US3026686A - Ice making refrigeration apparatus and the like - Google Patents

Description

c. E. LOWE 3,026,686

ICE MAKING REFRIGERATION APPARATUS AND THE LIKE March 27, 1962 3 Sheets-Sheet 1 Filed April 3, 1961 INVENTOR 6Z2: lmre ATTORNEYS March 27, 1962 c. E. LOWE 3,026,686

ICE MAKING REFRIGERATION APPARATUS AND THE LIKE Filed April 5, 1961 3 Sheets-Sheet 2 INV EN TOR March 27, 1962 c E. LOWE 3,026,686

ICE MAKING REFRIGERATION APPARATUS AND THE LIKE Filed April 3, 1961 3 Sheets-Sheet 3 IN VENTOR ATTORNEYS 3,026,686 ICE MAKING REFRIGERATION APPARATUS AND THE LIKE Charles E. Lowe, P.0. Box 621, Orlando, Fla. Filed Apr. 3, 1961, Ser. No. 100,138 2 Claims. (Cl. 62-149) The present invention relates in general to heat exchange refrigeration systems, and more particularly to refrigeration systems for ice-making or cooling purposes which are cycled alternately through a freezing phase and a harvesting or defrosting phase in the operation of the system.

Automatic ice-making apparatus involving reversible cycle refrigeration systems have gone into wide commercial use. In such systems, ice is produced during the normal refrigerating or freezing phase of the apparatus when condensed liquid refrigerant is admitted to the evaporator, and the ice is discharged from the evaporator during the defrosting or harvesting phase when hot gaseeous refrigerant is delivered directly from the compressor to the evaporator. In such systems the operation of the system in reverse phase to the normal refrigerating phase involves absorption of heat at the condenser by the liquid refrigerant delivered from the evaporator to the condenser which contributes to the total refrigeration load imposed on the system. Such refrigeration systems have generally been of the heat pump type and have required a number of solenoid valves to etfect proper selective control of intercoupling of the components of the refrigeration system to establish-the various phases of operation forming the complete cycle of operation of the system. Substantial improvement in the economy of construction and operation of such apparatus is eminently desirable.

While the present invention is applicable to liquid chilling application, cooled storage room refrigeration and like applications, it will be described specifically in connection with the automatic production of ice to simplify understanding of the construction and operation of the system.

An object of the present invention is the provision of novel ice making apparatus having a cycle of operation wherein the apparatus is cycled successively through freezing and thawing phases, which is of economical construction and has a novel mode of operation providing improved operating efficiency.

Another object of the present invention is the provision of novel automatic ice making apparatus which is cycled automatically through freezing and harvesting phases,

wherein the harvesting phase duty cycle is substantially reduced providing greater production of ice during a given period of operation.

Another object of the present invention is the provision of a novel automatic ice making apparatus operating automatically through freezing and defrosting phases, wherein means are provided for supplying the heat for defrosting of the ice during the harvesting phase in a manner effecting a reduction in the total refrigeration load and more efiicient thermal operating characteristics.

Another object of the present invention is the provision of novel automatic ice making apparatus operating automatically through freezing and harvesting phases wherein the components are intercoupled and controlled in a manner effecting a substantial reduction in the number of valves required and therefore in the cost of production of the apparatus.

Other objects, advantages and capabilities of the present invention will become apparent from the following detailed description, taken in conjunction with the accomf ire States Patent panying drawings illustrating two preferred embodiments of the invention.

In the drawings:

FIGURE 1 is a diagrammatic view of the automatic ice making apparatus constructed in accordance with one preferred embodiment of the present invention wherein a plurality of solenoid valves are provided for controlling cycling of the apparatus between alternate phases of operation;

FIGURE 2 is a Wiring diagram of a control system for the apparatus of FIGURE 1;

FIGURE 3 is a diagrammatic view of a second preferred embodiment of automatic ice making apparatus constructed in accordance with the present invention, employing a 4-way valve for cycling the components between alternate phases of operation thereof, the valve being positioned in this figure to establish the freezing phase of operations;

FIGURE 4 is a diagrammatic view of the apparatus shown in FIGURE 3 with the valve positioned to establish the harvesting phase thereof; and

FIGURE 5 is a wiring diagram of a form of controlled circuit'for use with the apparatus of FIGURES 3 and 4.

