GB2185561A

GB2185561A - Refrigerated display cabinet

Info

Publication number: GB2185561A
Application number: GB08630615A
Authority: GB
Inventors: Franz Fondel
Original assignee: TYLER REFRIGERATION GmbH
Current assignee: TYLER REFRIGERATION GmbH
Priority date: 1986-12-22
Filing date: 1986-12-22
Publication date: 1987-07-22
Anticipated expiration: 2006-12-22
Also published as: GB2185561B; CH661856A5; GB8630615D0

Abstract

A refrigerated display cabinet has a unit comprising a blower 52 combined with a barrier 50 which unit is positioned easily by hand in a channel of the cabinet. To avoid adhering of the unpacked meats to the supporting plates 32, the direction of the blower is selected, such that the refrigerated air flow leaving a wet evaporator 34 first takes-off the heat from the food to be refrigerated across its exposed surfaces, and subsequently passes along the undersides of the plates 32 at a slightly higher temperature, to be finally urged by the blower into the wet evaporator. With the unit removed from the display cabinet cooling is effected by convection (Fig. 1). <IMAGE>

Description

SPECIFICATION Bar of shop assistants with refrigeration by recirculated and circulating air, resp.

The invention relates to a bar for servicing the customers in a shop, whereby an evaporator of a refrigeration plant and at least one blower are used for driving a refrigerated airflow along the evaporator and the food.

A refrigerated display case known from the German Patent no. 3,203,903 comprises a short, vertical front wall at its face, that is, atthat flank, the custo- mers approach; a glass plate inclined from the customers away is connected to that front wall, and they canlookatthefoodlyingintheinteriorofthedisplay case through the glass plate. The foodstuffs are placed on nearly horizontal bottom plates capable of being swung out, and are displayed there, whereby the level of the bottom plates is slightly lower than the lower edge of the inclined glass plate.Aslit-like space slightly narrowing towards the customers extends across the over-all width of the refrigerated display case below the bottom plates, andter- minates as an aperture extending upwards between the front edge of the bottom plates and a baffle, which is fastened to the back of the upper portion of the front wall of the refrigerated display case. The opposite end of the slit-like space turns into a vertical chute, which is formed bytailed membersofthe bottom plates bent upwards, and by a vertical backwall of the refrigerated display case, whereby this backwall is nearly double the heightofthefrontwall.

Aforwardworking plane is mounted for the seller nearthe upper edge ofthis backwall, and upwards its underside limits the vertical chute mentioned-before together, andyet releases an opening towards the upperedgesofthetailed members of the bottom plates.

At least two evaporators- or groups of eva p orators-are established in parallel and juxtaposition within a chuteformed in thisway, and are driven in push-pull, so that alwaysthe one evaporator is in the defrosting phase, and the other evaporator brings aboutthe refrigeration at the same time. As a result the air present in the chute and the airflowing through it, resp., cools down and simultaneously sinks down due to its gravity, and thereby draws the warmer air from the space above the bottom plates, on which the food to be refrigerated have been laid down.The air cooled down enters the narrow, slitlike space beneath the bottom plates, and is passed along the undersides of the bottom plates, and draws-offthe heat downwards through the bottom plates and the food lying on them. Thereafter the air slightly warmed up rises from the slit-like space aroundthefrontendsofthebottom plates along the baffle upwards, and reaches the space above the bottom plates and the food to be refrigerated, from which space it is exhausted towards the evaporator.

The loop of a relativelyslowconvectiveflow caused in this way is quite sufficient for refrigerating a plurality offoodstuffs, such as fruit, vegetables, chocolates, cheeze. This first type of the refrigeration of food in a refrigerated display case is also designated to be a "quiet refrigeration".

One or more blowers, however, can also be provided, and circulate the air, that is, accelerate the refrigerated airflowalong the loop. This secondtype ofthe refrigeration of food in a refrigerated display case is also designated to be a "recirculated refriger ation".

The acceleration of the air driven by the blowers in the loop does not only result in more intense drawing-offthe heat in the evaporator and consequently in an operation at lowertemperatures ofthe air, as compared with the "quiet refrigeration", but it also results in an augmented iceformation onthesurfaces ofthe evaporator, because the accelerated air flow draws-offthe humidity from the food with increased rates.- From this reason the provision ofthe second evaporator subjected to a defrosting phase, while the first evaporator is in the refrigerating phase, i.e. the two evaporators operate in push-pull, appears to be absolutely necessary.

Furthermore it is known that e.g. unpacked meats are said in the German Patent no. 3,203,903 to be deposited in the space of the refrigerated display case at a temperature between 0 and +5 degrees Centigrade, and at a humidity up to 80 per cent. To drawoffthe humidity as little as possiblefrom the displayed, unpacked meats within the display case, the circulating air is refrigerated by evaporating elements comprising surfaces of heat-exchange as large as possible.As a resultofthis measure the difference ofthetemperatures is diminished between the airwithinthe space ofthedisplay case andthe surfaces of the evaporator, and consequently the for- mation of frozen fog on these surfaces. - Together these statements prove that also only one evapora- tor comprising large surfaces, a so-called "wet evaporator" can be used in lieu of both evaporators arranged in juxtaposition, and comprising small surfaces, which operate in push-pull,that is, in the refrigerat- ing and defrosting phase, resp., without a disturbing formation of frozen fog to be expected.

