EP0769262A2 - Chest freezer - Google Patents

Abstract

The freezer cabinet has at least one storage space (39) with cold air inlets (18) and outlets (19) incorporated in its opposing sidewalls, fitted with a top cover (11) incorporating at least one transparent panel (27,28). This is positioned at a sufficient height above the air inlets and outlets to provide a still air volume (42) above the cold air circulation path (41) between the inlet and outlet openings.

Description

The invention relates to a freezer with a cooling space accessible from above, which is cooled by means of circulation cooling.

Frozen goods are stored and offered in stores in freezers accessible from above, in which they are kept at freezing temperature. Freezer chests with so-called "silent cooling" are known, in which cooling bodies are arranged on the side walls of the cooling room, so the cooling of the cooling room takes place only from the cooling room sides. The cooling effect is lowest where the greatest cold losses occur due to heat radiation, namely in the middle of the opening of the cooling room. It is therefore very difficult to maintain a sufficiently low temperature for the frozen goods in the middle of the opening.

The ambient air constantly brings moisture into the refrigerator, which is on the goods, the walls and the Heat sinks condensed and iced up there. This reduces the cooling capacity and causes further energy losses. In addition, the icing of the heat sinks requires frequent defrosting.

For these reasons, especially in freezers with large openings, the cooling space is cooled by means of circulation cooling. The cold air enters the cold room through a cold air inlet in the cold room wall. On the opposite wall of the cold room there is an air outlet through which air is drawn in and fed to an air cooling device which generates the cold air. The cold air flowing at the top of the cold room forms an invisible curtain against the ambient air and cools the cold room from above, i.e. exactly where the greatest cold losses occur. Ambient air is taken along by the cold air flow, which is why no ambient air and no moisture get into the cold room. The warm ambient air constantly entrained by the cold air has to be cooled to freezing temperature, which requires a lot of cooling energy. The moisture of the cold air condenses on the air cooling device, which therefore often has to be defrosted using heating energy. Outside of business hours, to reduce energy losses, thermal covers are placed on the freezers that do not allow a view or access to the frozen goods.

The object of the invention is to provide a device for substantially reducing the energy consumption of a freezer.

This object is achieved according to the invention with the features of patent claim 1 or 19.

In the freezer according to the invention, the cooling space is covered with a cover which projects so high above the cold air inlet that it encloses a still air volume above the cooling flow between the cold air inlet and outlet. This standing air volume forms an air cushion above the cooling flow, which on the one hand has a heat-insulating effect and on the other hand prevents the cold air from coming into contact with panes of the cover hood. As a result, the panes are kept at almost ambient temperature so that no condensate is deposited on their outside.

When the cover that seals off the ambient air is closed, no moisture gets into the cooling air circuit. Significantly less moisture condenses on the air cooling device, namely the evaporators of the refrigerant circuit, so that defrosting of the air cooling device also has to be carried out much less frequently. Experiments have shown that in a freezer with a cover, in which the lid is only opened occasionally, the air cooling device ices up about ten times slower than without a cover.

The cover hood has at least one cover designed as a transparent disc, through which the frozen goods can be seen from the outside without opening the cover. To remove frozen goods, the lid is opened briefly, so that an exchange of air from ambient air with the air inside the cover is only very rarely possible. Even if the lid is Removal of frozen goods is opened, the standing air volume is essentially retained because it is colder than the ambient air and therefore does not rise.

The cover gives the customer the impression that the frozen goods are stored carefully and well protected in the freezer and are not exposed to unlimited, random access. The frozen goods appear more valuable.

The walls above the cold air inlet and outlet are opaque and typically pulled up to the lid. The walls of the cover can also be designed as transparent panes. This means that the view of the frozen goods is just as good as that of a freezer without any cover.

Each disc is preferably arranged a minimum distance of 5 cm above the cold air outlet. This ensures that each inside of the pane is adjacent to the warm, resting air volume and not to the cold air and therefore cannot fog up.

The panes of the cover, which is transparent to visible light, and the walls of the cover hood can be provided on the inside with a coating reflecting the heat radiation. This significantly reduces heat radiation into the cold room. At the same time, the uncoated outside absorbs the heat radiation coming from the room. As a result, the cover or the covering hood remains heated and condensation is prevented.

