US3045438A - Ice making - Google Patents

Description

T. G. FCSTER July 24, 1962 ICE MAKING 2 Sheets-Sheet 1 Filed July 5, 1960 FIG. I

INVENTOR. THEODORE G. FOSTER ATTORNEY.

T. G. FOSTER July 24, 1962 ICE MAKING 2 Sheets-Sheet 2 Filed July 5, 1960 INVENTOR.

THEODORE e. FOSTER ATTORNEY.

same.

3,045,438 ICE MAKING Theodore G. Foster, North Syracuse, N.Y., assignor to Carrier Corporation, Syracuse, N.Y., a corporation of Delaware Filed July 5, 1960, Ser. No. 40,585 3 Claims. (Cl. 6265) This invention relates to ice making, more particularly to a refrigeration system for use in conjunction with apparatus for making ice cubes. 7

A variety of equipment has been evolved for producing rectangularly shaped particles of ice of the so-called ice cube form. In forming these ice cubes in commercial quantities, a grid is generally employed containing a plurality of cells confining a volume of the configuration of the ice to be formed, and a movable platen is arranged to close off the bottom of the grid to retain liquid to be frozen within the cells of the grid. Freezing of the liquid in the cells is accomplished by positioning the evaporator of a compression refrigeration system in heat exchange relationship with said cells whereby the liquid to be frozen, confined within. the cells, may be cooled to freeze After the ice is formed, the platen is lowered to permit harvesting of the ice from the cells of the grid. A preferred icemaking apparatus of this type is shown in co-pending application Serial No. 40,719 filed by William L. McGrath on July 5, 1960, now Patent No. 3,020,- 724.

In effecting refrigeration of the grid cells to form the desired ice, at number of problems are encountered due to the desirability of producing ice cubes of uniform size and quality. In order to produce a uniform quality of ice cubes, it is necessary that the temperature gradient of ice formation is a function of temperature. temperatures in each of the cells are substantially the same, the ice produced in each of the cells will not be the same. Where a compression refrigeration system is utilized in providing the desired refrigeration of the grid cells, it is further necessary to insure the fact that all of United States Patent'O the refrigerant flowing through the refrigeration system 7 will be in a gaseous state at the time of passage into the suction connection to the compressor. In effecting release of the formed ice from the grid cells, it is necessary to break the bond between the ice and the cell walls. This can most readily be accomplished by heating of the walls, and as is apparent it would be most desirable to be able to employ the refrigeration system to provide the necessary heat. t

It is with the above problems and desiderata in mind that the present means, including both method and apparatus, have been evolved. The novel means embodied in a unique compression refrigeration system serve to cool the liquid to be supplied to the grid, and serve further to permit selective cooling or heating of the cells ofthe grid, with the cooling action taking place only until all the cells of the grid are tilled with cubes of desired quality at which time beating of the grid may be effected by the refrigeration system to break any bond between the formed ice and the cell walls. The novel refrigeration system is so arranged as to provide -a uni form cooling gradient across each of the cells of the grid; and further utilizes the refrigeration effects involved in converting the refrigerant into a gas so as to provide efi'icientrefrigeration operation, and insuring the presence of only gaseous refrigerant in the suction line to the compressor. It is accordingly 3 primary object of this invention to provide means for effecting efficient cooling of the cells of a grid and platen type of ice cube forming equipment.

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Another object of the invention is to provide means for decreasing the time required to attain ice cube formation in the cells of a grid and platen type of ice cube forming equipment.

It is also an object of the invention to provide means for effectively breaking any bond between the formed ice cubes and the side walls of the cells of the grid in which said cubes are formed.

An additional object of the invention is to provide means freeing the formed ice from the ice forming grid as soon as possible after the completion of the iceforming cycle so that the ice cube forming equipment may be utilized with maximum efficiency.

It is also an object of the invention to provide relatively uniform refrigeration effects in all the cells of the grid of an ice forming machine so as to provide uniformity in the ice particles formed.

Another object of the invention is to provide a compression refrigeration system for use in ice forming equip ment in which all of the refrigerant is converted to a gaseous phase before passage to the compressor.