The relatively long path of the refrigerated air leaving the evaporatorthrough the narrow, slit-like space along the undersides of the bottom plates proves to be unfavorable in the "recirculated refrigeration".

For a considerable amount ofthe heat is drawn-off by the heat conduction on said way across the bottom plates likewise from the meats displayed on the bottom plates through their bases, so that the bases accept a lower temperature than the free surfaces of the unpacked meats. If the latter are said to be kept in the range oftemperatures between 0 and + 5 degrees Centigrade, the refrigerated air leaving the evaporator must be of a temperature nearzero degree Centigrade orslightly lower with the result that the bottom plates cool down lowerthan zero degree Centigrade, too. As a result the unpacked meats adhere on the bottom plates due to an ice formation, and must be torn away by seller's hand, while takingoff, whereby leftovers appear often on the bottom plates, which have therefore to be cleaned frequently. They can also be removed, after the blowers were switched-off, that is with a transient to the "quiet refrigeration", whereby the bottom plates reach temperatures above the freezing point after some waiting period.

It is an object of the invention, to provide a barfor servicing the customers of a shop with means making the barsuitableto be refrigerated both in a "quiet refrigeration" and in a "recirculated refrigeration", wherebythe temperature within the space of the food is lower than the temperature ofthe bottom plates, so that the food is prevented from adhering on the bottom plates due to an ice formation in the "recirculated refrigeration".

According to the invention a combination is provided, of a barrier suitable to be easily inserted by hand in the channel system, and of a blower, the direction of drive of which is selected, such that therefrigerated air emanating from the evaporator arrives directly at the free surfaces of the displayed food.

In the "recirculated refrigeration" the long path cf the airflow from the food to be refrigerated along the undersides of the bottom plates up to the input of the evaporator enables to receive an additional quantity of heat in the airflow, so that, when passing the evaporator, it tries to receive the humidity too, and is conducive to preventtheformation offrozenfog on the surfaces of the evaporator.

An exemplary embodiment of the invention is illustrated in the drawings and explained inthefollowing specification in more detail. There is shown in Figure 1 a bar for servicing customers of a shop being operated by means of a "quiet refrigeration ", as known per se; Figure2the bar of Figure 1, in whichthecombina- tion ofthe barrier and blower has been inserted in accordance with the invention, whereby the direction ofthe drive of the blower is also selected accord ingtothe invention; Figure 3 a side view of the combination of Figure 2 in more detail for illustrating the separation between the pressure and suction chambers ofthe blower; Figure 4 a schematic view ofthe combinations of barriers and blowers, as connected together.

A part-sectional view of a bar 10 for servicing customers of a shop is illustrated in Figures 1 and 2, and is established on a few feet 12 in butcher's or baker's shop, in a food store or in a similar shop. It comprises a troughlike, double-walled frame 16 filled with an insulating material 14, and having a short, vertical frontwall 18 at its front, which the customers approach, and a considerably higher,vertical backwall 20 at its back. A horizontal working platform 22forwrapping upthefood by the seller is mounted on the backwall 20 oftheframe 16, whereby a few supports 24 extend with inclination from thefront edge of the working platform 22 upwards, to support a horizontal operating desk 26.At the front an inclined glass plate 28 suitable to be easily removed by hand, the lower edge ofwhich substantially extends in the level of the upper edge of thefrontwall180ftheframe16,abutsagainstthis operating desk 26, on which the wrapped commodities are put by the seller, and, if desired, the money ofthe customers is laid down.

Supports provided with passages (not shown) are mounted within the trough-like frame 16 adjacent the front wall 18 and with spacing from the backwall 20, whereby a few bottom plates 32 can be laid on the supports 30 in a mutual close juxtaposition afterthe removal ofthe glass plate 28 by hand; the seller puts the food to be displayed on the bottom plates after the insertion of the glass plate 28, and he grasps through between the supports 24.

An evaporator 34 of a refrigeration plant provided with a plurality of air channels (notshown), and screened by a cover plate 36 against the space 38towards the front, where the food is preserved, is between the support 30 at the back and the backwall 20 oftheframe 16.

The cover plate 36 also rests upon the support 30 at the back, and terminates above for leaving a horizontal slit 40 with spacing from the underside ofthe working platform 22.

After the design of the present bar 10 for servicing the customers of a shop has been specified, the attention is drawn to its "quiet refrigeration", as known per se, whereby the course of the airflow is shown byarrows44(Figure 1).

