US3224219A - Refrigeration system for display cabinets, food storage cabinets, and the like - Google Patents

Description

2 Sheets-Sheet l L/u/a mea/v F500i/[RY CONDEMSOR CLOCK COMPRESI A. BOREN DISPLAY CABINETS, FOOD STORAGE CABINETS, AND THE `LIKE .lvvenc Hdam 5eme/r.

IGERATION SYSTEM FOR Dec. 21. 1965 Filed May 16, 1962' @l r com 4m Jl( ORAGE A. BQREN REFRIGERATION SYSTEM FOR DISPLAY CABINETS. FOOD ST CABINETS, AND THE LIKE 2 Sheets--SheefI 2 Filed May 16, 1962 INVENTOR.

Haam Bore/7.

United States 'Patent O 3 224 219 REFRIGERATION SYTEIVI FOR DISPLAY CABI- IEK'IS, FOOD STRAGE CABINETS, AND THE Adam Boren, 300 Deal Lake Drive, Asbury Park, NJ. Filed May 16, 1962, Ser. N0. 195,297 7 Claims. (Cl. (i2-27S) p This invention relates to a novel system of refrigeration for display cabinets, food storage cabinets, and the like, remotely located, and with widely different temperature requirements.

In accordance to the present invention a central unit supplies air through two lines to the remote cabinets: one supply line being cold, as below 20 P.; the other warm, as above |80 F. `The air supplied in insulated ducts at relatively high velocity and pressure. The air, further, is clean and dehumidied, and reaches each display or storage cabinet at the same two supply temperatures, regardless of the size or required temperature condition of the cabinet.

Each refrigeration cabinet contains a novel air mixing and depressurizing chamber that automatically maintains the local temperature condition to which it is preset, continuously and ata constant level. The warm (-|-80 F.) and cold (-20 F.) air supplies are mixed in each individual cabinet in accordance to its intended use and required temperature. Such temperature presetting attains a continuous constant condition; temperature variations being eliminated as no defrost cycling is needed in the invention cabinets hereof. There thus results no deterioration of frozen foods, and a minimum of shrinkage of meats and produce.

The invention system greatly simplifies installation of multiple types of display cabinets and storage cabinets, as in a supermarket; as well as materially reduce its cost. Condensate drains and electrical connections for local fan motors and defrost heaters are eliminated in the invention refrigeration cabinets and system. Simple insulated underoor ducts for the two system outgoing low and higher temperature air supply, referred to above, and one for the return (used) air from the cabinets, are located in the store region for such cabinets. The cabinets may be positioned at any point along the supply du-cts,

or simple extensions thereof, regardless of cabinet types or their requisite temperatures.

The operating temperature of each cabinet of the invention is adjustable and presettable over a wide range of temperatures. Thus, any such cabinet may be readily changed as to its operating use and temperature state. This permits flexibility of installation, as well as simplification of cabinet manufacture and stocking. An improved usable volume eiiiciency results in the novel improved cabinets hereof as no coils or blowers are used therein. Further, there is no restriction as to the .physical size or shape of such cabinets; as the conventional evaporator cooling coils are not incorporated therein.

The overall refrigeration system hereof is cheaper to manufacture, install, operate and maintain than those of the prior art. The central unit efiiciently provides the cleaned, dehumidiiied air at both the cold (e.g. less than 20 F.) and warm (eg. above +80 F.) temperatures; and reprocesses the returned (used) air. The central unit forces the air through ducts at relatively high pressure and velocity. Economical insulated distribution `ducts are used, Vas the refrigerant (c g. Freon) is not transported to the remote cabinets.

Finally, relatively large savings result in the simplified refrigeration cabinets hereof. The air mixing and depressurizing chambers are standardized. Location of the cabinets in the store, and their individual temperaice ture setting, are fully flexible. Ready change of product usage, temperature and cabinet arrangement is feasible with my invention system.

The above and other features, advantages and objects of the present invention will become more apparent from the following description of an exemplary embodiment thereof, illustrated in the drawings, in which:

FIG. 1 is a diagram of the invention refrigeration system. p

FIG. 2 is an enlarged diagrammatic showing of the exemplary central refrigeration air supply unit of the invention.