A further object of the invention is to utilize all the refrigeration effects produced in converting the refrigerant to a gas.

These and other objects of the invention which will become hereafter more apparent are attained by provision of a novel refrigeration system for an ice making machine. pression type utilizing a primary and secondary evaporator in series, with the primary evaporator positioned in heat exchange relationship with the ice forming element, and the secondary evaporator positioned in heat exchange relationship with the supply of liquid to be frozen. The liquid line from the condenser of the refrigeration system is arranged in heat exchange relationship with the suction line to the compressor so as to insure full conversion of the refrigerant to the gaseous phase before passage into the compressor. By means of a by.- pass valve positioned between the compressor and the condenser, the hot compressed refrigerant from the c0mpressor may be fed directly to the evaporator to heat the ice forming element to effect breaking of any bond between the formed ice and the ice forming element during the harvesting portion of the ice making cycle.

An important feature of the invention resides in the fact that the use of a secondary evaporator section permits the primary evaporator section effecting ice forming to operate flooded, thereby providing a relatively uniform refrigerant cooling gradient across the ice forming ele men-t.

Another feature of the invention resides in the fact that the heat exchange between the liquid and suction lines of the refrigeration system insures the conversion of the refrigerant to the gaseous phase before passage to the compressor.

An additional feature of the invention resides in the fact that all of the refrigeration effects produced in converting the refrigerant to a vapor phase are utilized.

A further feature of the invention resides in the arrangement of the cooling refrigerant evaporator coils of the novel refrigeration system in proximity to the lower portions of the grid cells of a grid and platen type ice making machine whereby the cooler portionof the liquid to be frozen will be placed in heat exchange relationship with the evaporating refrigerant so as to increase'the efficiency with which the ice may-be formed. T

It is also a feature of this invention that the novel refrigeration system is provided with a bypass line and valve arranged to permit compressed refrigerant to be passed into heat exchange relationship with the ice forming element to break the bond between the formed ice and the ice forming element.

The novel refrigeration system is of acom The specific structural details of a preferred embodiment of the invention, and their mode of functioning will be made most manifest and particularly pointed out in clear, concise, and exact terms in conjunction with the accompanying drawings, wherein:

FIGURE 1 is a perspective view of a grid and platen type of ice making machine with parts broken away to reveal the details thereof illustrative of the type of apparatus in conjunction with which the instant novel refrigeration system may be employed;

FIGURE 2 is a schematic diagram of the novel refrigeration system here employed; and

FIGURE 3 is a circuit diagram illustrating a control means suitable for regulating the operation of the novel refrigeration system and the ice making apparatus.

Referring now more particularly to the drawings, like numerals in the various figures will be taken to designate like parts.

The ice making machine to which the instant refrigeration system is applied is more fully described in the aforementioned co-pending application. The ice making apparatus here shown in FIGURE 1 is arranged within a rectangular housing 11 formed of sheet metal, or the like relatively rigid sheet material supported'on a framework 9 of angle irons or the like. A bunker 12 is formed at the bottom of the housing 11, and provided with a hinged door 13 permitting access to the interior of the bunker 12. Leading to the bunker is a chute 14 extending from an opening in horizontal partition 15 arranged above the bunker 12. Vertical partition 16 extends upwardly from horizontal partition 15 and separates the heat dissipating components of the refrigeration system, to be hereinafter described, from the ice forming equipment, and the water supply equipment, as seen to the left in FIGURE 1.

The novel refrigeration system which may here be employed with optimum effectiveness as best seen in FIG- URE 2 comprises a compressor 20 constituted by a scaled motor compressor unit such as is conventionally employed in compression refrigeration systems. The compressor 20 is coupled via discharge line 21 to condenser 22 which is connected via liquid refrigerant line 23 through thermal expansion valve 24 to primary platen evaporator 25 in series with secondary water pre-cooling evaporator 26, from which suction line 27 extends back to compressor 20 to complete the closed fluid circuit through which refrigerant is circulated. It will be observed that part of liquid line 23, and suction line 27 are arranged in heat exchange relationship at 30.

