JPS6217582A - Defrostation method of refrigerating 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 relates to a method for removing a cold air circulation type freezing/refrigerating open cooler case in which at least one layer of air curtain is formed in the opening to cool and preserve products. .

[Prior art and its problems]

A multi-stage oven seal case shown in FIG. 8 is known as this type of oven seal case. In FIG. 8, the main case 1 has an opening 1a for taking out the product on the front side, an outer box 2 formed of a heat insulating wall, and an inner box disposed with an appropriate gap between the outer box 2 and the outer box 2. A display room 5 partitioned into multiple stages by shelf boards 4 is formed inside the inner box 8. Further, a cold air circulation path 6 is formed between the outer box 2 and the inner box 8'.

Both ends of this cold air circulation path form a Suita lower and a suction port 8 above and below the opening 1a, respectively. The Suita lower is provided with an air rectifier 10 having honeycomb-shaped ventilation holes and a cool air circulation fan 9.

Note that 14 is a drain outlet.

In the oven sillar case described above, during cooling operation, air is made to flow through the cold air circulation path 6 in the direction of arrow A by the cold air circulation fan 9, and is cooled by the cooler 10 to become cold air, and this cold air is blown out from the Suita lower. Opening 1a
An air curtain 1 for isolating the inside of the display room 5 from outside air
1 and cools the inside of the display room 5. Furthermore, during the defrosting operation, the operation of the cooler 10 is stopped, so the temperature of the circulating air begins to rise. This raised circulating air removes frost formed on the cooler 10. In this case, cooler 1
0 performs defrosting while gradually increasing the temperature from below using circulating air, so when defrosting is complete, the product temperature in the display room 5 will be covered with an air temperature higher than the cold storage temperature for a long time, so the storage period of the product will be shortened. This results in a reduction in the number of stores, resulting in product loss and putting pressure on the profits and losses of store management. When the next cold storage operation starts, the air flowing through the cold air circulation path is cooled, but the air temperature in the display room 5 remains elevated for a certain period of time, and it takes time for the air temperature to drop to the cold storage temperature. Requirements are also a factor in product loss. FIG. 4 is an explanatory diagram showing the temperature change characteristics of this oven sealer case.

[Purpose of the invention]

In view of the above points, this invention has been developed to provide a cold air circulation type frozen/refrigerated oven syringe case that shortens the defrosting time during defrosting operation, suppresses the temperature rise of products, and maintains their freshness for a long time. Aims to provide a frost method.

[Key points of the invention]

The above object can be achieved by the following configuration of the present invention. That is, in a cold air circulation type oven syringe case in which a ventilation passage containing a built-in 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 an air curtain is formed in the opening. , atllc2 fan is configured to be switchable between low-speed rotation and high-speed rotation, and when defrosting starts, this fan switches from low-speed rotation during cold preservation operation to high-speed rotation, and during defrosting, the cooler outlet air or the cooler temperature is changed. When a predetermined temperature lower than the defrosting end temperature is reached, this fan switches from high-speed rotation to low-speed rotation, finishes defrosting at low speed, and when cooling operation starts after defrosting, this fan changes from low-speed rotation to high-speed rotation. During cold storage operation, this fan switches from high-speed rotation to low-speed rotation either when the cooler outlet air, cooler or internal temperature reaches the predetermined cold storage temperature, or after a certain period of time has passed after defrosting is completed. In this defrosting method, the defrosting method is different at the start of defrosting and at the end of defrosting.In the former, the fan is rotated at high speed to perform accelerated air defrosting, and halfway through, the fan is switched to low speed rotation to perform low speed air defrosting. This reduces defrosting time, and when cold storage operation starts after defrosting, the fan is rotated at high speed to perform accelerated cold air circulation operation, which quickly lowers the temperature of the product to the cold storage temperature, reducing product loss. The purpose is to extend the storage period.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a fan circuit diagram of the present invention, and FIG. 2 shows its temperature change characteristics and time chart. Note that the cross-sectional view of the oven-silver case is the same as that of the conventional example, so FIG. 8 will be referred to.