In the operation of the refrigeration plant, while the liquid refrigerant is led to the evaporator 34, the air cooling down in the air channels ofthe evaporator 34 dropstothebootom42ofthetroughlikeframe 16 through the passages of the support 30 at the back due to its gravity, whereby the warmer air is drawn into the evaporator34through the slit40from the space 38 comprising the food. The mass of the refrigerated, heavy airfinally reaches the undersides of the bottom plates 32, which remove the heatfrom the food lying on them through their areas of deposition due to the heat convection. Finally the refrigerated air entersthe space 38 by rising up through the passages ofthe support 30 atthefront, and then re moves the heat th rough the exposed surfaces ofthe food.The airwarmed up by the food rises again and is sucked in by the evaporator 34through the sI it 40.

In the "quiet refrigeration" the speed ofthe airflow substantially depends on the difference ofthe temperatures between the air entering the upper end of the evaporator 34 and the air leaving the lower end of the evaporator 34through the passages of the sup- port 30 at the back, and is consequently greatest short after switching-on the refrigeration plant. Subsequentlythis speed decreases down to a small, but constant value, whereby the temperature, however, cannot sink down to the freezing point ofthe water.

As one can see from Figure 2, the bar 1 Oforservic ing the customers of a shop can also be driven buy a "recirculated refrigeration". For this purpose the combination of a barrier 50 and blower 52 is inserted by few movements of the hand into the channel system guiding the airflow, whereby the direction of the drive of which blower is selected, such thatthe flow ofthe refrigerated air leaving the evaporator 34 immediately reaches the free surfaces of the food to be refrigerated, thus is the space 38 through the slit 40, as it is also indicated by arrows 56. The refrigera ted air draws off some quantity of heat from the food within the space 38 with the resultthatthe air, which is driven from the space 38 through the passages of the support 30 at the front bel ow the bottom plates 32, is warmerthan that air entering the space 38. The bottom plates 32 very fast accept the temperature of thiswarmerairsliding alongtheirundersidesbythe heat convection, and normally remains on a temperature above the freezing point of the water, so that the food is prevented from adhering to an ice formation.

According to the invention the barrier 50 ofthe channel system combined with the blower 52 is hinged on a rail 58 ofthe support 30 at the back as airtight as possible, so that the own weights of the bar 50 and ofthe blower52 press down a pluralityof sealings 54 extending around the periphery ofthe underside of the barrier 50 against the bottom plates 32, as it could be seen from Figures 3 and 4.The continuous barrier 50 extends between the two sidepanels 46 across the width ofthe bar 10, so that it effectively disrupts the convective air flow of the "quiet refrigeration". As mentioned before, the blower 52 arranged in the middle of the barrier 50 is driven in that direction, in which the airflow causing the "recirculated refrigeration" is opposite to that of the "quiet refrigeration".

Preferably a protective plate 60 is mounted in a predetermined distance from the barrier 50, and preventsthe interior of the blower 52 from receiving droplets of water, which can deposite by a condensation atthe undersides of the bottom plates 32. The same istruefor liquids, which leak between a pair of juxtaposed bottom plates 32. Furthermore the flow rate of the airthrough the blower 52 can be limited in a suitable manner by adjusting the space between the top of the barrier 50 and the underside of the protective plate 60.

As Figure 4 shows furthermore, the blowers 52 of a pair of bars 10 for servicing the customers of a shop established in juxtaposition, or of two portions of such a bar 10 closed bya pairofside-panels46 laterally, can easily be connected in common through a plug connection 62 to the power supply.

Claims

1. Barforservicing the customers of a shop com- prising an evaporatorfed bya refrigerantfrom a refrigeration plant, and refrigerating an airflow through a channel system of a closed loop, in which the refrigerated airflow is guided from the evapora toroverthefoodto be refrigerated and is fed backto the evaporator, and at least one blower for accelerating the refrigerated air flow, wherein a combination of a blower and a barrier is used, which is suitable to be inserted by hand easily into the channel system, and wherein the direction of the drive of the blower is selected, such that the refrigerated airflow leaving the evaporator is immediately supplied to the free surfaces of the food to be displayed.

2. Bar according to claim 1,wherein the blower is centrally mounted in a recess of the barrier present in the form of an elongated, cornered clamping ridge, which is provided with sealings at its pivot and at its bottom.

2. Bar according to claim 1,wherein the blower is mounted in a recess ofthe barrier being shaped as an elongated, cornered clamping ridge, which is provided with sealings at its pivot and at its bottom.

3. Bar according to claim 1 or2,whereinaprot- ective plate is mounted in a predetermined distance overthetop of the barrier for protecting the blower against dropping liquids, and limits the flow rate of the air through the blower.

Amendmentsto the claims have beenfiled, and have the following effect: (a) Claims 1 and 2 above have been deleted or textually amended.

(b) Newortextuallyamendedclaims have been filed asfollows:

1. Barforservicingthe customersof a shopcom- prising an evaporator fed by a refrigerant from a refrigeration plant, and refrigerating an airflow, and comprising a closed flow route, in which the refrigerated airflow is guided from the evaporator over the food to be refrigerated and is fed backtothe evaporator, wherein a barrier carrying a blower is suitable to be inserted by hand in the flow route, and to be arranged in the flow route, and whereinthe direction of the drive ofthe blower is selected, such that the refrigerated air leaving the evaporator arrives at the free surfaces of the displayed food immediately.