US2672016A - Ice-making and refrigerating system - Google Patents

Description

March 16, 1954 G. MUFFLY 2,672,016

ICE-MAKING AND REFRIGERATING SYSTEM Filed Sept. 20, 1948 4 Sheets-Sheet l March 16, 1954 G. MUFFLY ICE-MAKING AND REFRIGERATING SYSTEM 4 Sheets-Sheet 2 Filed Sept. 20. -1948 INVENTOR. 'Ze/r/f Mu :ff/5.

March 16, 1954 G. MUFFLY ICE-MAKING AND REFRIGERATING SYSTEM 4 Sheets-Sheet 3 Filed Sept. 20, 1948 NVENTOR. /f/z kiff/Uy,

4 Sheets-Sheet 4 FRIGERATING SYSTEM G. MUFFLY March 16, 1954 ICE-MAKING AND RE Filed sept. 2o, 1948 XXV mf ,M

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Patented Mar. 16, 1954 UNITED STATES PATENT OFFICE ICE-MAKING AND REFRIGERATIN G SYSTEM Glenn Muflly, Springfield, Ohio Application September 20, 1948, Serial No. 50,101

18 Claims.

This invention applies to the iields of ice making and refrigerating systems, and particularly to systems in which refrigerant flow is shifted or reversed so that certain heat exchangers are used part of the time for cooling or ice-- making and part of the time for heating. Several issued patents and copending applications of mine are mentioned herein to clarify the specication Without repeating the details of these other applications.

Among the many objects of this invention I mention the following:

'I o provide for separation of ice from Water so that the ice may be stored separately.

To provide a control for stopping the refrigerating system in response to the accumulation of a supply of ice in the ice storage compartment and to synchronize this stopping of the system with the ending of one of the shorter cycles of ice freezing, so as to avoid the production of incompletely formed pieces of ice.

To provide a quadruple valve mechanism for control of both liquid refrigerant and refrigerant vapor in the reversible type of refrigerating system employed in the present process of ice making.

To provide means for adjusting the cyclic operation of the above mentioned valve mechanism to obtain longer or short cycles and to provide manual control for running prolonged cycles with either direction of flow.

To supply such a valve mechanism with energy obtained from refrigerant flow and to selectively by-pass more or less of the refrigerant and thereby vary the length of the cycle of valve operation.

To provide for operation of an ice-making system including a tank equipped with means for maintaining a fixed water level while the system is idle and a higher water level while the system is operating.

To utilize the higher water level maintained during operation of the system to produce a flow of water suicient to carry oating pieces of ice from the ice-making tank.

To maintain the overflow of water from the icemaking tank after the ice-making system has stopped so that pieces of ice last frozen will be transferred to the dry storage compartment.

To provide an overiiow tank to accommodate the excess water represented by the difference between the two Water levels in the ice-making tank.

To provide a float-controlled water inlet valve responsive to the water level in the overflow tank only during periods of operation.

To provide means for removing water of meltage from the ice storage compartment and returning it to the ice-making tank, wihch has a higher water level.

To provide control means for starting the icemaking system in response to a reduction in the quantity of stored ice and influenced by higher ambient temperatures to hasten such starting.

To provide more effective agitation of water in the ice-making tank and means for draining impurities from the bottom of the tank.

To utilize the water agitating means to provide energy for removing ice blocks from the ice-making tank and separating them from the water.

To provide an ice delivery chute for removal of floating ice from the ice-making tank and to equip this chute with means for orienting the iioating pieces of ice so as to avoid the formation of a jam which might block the overflow passage.

To provide ice pockets or molds in opposite sides of a vertically disposed evaporator assembly.

To provide an arrangement of ice molds in nested back-to-back relationship with evaporator means between them in heat exchange with both sets of molds.

To provide a simplied form of multiple switch actuated by a clock mechanism.

To provide a thermostatic switch with magnetc means for maintaining the switch in its closed position and means for de-energizing the magnetic means at predetermined intervals so that the thermostatic switch is allowed to open only at such times.

To provide a refrigerating system with an auxiliary motor or motors and switch means for starting them after the system has started and for stopping them with a considerable time delay after the stopping of the system.

To provide a clock-operated switch and means for stopping the clock coincidentally with the opening of the switch so that an operating period of the system always comprises a whole number of complete ice-making cycles.

To arrange a single expansion valve so that refrigerant continues to flow thru it in the same direction when the direction of refrigerant ow thru the system is reversed.

To provide a thermostatic expansion valve with two bulbs or thermostatic members so that the superheat is regulated at one time by the temperature of one tube with which one of the bulbs makes contact and at another time by the which is open at vits lower end near the bottom of the ice storage tank I8. The section port of the venturi forms the outlet of the tube 12 and is restricted so that the rate of return water flow thru it is very low. A screen 14 protects the inlet of the pipe 12 so that dirt cannot enter to clog the small suction port of the venturi.

The reason for using a small port is that even with this restriction the tube 12 will be passing air instead of water most of the time and the rate of air entry to the venturi must be small enough so that the pump continues to draw water from the overflow tank and deliver it to the various outlets 64. A quantity of air will be circulated with this water to aid in the agitation which causes the ice to freeze in clear form and it also aids in raising the water level so that the ice blocks float from the tank IE. At the time the system steps the tube 12 will be full of air, which serves to break any syphoning effect from the main tank te the overflow tank and to theice storage space. Even if such syphoning did occur the eflllalzrlg of water levels would soon stop it and no damage would be done, as no additional water would be admitted to either tank from the supply line,

During operation the water level in the overflow tank will be at approximately the level 54, but after some of the water has been formed into ice and the ice moved into the storage tank I8 the water level of both the main tank and the overflow tank will fall somewhat. The reduction of water quantity in the overflow tank, which occurs only while the system is operating, allows the float 1B to drop, carrying with it the rod 18 which actuates the bell crank 80 which in turn depresses the stem of valve 82 to allow water to flow from the water suply line 84 into the overflow tank. This water inlet valve is located in the upper part of the overflow tank at about the level of the overflow chute so that the valve is accessible for replacement or for adjustment to raise or lower the water level at which the valve is opened. The Water supply line 84 is preferably cooled by heat exchange with the main suction line or valve body 86, as indicated in Figure 3. Insulation 81 is used to reduce heat transfer to incoming water or cold vapor and from warm liquid refrigerant wherever required.