FIG. 3 is a cross-sectional View through a display cabinet hereof.

Referring to FIG. l, the central refrigerationair supply unit 15 provides air at low temperature (eg. below -20 F.), throughoutput duct 16; and air at higher temperature (eg. above E), through duct 17. The air is supplied cleaned and dehumiditied, and under a relatively high pressure and velocity that is optional for particular systems. The low and high temperature air under pressure is supplied to and through the cabinet areas in the .market bydistribution ducts 20 and 21. These distribution ducts are economically made of fiber glass, cork, Styrofoam, etc.

Theairducts 20, 21 are connected to the individual display cabinets and/ orstorage cabinets 25 through respective branch ducts. The return or used air from thecabinets 25 is returned tocentral unit 15 throughbranch ducts 26 feeding intoreturn distribution duct 27. Duct 27 couples to thereturn input duct 28 ofunit 15. Thedistribution ducts 20, 21 and 27 are directed in any desired paths, as will be understood by those skilled in the art. The threebranch ducts 22, 23 and 26 for each cabinet are suitably coupled to the distribution ducts byrespective tape 30, 31 and 32.

General operation of system The air returning vfrom thecabinets 25 throughreturn distribution ducts 27 feeds into secondary blower fan chamber 35. The returned air is thereupon propelled along connectingducts 36, 37, 38 to one (40) of two alternated dehumidifying-precooling-purifyingchambers 40, 40'. The .precooled dry air is conducted thruduct 41 into primaryblower fan chamber 42. It is forced under high pressure and velocity through an evaporatorcooling coil unit 43; and a portion independently through aheating coil unit 44.

The high pressure cold air atoutput duct 16 is at below 20 F. in the exemplary system; the warm air at line 17, at above |80u F. Different installation requirements may indicate somewhat different temperature values. The air supply is therefore at relatively highpressure and flows at relatively high velocity through thedistribution ducts 20, 21 to thevarious utilization cabinets 25. The air from thecabinets 25 returns throughducts 27 to complete the circuit. Details of the operation and components ofcentral unit 15 will be set forth hereinafter in connection with FIG. 2.

While one of the two dehumidifying-precooling-purifyingchambers 40, 40' is in basic operation, as described hereinabove, the other one is being defrosted. Thus the `chamber unit 40 in FIG. 1 is shown in its defrost phase,

whileunit 40 is in normal operation. Atime clock control 45 is used to predeterminedly cycle the operationdefrost phasing of theunits 40, 40', `as detailed hereinafter. Suitable motorized dampers (see FIG. 2) are used to redirect the air from chamber 35 intounit 40 or 40', and from the output of units 40' or 40' intochamber 42.

Adefrost chamber 46 connects to an outside-air intake duct 47, and contains ablower section 48 andheater section 49. In the phase shown in FIG. 1, the defrost heated-air fromchamber 46 is directed through its output duct 50 and duct 51 intounit 40. During this cycle, heated air fromchamber 46 defrosts accummulations of frost on the evaporator coils in unit 40', and exits throughduct 91 to the outside air. Whenunit 40 is switched into the defrost cycle connection withchamber 46, the defrosted alternate unit 40' replacesunit 40 between secondary blower fan chamber 35 and primaryblower fan chamber 42. This recycling or alternation ofunits 40 and 40 between their operational and defrost phases is initiated by theclock control 45, on a preset automatic basis; as for 30 or 60 minutes, or other interval.

The evaporator coil cooling sections inunits 40, 40' and 43 are of conventional construction. A refrigerant gas, as Freon, as passed through these coils. Acompressor 55 compresses the Freon gas from thereturn section line 54, in its cylinder 56. The compressed hot (Freon) gas Hows intooutput line 57 ofcompressor 55 in a conventional manner. Thehot gas output 57 ofcompressor 55 is by-passed en route to thecondenser 58 in order to extract and utilize a substantial portion of its contained heat incentral unit 15. Such heat utilization reduces the power requirement of thesystem 15, thereby improving its overall eciency. The somewhat cooled compressed Freon returns fromunit 15 to input line 59 ofcondenser 58; and thereupon enters aliquid Freon receiver 60 throughline 61 The liquid refrigerant (Freon)line 64 supplies the refrigerant to the several evaporator coolings coils of thesystem 15, as at 40, 40', 44.Liquid line 64 is fed fromreceiver 60 through preset valve 62 andconnection line 63. The indicated compressor, condenser and receiver are of conventional construction and in the exemplary embodiment use Freon as the refrigerant. While the heat utilization by-pass tounit 15 betweenoutside lines 57 and 59 is desirable, it is to be understood that the heating requirement atchambers 44 and 49 'may be otherwise supplied. Thus electrical resistive heating may be used to supplement or supplant that of such bypass.

