JPS61110866A - Cold air circulation type open showcase - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Technical Field to which the Invention Pertains] This invention provides a defrosting system that is equipped with internal and external ventilation passages each equipped with a built-in fan so that a double-layered air curtain is formed at the opening during cooling operation. The present invention relates to a cold air circulation type open showcase in which outside air, which is sometimes introduced so as to flow backward through the outside ventilation path, flows through the inside ventilation path to defrost the air.

[Prior art and its problems]

Conventionally, this type of open showcase is shown in Figures 3 and 4.
A multistage type shown in the figure is known.

In the figure, the main case 1, which has an opening 1a for taking out the product on the front side, has an outer box 2) formed of a heat-insulating wall and an outer box 2).
An inner box 3 is provided with an appropriate gap between the inner box 3,
A display room 5 partitioned into multiple stages by shelf boards 4 is formed inside the inner box 3.

Further, a partition wall 6 is provided between the outer box 2 and the inner box 3 so as to divide the gap into two, thereby forming an inner ventilation passage 7 and an outer ventilation passage 8. Both ends of the inner ventilation passage 7 have openings 1a.
The upper and lower sides form a blowout lower a and a suction lower b, respectively, and both ends of the outer ventilation passage 8 are adjacent to the blowout lower a and the suction lower b, respectively, and form a blowout port 8a and a suction port 8b on the outside thereof. The blowout lowers a and 8a are equipped with an air regulating fluid 9 having honeycomb-shaped ventilation holes, and inside the inner ventilation passage 7 there is a cooler 11, a fan 12, a defrosting heater 21, and a temperature control device. Overheat preventers 21a and 21b are provided to detect and open/close energization to the defrosting heaters 20a and 20b, and a reversible fan 13 is provided in the outer ventilation passage 8.

In the above-mentioned open showcase, during the cooling operation, indoor air is circulated through the inner ventilation passage 7 in the direction of arrow A by the fan 12, and is cooled by the cooler 11 to become cold air, and this cold air is blown out from the blowing lower. opening 1
At (a), an air curtain 15 is formed to isolate the inside of the display room 5 from outside air and cool the inside of the display room 5. Further, indoor air circulated through the outside ventilation passage 8 in the direction of arrow A by the fan 13 causes the air curtain 1 to
An air curtain 16 is formed on the outside of the display room 5 to protect it, and the inside of the display room 5 can be cooled and kept cool even more efficiently. Further, during defrosting operation, the operation of the cooler 11 is stopped and the fan 13 rotates in reverse, so that the defrosting heaters 21a and 21b
is energized.

As shown in FIG. 4, by the reverse rotation of the fan 13, warm outside air is sucked into the outer ventilation passage 8 from the outlet 8a. This outside air flows back through the outside ventilation passage 8 in the direction of arrow B, and then flows through the suction port 8.
b, and in this case non-cooled air is sucked into the inner ventilation passage 7 as shown by arrow C by the fan 12 forming the air curtain 15, and is made to flow in the direction of arrow A, where it is heated by defrosting heaters 21a and 21b. Cooler 11
The frost formed on the outside is removed by the heat of the heated outside air. As shown in FIG. 5, when the entire cooler 11 reaches the defrosting end temperature T2, the defrosting thermometer 20 senses the temperature and ends the defrosting.

However, in this case, the temperature of the cooler 11 is gradually raised from below by the heated outside air, and defrosting is performed while melting the frost. There is a wide temperature difference. When the next cooling operation starts, the air flowing through the inner ventilation passage 7 is cooled, but since it takes time for the upper part of the cooler 11 to reach a certain temperature, the temperature of the products in the display room 5 remains in the cooling operation. Even at the beginning, the price is rising for a certain period of time, causing product damage and shortening the storage period, resulting in product loss and putting pressure on profit and loss.