Refrigerant flow is periodically shifted by the valve mechanism 85, which will be more fully described in connection with later views. After all of the ice blocks have floated free from the molds associated with the left-hand evaporator 22 and full-sized ice blocks have formed in the molds cooled by the right-hand evaporator 24 the operations of these evaporators will be reversed so that the left-hand evaporator 22 is refrigerated while the right-hand evaporator 24 is heated by warm liquid refrigerant to release the ice blocks from the molds associated therewith.

This operation continues with ice being formed by one evaporator while it is being thawed free by the other until the accumulation of ice in the storage chamber I8 builds up to approximately the level of the control bulb 88. When this control bulb is cooled to nearly the 32 ice temperature the system Will stop at the next shift from one evaporator to the other, the control being so arranged that the compressor is not stopped in the middle of an ice-forming cycle. This provides for finishing whatever freezing cycle is in process at the time the ice supply in tank I8 reaches the level of the control bulb 88,- so as toavoid the release of thin shells or partially formed blocks of ice such as 34 in Figure 1.

The control bulb 88 is located within the tube 9B which has good thermal contact with the metal lining 92 of the ice storage compartment. A smaller tube 94 connects the bulb 88 with the control apparatus, as will be explained in connection with Figure 3. This location of the control bulb is such that'I it can be removed readily as disclosed in my copending Patent S. N. 771,181, filed August 29, 1947, now Patent No. 2,641,109. The tube 9U is of large enough inside diameter to allow removal of the bulb and it is sealed to the smaller tube at its open end as by a Split rubber plug 96.

The perforated portion 46 of the ice delivery chute is hinged at 98 to allow access to the overflow passage 48 so that the pan-shaped screen |00 can be removed for cleaning. This screen is to trap foreign matter which may have gotten into the water so as to keep it from entering the pump suction tube 65.

The drain cock |02 may be connected with the water delivery manifold as shown or may be separately connected with each section of the tank I6.

Its purpose is to facilitate drainage of the tank I6 when required. Such drainage is advisable periodically, the frequency depending upon the hardness of the supply water. This method of freezing ice produces ice which is purer than the water from which it is formed, thus resulting in a concentration of minerals in the remaining water and a mineral deposit at the bottom of the tank, hence the need for occasionally draining at least some of the water from the tank to remove the accumulated minerals.

The pipe connections of the refrigerating system are not shown in Figures l and 2 but are shown diagrammatically in Figure 3, which illustrates the refrigerating system employed in Figure l. The solid arrows of Figure 3 indicate the path of refrigerant flow corresponding to the conditions seen in Figure 1, where the left-hand evaporator 22 is being heated with hot liquid refrigerant and the right-hand evaporator 24 is being cooled by evaporation of this samerefrigerant. This control of cycling from right to left is produced by the valve mechanism 8E, which will be described in more detail later, but for the present its effect will be understood by tracing the paths indicated by arrows. The path of refrigerant flow with the valve mechanism set to refrigerate the right-hand evaporator is as follows, starting with the motor-compressor unit High pressure refrigerant vapor leaving the compressor thru the discharge tube Ill' goes to the condenser IBB where it is changed to its liquid phase and the liquid is delivered to the receiver II. Warm high pressure refrigerant liquid leaves the receiver thru the tube H2 and passes thru the valve mechanism SS to the tube IIA leading to the by-pass check valve H5 and to the opposite end of manifold l I5 of the evaporator 22. Since the liquid refrigerant is introduced to the evaporator under high pressure it does not evaporate but heats the evaporator to cause the release of ice from the left-hand section. The high pressure liquid-refrigerant, having been cooled by giving up much of its specific heat to the ice being thawed free, now flows from header I I8 thru the expansion valve |20 (which is shown as being of the thermostatic type and having-two bulbs andy I20v) f into the liquid header |122 `and tubes 26 of the evaporator -24 where it evaporates. rPhe four 'check valves |23 4are sogarranged 4that liquid cannot by-pass the from the compressor thru the condenser, the re- 1- -ceiverand the tube i i2 but at `the valvemechanism .Se the warm liquid refrigerant entering from the tube ||2 is directed into the tube |26 which carries it to the manifold |24 of the evaporator 24, which is ynow being heated by the warm liquid refrigerant to release ice. The refrigerant is still liquid as it enters the manifold |22 and ilows thru the expansion valve |29, but it has been cooled by the heat transfer from it to the .ice being-released.

Flow thru expansion valve i 2t of Figure 3 is in thesame direction as before, -but the check valves |23' now direct .the flow .so that it is from E22 to I I8. As this cold high pressure liquid refrigerant flows -thru the expansion valve 22E) its .pressure is reduced so that it evaporates in the evaporator 2.2 Yand the Yresulting vapor flows thru the tube lili tothe valve mechanism 35 which directs the ksuction vapor into vthe suction tube |255. The manifolds H3 and |22 always carry liquid .for either cycle of operation, hence it Ais permissible to use restricting orifices between them and the compartment as indicated at |26 in Figure 2.

This conserves vcooling eiect and is convenient lfor service.

Soon after the system is started the discharge tube |536 rises to a temperature which causes the switch |32 to close, starting the motor 13 of water pump 56. This delay in starting the water 'pump lightens the starting load of the system and provides some delay in stopping the water pump after the compressor has been stopped. This `operation of the water pump after the compressor stops is to complete the delivery of ice to the `storage compartment though it is not essential that all of the ice be so delivered before the water pump stops.