The cover of the cover hood is preferably designed as a sliding door, which, in contrast to pivoting doors, causes only slight air turbulence when opening and closing the door and there is only a very small amount of exchange of ambient air and cooling air or static air volume.

The cover can be an integral part of the freezer and firmly connected to the cold room walls. However, the cover can also be designed as a whole to be removable from the cooling space, so that it is more accessible for easier filling, maintenance or cleaning.

The cover can be cuboid or single or double desk-shaped. In the case of the desk-like cover hood in particular, a protruding writing medium for attaching marking and advertising boards can be arranged at the highest or another point on the cover hood.

The cover preferably has an outside air inlet and a higher outside air outlet, a heating device being arranged in the area of the inlet, from which inflowing outside air is heated, which then flows along the inside of the cover to the outside air outlet. The air flowing in through the outside air inlet is heated at the heating device, thereby becoming lighter than the surrounding cooler air of the standing air volume, rises to the higher-lying outside air outlet and leaves the cooling chamber again through the outside air outlet. With the help of the heating device, a thermal air flow is generated along the lid. The heated transparent lid heated so that it almost reaches room temperature. As a result, a condensation of moisture on the outside of the pane of the lid can be prevented even in the case of high atmospheric humidity of the outside air, so that even under these circumstances the view of the goods inside the refrigerator is always guaranteed and cannot be hindered by fogging of the panes. The air flow along the inside of the cover has a low flow rate, so that the standing air volume enclosed by the cover hood is not significantly influenced.

The heating device can be designed as a lighting device which on the one hand illuminates the cooling space and on the other hand heats the inflowing outside air.

The lighting device can have a reflector which reflects the light in the direction of the cooling space and at the same time forms a heating element. The light is directed by the reflector exclusively onto the refrigerator compartment, so that a person standing next to the freezer cannot be blinded by the lighting device. The refrigerated goods in the cold room are therefore clearly visible. At the same time, the reflector absorbs heat radiation from the lighting device, so that the air flowing into the lighting device is heated on the side of the reflector facing away from the lighting device and flows from there to the outside air outlet. By absorption of the heat radiation component from the light source, light in the visible range (cold light) is preferably radiated into the cooling space, which minimizes the heat input into the cooling space.

The lighting device is preferably a gas discharge lamp, which is enclosed by an elongated housing. The housing serves as a support or as a handle for one person with the lid open and at the same time protects the lighting device from damage when filling or removing refrigerated goods from the cold room.

The cover provided with a heating device is preferably of single or double-console design. The outside air inlet is a longitudinal opening at the lower end of the pent roof, and the outside air outlet is a longitudinal opening arranged in the region of the upper end of the pent roof.

In a second solution according to the invention, a cover is provided for retrofitting an open-top freezer with circulation cooling, the transparent cover of which is arranged so high above the cooling flow that a still air volume forms below it. For conventional freezers, this creates the possibility of retrofitting an all-day cover that ensures energy savings, better protection, good visibility and easy accessibility of the frozen goods.

Exemplary embodiments of the invention are explained in more detail below with reference to the drawings.

Fig. 1

eine perspektivische Ansicht einer Gefriertruhe mit einer doppelt pultförmigen Abdeckhaube und einer quaderförmigen Abdeckhaube an einer Stirnseite der Gefriertruhe,

Fig. 2

einen Querschnitt entlang der Linie II-II der Fig. 1,

Fig. 3

einen Querschnitt entlang der Linie III-III der Fig. 1,

Fig. 4

eine perspektivische Ansicht eines zweiten Ausführungsbeispiels mit einfach pultartiger Abdeckhaube,

Fig. 5

einen Querschnitt einer Gefriertruhe eines dritten Ausführungsbeispiels mit einer Heizvorrichtung zur Erwärmung einströmender Außenluft, und

Fig. 6

einen Querschnitt der als Beleuchtungsvorrichtung ausgebildeten Heizvorrichtung.

