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(11) | EP 0 259 770 A2 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Refrigerated display cabinet |
| (57) A refrigerated display cabinet (10) which is provided with air circulation mechanism
is disclosed. The air circulation mechanism comprises at least two air passageways
(15a, 15b, 15c) defined on bottom portion of interior space of the cabinet (10), and
blower fan (17a, 17b) placed on each air passageway (15a, 15b, 15c). An evaporator
(16) of refrigeration unit is disposed on one of air passageway (15c) for cooling
the air passed therethrough. The operation of fan (17a, 17b) in each air passageway
(15a, 15b, 15c) is individually controlled to continue the air circulation within
the interior space of cabinet (10), even if the refrigeration unit stopped its operation.
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[0001] This invention relates to a refrigerated display cabinet in which the temperature and humidity is uniformly maintained.
[0002] Generally, as shown in Figure 1, a refrigerated display cabinet 1 is provided with a refrigeration unit which comprises an evaporator 3 for cooling down the merchandise storage/display compartment A of cabinet 1, a compressor and condenser both of which are disposed in a working chamber of cabinet 1. The merchanidse storage/display compartment A has divided its space into a plurality of display space by a plurality of shelves S and improved the displaying effect by fluorescent light 9 which is disposed on the rear surface of each shelf S. The compartment A is generally cooled down by forced convention; the air in the storage/display compartment A is passed through the evaporator 3 disposed at the lower portion of storage/display compartment A for cooling down and convection by fan 4. That is, as show in Figure 2, the bottom portion of storage/display compartment A defines the air circulation way 2 in which evaporator 3 is disposed. Therefore, cooled air is forced convection due to operation of fan 4 while the refrigeration unit is operated. That is, as show in Figure 2, the bottom portion of storage/display compartment A defines the air circulation way 2 in which evaporator 3 is disposed. Therefore, cooled air is forced convection due to operation of fan 4 while the refrigeration unit is operated.
[0003] The operation of refrigeration unit is controlled by a temperature control device, for example, a thermostat to maintain the predetermined temperature in storage/display compartment A. That is, as shown in Figure 3, a compressor 6, the fan 4 for the evaporator 3 and a fan 5 for a condenser are parallel connected with one another and also connected to a power source 8, respectively, through the thermostat 7. In this structure of the refrigeration unit, if the temperature of storage/display compartment A is below the predetermined temperature, the operation of the refrigeration unit is totally ceased, i.e., operation of the compressor 6 and the two fans 4, 5 is ceased. As a result, forced convention of cooled air and stirring of the air in the storage/display compartment A is stopped.
[0004] If the above explained situation, such as the stopped operation of refrigeration unit, is continued to extend for a long time, the temperature in upper portion of the storage/display compartment A is only gradually increased due to the generation of heat by the fluorescent light 9 and/or invading heat from the external environment through the glass panel of the display cabinet. Therefore, the temperature and humidity in storage/display compartment A is not maintained uniformly.
[0005] It is a primary object of this invention to provide a refrigerated display cabinet which uniformly maintains the temepature and humidity of merchandise storage/display space therein.
[0006] It is another object of this invention to provide a refrigerated display cabinet which accomplishes the above object with a simple modification of the conventional display cabinet.
[0007] A refrigerated display cabinet in accordance with this invention has a storage/display compartment for merchandise, and is provided with a refrigeration unit for cooling the storage/display compartment and an air circulating mechanism which comprises an air passageway and at least one blower fan. An evaporator of the refrigeration unit is disposed in the passageway for cooling the air passed therethrough. The air passageway is divided into at least two ways and the evaporator is disposed in one of the air passageways. At least one of the blower fans is placed on each air passageway and operated individually.
[0008] Further objects, features and other aspects of this invention will be understood from the following detailed description of preferred embodimetns of this invention referring to the attached drawings.
Figure 1 is a cross sectional view of a conventional refrigerated display cabinet.
Figure 2 is a sectional view taken along the line II-II in Figure 1.
Figure 3 is a diagrammatic electrical circuit view of a refrigeration unit utilized in the refrigerated display cabinet of Figure 1.
Figure 4 is a cross sectional view of a refrigerated display cabinet in accordance with one embodiment of this invention.
Figure 5 is a sectional view taken along the line V-V in Figure 4.
Figure 6 is a diagramatic electrical circuit view of a refrigeration unit utilized in the refrigerated display cabinet in Figure 4.
Figure 7 is a diagramatic electrical circuit view of a refrigeration unit in accordance with another embodiment of this invention.
[0009] Referring to Figures 4 and 5, a refrigerated display cabinet 10 according to this invention comprises an upper storage/display compartment 11 and lower mechanical compartment 12 for working parts. The upper compartment 11 is defined by an upper insulating wall panel 111, a lower insulating wall panel 112, side panels 113, 114 extending between the upper panel 111 and lower panel 112, a front and rear insulating panel 115, 116 and front glass windows 117 which are slidably mounted to open and close a front opening of cabinet 10 defined by upper, front and both side panels. A plurality of shelves 13 are horizontally disposed in the storage/display compartment 11 to divide the compartment 11 into a plurality of display spaces. A bottom plate 14 is also disposed in the lower portion of compartment 11 placed above the upper portion of the lower panel 112 with a gap to define an air circulating passageway 15. The refrigeration unit to cool down and maintain the temperature of storage/display compartment 11 normally comprises a compressor 20, a condenser, an evaporator 16 and a blower fan 21 for the condenser. The compressor, the condenser and the blower fan for the condenser are disposed in mechanical compartment 12.
