure air at 90 degrees Celsius. Then, the air at 90°C is cooled down to 40°C in the primary cooler 33.

Next, the 40°C air is adiabatically expanded in the expander 32 and cooled to -80°C, and this air is sent into the ultra-low temperature freezer 10.

In this embodiment, the defrost device 40 is provided inside the ultra-low temperature freezer 10, as shown in FIG. 1, but the position where the defrost device 40 is placed is not limited. However, it is preferable to arrange it downstream of the expander 32 of the air refrigerant refrigerator 30.

In this embodiment, one defrost device 40 is provided. The defrost device 40 removes frost contained in the air when the air cooled to -80° C. is sent into the ultra-low temperature freezer 10 by the air refrigerant refrigerator 30. The configuration of the defrost device 40 will be described below.

As shown in FIGS. 2 and 3, the defrost device 40 includes a housing 41, a filter section 42 provided in the housing 41, and a first flow path through which air from which frost has been separated flows into the ultra-low temperature freezer 10. 43, a first valve 44 provided in the first flow path 43, a second flow path 45 through which frost passes when frost is discharged from the housing 41, and a second valve provided in the second flow path 45. 46.

The housing 41 is formed with a suction port 41A through which air containing frost cooled in the air refrigerant refrigerator 30 is sucked.

The filter portion 42 is attached with frost contained in the air sucked in from the suction port 41A, and separates the frost from the air. In this embodiment, the filter section 42 is arranged to extend in the horizontal direction, as shown in FIGS. 2 and 3. According to this configuration, since the filter portion 42 can be provided over a wide range, frost can be suitably attached to the filter portion 42.

The filter section 42 is configured to include countless voids. When the air containing frost passes through the filter section 42, the frost F adheres to the filter section 42, as shown in FIG. On the other hand, the air from which the frost has been separated passes through the filter section 42 and moves upward, and when the first valve 44 is open, it is sent into the ultra-low temperature freezer 10 via the first flow path 43 (Fig. (See arrow 2). That is, at this time, normal cooling operation is performed in the ultra-low temperature freezer 10.

If normal cooling operation is continued, when the amount of frost F adhering to the filter section 42 exceeds a predetermined value, it falls to the lower surface of the casing 41 due to its own weight, as shown in FIG. The fallen frost F is accumulated on the lower surface in a so-called powder state. Note that the defrost device 40 may further include a falling part that assists the frost adhering to the filter part 42 to fall due to its own weight. Although the falling part is not particularly limited, an ultrasonic vibrator or a blowing part that blows shot air can be used, but an ultrasonic vibrator is preferable from the viewpoint of preventing clogging in the filter part 42.

Furthermore, in order to assist the frost adhering to the filter part 42 to fall due to its own weight, the air flow may be reversed (downward in FIG. 2) to cause the frost adhering to the filter part 42 to fall.

When a predetermined amount of frost F has accumulated on the lower surface of the casing 41, as shown in FIG. The frost F can be discharged from the second flow path 45. That is, the first valve 44 and the second valve 46 function as a discharge section that discharges frost to the outside as it is. That is, at this time, in the ultra-low temperature freezer 10, normal cooling operation is stopped and defrosting operation is performed. Preferably, the second valve 46 is located within the ultra-low temperature freezer 10. Here, for example, if the second valve 46 is placed outside the ultra-low temperature freezer 10, there is a possibility that frost will melt and freeze inside the second valve 46. In this embodiment, the second valve 46 is placed inside the ultra-low temperature freezer 10, so that the above-mentioned freezing can be prevented.

The frost discharged outside the defrost device 40 is received by a drain pan, for example, and is melted and drained using a heater installed in the drain pan or warm air, thereby preventing re-sublimation and removing the frost. It can be easily done.

Since the defrost device 40 according to the present embodiment is placed in the ultra-low temperature freezer 10, it can defrost in a low-temperature atmosphere, and can preferably discharge frost formed in the defrost device 40 as it is. .

Note that a heater section may be attached to the filter section 42 of the defrost device 40. According to this configuration, even if frost adhering to the filter section 42 melts and plate-shaped ice forms on the filter section 42, the ice can be melted by the heater section, so that the defroster 40 can This prevents the defrosting from becoming impossible due to blockage.

Hereinafter, a defrosting method of the defrost device 40 of the ultra-low temperature refrigeration system 1 according to the present embodiment will be described. The defrosting method includes a suction process in which air with frost is sucked in from the suction port 41A of the housing 41, a separation process in which the frost is attached to the filter section 42 and separated from the air, and a step in which the frost is separated in the filter section 42. The method includes a step of sending the frozen air into the ultra-low temperature freezer 10, and a discharging step of discharging the frost that has fallen from the filter section 42 to the outside. In the discharge step, with the first valve 44 closed and the second valve 46 opened, frost is discharged from the second flow path 45 by the wind pressure of the air sucked in from the suction port 41A.

As described above, the defrost device 40 according to the present embodiment includes the suction port 41A into which air with frost is sucked in, the filter section 42 to which frost is attached and which separates the frost from the air, and the filter section 42. It has a first flow path 43 through which the air from which the frost has been separated is sent into the ultra-low temperature freezer 10, and a discharge section through which the frost that has fallen from the filter section 42 is discharged to the outside. According to the defrost device 40 configured in this manner, the frost can be discharged outside as it is by the discharge section. Therefore, it is possible to suitably prevent frost from melting and plate-shaped ice forming on the filter portion 42, which would cause the defrost device 40 to become clogged and unable to defrost.