By providing some insulation |36 around the bulb |38 and a portion of the tube Ult the length of time during which the pump operates after the compressor has stopped will be increased and the length of time between the starting of the compressor and the starting of the water pump will be reduced. Since the bulb temperatures at which Iit is desired to close and reopen the switch |32 are :higher than ambient the thermostatic switch |32 will employ a liquid charge and operate on liquid expansion or it will operate on vapor pressure of liquid in the bulb |38 while the bellowschamber |40 and the tube |42 are lled with liquid.

The fthermostaticeswitch 5| 44 which-controls 'the i8 motor-compressor unit is connected with the bulb @8 which is seen in Figure 1 -near the upper level to which ice can accumulate in the tank i 8. The height of this bulb relative to the ice storage compartment may be adjusted by movement within the outer tube 98.

If this were the only bulb connected with the switch |46 it is seen that operation of the system will continue until `the ice level in the storage chamber builds up to about the level of the bulb, but `this would result in stopping the system in response to the dropping -of ice blocks into the storage chamber regardless ofthe position inthe cycle of ice making. The chances are that such stoppage would occur with ice blocks partly formed on one side, as shown in Figure y1,and with some ice still to be freed from the other set of molds.

The partially formed ice blocks would melt free of themselvesfduring a prolonged idle period and if the period were greatly prolonged they would melt entirely before the next start of the system, but the system would start with its control (the valve mechanism t5) in the middle of a cycle so that the -nrst batch of ice formed would consist of partially formed blocks somewhat as shown attached to the right-hand molds in Figure 1. l'n .order .to prevent this starting and stopping midway of ice formation the thermostatic switch It@ is connected with two bulbs, the second one iti? being clamped to the suction tube |23. These bulbs se and lll-t are in open communication with each other and with the kbellows chamber |48 of the switch Uitl thru tubes et and |59.

The proper operation of switch |64 requires a charge of volatile fluid such that the liquid portion thereof is somewhat more than enough to fill the bulb S8 and the portion of the tube 94 which is within the upper portion of tube 90 soldered or otherwise held in intimate thermal contact with the wall 92 lof tank i8, The excess of liquid beyond this will collect in the next colder part of the thermostatic system, which is the bulb |46, because of its association with the suction tube. The point at which the bulb l 4t is clamped to the suction tube is within the condensing unit compartment 2li of the cabinet and Anear enough to the compressor so that this portion of the suction tube is not normally frosted.

There is, however, a periodic frosting of the suction tube each time the valve mechanism 36 operates to reverse the ow of refrigerant thru the evaporators, since this connects an evaporator which is full of liquid with the suction side of the compressor. This might damage the compressor if the suction tube led directly to the compressor cylinder, but it is here assumed that the suction tube leads to the casing of the sealed unit IM so that a slight flow of liquid refrigerant to the unit casing does not damage the compressor. This momentary frostback does, however, cool the 'bulb MP5 to a temperature lower than the cutout temperature of the switch Me and liquid will collect in the bulb it until this bulb is full, leaving only vapor in the balance of the control except that the Ibulb 88 will contain some liquid and some vapor. Under this condition, while the bulb |45 is momentarily cooled, the switch |44 is responsive to the temperature of the bulb '38 and if this temperature is at 'the required cutout point of say 33 F. the vswitch IM will open and stop the compressor.

It will be seen that the compressor'will not be stopped bythe cooling of bulb l 46 alone, no matter how cold that bulbge'ts, lneither will 'it be 'stopped Iby the .cooling fof bulb 88 "alone vt'o 133 or colder, but when bulb 88 has been cooled to the cutout temperature of the switch |44, which may be 33 F., the switch will open the next time the bulb |46 is cooled to some temperature lower than the cutout point. After the system is thus stopped all of the volatile liquid of this control will collect in the bulb 88 which is the coldest zone and in the next coldest zone which is that part of tube 94 Within tube 90. Warming of bulb 88 due to ice removal or meltage will restart the system. Extra high room temperature causing heat leakage to the bulb 88 and to the tube 94 will hasten the starting, thus providing a, quicker start when the demand for ice is most apt to be heavy. In order to allow some greater tolerance on the quantity of the volatile charge of switch |44 the tube .94 may be made somewhat larger than is usual in thermostatic controls, thus allowing plenty of room for all of the liquid part ofthe charge. y

Figure 4 is similar to Figure 3 but shows some modifications including the substitution of a solenoid-operated valve mechanism |52 for the valve mechanism 86 of Figure 3, where valves are actuated by mechanical power derived from the refrigerant ow of vapor. The valve mechanism |52 of Figure 4 is described in detail in my copending application S. N. 45,343 led August 20, 1948.

vAs shown in Figure 4 the coil of solenoid |54 is not energized since its terminal |56 connects thru the wire |58 to the open terminal |60 of clock-actuated switch |62. The motor-compressor unit |04 is shown as energized by flow of current thru the line conductor |64 and thru switch |62 to motor lead |66. The other conductor |68 connected with the compressor motor isl connected thru the closed switch to the opposite line conductor |12. The valve mechanism |52 is assumed to be in the position causing ilow to follow the solid arrows, which in this case indicate defrosting of the right-hand evaporator 24' and cooling of the left-hand evaporator 22'.

When solenoid |54 vis energized this valve mechanism will shift to the position in which refrigerant flow follows the dotted arrows, thus defrosting the left-hand evaporator and cooling the right-hand evaporator in accordance with the operation first described in connection with Figure 3. The control bulb 86 is assumed to be 1ocated as seen in Figures 1 and 3 but the switch |10 has no second bulb as does the switch |44 of Figurev 3. Instead of the two-bulb method of causing switch |44 to open only at the moment of a shift in the ice-making cycle this leffect is attained in switchl |10 of Figure 4 by a different method.