Referring to the drawings, wherein like reference char acters designate corresponding parts throughout the several figures and particularly to the embodiment of the apparatus disclosed in FIGURES 1 and 2 thereof, the automatic ice making apparatus of this embodiment in cludes the usual motor-driven compressor 16 having a high pressure compressor discharge line 11 and a low pressure compressor suction line 12. The high pressure discharge line 11 divides into two branch lines 13 and 14, the branch line 13 leading to the condenser 15 and the branch 14 to the evaporator 16 through the solenoid controlled valve 17. The condenser 15 in the embodiment herein shown is of the type formed of an outer tank or shell into which the hot gaseous refrigerant is admitted from the inlet branch 13, having an internal water coil in communication with an exterior source of cool water to Withdraw heat from the hot gaseous refrigerant admitted to the condenser through heat exchange with the 'water in the water coils and condense the refrigerant to the liquid state. It will be appreciated, however, that any other form of condenser of the many different types now known in the trade may be used instead of the particular type of condenser herein shown. A condenser outlet line 18 leads from a point near the lower end of the condenser 15 through the heat exchanger 19 in thermal communication with the compressor suction line 12, and thence through a capillary tube 20" to injector tube 21 extending into and opening internally of the refrigerant chamber 22 of the evaporator 16 at a level in the upper regions of the chamber '22.

The evaporator 16 may be of the type disclosed in my copending application, Serial Number 833,411 filed August 13, 1959, in that it is in the general form of a downwardly opening cup or bored cylinder having radially outwardly and inwardly facing concentric surfaces on which ice is to be formed, between which an annular cylindrical refrigerant chamber 22 is provided through which refrigerant is metered by the capillary tube 20. Inner and outer spray rings 23 and 24 are disposed adjacent the upper ends of the inner and outer concentric evaporator surfaces and are supplied with water from an external source to spray water downwardly upon the evaporator surfaces to form ice which is frost-bonded to these surfaces until the harvesting phase begins.

A transfer tube 25 extends upwardly and from a point near the bottom of the annular refrigerant chamber 22 of the evaporator 16 to a point near the bottom of a refrigerant accumulator 26. The accumulator 26 is preferaoaacse ably an insulated tank of considerably greater capacity than the refrigerant chamber 22 of the evaporator. An outlet line 27 extends from the upper end of the accumulator 26 through a solenoid controlled valve 28 to the T-fitting 29 at the end of the compressor suction line 12, the line 27 being one branch of the suction line 12. Another branch line 30 extends from the T-fitting 29 through the solenoid valve 31 to the upper end of the refrigerant chamber 22 of the evaporator 16.

One form of electrical control circuit which may be used to effect automatic cycling of this apparatus through successive freezing and harvesting phases is illustrated in FlGURE 2, wherein the compressor motor indicated at 32 is in one parallel branch circuit 33 disposed across the 110 v. supply lines 34-35 With a two pole main power switch 36 interposed in the two leads connecting the branch circuit 33 with the 110 v. supply lines and a bin switch 37 responsive to the level of ice in the usual ice collecting bin interposed in one of the leads to the branch circuit 33. An additional branch circuit 38 is coupled across the supply lines 3435 in parallel circuit relation with the branch circuit 33 and includes low pressure and high pressure safety switches 39 and 40 and a cycling or harvesting switch 41 arranged in series relation in the branch 38. The cycling switch 41 may be a temperature switch responsive to the temperature in the zone of the evaporator 16 or a pressure switch, a time clock switch, or any other well-known type of cycling switch, and includes a movable contact which, in the freezing phase, engages a stationary contact as illustrated in broken lines in FIGURE 2, closing the circuit through the coils of solenoid controlled valve 31 and through circulating pump motor 43, which supplies pressure for the water supply to the spray rings 23 and 24, and in the harvesting phase position illustrated at solid lines in FIG- URE 2 engages a stationary contact closing the circuit through the coils of the solenoid controlled valves 17 and 28 and through an ice crusher motor 42.