Expansion valve 24 is controlled by means of thermostatic bulb 31 arranged in heat exchange relationship with suction line 27 so that the amount of refrigerant flowing from the condenser 22 to the evaporator is regulated in response to the temperature of refrigerant in the suction line.

A bypass line 32 is extended from discharge line 21 from a point before condenser 22 to evaporator 25, permitting the flow of compressed refrigerant directly from the compressor to the evaporator. Regulation of the flow of refrigerant through the bypass line 32' is effected by means of solenoid valve 34 the operation of which will be more fully described hereafter in connection with the novel control means.

The water supply circuit here employed as best seen in FIGURE 1 includes a water Storage sump 35 to which water is fed by water main connection 36 which feeds water to sump 35 through any desired control valve means. Sump discharge line 41 leads the water from the sump through pump 42 via flexible water header supply line 43 to water distribution header 45. The water header distributes the water to' the cells of the ice forming grid 55. Rod 122 mounted in brackets 124 extends through projections from the corners of grid 55 and support the grid on framework 9. A platen 65 is pivotally mounted on rod 66 carried in bearings 67 on framework 9 to close off the bottom of the grid cells so that liquid to be frozen may be retained therein. The particular ice making apparatus here employed is provided with a platen arranged beneath the grid cells, with liquid to be frozen supplied to the grid cells via nozzles 48 on a water header 45, and with a water collection pan 70 beneath the grid and platen as more fully described in the aforementioned co-pending application. It will, however, be appreciated that a variety of other grid and platen types of refrigeration apparatus may be employed.

The platen 65 is of a plate-like configuration substantially coextensive with the bottom area of grid 55, and is preferably formed with a serpentine passageway so as to accommodate the tubing employed in fabricating evaporator 25. The primary portion of evaporator 25 arranged within the serpentine passageway in platen 65 is connected to the secondary evaporator portion 26, and to the suction line of the refrigeration system by flexible refrigerant conduits 69 so as to permit movement of the platen with respect to the relatively fixed refrigeration system components.

The control circuit illustrated diagrammatically in FIGURE 3 controls the operation of the aforedescribed refrigeration system, water supply system and grid and platen ice forming components to attain a continuous supply of uniform ice of desired quality and quantity. An electrical circuit as shown in FIGURE 3 couples pump motor 100, platen moving gear motor and refrigeration system compressor motor 106.

Coupled to the compressor motor is an overload relay 107, a starting relay 108, a running capacitor 109, and a starting capacitor such as conventionally employed in refrigeration system motor compressor units.

The gear motor 85 utilized for effecting movement of the platen with respect to the plate is coupled to the plate via a crank arm 86 and connecting rod 87 such as more fully described in co-pending application Serial No. 40,718 filed in the name of Carl G. Alt.

In addition to the gear motor cam switch 117, the gear motor energizing circuit is provided with a gear motor manual switch 130, as shown in FIGURE 3. Gear motor switch is of a single pole double throw type and is provided to permit manual energization of the gear motor for cleaning purposes.

Control of the condenser fan motor 101 is provided by means of a condenser fan switch 132. Switch 132 is of a single pole single throw pressure sensitive type. Ranco switch 010-2005 is found suitable for the purpose. As seen in FIGURE 2 the pressure sensitive element 133 of switch 132 is arranged in communication with refrigerant discharge line 21 so as to sense the compressor head pressure, whereby the switching action will be made a function of this head pressure. Solenoid valve 34 is arranged for control of refrigerant flow through the previously described refrigeration system.

A platen switch 135 of a single pole double throw lever action type is arranged in the circuit of pump motor 100 and solenoid valve 34. This platen switch 135 is arranged so as to close the circuit to the pump motor 100 when the platen is in contact with the grid, and simultaneously close the solenoid valve 34. When the platen moves away from the grid, the solenoid valve is energized to open, and the pump motor is deenergized.