Show it:

Fig. 1

a perspective view of a freezer with a double desk-shaped cover and a rectangular cover on one end of the freezer,

Fig. 2

2 shows a cross section along the line II-II of FIG. 1,

Fig. 3

2 shows a cross section along the line III-III of FIG. 1,

Fig. 4

2 shows a perspective view of a second exemplary embodiment with a simple desk-like cover,

Fig. 5

a cross section of a freezer of a third embodiment with a heating device for heating incoming outside air, and

Fig. 6

a cross section of the heating device designed as a lighting device.

In Fig. 1 a freezer is shown, which consists of a rectangular elongated chest tray 10, the top of which is covered by covers 11, 12. While a cuboid cover 11 is provided on one end face of the chest trough 10, the remaining part of the chest trough 10 is covered by a double-pod-shaped (roof gable-like) cover hood 12. The chest trough 10 and the cover hoods 11, 12 together form an airtight space from which no cooling air can escape or into which no ambient air can penetrate.

2 shows a cross section of the freezer with the cuboid cover 11. The chest trough 10 consists of hollow side walls 15, 16 and a likewise hollow bottom wall 17. The cavities of the side and bottom walls 15, 16, 17 are connected to one another so that they form a U-shaped air duct. The U-shaped side and bottom walls 15, 16, 17 surround an upwardly open cooling space 39. At the upper end of one side wall 15 there is a cold air inlet 18 towards the cooling space 39, and on the other side wall 16, the cold air Inlet 18 at exactly the same height, a cold air outlet 19 is provided.

In the bottom wall 17, a blower 21 is arranged transversely to the longitudinal axis of the chest trough 10, which sucks in air through the cold air outlet 19 from the cooling chamber 39 and blows out through the cold air inlet 18 into the cooling chamber 39. Adjacent to the blower 21, an evaporator 22 of a refrigerant circuit, not shown, is arranged in the bottom wall 17 as an air cooling device and cools the air conveyed by the blower 21 as it passes through the evaporator 22. Immediately next to the evaporator 22, a heater 23 is arranged, which serves to heat and defrost the evaporator 22 when the circulating cooling air is too iced up due to condensation of moisture. The chest trough 10 stands on a base 25 which can contain further units.

The cover 11 is formed laterally by vertical double glass panes 26 and at the top by two horizontal glass sliding doors 27, 28 which are offset in height from one another and which are transverse to the longitudinal axis of the chest freezer are slidable. The glass panes 26, 27, 28 are framed by frame strips 29 and held together.

3 shows the chest trough 10 with a second cover 12 which is adjacent to the first cover 11. The second covering hood 12 is formed by vertical, double-glazed side walls 30 and glass sliding doors 31, 32 which are inclined slightly upwards towards the center of the chest. They can be moved in the longitudinal direction of the freezer. The glass walls 30, 31, 32 are held or guided by frame strips 33, 34, 35, 36. The upper edge-side frame strips 34, 35 and the upper middle frame strip 36 have guides for the sliding doors 31, 32, of which two adjacent ones are each offset in height from one another.

On the upper middle frame bar 36, a sign carrier 37 with a triangular cross section is provided, on which advertising, information and price signs can be attached on both sides.

In both embodiments, the space of the chest trough 10 enclosed by the side walls 15, 16 and the bottom wall 17 is the cooling space 39, in which frozen goods 40 are stored. In the upper area of the cooling space 39, at the level of the cold air inlet 18 and the cold air outlet 19, no frozen goods are stored so as not to impede the cold air flow 41 flowing in the direction of the arrow from the cold air inlet 18 to the cold air outlet 19.

The cold air flowing from the cold air inlet 18 into the cooling space 39 has a temperature of approximately -30 ° C. and heats up by absorbing heat, for example heat from the frozen goods 40, to approximately −20 ° C. upon entry into the side wall 16 through the Cold air outlet 19. Subsequently, the heated air flows through the side wall 16, sucked in by the blower 21, to the evaporator 22, where it is cooled again to below −30 ° C., and finally to the cold air inlet 18 and into the cooling space 39 to pour. The flow rate of the cooling flow 41 is 0.3 to 0.8 m / sec.