In the operation of the embodiment shown in FIG- URES 1 and 2, assuming that the unit is charged, bin switch 37 and safety switches 39 and 40 are all closed, and the main power switch 36 has just been closed, the compressor motor 32 is energized and a circuit is established through the solenoid valve coil 31, the cycling switch 41 being in the broken line position due to a higher range temperature at the evaporator. Energizing of the coil of the solenoid valve 31 opens the suction branch 30 from the evaporator 16 to the compressor suction intake 12, the circulating pump motor 43 will be energized causing water to be sprayed from the spray rings 23, 24, and the coils of the valves 17 and 28 will be de-energized leaving them in closed condition. Thus, hot gaseous refrigerant discharged through the high pressure line 11 from the compressor will be led through the condenser inlet branch 13 to the condenser 15, where the hot gaseous refrigerant will condense and reject heat to the water flowing through the interior water coils of the condenser. The condensed liquid refrigerant will then be conducted through the line 18, heat exchanger 19, and capillary tube to the injector tube 21 to feed the cooled liquid refrigerant into the refrigerant chamber 22 of the evaporator 16. The evaporator of the liquid refrigerant in the evaporator 16, which is under lower pressure, withdraws heat from the water sprayed on the concentric inner and outer surfaces of the evaporator 16, forming two concentric tubes of ice which are adhered to the evaporator surfaces, the evaporated refrigerant being drawn through the branch suction line and compressor suction intake 12 to the compressor 10 to again be compressed and discharged to the condenser.

When the control for the cycling switch 41 senses a selected condition at the evaporator, for example, a low temperature condition produced upon the formation of a selected amount of ice on the evaporator surfaces, the

cycling switch 41 is tripped to assume the solid line position illustrated in FIGURE 2, wherein the coils of solenoid valves 17 and 28 are energized to open these valves, the ice crusher motor 42 is energized, the circulating pump motor 43 is de-energized, and the coil of solenoid controlled valve 31 is de-energized closing the branch suction line 30. The high pressure discharge line 11 of the compressor 10 is then placed in direct communication with the refrigerant chamber in the evaporator 16 through the branch conduit 14 and valve 17, which places the evaporator refrigerant chamber 22 under high pressure and expels the liquid refrigerant from the evaporator through the transfer line 25 to the accumulator 26, the top of the accumulator 26 now being in communication with the compressor suction intake 12 through the open solenoid valve 28 and line 27. In this harvesting phase of the cycle of operation of the apparatus, no substantial amount of liquid refrigerant flows through the line 18, heat exchanger 19, and capillary tube 20 as both the condenser 15 and the refrigerant chamber of the evaporator 16 are under high pressure. Since the liquid refrigerant which was in the refrigerant chamber at the conclusion of the freezing cycle is wholly removed to the accumulator 26 at the beginning of the harvesting phase, the hot gaseous refrigerant is quickly placed in intimate heat exchange relationship with the concentric cylindrical surfaces bounding the refrigerant chamber to quickly break the frost bond adhering the ice to the evaporator surfaces and without subjecting the hot gaseous refrigerant to the heat losses which would occur if the liquid refrigerant were required to be evaporated from the refrigerant chamber.

When the cycling switch 41 is again tripped in response to discharge of the ice from the evaporator 16, the solenoid valve 31 is again de-energized, opening this valve, and the solenoid valves 17 and 28 are closed, re-establishing the refrigerant paths described in connection with the earlier description of the freezing cycyle. Since the opening of the valve 31 at the commencement of the next freezing cycle re-establishes low pressure conditions in the refrigerant chamber of the evaporator 16, the stored liquid refrigerant in the accumulator 26 is then forced by its own pressure back through the transfer tube 25 to the evaporator to begin further withdrawal of heat from the water sprayed on the ice forming surfaces of the evaporator 16 without requiring an entirely fresh charge of liquid refrigerant to be supplied from the condenser 15. Thus, a far more efficient use of the heating and cooling capacities of the refrigerant is made, resulting in a substantial reduction in the total refrigeration load of the apparatus as compared with prior art reversible cycle ice making machines.