The evaporator cooling coils ofchamber unit 42 and of the dehumidifying-precooling-purifyingunits 40, 40' are supplied in parallel from the liquid (Freon)line 64. Thecoil 43 is fed by a connectingline 65 through alocal expansion valve 66, with theline 67 for return to thesuction line 54. The evaporator soil set of unit 4l) is supplied byline 70 through a local expansion valve 71, and a return line 72; and that ofunit 40 throughline 73, local expansion valve 74, and returnline 75.

Theevaporator cooling coil 43 ofchamber 42 operates on air that is dry, and therefore does not frost up.Coil 43 is directly connected acrosslines 54, 64 continuously. Theunits 40 and 40' are regularly cycled or alternated in their system operation; being defrosted when out of circuit. Towards this end electrically operatedsolenoid valves 76 and 76 are respectively inserted inlines 70 and 73 to the evaporator coils inunits 40 and 40'.Valve 76 is normally open; valve 76', normally closed. These are alternately cycled, electrically, bycontrol clock 45, admitting liquid Freon tounit 40 or 40' only while it is in its operating phase; and shutting off such flow when in its defrost phase.

The heating by-pass arrangement forheating coil 44 inunit 42 andcoil 49 inunit 46 is in series connection between compressedhot gas lines 57 and S9. These are connected by line 77 fromline 57 tocoil 49;line 78 betweencoils 49 and 44; and to line 59 ofcondenser 58 through connectingline 79. As stated hereinabove, other conventional means for heating at thechamber sections 44 and 49 may be used. The chamber sections ofunit 42 containingevaporator cooling coil 43 andheating coil 44 are thermally insulated from each other.

Operation ofcentral unit 15 FIG. 2 illustrates thecentral unit 15 in enlarged schematic form, in the phase whereinunit 40 is in operation, andalternate unit 40 in defrost The evaporator cooling coil and heating coil circuits (FIG. 1), are omitted for clarity of presentation. The return air from thecabinets 25 enterscentral unit 15 throughinput duct 28 at chamber 35. The air passes a set ofiilters 81 to trap its dust particles. A secondary blower fan propels the air intounit 40 or 40 in accordance with the phase setting of the ducts and motorized dampers for this purpose, as will now be described.

In the illustrated phase, the air from chamber 35 is directed fromexit duct 36 throughduct 37 past normallyopen damper 82 toline 38 intounit 40.Adjacent dampers 83 and 84 are normally closed; anddamper 85, normally open. Dampers 82-85 are motor operated through control motor 86 and geared shafting 87, 88, 89 indicated by dashed lines. Alternatively each damper may be controlled by an individual motor. In this phase, also,duct 90 at cooling end ofunit 40 is made to communicate directly toexhaust duct 91 through normallyopen damper 85;damper 84 being shut at such period.

The filtered warm return air from chamber 35 is thereupon propelled intounit 40 for dehumidifying, precooling and purifying. It passes first through a wider-spaced multi-row iinevaporator coil 92 which serves as a primary air dehumidifier and precooler. The air then passes through a closer-spaced multi-row iinevaporator coil 93, at a substantially lower temperature thancoil 92, which serves as a secondary dehumidifier and precooler. The next stage inunit 40 is abank 94 of conventional chemical dehumidiiiers for the cooled air passing through, followed by an electrostatic filter 95 which optionally may contain an ozone generator.

The air thus emerges fromunit 40 substantially precooled, e.g. to 0 F.; relatively moisture free, clean, and odor free. In an identical manner, air when projected intounit 40 throughduet 90, in the alternate cycles, is precooled, cleaned and dehumidified throughcomponents 92', 93', 94 and 95. In the illustrated phase, the precooled air fromunit 40 passes intoduct 39, through normallyopen damper 96, and on throughduct 41 intoprimary chamber 42.Dampers 97, 98 are normally closed in this phase, while damper 99 is normally open.