Above the cooling flow 41, a stationary air volume 42, 42 ′ is formed, which has a significantly higher temperature than the air of the cooling flow 41 and is delimited to the side and upwards by the walls of the covering hood 11, 12. No significant air exchange takes place between the stationary air volumes 42, 42 'and the cooling flow 41. The air volumes 42, 42 'bring about good thermal insulation of the cooling flow 41. The stationary air volume 42, 42' does not have to be absolutely standing, it is sufficient if it moves much more slowly than the air of the cooling flow 41. At no point in the resting air volume 42.42 ', the air speed is greater than 0.2 m / sec., Preferably not greater than 0.1 m / sec.

The lower ends of the side windows 26, 30 are arranged at a distance A above the cold air inlet 18. Given the present distance A of approximately 10 cm, it is ensured that the lower end of the side windows 26, 30 also adjoins the stationary air volume 42, 42 ' and therefore no thermal bridge arises or the windows 26,30 can mist up.

The almost airtight covering of the chest trough 10 prevents the supply of air moisture into the cooling air circuit. The icing of the evaporator 22 therefore proceeds very slowly, so that defrosting of the evaporator 22 with the aid of the heater 23 only has to be carried out extremely rarely, namely approximately once a week, depending on the circumstances.

The glass panes of the walls 26, 30 and the sliding doors 27, 28, 31, 32 are provided on the side facing the interior of the chest with a heat-reflecting coating, which largely reflects the heat radiation. The panes heat up due to the absorption of room heat radiation, but radiate practically no heat inside. As a result of the temperature of the air volumes 42, 42 ′ adjoining the inside of the panes and the self-heating of the glass panes by heat absorption, the outside temperature of the panes is high and fogging of the panes is prevented. The coating is e.g. a tin oxide coating that reflects approx. 70% of the incident long-wave IR heat radiation.

The panes of the cover hoods 11, 12 are made of glass, but can also be made of other transparent materials, for example plexiglass.

The covers 11, 12 are firmly connected to the chest trough 10, for example by screwing, but can also be removed from the chest trough 10 for maintenance, repair or care purposes if required.

FIG. 4 shows a second embodiment of a freezer, in which a cover 51 designed in the form of a console is fastened on the chest tray 50. A label holder 52 is provided at the upper rear end of the desk-shaped cover 51.

5 shows a third embodiment of a freezer in cross section, which has a double-hood-shaped cover hood 60, the walls of which are formed by side walls 61, 62 and sliding glass doors 63, 64. The side walls 61, 62 each have at their upper ends a slot-like outside air inlet 65 running horizontally in the longitudinal direction. At the upper end of the side walls 61, 62 in the area of the outside air inlets 65, a lighting device 67 designed as a heating device is fastened within the enclosed space, which also extends in the longitudinal direction of the cover hood 60 and is arranged in the area of the outside air inlet 65. At the upper end of the sliding doors 63, 64 forming the roof of the covering hood 60 there is a longitudinally extending outside air outlet 66 through which the heated outside air flows out.

The lighting device 67 shown in FIG. 6 has a fluorescent tube 68 which is enclosed by a tubular housing 69, approximately half a tube circumference being designed as a transparent protective glass 70 and the second half of the circumference as a reflector 71. The reflector 71 is arranged in such a way that it reflects the light radiated upward from the fluorescent tube 68 downward into the cooling space 39, so that the goods 40 in the cooling space 39 are well illuminated. At the same time, the reflector 71 absorbs heat radiation of the fluorescent tube 68 and emits it to the outside of the lighting device 67.

The lighting device 67 is fastened to the respective side walls 61, 61 with suitable fastening devices. When the sliding doors 63, 64 are opened, they remain in their position, so that good lighting of the cooling space 39 is ensured even when the cover 60 is open.

The housing 69 of the lighting device 67 protects the fluorescent tube 68 against unintentional damage when removing or filling up refrigerated goods 40. An operator can also rest on the housing 69 of the lighting device 67 with one hand without the fluorescent tube 68 being damaged in the process.

When the lighting device 67 is switched on, the reflector 71 of the lighting device 67 is heated by its thermal radiation. The reflector 71 gives off the heat absorbed in this way and heats the air surrounding it. The heated air has a lower specific weight than the surrounding air of the standing air volume 42 ″, so that an air flow 72 of heated air rises along the sliding glass doors 63, 64. The heated air finally flows out of the cover 60 through the outside air outlet 66, while new, unheated outside air flows in through the outside air inlet 65, which in turn is heated by the lighting device 67.

