JPH0451749B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a flat low-temperature show case in which an air curtain is formed in the opening for storing and taking out products formed on the top surface.

(b) Prior Art The flat low-temperature show case shown in Japanese Unexamined Patent Application Publication No. 59-112171 (F25D17/08) and Japanese Utility Model Application No. 59-21479 is a flat-shaped low-temperature show case in which cold air is blown out from an air outlet to an opening and forms an air curtain. By creating a velocity gradient in the airflow, the speed of the outer flow that contacts the outside air is slower than that of the inner flow that contacts the cold air mass in the storage room. As a means of creating this velocity gradient, the length of the rectifying member disposed at the outlet may be made longer at the outer part than the inner part, or by making the opening area of the inner part of the rectifying channel longer than the inner part of the rectifying member. It is adopted to increase the opening area of the outer part.

(c) Problems to be Solved by the Invention According to the above-mentioned conventional technology, among the cold air blown out from the outlet to the opening, the outer flow that comes into contact with the outside air has a low velocity and the entrainment effect occurs immediately after being blown out from the outlet. Due to the fact that outside air is drawn in by the air outlet, the moisture contained in the outside air adheres as dew or frost to the outer part of the rectifying member, which is the outer part of the air outlet, and the rectifying channel becomes clogged and the air curtain is disturbed. There was a problem that the refrigeration load at the opening increased. This problem is especially true for flat low-temperature cases with air curtains formed on the top surface.
Because the cold air, which is denser than the outside air, crosses downward in a descending manner, it is generated more than in a multi-stage low-temperature case where an air curtain is formed at the front opening. As can be seen, a condensing part of the heat pipe is provided on the surface of the outlet, and the heat generated by the condensing part prevents condensation on the surface of the outlet, and as a result, the outer part of the cold air flow that forms the air curtain is slightly heated. However, because the back side of the surface of the outlet is continuously hit by the cold air just before it is blown out from the outlet,
The back side of the outlet surface is directly cooled, resulting in a significant temperature drop on the outlet surface, which creates a problem that cannot be addressed by the configuration of JP-A-56-18274 in the low-temperature case with refrigeration specifications.

(d) Means for Solving the Problems The present invention is aimed at solving the above problems, and as a means thereof, the apron and A metal mounting plate is provided with a space therebetween and holds the rectifier, and a heating element is provided on the mounting plate.

(E) Function According to the above means, the mounting plate acts as a mounting member for the heating element and a holding member for the rectifier, while the gap formed between the apron and the mounting plate prevents heat transfer from the heating element to the apron. It has the effect of alleviating the

(F) Embodiment An embodiment of the present invention will be described below based on the drawings.
This is a flat low-temperature case whose main body is composed of a heat insulating wall 3 formed with. The heat insulating wall is the front wall 3
A transparent window 4 made of glass is erected on the upper part of A, and a bumper rail 5 is installed along the front lower part of this transparent window, and an apron 3C that projects forward is formed on the upper part of the back wall 3B. are doing. Reference numeral 6 denotes a substantially U-shaped partition plate disposed at an appropriate distance from the inner wall of the heat insulating wall, and along with the arrangement of this partition plate, a plate fin type cooler 7 and an axial flow blower capable of forward and reverse rotation are installed. A storage chamber 12 is formed in the heat insulating wall 3, and a passage 11 having one end opened forward to form an air outlet 9 and the other end opened upward to form a suction port 10 is formed in the heat insulating wall 3. A transparent plate 13 is erected on the upper part of the front wall 6A of the partition plate, which together with the transparent window allows the storage chamber 12 to be viewed from the outside and substantially raises the load line of the storage chamber 12. A mounting portion 6C on which a rectifying device to be described later is mounted is formed on the upper part of 6B. Reference numeral 14 denotes a flow straightening device such as a honeycomb material arranged at the air outlet, and 15 is a lattice member which is also arranged at the air outlet 9 and is located closer to the opening 2 than the flow straightening device.
It is placed on C. Reference numeral 16 denotes a product drop prevention member such as punching metal or a net placed below the suction port.

Reference numeral 17 denotes a heating element such as a 40W electric heater placed near the outer part of the rectifier 14 on the passage 11 side of the rectifier 14, and a mounting plate that also serves as a holding plate for the rectifier 14 and a cold air directing plate. 19, and constantly generates heat regardless of whether the low-temperature case 1 is being cooled or defrosted. Said mounting plate 1
Reference numeral 9 is made of a metal plate bent into an approximately L-shape, and the front end of the top part is separated and attached to the apron 3C with screws, so that the center and rear end parts of the top part are attached to the apron 3C. A vertical portion that is attached at a distance and extends downward from the rear end faces the upper rear half of the rectifying device 14 and supports the heating element 17. Reference numeral 20 denotes a substantially L-shaped holding plate that presses down the lattice member 15, and is arranged from the front surface to the lower front part of the apron 3C, and its rear part is placed in the gap between the apron 3C, the lattice member 15, and the flow straightening device 14. 21, both the grid member 15 and the presser plate 20 are fixed to each other. With the installation of the mounting plate 19 and the holding plate 20, the mounting plate, the holding plate, and the gap 20 can prevent direct contact between the apron 3C, the rectifying device 14, and the lattice member 15, and the mounting plate 19 and Heat conduction from the presser plate 20 to the apron 3C is relaxed.