The dampers 96-99 are operated cyclically bycontrol motor 100. They are coupled tomotor 100 by suitable geared shafting as indicated, and as will now be understood.Control motors 86 and 100 are operated cyclically byclock controller 45 through electric cables schematically indicated at 101, as aresolenoid valves 76, 76 (see FIG. 1). Further, instead of twocentral motors 86, 100, an individual motor may be used at each damper. The successive alternate cycling effects the defrost mode forunit 40, and the operation mode forunit 40. The alternate cycle is accomplished by reversal of all the damper settings from those illustrated. Those dampers (82, 85, 96, 99) shown normally open in FIG. 2 are closed; and those dampers (83, 84, 97, 98) normally closed, are openedf Thebasic clock controller 45 is suitably connected to operateunits 40 and 40 in the alternate modes described hereinabove, through control motors 86,100 andsolenoid valves 76, 76', as will be understood by those skilled in the art. When the precooled, cleaned and dehumidied return air from unit 40 (or 40') entersduct 41, it passes intochamber 42. There the primary blower fan propels this cooled dry air in part throughcooling coil seotion 43, and in part throughheating coil section 44.Blower fan 105 impels the air at high pressure and thus high velocity.

Theevaporator cooling coil 43 is closely-spaced and of multi-fin construction. Theenclosures 43 and 44 are suitably separated and insulated from each other. The

.5supply 4output duct 16 ofprimary cooling section 43 feedsdistribution duct 20. The supply duct 17 ofheating section 44 feedsdistribution duct 21. The heating coil atsection 44 is fed yby the hot gas (Freon) line 78 (see FIG. 1), couples to line 59; and is in series withheater coil 49, as already described.

The alternated defrosting cycles forunits 40 and 40' are preset and effected through themaster clock controller 45, damper control motors 86,100, andelectrical solenoid valves 76. 76', in the manner hereinabove set forth. In FIG. 2unit 40 4is shown connected in the defrost phase. Thedefrost system chamber 46 contains a blower fan 110 which sucks in outside air throughintake duct 47 that is cleansed -by air lter 111. Theheating coil 49 raises the air temperature, which thereupon is propelledthrough duct 50' to opened damper 99 and on tounit 40 through duct 51. A defrost air temperature into unit 40' of over 80 F. is desirable.

The defrost hot-air in turn dehydrates the chemical dehumidifier component 94', and defrosts icy accumulations on the evaporator coils 93 and 92. The now moistureladen air inunit 40 exits through openeddamper 85 andexhaust duct 91 to the outside air. A defrost cycle of 30, 60 or more minutes is commercially suicient in the exemplary system. During the defrosting ofunit 40alternate unit 40 has been preconditioning the supply air forprimary chamber 42, but accumulating moisture and frost on its coils (92, 93) in the process, Cycle change throughclock controller 45 is rapidly accomplished. Whenunit 40 is put into defrost unit 40' thereupon resumes preconditioning air forprimary chamber 42. The air supplied todistribution ducts 20, 21 and thecabinets 25 thus remains effectively continuous.

Operation of refrigeration cabinets Atypical display cabinet 25 of this invention is seen in plan view in FIG. 1, with its automatically functioning but preset chamber 115 shown schematically; and in vertical cross-sectional view in FIG. 3. The exemplary air mixing and depressurizing chamber 115 is disposed in a flat space along the bottom of thecabinet 25. It contains no motors, fans, evaporator cooling coils etc., and is therefor compact, economical, and flexible of orientation in any desired cabinet size, shape of end use.

Each cabinet is individually presettable over a wide range of operating temperatures, dependent upon its usage; and maintains its preset temperature constantly and constant. There is no shut-down period for defrosting coils in the cabinet as in prior art constructions. Hence there is no deterioration of foods stored. Typical display and/or storage cabinet (25) t preset temperatures, all directly afforded by my invention, are:

F. (a) For ice cream -20 (b) For frozen foods -5 (c) For frozen meats and fish 0 (d) For fresh meat +32 to 36 (e) Fordairy products 36 to 40 (f) Forproduce 40 to 45 The air mixing and depressurizing chamber 115 has two inlet air openings namely opening 116 for cold supply air; and opening 117 for the warm supply air. Cold air is supplied byinlet duct 22; and warm air, byinlet duct 23; both being tapped at 30 and 31 respectively to thedistribution ducts 20, 21. The exemplary system uses cold air supply at below 20 F. and warm air supply at above +80 F., as aforesaid; and other temperature values may be instead used where desired.