The switch |62 has two positions, the one shown by full line |14 and the one indicated by the dotted line |16. In either of these positions the compressor motor is energized and the coil of magnet |80 is energized, but only in the dotted position |16 is the solenoid |54 energized. The purpose of the magnet |80 is to hold the switch |10 closed after the bulb 88 has been cooled to the cutout temperature of say 33 by the accumulation of ice in the storage chamber I8, thus the system will continue to operate after the ice quantity has built up to the cutout point until the next time that the switch |62 is operated.

When switch |62 operates in either direction the circuit thru the winding of the magnet |80 is momentarily open and at this time the thermostatic switch |10 willopen if its bulb 88 has previously been cooled to the cut-outtemperature. Since the opening of switch |10 opens the circuits of the magnet |80, the clock motor winding |82,.the winding of solenoid |54 and of the motor compressor unit |04, the entire system will stop with the exception of the motors |34 and |84 which are controlled by the thermostatic switch |32. The clock motor winding |82 will remain idle so that at the next reclosing of the switch |10 the clock motor starts at the beginning of an ice-making cycle on one or the other of the two evaporators.

The switch |32 is arranged to control the pump motor |84 in the same manner as Figure 3. It also controls the motor |84, which may operate a fan in the event that the condenser |88 is air cooled -or it may operate an ice elevator for taking ice from the surface of the water in the icemaking tank I6 and delivering it to the storage chamber |8 if it is preferred to use such an elevator rather than the means shown in Figure 1 for removing the ice from the water in which it oats when released. The clock-actuated switch |62 is not illustrated in detail in Figure 4, as such switches are well known, but attention is called to the fact that the clock mot-or is in this case so connected that it stands idle While the compressor is idle, having stopped at the instant that switch |10 opened, but the switch |62 always recloses on the other contact or contacts at such times so that when the switch |10 is again closed by a rise of temperature of the bulb 88 the 4clock motor restarts, being of a self-starting type, at the beginning of an ice-making period on one or the other of the two evaporators.

It will be seen that the switch |44 of Figure 3 with its two bulbs could be used in the hook-up shown by Figure 4, as there will be the same frostback of the suction tube |28 at the instant of the valve operation to shift from cooling one evaporator to cooling the other, but thevvalve mechanism of Figure 4, not being self-actuated,

' requires the solenoid |54 and this solenoid in turn requires a periodically actuated switch such as the clock-driven switch |62. In Figure 4 the clock-actuated switch |62 cooperates with the magnet to cause the switch |10 to open at the desired time.

Figure 5 shows diagrammatically a clockdriven switch |86 of the general type disclosed in my U. S. Patent No. 2,027,192 issued January 7, 1936 wherein Figure 6 shows a terminal brush |50 contacting the motor commutator sleeve |54 which is mounted on the insulating element |55 carried by the clock-driven shaft |55. In the present case a similar wheel or drum |81 of insulating material carries four arcuate metal contact members, H, L, H', L and a complete circular metal contact member |88. The brush is in constant contact with the circular member |86 while the brushes |62, |94, |96 and |88 are in intermittent contact with the arcuate metal members I-I, L, H and L respectively. The connecting wires 200 lie partly or wholly buried Within the drum |81, at least enough to prevent the brushes |96 and |08 contacting one of them.

When the contact brush |82 is in Contact with the arcuate member H the solenoid valve 202 is energized to open so that high pressure refrigerant flows thru the tube ||2 to the tube ||4. Also when the brush |94contacts the arcuate member L the solenoid valve 204 is opened for refrigerant vapor to ilow from the tube |26 to the suction tube |28. At this time the lsolenoid valves 206 and 208 are closed because their corresponding brushes |86 and |98 are in contact with the drum or insulating materieller instead of with their contact members 'I-I 'and L.

It is thus seen that in the position indicated by Figure 5 the left- hand evaporator 22 or 22 is being defrosted and the right-hand 'evaporator' 24 vor 24 cooled, applying Figure 5 to either Figure 3 or Figure 4. As the drum continues to ro= tate to the right as indicated in Figure 5, Where the drum IST is shown in development, it will be seen that the first effect of drum rotation is to cause the brush IQZ vto break connection with the arcuate contact H, allowing the liquid valve 202 to close While low-side valve 2M remains open for a short time represented by the space B.

During this short interval liquid refrigerant continues to flow from the left- hand evaporator 22 or 22 thru thev expansion valve l2@ to the activefevapor'ator 24 or 2d. This continues for ay minute or ytvvo of operation which allows 'the liquid "pressure Within the inactive (left side) evaporator 4to drop to say 35 pounds and then the su-@uen valve 2st closes and brushes its and'lt make 'contacts with L and H respect'ivel`y in this sequence, thus opening the lows'ide valve '20S an instant before high-side valve 205 is opened.

'After an operating period during which the right-hand evaporator is defrosted and the lefthand evaporator is cooled 'a similar shift occurs, first shutting valve ZUG to stop liquid supply `to the right-hand evaporator until it drops to a pressure of lsay 35st, then closing suction valve 20S vand opening the valve 2M, and a moment later 4opening the valve 252 to start refrigeration of the right-hand evaporator while the left-hand evaporator is deirosted'bymeans of Warm liquid refrigerant.

A The arrangement s hovvn by Figure 5 allows thef use of four conventional solenoid valves in place of the valve mechanism 85 "of Figure 3 or the valve mechanism 52 of Figure 4. While a valve mechanism which combines four valves jin `one as 'per Figure or 4 is preferred, the arrangement shown by Figure 5 allows use at the expense "of greater cost and a 'more complicated electricalsystemof stock solenoid valves. 'Other valves adaptable for use in this system 'are slioivn byFigure 9'of my issued PatentNo. 2,145,773, by Figures '1, 6 and 28 lof my issued 'Patent No.

2,145,774, by the drawing olf my Patent No.