During cooling operation, the low-temperature case 1:
The blower 8 is rotated in the forward direction to forcefully circulate the cold air that has undergone heat exchange in the cooler 7 as shown by the solid line arrow in Figure 2, forming a cold air curtain AC in the opening 2, and also to supply refrigerant to the cooler 7. When defrosting operation stops,
The blower 8 is rotated in the reverse direction to flow air (outside air) as indicated by the chain arrow in FIG. 2 to defrost the cooler 7.

The rectifying device 14 has a large number of rectifying passages 18A to 18H that are rectangular or circular. The dimensions of this rectifying passage become progressively longer from the inner part 18A to the outer part 18H, and the speed of the air curtain AC has a gradient during the cooling operation. That is, as shown by arrows AC1, AC2, and AC3 in FIG. 1, the speed of the air curtain AC decreases sequentially from the inner flow AC1 to the intermediate flow AC2 and to the outer flow AC3. The cold air, which forms the outer flow AC3 of the air curtain, is directed by the mounting plate 19 and heated by the heating element 17 just before flowing into the rectifier 18, and has a lower temperature than the outside air, forming the inner flow AC1 and the intermediate flow AC2. It becomes dry cold air that is hotter than cold air. The heating element heats the outside air that is introduced into the passage 11 from the outlet 9 and reaches the cooler 7 during the defrosting operation.

Furthermore, since the outer portion of the rectifying device 14 is heated by the passage of the outer flow AC3 through the rectifying path 18H, the radiant heat of the heating element 17, and further heat conduction from the mounting plate 19, dew condensation or Frost formation can be prevented and clogging of the rectifier 14 can be avoided.

Furthermore, since the heating element 17 heats the outer portion of the rectifying device 14, power consumption is small and the rate of increase in the refrigeration load is also small.

Further, since the mounting plate 19 acts as a mounting member for the heating element 17 and a holding member for the rectifying device 14, the heating element 17 is located near the outer part of the rectifying device 14 as the rectifying device 14 is arranged.

Furthermore, the gap formed between the apron 3C and the mounting plate 19 acts to reduce heat transfer from the heating element 17 to the apron 3C, and also prevents cold air from coming into contact with the lower surface of the apron 3C facing the mounting plate 19. Apron 3
In addition to being able to alleviate excessive cooling of the heating element 17
Much of the heat generated by the rectifier 14 can be used to heat the outer portion of the rectifier 14.

(g) Effects of the invention The present invention described above has the following effects.

Since the mounting plate acts as a mounting member for the heating element and a holding member for the rectifier, the arrangement of the rectifier causes the heating element to be located near the outer part of the rectifier, and as a result, the arrangement of the rectifier becomes important. It's easy to do.

The gap formed between the apron and the mounting plate acts to reduce heat transfer from the heating element to the apron, and also to prevent cold air from coming into contact with the lower surface of the apron, which faces the mounting plate. In addition, excessive cooling of the apron caused by cold air can be alleviated, and most of the heat generated by the heating element can be used to heat the outside portion of the rectifier, and as a result, the heating element can be used effectively.

[Brief explanation of drawings]

The drawings all show embodiments of the low-temperature show case of the present invention, with FIG. 1 being an enlarged longitudinal cross-sectional view of the main part of the show case, and FIG. 2 being an overall longitudinal cross-sectional view of the show case. 2...Opening, 7...Cooler, 8...Blower, 9
...Outlet, 11...Aisle, 12...Storage room, 1
4... Rectifier, 17... Heating element, AC3... Outside flow.

Claims (1)

[Claims] 1. Between the heat insulating wall forming the main body with an opening for storing and taking out products on the upper surface and the partition plate defining the storage chamber, there is an air outlet with one end facing the opening and equipped with a flow rectifier, etc. A passage is formed whose end is an inlet opposite to the air outlet, a heating element is provided on the passage side of the rectifier and near the outer part of the rectifier, and a blower disposed in the passage generates heat in the cooler. In a low-temperature case in which an air curtain is formed in the opening by forced circulation of exchanged cold air, an apron is provided on the lower surface of the apron that extends forward from the upper part of the back wall of the heat insulating wall, and is spaced apart from the apron. A low-temperature case comprising a metal mounting plate for holding down a rectifier, and the heating element provided on the mounting plate.