A manual control switch 138 is arranged in the circuit to compressor motor 106, pump motor 100, solenoid valve 34, gear motor 85 and condenser fan motor 101. Manua1 control switch 138 is a three position switch which permits manual control of the ice making apparatus components so as to permit: complete shut off of the unit; operation of only pump motor 100; or operation of all components. When the apparatus is completely shut off, cam 138 is moved to a position where neither contact arm engages a contact. To operate only the pump motor, cam 138'is moved to a position where the left contact is engaged by the left contact arm and the right contact is open. For operation of all components, cam 138' is moved to a position urging each contact arm int-o engagement with a contact.

Main control switch 140 serves to automatically control the cycles of operation of the ice making apparatus in response to pressure and temperature conditions. Switch 140 is preferably of the Ranco dual control single pole double throw type. As seen in FIGURE 2, switch 1'40 is formed with a pressure sensing cut off element 141 arranged in communication with suction line 27 of the refrigeration system and a temperature sensitive cut in element 142 arranged to sense the temperature in the grid cells preferably by being fastened to the grid 55. For convenience, the temperature sensitive cut in element 142 is'shown in FIGURE 2 to be mounted on the platen of the instant ice forming apparatus.

A bin switch 145 is mounted in the ice storage bin or bunker and is arranged to control the operation of the ice making apparatus in response to the quantities of ice produced.

The novel refrigeration means here provided are particularly adapted for use in conjunction with a grid and platen type of ice making apparatus to effect the uniform freezing of liquid to be frozen in the cells of the ice forming grid so as to produce uniform quality ice cubes in each of the grid cells at a relatively rapid rate. The novel refrigeration system as best seen in FIGURES 1 and 2 is of a compression refrigeration type in which the compressor 20, condenser 22, and two part evaporator 25, 26 are arranged in a fluid circuit through which refrigerant may be circulated.

The compressor 20 compresses refrigerant in its gaseous phase, and discharges the high pressure high temperature refrigerant vapor into the air cooled condenser 22 which is in heat exchange relationship with the ambient air. Depending on the temperature of the ambient air, and the pressure in discharge line- 21, condenser fan motor 101 will be set into operation. Thus if additional cooling is required to lower the head pressure in line 21 the fan motor will be operated to increase the rate of air flow over the condenser coils, or if head pressures are too low, the fan motor will be quiescent so as to minimize the rate of heat exchange between the ambiance and the refrigerant in the condenser, whereby refrigerant head pressures will build up in the refrigeration system.

' From the condenser, during the normal refrigeration cycle, the condensed refrigerant vapor now in a liquid phase, flows through liquid line 23 to thermal expansion valve 24.

Expansion valve 24 meters refrigerant into primary evaporator portion 25 which is in heat exchange relationship with the cells of the ice forming grid. In the illustrated embodiment of the invention; this is accomplished by arranging evaporator 25- within the platen of the ice forming apparatus. Inthe primary evaporator 25, the refrigerant absorbs heat from the liquid to be frozen in the grid cells. The heat absorbed serves to vaporize the refrigerant in evaporator 25 which then flows into secondary evaporator 26 arranged to direct the evaporating refrigerant therein int-o heat exchange relationship with the supply of liquid to be frozen in the supply sump. The secondary evaporator may be disposed in the liquid in the sump or may be arranged adjacent the sump. This two part evaporator arrangement serves to substantially insure flooded operation of primary evaporator 25, whereby uniform refrigerant effects in each of the grid cells will be obtained; thus producing uniform ice cubes.

In addition, during the freezing cycle a body of liquid adjacent the secondary evaporator 26 is solidified. During the defrost cycle, the condensing refrigerant flows through the secondary evaporator 26 and frees the ice formed adjacent the secondary evaporator. The ice rises to the top of the liquid in the sump 35. At the initiation of the next cycle, (this ice is used to additionally cool the incoming warm liquid to be frozen.

6 From secondary evaporator 26, the refrigerant vapor flows through the suction line 27 where any moisture in the vapor will be further vaporized as a result of the action of the high temperature refrigerant in discharge line 21. Vaporized refrigerant flows back to the compressor through suction line 27 for recycling through the refrigeration system.

After the desired ice is formed in the grid cells, the refrigeration system may be employed to break the bond between the for-med ice and the grid cell walls by closing valve 34 which causes compressed refrigerant from compressor 20 to be diverted through bypass line 32 to evaporator 25. The diverted condensing refrigerant heats the grid to free the formed ice.