2,368,675 vand by Figure 1 of my 'Patent No. 2,407,794, butthe valve mechanism hereinafter described 'in connection with 'Figures' to l0 inelusive is preferred because of 'its simplicity'and lower cost.

n .Figures' to l0 inclusive illustrate details'of'the valve assembly 8e shovvn in Figures 1 'and 3, Where the valves are actuated on a timed cycle bythe flow of refrigerant vapor. This method of valve actuation is similar to that shown by Figures 9, 10 and l1 of 'my issued vPatent No. A

ablefor use in the reversible heat pumpI type of system and is adjustable fromvthe loutsidefto vary the lengthof cycleor to stop the cycling for continuous operation with either desired dirction ofslovv.d v n l v Referringto`Figure'- 6,' hot liquidrefrigerant (as in a liquid-defrost ice maker) or nigh pressure refrigerant vapor (asin "a reversibie heat pump systemienters thru the tube H2, flows past the open valve 2 I2 into passage 2 M and exits thru the tube H4 tothe evaporator which is being Vde'- frosted to release ice vin'an ice-making system or to the heat exchanger serving as the condenser in a reversible heat pump system. Suction vapor enters thru the tube 126110 the passage 215 and flows past the open valve 253 to the interior of the main suction chamber, 220 (Figure I7) and exists thru the "tube E28 tothe suction side of 4the compressor. it will be noted that high pressure valve 222 and low pressure valve 224 are 'closed and that each of these valves is held closed by high pressure 'refrigerant which vurges each valve in its closing direction against the lower pressure of suctionvap'on y Each of these closed valve is rigidly joined with one of the open valves and both pairs of valves are operable by means of Ylevers '22,6 and 223 which have forked ends embracing the stems of the paired valves ,in a Vmanner to bear against shoulders on the valve stems'to move the valves. These forked ends nt loosely between their respective shoulders as it is desirable to have a considerable amount of backlash 'so that the valve- operating levers 226 and 228 move an appreciable distance before engaging the opposite shoulders to effect reversal of the valves.

In my copending application Serial No. 45,343 filed August 20, 1948, Ivshovv an arrangement of valves similar vto that seen in Figure 6, but arranged to be operated by a solenoid with a balancing member I I8 to equalizethe pull of the solenoid on the two :pairs of valves. Equivalent balancing Ameans may voptionally be included in the valve mechanism here shown, but 'is not consideiednecessary because of the fact that veach closed valve Ais urged against its seat by .high pressure refrigerant. In the present disclosure one of the forked members `vvill come to vrest with spring pressure urging it against the shoulder which holds one of the valves closed. Mechanical inaccuracies unavoidable in production v/ill cause the other forked member to stop short of or lightly contact the shoulder which urges the other closed valve in its closing direction.

As explained above the vvalves will be held closed by the high pressure liquid or high pressure vapor. Without goingfto the expense of providing the equalizing mechanism it is possible to insure pressure of each forked member in the direction of closingits respective Valve by in corporating a slight flexibility in the mechanism which connects the two forked levers. For instance as seen in Figure 8 the twovforked levers 226 and 228 are keyed to the shaft v22363, and such flexibility `could be incorporated in the levers, in the shaft or in the mounting of the leverson the shaft. s l

Again referring to Figure 6 it will be seen that when the two forked levers are simultaneously moved to the 'left valves 222 and 2Min/ill be opened and valves 2l2 and 258 moved toward their seats. AS highy pressure valve 2 i2 approaches its seat it acts as a check valve because ofthe high pressure refrigerant back of it. As suction vapor valve 2i8 approaches its `seat it Will also act as a check valve because high pressure valve'222 'has'been opened'and thereis'n'ow higlripressurey refrigerant in 'the chamber 2 it urging'the 'vali/e2 f8 "againstits seat.I

After 'such'actu'ati'n' of the lvalvem''echariisin vof Figure '6,v moving'of four valves to 'the'lfu -high pressure refrigerant will flow past thevalve 222 into the chamber 2I6 where valve 2|8 is now closed, hence the high pressure refrigerant will flow out thru the tube |26. At the same time suction vapor entering thru the tube ||4 to the passage 2|4 must flow past the open valve 224 to the chamber 220 and out thru the tube |28 since the valve 2 |2 is closed.

Instead of actuating these valves by means of a solenoid, as described in my above mentioned copending application number S. N. 45,343, the actuation is eiected by means of the coil spring 232, which is under compression between the pivot 234 on rocker 228 and the pivot 236 on the longer arm of bell crank 238. In the position shown in Figure 7 the bell crank, which is pivoted upon the shaft 230, has been moved in a clockwise direction by means of the connecting rod 240 until the spring 232 is urging the rocker 228 to move in a counterclockwise direction.

Figure 7 thus represents a position of the mechanism which might be assumed at the instant prior to actuation of the valves by the spring 232. Assuming now that such actuation takes place, the forked end of rocker 228 will move to the left, opening valve 224 and closing valve 2|8. Since the rocker 228 and lever 226 are both keyed to the shaft 236, a similar movement will be made by the lever 22 6, thus effecting simultaneous operation of both pairs of valves. It will be seen that shaft 230 (Figure 8) passes thru the wall dividing chambers 220 and 24|.

To prevent leakage around this shaft the face of the hub of arm 226 and the face of the wall surrounding the hole on the high pressure side, that is, in chamber 24|, are accurately finished to provide a substantially leak-proof contact with each other. If desired a washer of compressible material may be employed between these faces as indicated by 242. The higher pressure always prevailing in chamber 24| ensures that the thrust on shaft 230 will always be to the right to maintain pressure on this washer.

The connecting rod 246 is driven by the pin 244 on the low speed gear 246, which may make one revolution per hour. Assuming that this is the speed of the gear 246 it will be seen that the valves will be snapped from one position to the other at intervals of 30 minutes. In order to drive the gear 246 at such a low speed a train of clock gears is employed comprising a number of driven gear wheels 248 and an equal number of driving pinions 256.