The glass panes are caused by the heated air flowing along the inside of the sliding glass doors 63, 64 of the sliding glass doors 63, 64 to a temperature which approximately corresponds to the temperature of the outside air. As a result, condensation of outside air humidity on the outside of the sliding glass doors 63, 64 is ruled out even when the outside air is very humid. The view through the panes of the closed sliding glass doors 63, 64 of the refrigerated goods 40 is therefore always free.

The standing air volume 42 ″ is not set in motion by the air flow along the inside of the sliding glass door, so that its insulating effect is not disturbed.

Claims (20)

Freezer with at least one cold space (39) accessible from above and cooled by a circulation cooling system, in the wall (15, 16) of which a cold air inlet (18) and a cold air outlet (19) are provided,
characterized,
that a covering hood (11, 12, 51, 60) with at least one cover (27, 28, 31, 32, 63, 64) designed as a transparent disc is provided above the cooling space (39), which is at such a height compared to the cold air Inlet (18) and the cold air outlet (19) is arranged so that there is an essentially still air volume (42, 42 ') above a cooling flow (41) between the cold air inlet (18) and the cold air outlet (19). forms. Freezer according to claim 1, characterized in that the cover (11, 12) has transparent disks (26, 30) as walls. Freezer according to claim 1 or 2, characterized in that each disc (26-28,30-32) of the cover (11, 12, 51) is a distance A higher than the cold air inlet (18), A being at least 5 cm. Freezer according to one of claims 1-3, characterized in that at least some of the disks (26-28,30-32) of the cover (11, 12) are attached to their Have a reflective coating on the inside. Freezer according to one of claims 1-4, characterized in that the lid is a sliding door (27,28,31,32). Freezer according to one of claims 1-5, characterized in that the cover (11, 12) can be removed from the cooling space (39). Freezer according to one of claims 1-6, characterized in that the covering hood (11) is cuboid, the height above the cold air inlet (18) preferably being 5 to 30 cm, in particular 10 to 15 cm. Freezer according to one of claims 1-6, characterized in that the cover (12) has a desk-like shape, the height being at least 5 to 30 cm, preferably 10 to 15 cm. Freezer according to claim 8, characterized in that the cover has vertical side walls (30) and sloping sliding doors (31, 32) above as the roof wall. Freezer according to one of claims 1-9, characterized in that the cover (12) has an upstanding label holder (37) on its upper side. Freezer according to one of claims 1-10, characterized in that the covering hood (60) has at least one outside air inlet (65) and at least one higher outside air outlet (66), and
that in the area of the outside air inlet (65) a heating device (67) is arranged, from which the inflowing outside air is heated, which flows along the inside of the cover to the outside air outlet (66). Freezer according to claim 11, characterized in that the heating device (67) is a heat-emitting lighting device. Freezer according to claim 12, characterized in that the lighting device (67) has a reflector (71) arranged in the outside air flow (72), which reflects the light in the direction of the cooling space (39) and at the same time absorbs the heat radiation impinging on it. Freezer according to one of claims 11-13, characterized in that the heating device (67) is arranged above the cold air inlet (18) or cold air outlet (19) of the cooling space (39). Freezer according to one of claims 12-14, characterized in that the lighting device (67) is a gas discharge lamp (68). Freezer according to claim 15, characterized in that the gas discharge lamp (68) is enclosed by an elongated housing (69). Freezer according to claim 16, characterized in that the housing (69) forms a handle. Freezer according to one of claims 11-17, characterized in that the outside air inlet (65) in the area of the lower end of the desk roof (63, 64) of the desk-like cover (60) and the outside air outlet (66) in the area of the top end of the desk roof ( 63,64) is arranged. Cover for retrofitting an open top freezer according to the preamble of claim 1, characterized in that the cover (11, 12, 51, 60) has at least one cover (27, 28, 31, 32, 63, 64) designed as a transparent disc which, when the cover (11, 12, 51, 60) is placed on the cooling space (39), is arranged at such a height in relation to the cold air inlet (18) and the cold air outlet (19) that there is a static air volume ( 42,42 ') above a cooling flow (41) between cold air inlet (18) and cold air outlet (19). Covering hood according to claim 19, having the features of one of claims 2-18.

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