A thermostatically controlleddamper 118 in the Warm air supply inlet 117 controls the amount of warm air entering for the required air temperature mixing for thecabinet 25. A pressure controlled damper 120 determines the amount of total mixed air (hot and warm), and its pressure, to exit from theair mixing enclosure 122. The rate of warm air entry is regulated by the degree of opening of pivoteddamper 118, directly controlled byrod 119, through bi-metallic temperaturesensitive thermostat 124.Thermostat 124 is located in theregion 125 of the emerg. ing mixed air at the cabinet temperature; and when manually preset serves to maintain the air output mixture at a constant temperature level.

The air depressurizing damper comprises abowlshaped element 126 suspended near theair inlets 116, 117 by rod 127. Apressurestat 128 controls thedamper bowl 126 location with respect to theinlets 116, 117, to elect the predetermined resultant mixed air proportion and volume output and mixture temperature.Pressurestat 128 is sping-loaded, pressure sensitive, and presettable manually. The air mixing and depressurizing chamber 120 is thus held at the desired pressure and mixing temperature.

The mixed air exits from region into theplenum chamber 130 along the .back of thedisplay cabinet 25. The air then exits through directionalair Ioutlet louvres 131 over theproduct 135 in the cabinet, in the direction indicated byarrows 132. The directed air thereupon enters returnlouvres 133 into the returnair plenum chamber 135 along the front of thecabinet 25. The amount of return air is controlled by a manuallypreset damper 136 located in the air exit Iof the returnair plenum chamber 134. The air then returns to thedistribution duct 27 through itsbranch duct 26.

Although the present invention has been set forth in connection with an exemplary embodiment, it is to be understood that modifications may be made there-in as to its arrangement, application and temperature ranges that fall Within the broader spirit and scope of my invention as set forth in the appended claims.

I claim:

1. In combination with a closed cycle refrigeration system for refrigeration units such as display cabinets and foo-d storage cabinets which have means for mixing hot and cold air supplied to hot and cold inlets thereof and a return outlet for the mixed air comprising a central unit with separate heating and cooling sections for air supplied to an inlet of the central unit, said central unit having hot and cold air -outlets connected to and downstream of said heating and cooling sections, respectively, means for connecting said hot and cold air outlets of said central unit with the hot and cold air inlets of the storage cabinets, respectively, dehumidifying and cooling means having an inlet and outlet, means for supplying mixed air deriving from said outlet of the refrigeration unit to the inlet of said dehumidifying and cooling unit, and means coupling the outlet of said dehumidifying and cooling means as the only air supplied to the inlet of said central unit, said air supplied to said central unit from said dehumidifying and cooling means thereby being supplied to the heating and cooling sections of said central unit.

2. The system of claim 1 further including means for cleaning the air deriving from said refrigeration equipment prior to the said air being applied to the inlet orifice 4of said -central unit, said cleaning means being disposed in the path between the outlet of said refrigeration unit and the inlet of said central unit.

3. In combination with a closed cycle refrigeration system comprising a central unit with heating and cooling sections for air supplied thereto, said unit having hot and cold air outlets connected to and downstream of said heating and cooling sections, respectively, a refrigeration unit having a hot air inlet and a cold air inlet and means for mixing the hot and cold air supplied to its inlets, means for connecting the hot air outlet of said central unit with -the hot air inlet of said refrigeration unit, means for connecting the cold air outlet of said central unit with said cold air inlet of said refrigeration unit, said refrigeration unit having an outlet for withdrawing the mixed air, dehumidifying and cooling means connected downstream from the outlet of said yrefrigeration unit to dehumidify and cool only the mixed air deriving from said refrigeration unit, and means for connecting the outlet of said dehumidifying and cooling means -as the only air inlet t said central unit so that the only air that is heated and cooled in said central unit is derived from said dehumidifying and cooling unit.