[0010] As clearly shown in Figure 5, the gap between the bottom plate 14 and the lower panel 112 is vertically divided into three air passageways 15a, 15b, 15c by two vertically placed partition plates 14a, 14b. The three passageways 15a, 15b, 15c communicate with the storage/display compartment 11 through a gap G1 defined between the bottom plate 14 and the rear panel 113, and also a gap G2 defined between the bottom plate 14 and the front panel 116. The evaporator 16 of the refrigeration unit is disposed in the central passageway 15c to cool down the air passing through the central passageway 15c.
[0011] A plurality of blower fans 17 are disposed on the discharge side of the air passageways 15. That is, each blower fan 17 is affixed on a supporting plate 18 being disposed in the respective air passageways 15a, 15b, 15c, and this supporting plate 18 is placed on the discharge side of the air passageways 15 to cross over the passageways 15. A penetrating hole 181 is formed through supporting plate 18 to oppose each blower fan 17 to secure the air circulation.
[0012] In this construction, the operation of the blower fans 17 which are disposed in the central air passageway 15c and disposed in both side air passageways 15a, 15b is respectively controlled, i.e., if the blower fans 17a disposed in the central air passageway 15c are operated, the blower fan 17b disposed in both side air passageways 15a, 15b cease their operation, and vice versa. That is, as shown in Figure 6, the compressor 20, the fan 21 for the condenser and the blower fans 17 disposed in the air passageways are parallel connected with one another, and connected with a power source through a single pole double throw type thermostat switch 22. The common terminal 22c of the thermostat switch 22 is connected to a power source 23, and one of the selecting terminals 22a is connected to the compressor 20, the fan 21 for the condenser and the blower fan 17a disposed in the central air passageway 15c. The other selecting terminal 22b of the thermostat switch 22 is connected to the blower fan 17b disposed in both side air passageways 15a, 15b.
[0013] As to operation of the refrigerated display cabinet, if the temeprature in storage/display compartment 11 exceeds the predetermined temperature, the thermostat switch 22 functions to connect between the common terinal 22c and one of the selecting terminals 22a to operate the compressor 20 and the two fans 17a, 21. Therefore, the refrigeration unit is operated to refrigerate the storage/display compartment 11 due to forced convention of cooled air. That is, the air in compartment 11 is passed through the evaporator 16 due to the operation of the blower 17a (the circulation of cooled air is indicated by a solid arrow in Figures 4 and 5). At that time, the cooled air is forced convention within storage/display compartment 11, thus temperature and humidity in the storage/display compartment 11 could be uniformly maintained.
[0014] On the other hand, if the temperature in the storage/display compatment 11 is below the predetermined temperature, the thermostat switch 22 functions to connect the common terminal 22c to the other selecting terminal 22b to cease the operation of the refrigeration unit and to start up the operation of the blower fan 17b. Therefore, the air in the compartment 11 is forced convection by operation of the fan 17b while passing through the side air passageways 15a, 15b (the flow of air in the compartment is indicated by a dotted line arrow in Figures 4 and 5). As a result, the temperature and humidity in the compartment 11 is uniformly maintained.
[0015] In the above explained display cabinet, if the operation of the refrigerating apparatus is stopped for a long time, the frost on the evaporator melts. Thereafter, when the refrigerating apparatus is started up again, it is feared that air of high humidity which contains defrosting drops flows into the storage/display compartment 11. Thus, the humidity in compartment 11 is drastically increased. to resolve this disadvantage, as shown in Figure 7, a thermostat switch 24 is serially connected to the fan 17a to control the operation of the fan 17a in dependence on the temperature condition in the evaporator 16. That is the thermostat switch 24 energizes the fan 17a, if the tempeature in the evaporator 16 is below the predetermined temperature, and ceases the operation of the fan 17a under high temperature condition in the evaporator 16. Therefore, the fan 17a for the evaporator 16 is not operated, even if the refrigerating apparatus is operated, thereby to prevent the inflow of high humid air into the storage/display compartment 11.
[0016] This invention has been described in detail in connection with the preferred embodiments, but these are examples only and the invention is not restricted thereto. It will be easily understood, by those skilled in the art that other variations and modifications can be easily made within the scope of this invention.
1. A refrigerated display cabinet (1) having a storage/display compartment (11) for
merchandise, and provided with a refrigeration unit for cooling the compartment (11)
and an air circulating mechanism which comprises an air passageway (15) and at least
one blower fan (17), an evaporator (16) of said refrigeration unit being disposed
in said passageway (15) for cooling the air passing therethrough, characterized in
that said air passageway (15) is divided into at least two passageways (15a, 15b and
15c) and said evaporator (16) is disposed in one of said passageways (15c), and at
least one blower fan (17a, 17b) is placed in each air passageway and controlled individually.
2. The refrigerated display cabinet of claim 1 wherein one of said blower fan (17a)
which is placed in the cooling air passageway (15c) is controlled by the temperature
condition in said evaporator (16).