`The pinion 252 which drives the last gear 246 differs in being cut on the end of a longer hub member which has an external bearing in the support 254. It is also desirable that this pinion 252 and the last gear 246 be of coarser pitch than the other gears because their very low speed increases the tooth load. The rst of the pinions 250 (not seen) is mounted on the hub of the worm gear 256 and drives the first of the gears 248. This worm gear is driven by the singlethreaded worm 258, which is preferably one piece with the shaft 266, on the lower end of which is mounted the gas-driven wheel 262.

This gas-driven wheel may operate at 1000 or more revolutions per minute in order to drive the final gear 246 at one revolution per hour. 'Ihe speed of the gas-driven wheel will depend upon the density and the rate of flow of vapor passing thru the hole 264 in the wall 266, which ts tightly within the casing 268 so that vapor flowing from the chamber 226 to the chamber 216 must pass thru either the hole 264 or hole 212...

In order to adjust the speed of the gas-driven wheel 262 and thereby the timing of the valve mechanism I have provided a shutter 214 which can completely close either the inlet of hole 264 or the inlet of hole 212. It will be obvious that the gear train can be stopped by completely closing the hole 264 or that the speed of operation will be greatly increased by completely closing the by-pass hole 212.

Figure 9 shows the means for adjusting the shutter 214 from the outside of the casing 268. This adjustment is a service operation rather than one to be performed regularly by the user, as the timing of the valves will remain substantially constant in any given installation so long as the same compressor is used carrying susbtantially the same load with the same type of control. Even where a thermostatic expansion valve is used, causing a considerable change of suction vapor density from start to end of a running period, the timing will be substantially constant as to -the length of cycle even though the gas-driven wheel 262 operates at a considerably higher R. P. M. during the early part of the cycle than it does during the latter part of the cycle. It may, however, be desired at times to change the operating cycle for some reason such as increasing the size of the ice blocks by lengthening the cycle or reducing their size by shortening the cycle. In such case the plug 216 is removed and the screw 218 adjusted to shift the position of the shutter 214 to cover more of the hole 212 so as to shorten the cycle or to cover more of the hole 264 so as to lengthen the cycle.

It will be seen in Figure 9 that the shutter 214 is pivoted on the wall 266 by means of the screw 280. This shutter has two upturned ends, the curved end 282 serving as contact for the screw 218 while the opposite upturned end 284 is notched to receive and retain one end of the spring 266, which may be a plain hairpin type as shown or may include one or more coils around the screw 286. The opposite end of the spring is anchored on the wall 266 as by the screw 288. If the screw 218 is removed entirely the shutter 214 is stopped by contact with the bearing support 254 before its curved end moves out into contact with the shell 268. This allows for assembly of the shell to the mechanism before the screw 218 is inserted. Since chamber 220 contains only low pressure refrigerant vapor, usually at slightly more than atmospheric pressure, there is very little leakage thru the threads of the screw 218 and this leakage is normally outward.

The screw 218 could be provided with a packed stem4 or with a bellows seal, but this is not considered necessary since the tapered pipe plug 216 will be in place at all times except while a service adjustment is being made to change the cycle of the system. In the event that this valve mechanism is to be used in a heat piunp system, where the user will at times wish to shift the operation from a cooling cycle to a heating cycle or vice versa, the shutter 214 or its equivalent may be operated thru a bellows or diaphragm by manual or thermostatic means, as will be described in connection with Figure l0.

The wall 266 which divides the interior of casing 268 is connected with the valve mechanism by means of the members 26|) and 262 which may be part of one casting or forging or may be separate members attached to connect the wall 266 and its mechanism with the valve body which closes the upper end of the casing 268. In these acca-orc:

drawings thevalve body andthe entire frame is.

shown as-cast in. one piece and in. any event theymay be assembled in one-piece so that the` entire mechanism can be tested before rthe shell 268-'. is added.

For test purposes a separateair jet may be usedto drive the wheel 262 and suitable connections made for leak-testing of the valves.

equivalents of the air jet to various suction vapor dens-ities andrates of flow to determinethe. de.- sired factory setting of the shutter 2'E4. After assemblyfand testk of the mechanism the shell 226i)- is pushed over the wall 286 which is forcibly engaged by the shoulder 291i of the shell before theropenend of they shell malzes contact. with4 the shoulder 295 on the main valve body. This leaves. a small gap'Zll. which is lled with the silver solder or other material used in hermetical- 1yseal-ing the assembly.

Since it is also required to seal the shell toA the Wall 3mi across the bottom and up the two sidesfof the chamber 21H, I provide several small holes as shown at 352 for introduction `of solder or for exit of solder in the event that the. solder. or spelter is attached to one of the membersv prior to--their-assembly. Such attachment:might` be by means of a groove cut in the contactlface of-` the wall 366.

Figure 10 shows a valvearrangement. for use.

inmanual controlthru the. medium of the. gasdriven mechanism. In this case a lesser gear reduction used, as by merely omitting some of the gears so that the valve shift occurs in a few seconds instead of in several minutes. seen in Figurelo the ball check valve SI2 normally closes the port 3M so that the gas-driven w-heel Z'EZstands idle.. When it isdesired to shift from one operating cycle to the other the push button 316 isY depressed so that the rod SiS holds the ball 3I2oi of its seat, closing the byepass passage 32! instead of the port 3M. When the shift occurs it is instanthr detectable by sound, by a change in the rhythm of the motor-compressor unit and by temperature changes of the connecting tubes. user merely releases the button 31S and the ball 32falls bach onto its seat, closing the port 3M andthereby stopping the gear mechanism.

The bellows 322 is protected by the cover 324 to avoidi-njury. By omitting the button andy in` operation in one manner and a variable cyclei The rod 3&8 maybe of operation in the other. arranged sothat it does not extend thru the casing 258 except when. actuated, or the. cover 326. may be made deep enough soy that the rod maybe retracted furthe purpose of assembling.

the cover over the mechanism. The-stop ypin 326 is. to keep ball SI2 from falling out of place.