The defrost device 40 also includes a second flow path 45 through which frost attached to the filter section 42 is discharged, a first valve 44 provided in the first flow path 43, and a second valve 44 provided in the second flow path 45. The discharge section further includes a valve 46, and the discharge section discharges frost using the wind pressure of the air sucked in from the suction port 41A with the first valve 44 closed and the second valve 46 opened. According to the defrost device 40 configured in this way, automatic defrosting is possible without an operator.

Furthermore, the filter section 42 is arranged to extend in the horizontal direction. According to the defrost device 40 configured in this way, the filter section 42 can be provided over a wide range, so that frost can be suitably attached to the filter section 42.

Furthermore, the defrost device 40 further includes a dropping part that drops frost attached to the filter part 42. According to the defrost device 40 configured in this manner, clogging in the filter section 42 can be effectively prevented.

Furthermore, the defrost device 40 further includes a heater section attached to the filter section 42. According to the defrost device 40 configured in this way, even if frost adhering to the filter section 42 melts and plate-shaped ice forms on the filter section 42, the heater section cannot melt the ice. Therefore, it is possible to prevent the defrost device 40 from being blocked and unable to defrost.

Although the present invention has been described above through the embodiments, the present invention is not limited to the above-described embodiments and modifications, and can be variously modified within the scope of the claims.

For example, in the embodiment described above, the filter section 42 was arranged to extend in the horizontal direction, as shown in FIGS. 2 and 3. However, as shown in FIG. 4, the filter section 142 may be arranged to extend in the vertical direction. According to this configuration, frost can be efficiently attached to the filter portion 142 because it is arranged perpendicularly to the direction of travel of the air. Furthermore, as shown in FIG. 5, the filter section 242 may be arranged so as to be inclined with respect to the horizontal direction and the vertical direction.

Furthermore, in the embodiment described above, one filter section 42 was provided. However, as shown in FIGS. 6A and 6B, a plurality of filter sections 42 (three in FIG. 6A) may be provided along the vertical direction. When a plurality of filter parts 42 are provided along the vertical direction, a part of the housing 41 is configured to be openable and closable, so that the filter part 42 to which frost F has adhered can be taken out, as shown in FIG. 6B. .

Furthermore, in the embodiment described above, one filter section 142 was provided. However, as shown in FIGS. 7A and 7B, a plurality of filter sections 142 (nine in FIG. 7A) may be provided along the horizontal direction. When a plurality of filter parts 142 are provided along the horizontal direction, a part of the housing 41 is configured to be openable and closable, so that the filter part 142 with frost F attached can be taken out, as shown in FIG. 7B. .

Furthermore, in the embodiment described above, the discharge section was configured by the first valve 44 and the second valve 46. However, the discharge section may be a conveyor or other conveyor placed on the bottom surface of the defrost device 40, and when a predetermined amount of frost accumulates on the conveyor, the conveyor discharges it out of the casing 41. It's okay.

This application is based on Japanese Patent Application No. 2022-140646 filed on September 5, 2022, the disclosure content of which is incorporated by reference in its entirety.

1 Ultra-low temperature refrigeration system,
10 Ultra-low temperature freezer,
20 circulation path,
30 air refrigerant refrigerator,
31 Compressor,
32 Expander,
33 Primary cooler,
40 defrost,
41A Suction port,
42, 142, 242 filter section,
43 first flow path,
44 first valve,
45 second flow path,
46 Second valve.

Claims

A suction port through which frost-covered air is sucked,
a filter portion to which the frost adheres and separates the frost from the air;
a first flow path through which the air from which the frost has been separated in the filter section is sent into an ultra-low temperature freezer;
A defrost device comprising: a discharge section that discharges the frost falling from the filter section to the outside.
a second flow path through which frost attached to the filter portion is discharged;
a first valve provided in the first flow path;
further comprising a second valve provided in the second flow path,
The defrost device according to claim 1, wherein the discharge section discharges the frost using wind pressure of the air sucked in from the suction port with the first valve closed and the second valve opened.
The defrost device according to claim 1 or 2, wherein the filter section is arranged to extend in a horizontal direction.
The defrost device according to claim 1 or 2, wherein the filter section is arranged to extend in the vertical direction.
The defrost device according to claim 1 or 2, further comprising a dropping part that drops the frost attached to the filter part.
The defrost device according to claim 5, wherein the falling part is an ultrasonic vibrator.
The defrost device according to claim 5, wherein the falling part is a blowing part that blows shot air.
The defrost device according to claim 1 or 2, further comprising a heater section attached to the filter section.
The defrost device according to claim 1 or 2, wherein the internal temperature of the ultra-low temperature freezer is -50°C or less.
a suction process in which air with frost is sucked in from the suction port;
a separation step of attaching the frost to a filter part and separating it from the air;
sending the air from which the frost has been separated in the filter section into an ultra-low temperature freezer;
A defrosting method comprising: a discharge step of discharging the frost that has fallen from the filter portion to the outside.