Another embodiment of the apparatus is illustrated in FIGURES 3, 4 and 5 wherein a solenoid controlled 4- way valve and a check valve are employed instead of the 3 solenoid controlled valves 17, 28 and 31 of the first-described embodiment. In the form shown in FIG- URES 3, 4 and 5, the components and communicating lines which correspond to those of the first-described embodiment are designated by reference characters which are the primes of the reference characters used in the first embodiment. In this modified form, the branch 14' of the compressor high pressure discharge line 11' leads to an inlet 45 of a four-way valve 46. One outlet 47 of the four-way valve 46 communicates with the branch suction line 30' extending to the refrigerant chamber 22 of the evaporator 16, another outlet 48 of the four-way valve 46 communicates with the compressor suction line 12, and a third outlet 49 communicates with a line 50 extending to the top of the accumulator 26, a check valve 51 being interposed in the line 50 which closes on high pressure at the valve outlet 49 and opens on low pressure at the valve outlet 49. The four-way valve 46 includes a valve member 52 which is axially shiftable' along the valve in response to pressure conditions established by a pilot valve 53 under control of solenoid coil 54 to communicate the valve outlet 48 with one of the valve outlets 49 or 47 and leave the other valve outlet in communication with the valve inlet 45.

An electrical control circuit for this modified form of the apparatus is illustrated in FIGURE 5, wherein the cycling of harvesting switch 41 selectively assumes either a freezing cycle condition illustrated in broken lines wherein the circuit is completed through the circulation pump motor 43 or a harvesting cycle position illustrated in solid lines wherein the circuit is established through the crusher motor 42 and the solenoid coil 54 controlling the four-way valve 46.

In the operation of this modified form, assuming the bin switch 37 and the safety limit switches 39' and 40 to be closed and the cycling'switch 41' to be in the broken line position, upon closing of the main power switch 36', the compressor motor '32 and the circulation pump 43 are energized and the pilot valve solenoid coil 54 is de-energized positioning the valve member 52 of the 4-way valve 46 in the position illustrated in FIG- URE 3 wherein the outlets 47 and 48 are in communication with each other. In this condition, the hot gaseous refrigerant discharged through the compressor discharge line 11' flows through the condenser inlet branch 13 and is condensed in the condenser 15', and thence passes through the line 18', heat exchanger 19', and capillary tube 20' to the refrigerant chamber 22' of the evaporator 16 where heat exchange occurs with the water sprayed on the surfaces of the evaporator 16' to form ice on these surfaces. The refrigerant chamber 16' is in communication with the compressor suction line 12 through the line 30 and 4- way valve outlets 47 and 48. Since the check valve 51 in the line 50 is in communication through the valve 46 with the valve inlet 45 and compressor discharge branch line 14', the check valve 51 is closed and the accumulator 26' is effectively out of the refrigerant circuit. When sufficient ice has formed on the surface of the evaporator 16' the cycling switch 41' is shifted to the solid line position, de-energizing the circulating pump motor 43', energizing the crusher motor 42 and energizing the solenoid coil 54 to activate the pilot valve 53 to shift the valve member 52 of the fourway valve '46 to the position shown in FIGURE 4 wherein the valve outlets 48 and 49 are in communication with each other. Now, the high pressure discharge line 11' and branch 14' are in communication with the refrigerant chamber 22' of the evaporator 16' through the four-way valve inlet 45 and outlet 47 and the line 30', placing the refrigerant chamber 22' under high pressure and expelling the liquid refrigerant therein through the transfer line 25' to the accumulator 26', the accumulator outlet line 50 being now open through the check valve 51, fourway valve outlets 49 and 48, and the compressor suction line 12'. When the ice is discharged from the evaporator 16 the cycling switch 41' is again shifted to the broken line position, deenergizing the solenoid coil 54 to cause the valve member 52 of the four-way valve 46 to be returned to the FIGURE 3 position, wherein suction line 50 from the accumulator is again closed by the closing of the check valve 51 and the refrigerant chamber of the evaporator 16' is again in direct communication with the compressor suction line 12'. The stored liquid refrigerant in the accumulator 26' is then transferred by its own pressure back to the evaporator 16' into direct heat exchange relationship with the Water sprayed on the iceforming surfaces of the evaporator.

While but two preferred examples of the present invention have been particularly shown and described, it is apparent that various modifications may be made therein within the spirit and scope of the invention, and it is desired, therefore, that only such limitations be placed on the invention as are imposed by the prior art and set forth in the appended claims.