It is thus seen that an improved refrigeration system has been provided for use in conjunction with a grid and platen type of ice making apparatus for both freezing and defrosting of the formed ice. The use of a flooded evaporator in heat exchange relationship with the ice forming grid cells permits the relaitvely uniform cooling of all of the grid cells to form ice of uniform quality. Additionally, the heat exchanger in the suction line of the compressor insures vaporization of the refrigerant prior to entering to the compressor.

The above disclosure 'has been given by way of illustration and elucidation, and 'not by way of limitation, and it is desired to protect all embodiments of the hereindisclosed inventive concept within the scope of the appended claims.

I claim: 1. In an ice maker, the combination of an ice forming element, a supply sump for liquid to be frozen, means for supplying the liquid from the supply sump to the ice form-' ing element, and means for refrigerating the ice forming element, said refrigerating means comprising primary heat absorbing refrigerant evaporating means in heat exchange relationship with the ice forming element; secondary heat absorbing refrigerant evaporating means in contact with the liquid to be frozen in the supply sump to form ice on a portion thereof, said secondary means being in fluid communication with said primary means receiving liquid refrigerant therefrom to insure the presence of liquid refrigerant throughout said primary means whereby uniform refrigeration effects will be produced throughout the ice forming element, means for discontinuing refrigeration of the ice forming element and the supply of liquid refrigerant to the secondary means, and means for supplying gaseous refrigerant to the primary means and to the secondary means to free ice therefrom, ice freed from the secondary means remaining in the sump to cool incoming warm liquid to be frozen.

2. In a method of refrigerating an ice forming element having a supply sump for liquid to be frozen, the steps which consist in evaporating liquid refrigerant in heat exchange relation with the ice forming element, passing liquid refrigerant remaining after its passage through the ice forming element through a secondary evaporator in the sump in contact with liquid to be frozen in the sump thereby forming ice on the secondary evaporator and providing a uniformrefrigerating effect throughout the ice forming element, discontinuing passage of liquid refrigerant to the ice forming element and the secondary evaporator, passing gaseous refrigerant through the ice forming element and the secondary evaporator to free ice therefrom, and employing the ice freed from the secondary means remaining in the sump to cool incoming warm liquid to be frozen.

3. In an ice maker, the combination of a grid having a plurality of cells therein in which liquid to be frozen may a. condenser receiving compressed refrigerant from the compressor, a primary evaporator in said platen coupled to said condenser via an expansion valve metering the condensed refrigerant to said primary evaporator, a secondary evaporator in said sump coupled to said primary evaporator to receive liquid refrigerant therefrom and to said compressor to supply gaseous refrigerant thereto, said secondary evaporator being placed in contact with liquid in said sump to form ice on a portion thereof, said primary evaporator operating flooded during the freezing operation to provide uniform refrigerating effects over the platen so as to uniformly freeze the liquid confined in the cells of the grid, appropriate refrigerant conduits connecting said compressor, condenser, expansion valve, primary evaporator, and secondary evaporator in such order to form a closed circuit through which refrigerant may flow, means for discontinuing the supply of condensed refrigerant to said primary and secondary evaporators, and means for supplying gaseous refrigerant to said primary evaporator and to said secondary evaporator to free ice therefrom, ice freed from the secondary evaporator remaining in the sump to cool incoming warm liquid to be frozen.

7 References Cited in the file of this patent UNITED STATES PATENTS 666,703 Seilacker Ian. 29, 1901 894,285 Rasshach July 28, 1908 1,322,660 Voorhees Nov. 25, 1919 2,259,920 Baer Oct. 21, 194 1 2,613,506 Cook Oct. 14, 1952 2,701,453 Henderson Feb. 8, 1955 2,737,024 Swenson Mar. 6, 1956 2,739,457 Chapman Mar. 27, 1956 2,775,100 Howe Dec. 25, 1956 2,949,752 Bayston Aug. 23, 1960 FOREIGN PATENTS 238,325 Switzerland Oct. 16, 1945

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