By combining. the bellows 322 of Figure` 10 with thefshutter 2'1'4 of Figure 9 and making thev bellows thermally responsive by means of a thermally. responsive iiuid enclosed between the bellows and its casing 324. a thermostatic control of thespeed ofthe-.gear train is` obtained. 'Ihusa` bulb connected by means of a capillarytube withr the'V sealed cover 3241- would. when warmed,` causa A, scale of comparison can readily lee-established for When this change occurs .the

the .rodi 3l Seto push againstvthe. upturned icurved;

endl 282 of: shutter 2M, as the screw 2?*'82 does in Figure. 9, causingy the shutter. to move` in the direction of opening port 2M and closing port 27.2 and thus speed up the gear trainto.y hasten theV operation4 of the valve mechanism. The bulb could be located in contact with theinlet tube of expansion valve i213' in Figure 3, so as to be warmed by arise of temperature of high pressure liquidrefrigerant ilowing from either evaporatorthat is bein-g defrosted.

TheI effectof this would be to cause or hasten operation of valve mechanism 86' in response to arise of temperature of the liquid refrigerant thatr has` passed in. heatexchange with the molds 2l'` of the assembly 22901' 2.4. With such an arrangement: the mechanismof Se.; would* be designed `to-cause somewhat; longer cycles than are necessary to-allow time for ice to release, but rthe cycle would be shortened by a rise of reY frigerant liquid temperatureY atk entry to the expansion valve, such. rise. ofk temperature being dependent upon the ice: blocks having been-re leased.

It is'thus-seenthat'the valve mechanism shown by Figures 6 ato 10 inclusive may be used-invari-4 ous types-of systems. for operation undervariousA position and the plug y31m ypressed fin .and brazed or soldered'. The two plugs 336 and 338 aresimilarly installed if` the passages l-dand'llt are drilled. If these passages arev` in theforging'or casting` the plugs will not-bey required. Thevalve 21B/.is attached to the stem- Sflli, as ily-upsetting the stem, While the opposite valve 224 `may either be similarly attached or formed' of onepiece-y with thestem. At leastoneA of these valvesis pushed onto the stem against a shoulder and-the stem riveted or spun over to retain the valve.

Water circulation may be stopped in the icemalr-ing tanker a section thereof while its evaporator is being heated to `release ice. ThisA conserves some energy and avoids some-loss of icey weight.` This may be done by` stopping the water pun-1p -inan ice-maker which freezes iceV i-n all molds at one time, but in a system such asshown by Figure -3 the water circulation is diverted by means of valves 3'56 and 3M, which may be vsoleheid-operated.

instance the switch shown in Figure 5 might have two kextra brushes such: as l92 to ESS-and corresponding contact members on the dru-mi3? to open- .one orthe other of the valves. An alternative would be to use twopumps 56 driven' by separate motors and employ the switching means to start and stop one motor at a time.

The two pumps may be operated simultaneous? lyfor a short period or bothvalves 350 and 352 be held open for a time to provide periodically an eXtra iow of water from the tank i6 to clear it of floating ice.

to allow warmer water toA settle tothe bottom of the tank; 1 (due. to its-.reverse 1 thermal expansion) The part forming the two fvalves2l2` andv Such solenoid valves may becontrolledby thermostatic or timedmeans, for- Conversely water flow to all' outlets Sil-.may be stopped for a short periodV and to suspend the forced ow of water so that ice blocks ready to oat from molds are allowed to do so freely.

In Figure 1 it may be advisable to place a dividing wall consisting of a single sheet of metal midway between 22 and 24, which are then spaced farther apart, with separate sets of water jets 64 on opposite sides of the wall to localize the agitation.

The check valves l I5 and I25 are connected to allow flow of warm liquid directly to the evaporator tubes associated with any of the molds 21 which are slowest in releasiing ice, thus equalizing the ice-releasing time. These valves allow free flow of liquid for ice releasing but are closed to vapor flow in the opposite direction.

Wherever cold suction vapor flows thru a conduit located in a Warm space, such as the condensing unit compartment 20, it is advisable to insulate such conduits as indicated by 01 in Figure 3. Also it is advisable to insulate any hot liquid conduit exposed to low temperature, such as that of the ice storage compartment I8. It will therefore be found best to locate the liquid valves 202 and 206 in the condensing unit cornpartment Z0 and to locate suction control valves 204 and 208 in the ice storage compartment I8, as this reduces the areas requiring separate insulation.

I claim:

1. In an ice-making apparatus, an ice-making chamber, a compartment for storage of small pieces of ice, a pump for providing water agitation for the purpose of producing clear ice, a tube connected with said pump, a venturi connected with said tube, and a second tube leading from a lower portion of said ice storage compartment to the side inlet of said venturi for the purpose of lifting water from the bottom of said storage chamber and delivering it to said icemaking chamber.

2. In a refrigerating system of the reversible type, a pair of heat exchangers arranged to serve alternately as evaporator and condenser, valve means for reversing refrigerant flow, means enclosed within the refrigerant circuit of said systern for taking energy from the flow of said refrigerant and applying it to the actuation of said valve means, and means operable from outside of said circuit for controlling the operation of said valve means to effect the reversal of refrigerant ow.

3. In an ice-making apparatus including a refrigerating system for making and releasing individual pieces of ice, a cooling element forming a part of said system, means for storing said ice after its release, transfer means for moving said ice to said storage means, a motor for operating said transfer means, and control means adapted to stop operation of said cooling element to stop the formation of ice and thereafter to stop said motor.