4. The refrigeration system ofclaim 3 wherein said dehumidifying and cooling means includes -a pair of dehumidfifying and cooling units, means for selectively connecting only one of said dehumidifying and cooling units between the outlet of said refrigeration unit and the inlet of said central unit, and means for defrosting the other of said dehumidifying and cooling units while the iirst named dehumidifying and cooling unit is connected between said refrigeration unit outlet and said central unit inlet.

5. The refrigeration system ofclaim 3 wherein said heating section of said central unit includes a rst heat exchange coil and the cooling section of said central unit includes a second heat exchange coil, means for circulating a refrigerant in a closed loop through both of said heat exchange coils, said last named means including a compressor having its inlet connected downstream of said second heat exchange coil to be responsive to the heated refrigerant deriving from said second heat exchange coil, said compressor having an outlet connected upstream of said rst heat exchange coil for supplying heated refrigerant to said rst coil, means for condensing and recovering refrigerant connected downstream from said rst coil and having an outlet connected upstream of the inlet for said second coil for supplying cooled refrigerant to said second coil.

6. The refrigeration system of claim 5 wherein said dehumidifying and cooling means includes a pair of dehumidifying and cooling units between the outlet of said refrigeration and the inlet of said central unit, means for defrosting the other of said dehumidifying and cooling units while `the first named dehumidifying and cooling unit is connected between said refrigeration unit outlet and said central unit inlet, and means connected in parallel with said second heat exchange coil for supplying the cooled refrigerant to only the dehumidifying and cooling unit connected with the inlet of said central unit.

7. The refrigeration system of claim 6 wherein said defrosting means include means for supplying heated air to the dehumidifying and cooling unit being defrosted, said last named means including another heat exchange coil connected in said closed loop between said compressor and said first heat exchange coil, said another heat exchange coil heating the air supplied to said dehumidifying and cooling unit being defrosted.

References Cited by the Examiner UNITED STATES PATENTS 2,343,467 3/1944 McGrath 165-17 2,609,743 9/1952 Ashley 165-22 X 2,755,072 7/1956 Kreuttner 165-22 X 2,811,223 10/1957 Newton 62-271 X 2,815,915 12/1957 Salerno 236-13 2,821,343 6/1958 Payne 236-13 2,850,242 9/1958 Newton 236-13 2,867,988 1/1959 Brandt 62-275 X 2,880,752 4/1959 Kreuttner.

2,946,201 7/1960 Munters 62-271 X 2,969,959 1/1961 Kuhn et al. 165-17 OTHER REFERENCES IBM Technical Disclosure Bulletin vol. 1, No. 4, p. 25, December 1958.

CHARLES SUKALO, Primary Examiner.

Claims (1)

1. IN COMBINATION WITH A CLOSED CYCLE REFRIGERATION SYSTEM FOR REFRIGERATION UNIT SUCH AS DISPLAY CABINETS AND FOOD STORAGE CABINETS WHICH HAVE MEANS FOR MIXING HOT AND COLD AIR SUPPLIED TO HOT AND COLD INLETS THEREOF AND A RETURN OUTLET FOR THE MIXED AIR COMPRISING A CENTRAL UNIT WITH SEPARATE HEATING AND COOLING SECTIONS FOR AIR SUPPLIED TO AN INLET OF THE CENTRAL UNIT, SAID CENTRAL UNIT HAVING HOT AND COLD AIR OUTLETS CONNECTED TO AND DOWNSTREAM OF SAID HEATING AND COOLING SECTIONS, RESPECTIVELY, MEANS FOR CONNECTING SAID HOT AND COLD AIR OUTLETS OF SAID CENTRAL UNIT WITH THE HOT AND COLD AIR INLETS OF THE STORAGE CABINETS, RESPECTIVELY, DEHUMIDIFYING AND COOLING MEANS HAVING AN INLET AND OUTLET, MEANS FOR SUPPLYING MIXED AIR DERIVING FROM SAID OUTLET OF THE REFRIGERATION UNIT TO THE INLET OF SAID DEHUMIDIFYING AND COOLING UNIT, AND MEANS COUPLING

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