[Purpose of the invention]

The object of the present invention is to provide a cold air circulation type open showcase that prevents the temperature rise of a cooler during defrosting operation, shortens the defrosting time, suppresses the temperature rise of products, and maintains the freshness for a long time.

[Key points of the invention]

This invention uses a heater to uniformly reduce the temperature rise in the cooler during defrosting by defrosting the air intake side of the cooler and the center of the cooler, and ends defrosting at a low temperature to reduce the product temperature. This was designed to suppress the rise.

[Embodiments of the invention]

FIG. 1 shows an embodiment of the present invention, and the same reference numerals as in FIG. 3 indicate the same members. Of the defrosting heaters 21a and 21b, which were conventionally attached to the lower part of the cooler 11, the defrosting heater 21b is disposed in the center of the cooler 11. That is, the overheat preventer 20b is disposed between the overheat preventer 20a and the defrost heaters 21a and 21b, on the leeward side of the defrost heater 21b.

In the above configuration, the fan 13 in the outside ventilation path during defrosting
is reversed, outside air is sucked into the inner ventilation passage 7 as shown by arrow C, and is heated by the defrosting heater 21a, thereby defrosting the lower part of the cooler 11. At this time, the air is defrosted to a low temperature that does not lose heat, but it is heated again by the defrosting heater 21b to raise the temperature, and the upper part of the cooler 11 is defrosted. Therefore, compared to the conventional defrosting method, the temperature of the entire cooler 11 rises to the defrosting end temperature T2 in a shorter time as shown in FIG. Therefore, during the next operation, the temperature rise of the entire cooler will be lower than in the conventional case, so that the temperature of the cooler 11 can be lowered to T in a short time. From the cooler lower temperature T to the upper temperature T shown in FIG.
Since the amount of heat that was conventionally required between the two is no longer necessary, the temperature rise of the product is smaller than the conventional temperature rise. Therefore, the freshness of the product is maintained for a long time.

When defrosting, if the temperature rise of the cooler differs between the upper and lower parts due to the size of the defrost heater capacity cooler, etc., change the set temperature of the overheat preventers 20a and 20b to equalize the temperature rise of the cooler. By doing so, it is also possible to suppress the rise in product temperature.

Although an open showcase with two-layer ventilation passages has been described as an example, the present invention can also be applied to a single-layer type and a multi-layer type.

〔Effect of the invention〕

According to this invention, the defrost heater is provided on the inlet side and in the center of the cooler provided in the ventilation passage, so that the temperature of the cooler heated by the defrost heater during defrosting is uniform. Therefore, the cooler can be returned to the original cold storage temperature in a short time after cold storage starts, and the temperature rise of the product can be kept low.

[Brief explanation of the drawing]

Fig. 1 is a structural sectional view showing an embodiment of the cold air circulation type open showcase of the present invention, Fig. 2 is a temperature change graph for explaining this invention, and Figs. 3 and 4 are diagrams of a conventional showcase. The structural sectional view shown in FIG. 5 is a temperature change graph in a conventional showcase. 2...Outer box, 3...Inner box, 7...Inner ventilation passage, 8
...Outside ventilation passage, 11...Cooler, 12...Fan, 13...Reversible fan, 2Qa, b...Overheat preventer, 21a, b...Defrost heater. Figure 1 Time ()-1) Figure 2 Figure 3 Figure 4 Time (H) Figure 5

Claims (1)

[Claims] 1) A ventilation passage containing a cooler and a fan is formed between an outer box and an inner box of the main case having an opening on the front or top surface, and during cooling operation, the opening is closed by the fan. What is claimed is: 1. A cold air circulation type open showcase forming an air curtain in the cold air circulation type open showcase, characterized in that a defrosting heater is provided on the air inlet side of the cooler and in the central portion thereof. 2) In the cold air circulation type open showcase according to claim 1, each of the defrosting heaters provided on the air inlet side and the central part of the cooler is provided with an overheating preventer in the vicinity and on the leeward side thereof. Open showcase with cool air circulation.