4. In a refrigerating system employing a volatile refrigerant, a pair of evaporators, a plurality of refrigerant conduits connecting said evaporators in said system, a valve for diverting the flow of said refrigerant in its liquid phase relative to at least one of said conduits, a valve for diverting flow of said refrigerant in its vapor phase relative to at least one of said conduits, and a device energized by flow of the vapor of said refrigerant for actuating both of said valves.

5. In an ice-making system, a tank adapted to contain water and small pieces of ice in flotation, overflow chute means for conveying such ice from said tank, and means for orienting such pieces of ice as they enter said chute vmeans to cause them to move endwise therethrough.

6. In an ice-making system, a pair of evaporators connected in series, means for introducing high pressure liquid refrigerant to one of said evaporators to fill it and passing said refrigerant into the other of said evaporators at reduced pressure to cool it, timing means including gears driven by the iiow of refrigerant vapor from the evaporator being cooled, and valve means aotuated by said timing means to cause a reversal of flow of refrigerant thru said evaporators so that the one which has just finished a cooling period is heated by the introduction of high pressure liquid refrigerant while the evaporator which has just finished a period of being heated by liquid refrigerant receives liquid refrigerant at reduced pressure from the evaporator now being heated and is thus cooled by the evaporation of said refrigerant.

7. In an ice-making system including a water tank, two sets of molds arranged in back-to-back relationship to form a vertical assembly within said water tank, evaporator means included in said assembly and in heat exchange with said molds, and means for causing alternate cooling of said molds by the evaporation of a volatile liquid refrigerant in said evaporator means and heating of said molds by warm high pressure refrigerant passing thru said evaporator means.

8. In an ice-maker, means for employing warm high pressure liquid refrigerant to melt ice free, an expansion device for thereafter reducing the pressure on said refrigerant, means for effecting cyclic operation of said ice-maker, and means responsive to a temperature rise of said liquid at its entry to said pressure reducing device to shorten the cycle of operation then in process.

9. In an ice-making system, an ice-maker tank, an overflow outlet for said tank, a tank arranged to receive overflow water from said outlet and to have a lower water level during operation of said system and a higher water level during idle periods, and a fioat-actuated valve for supplying make-up Water to said system, the float which operates said valve being located in said iverlflow tank at a level below said higher water eve 10. In a refrigerating system of the reversible heat pump type, a plurality of solenoid valves for reversing refrigerant flow in a part of said system, a multiple switch connected with the solenoids of said valves, and a clock mechanism to operate said switch.

1l. A refrigerating system including a compresso-r and a motor for driving said compressor, a pump driven by an auxiliary motor for circulating fluid to be cooled by said system, a rst control means for starting and stopping the first said motor, a second control means arranged to start and stop the second said motor, a thermally affected member forming a part of said second control means and located in heat transfer relationship with a part of said system, and thermal insulating means arranged to protect said member.

12. In an ice-making system including a refrigerating system employing a volatile refrigerant, means for utilizing the specic heat of a high pressure liquid refrigerant to release ice from surfaces on which it has been formed, means for supplying water to said ice-making system for use in making ice, and means for utilizing the specific heat absorbing capacity of fculate avolatile refrigerant, means for causing said `rrefrigerant to reverse its direction of Vcirculaiienirietleeee e pertienef Seid Systeme ,reine exept expensiendeviee,leeeted,between ir/ Q Seetiensef Seid ,permetterci means 91 eel-usine ethe same direction for both directions "Qfvrefrigerentflew tbrueed. rerienef theeysiee- 1 5- In en ,rerieereime System esiented te Cr- ,eulete Yeletle leirieerentmeeee fer eeueine sedrefrieeleette reverse its dir eeiiefl 0f, eireule- Y,

non met leest@ .Dertien ef ,Seid Syetein, e 'refile- 4ierant expansion devicev located Y between tivo vsections, 0f Seid renten and sneek, velresfereneedto. dreetiiellieereni.SOW.thru Seid eXDeneen derefrigerant fioivthru said portion ofthe' system. 16, e refrieereiineeyeten @Deir ef evapo- ,re ters meens for eeusine. ,evepereiiel 0f reflieerent in. ,Seidl eveeerire ene .et e time, While the yof said refrigerant for modifying its oiv, gear reduction means Within saidfcircuit for actuating the second said means, means actuated o'y the `110W of said refrigeran'tto drive said gear reduction means, and bylpass 'valve 'adjustable from outside o'f vsaid circuit to 4vary the speed of said n v,gear reduction means. frigerant to flow, thru saidV expansion device .iny ,A

other Qf the evepel'eiere v1S heated by high -pree-` eurerefriserenten erpeheeli valve ef the thermeSietie-ine ,ellle-eeedte. regulate ewl O f liquid .refrigerant te we. eherer, ene effeeid evaperetore ie eetlve' ee en evepereter -,nd Deir; 0f4 thermal response elemente QHHQiedWitb Seid valve t0- contr/o1'it,one`fof saii Velements being associated with, 919@ 0f ,Said- QVWQTQQI t0, 311,56 theyllve te ,respond recharges., ef, Operating conditions of the active: evaporator.

GLENN MUF'FLY.

References yCited in the le of this patent UNITED STATES PATENTS Number Name Date 703,315 Smith June 24, 1902 703,353 Smith June 24, 1902 1,510,147 Keith Sept. 30, 1924 1,995,124 Kol'ster Mar. 19, 1935 2,077,820 Arp Apr. 20, 1937 2,145,774 Muly Jan. 81, 1939 "2,145,777 BuiTly Jan. 31, 1939 2,299,414 Spiegl O,ct.;2`0, 19.42 2,349,451 Motz Mayiz, i944 2,359,780 Muiy Oct.' 10,1944 -2,373,255 McGoldrick' l`Apr. 1'0, 1945 2,443,203 Smith June 15, 1948 2,449,132 Lucia Sept/@14, 1948 2,497,903-A M'uiTlyf l' Feb. 21, 1950 FOREIGN PATENTS Number Country Date 15,523y Great Britain May 7, 1897

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