In FIGS. 1 and 2, a cold air circulation fan 90 is a fan whose rotational speed can be switched between low-speed rotation and high-speed rotation. A fan switching relay 12 for switching the fan is connected to a temperature thermostat 18, and the temperature thermostat 18 is set at a TI lower than the defrosting end temperature T4. During defrosting, the 11L power is applied to the fan switching circuit by a timer (not shown), and the cold air circulation fan 90 is switched from low speed rotation to high speed rotation.

At this time, the air flow circulates in the same direction as arrow A in FIG. 1 to remove frost from the cooler 10. By rotating at a high speed, a larger amount of air having a temperature higher than that of the cooler 10 is passed through the suction cooler IO from the suction port 8 than when rotating at a low speed, and is blown out from the Suita lower, thereby forming an air curtain 11. Next, when the cooler outlet temperature or the temperature of the entire cooler is TI (around 0''C), that is, the frost that has formed in the cooler turns into water at 0°C, the temperature thermometer 18 operates and the cold air circulation fan 9 switches from high-speed rotation to low-speed rotation, and the water in the cooler 10 flows more easily and flows out to the drain port 14.Then, after a few minutes, switch to cooling operation.With the above method, a large amount of warm water is generated compared to the conventional method. Since air is sent into the cooler 10, the defrosting time in which the frost in the cooler turns into O''C water is greatly shortened. In addition, when defrosting with conventional low-speed rotation, there was a large temperature difference between the upper and lower parts of the cooler at the end of defrosting, depending on the frost resistance, and the melted frost could leave residue. Since the temperature of the entire cooler 10 is kept at 0°C during high-speed rotation, there is no need to worry about remaining melt, and the defrosting end temperature T4 can be kept lower than before, reducing the temperature in the display room. Since the temperature of the product is kept low, the temperature of the product is prevented from rising, and the residence time in high-temperature air is shortened, resulting in a reduction in product loss. Also, the cold storage temperature is T from the start of cooling operation after defrosting!
By setting the rotation at high speed during the period of time until the end, a large amount of cooling air is blown out from the outlet, and the temperature in the display room quickly reaches T! Since the temperature is lowered by humidity, it is possible to reduce product loss and improve store profits and losses.

〔Effect of the invention〕

According to this invention, at the start of defrosting, the fan is rotated at high speed to perform accelerated air defrosting, and halfway through, the fan is switched to low speed rotation to perform low speed air defrosting. By using a defrosting method that rotates the fan at high speed at the beginning, the defrosting time is shortened and the temperature rise of the products is suppressed, which reduces product loss and maintains freshness for a long period of time, improving store profits. reactor.

[Brief explanation of drawings]

FIG. 1 is a fan circuit diagram of the present invention, FIG. 2 is a temperature change characteristic and a time chart thereof, FIG. 8 is a sectional view of an oven seal-case, and FIG. 4 is a conventional temperature change characteristic diagram. 1... Case, 1a... Opening, 2... Outer box, 8
...Inner box, 4...Shelf board, 5...Display room, 6...
Cold air circulation path, 7...Blowout port, 8...Suction port, 9...
・Fan, 10... Cooler, 11... Air curtain, 18... Temperature thermostat, 14 Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] 1) In a cold air circulation type open showcase in which a ventilation passage containing a built-in cooler and fan is formed between an outer box and an inner box of a main body case having an opening on the front or top surface, and an air curtain is formed in the opening. , the fan is configured to be switchable between low-speed rotation and high-speed rotation, and when defrosting starts, this fan switches from low-speed rotation during cold preservation operation to high-speed rotation, and during defrosting, the cooler outlet air or cooler temperature is changed. When a predetermined temperature lower than the defrosting end temperature is reached, this fan switches from high speed rotation to low speed rotation and finishes defrosting at low speed, and when cooling operation starts after defrosting, this fan changes from low speed rotation to high speed rotation. During cold storage operation, this fan changes from high speed rotation to low speed rotation either when the cooler outlet air, cooler or internal temperature reaches the predetermined cold storage temperature, or after a certain period of time has passed after defrosting is completed. A defrosting method for frozen/refrigerated open showcases characterized by switching.