What is claimed is:

1. In ice-making apparatus and the like, a refrigeration system adapted to be cycled alternately through a freezing phase and a harvesting phase including an evaporator in the form of a downwardly opening, cup-shaped, vertically elongated body having a pair of radially spaced a cylindrical surfaces concentric with a vertical axis through said evaporator body extending substantially throughout the height thereof and defining inner and outer ice-forming surfaces and a closed bottom annular refrigerant chamber therebetween, water spray means adjacent the upper ends of said inner and outer ice-forming surfaces for spraying water thereon during the freezing phase, a compressor having discharge and suction sides, a condenser, an accumulator tank adapted to be disposed out of the fiow path of refrigerant between the compressor, condenserand evaporator during the freezing phase and to receive and store liquid refrigerant from the evaporator during the harvesting phase, said accumulator tank having a suction conduit connection at the upper end thereof with the suction side of said compressor for returning vaporized refrigerant to the compressor only during the harvesting phase, a transfer tube connecting the accumulator tank with said refrigerant chamber having open ends disposed near the bottom of each, valve means for connecting said refrigerant chamber with said suction side of the compressor during the freezing phase, conduit means continuously connecting said discharge side of the compressor with said condenser, conduit means for the flow of condensed liquid refrigerant from said condenser to said refrigerant chamber, valved means for directly applying hot gaseous refrigerant under pressure from the discharge side of said compressor to said refrigerant chamber at the beginning of the harvesting phase to heat said ice-forming surfaces and displace liquid refrigerant from said refrigerant chamber through said transfer tube to said accumulator tank and disconnecting said refrigerant chamber from said suction side, and valve means controlling said suction conduit connection of the accumulator for opening the same only during the harvesting phase, the valve means controlling said suction conduit connection closing the same at the beginning of the freezing phase to cause the liquid refrigerant in the accumulator tank to be forced back through the transfer tube into said refrigerant chamber.

2. In ice-making apparatus and the like, a refrigeration system adapted to be cycled alternately through a freezing phase and a harvesting phase including an evaporator in the form of a downwardly opening, cup'shaped, vertically elongated body having a pair of radially spaced cylindrical surfaces concentric with a vertical axis through said evaporator body extending substantially throughout the height thereof and defining inner and outer ice-forming surfaces and a closed bottom annular refrigerant chamber therebetween, water spray means adjacent the upper ends of said inner and outer ice-forming surfaces for spraying water thereon during the freezing phase, a compressor having discharge and suction sides, a condenser, a heat exchanger, a four-way valve having connections with the suction side of said compressor and with said refrigerant chamber, said compressor, condenser and evaporator forming a series flow circuit for refrigerant during said freezing phase, an accumulator tank adapted to be disposed out of said series flow circuit during said freezing phase and being adapted to receive and store liquid refrigerant from said evaporator during said harvesting phase, said accumulator tank having a valved suction conduit connection from the top thereof to said four-way valve, a liquid transfer tube connecting the accumulator tank with said refrigerant chamber having open ends disposed near the bottom of each, a branched conduit connected to the discharge side of said compressor having a first branch connected with said condenser and a second branch connected with said fourway valve means, said four-way valve means including means for connecting said refrigerant chamber with said suction side of the compressor through said heat exchanger during the freezing phase and concurrently dis- 7 connecting said refrigerant chamber from said second branch of the branched conduit connected to the discharge side of the compressor, conduit means for the flow of condensed liquid refrigerant from said condenser from said heat exchanger to said refrigerant chamber, said four-way valve means further including means for connecting said refrigerant chamber With the second branch of said branched conduit connected to the discharge side of the compressor for directly applying hot gaseous refrigerant under pressure from the compressor to said refrigerant chamber at the beginning of the harvesting phase to heat said ice-forming surfaces, said fourway valve means including means disconnecting said refrigerant chamber from said suction side of the compressor during the harvesting phase and connecting said suction conduit connection of said accumulator tank with said suction side for withdrawing only gaseous refrigerant from said accumulator tank to said compressor, said accumulator tank being "in open communication through said transfer tube with said refrigerant chamber during the harvesting cycle to receive liquid refrigerant from said refrigerant chamber responsive to pressures produced in said refrigerant chamber, and means closing said suction conduit connection at the beginning of the freezing phase to cause the liquid refrigerant in the accumulator tank to be forced back through the transfer tube into said-refrigerant chamber.

References Cited "in the file of this patent UNITED STATES PATENTS

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