US2296879A - Refrigeration - Google Patents

Description

p 1942- D. G. SMELLIEY 2,296,879

REFRIGERATION Filed July 20, 1938 3 Sheets-Sheet l r29 I as A 34 l5 E r INVENTOR Donald 6? Jzzze/Izk ATTORNEY S p 1942' D. s. SMELLIE 2,296,879

- REFRIGERATION 1 Filed July. 20, 1938 Sheets-Sheet 2 Y INVENIITOR D0nald c. Jmellz'e BY I "--4o' 7 Z 5.,

4 v g ATTORNEY Patented Sept. 29, 1942 REFRIGERATION Donald G. Smellic, Canton, Ohio, assignor to The Hoover Company, North Canton, Ohio, a corporation of Ohio Application July 20, 1938, Serial No. 220,201

30 Claims.

This invention relates to refrigerating systems and more particularly to a novel design for ice making evaporators for use with refrigerating systems.

Heretofore, refrigerating systems have been provided with metallic trays having internal grids whereby water placed in the tray was frozen into a plurality of small blocks or cubes. These systems have the disadvantage that the trays freeze solidly to their supporting shelves and require considerable force to be freed therefrom, and the individual blocks of ice can be removed from the grid only by melting. a large portion of the same or through the application of large forces applied by complex and extensive link mechanisms. Previous refrigerators also are characterized in that the very low temperatures carried on the evaporating coil and the absence of an exposed body of water within the storage compartment causes extreme dehumidiflcation of the air circulating within the storage compartment with resulting deterioration and damage to foodstuffs in the refrigerator. ,Also objectionable frost coated all surfaces of the evaporator. Furthermore, while previously refrigerating systems operate for a greater length of time in hot weather than in cold weather, the ice making capacity'of the machine is fixed to the maximum number of cubes which the ice'tray will hold regardless of the frequency of operation of the refrigerating mechanism. In order to'provide a greater quantity of ice it is necessary contin'u ally to empty the ice trays and to store the previously frozen ice until it is desired to use the same.

According tothis invention, there is provided a refrigerating system and evaporator structure in which individual blocks of ice are continually water container also serves as a medium whereby the air circulating through the refrigerating compartment is maintained at temperatures low enough safely to preserve food stuffs but not sumciently cold to cause frost formation, and the large body of water from which the ice is formed forms a convenient tank of cold drinking water.

In addition, the apparatus herein disclosed is provided with a heavily insulated low temperature freezing compartment within which desserts and .the'like may be frozen without. interfer ing with or impeding the normal functions of the refrigerator apparatus,

According to the invention, refrigeration is produced in one or another section of an ice freezing evaporator by altering the heat rejecting area of certain parts of the refrigeratingsystem. The alteration of the heat. rejecting area of the system is under the control of the ice being frozen whereby refrigeration being produced in a given area of the evaporator is discontinued and produced in another area thereof whenever the ice blocks formed by the refrigeration produced in the first mentioned area of the evaporator reach a predetermined size. Therefrigerating system as a whole is controlled in accordance with the temperature prevailing within the foodstuffs compartment; therefore, the rate at which causes the machine to cycle more frequently resulting in a greater production of ice during periods of such high temperature.

Other objects and advantages of the invention will become apparent as the description pro- .ceeds when taken in connection with the accompanying drawings, in which:

formed in a large body of water. and float to,

,the surface thereof when they reach a predetermined size. The production of ice is'continuous whenever the machine is operating and g from the refrigerating machine with a ladle,

and the ice forming mechanism is itself a storage device for previously formed ice blocks. The large body of water which is maintained in the refrigerating compartment-provides a'means for maintaining the air within the compartment Figure 1 is a diagrammatic representation of my invention applied to one form of refrigerating systems.

. Figure 2 is a detailed view on an enlarged scale of the mechanism which controls the heat re jecting area of the refrigerating system;

' Figure 3 is a detailed sectional view on an enlarged scale of the evaporator ice freezing system;

Figure 4 is a fragmentary view on an enlarged scale of a modified form of heat rejecting mechanism; 1 v Figure 5 is an end view of the mechanism illustrated in Figure 4;

Figure 6 is a sectional view on an enlarged scale of a detail;

Figure 7 illustrates a modified form of heat within reasonable limits of relative humidity; the rejecting mechanism;

Figure 8 is a detailed sectional view of a portion of the apparatus shown in Figure 7 on an enlarged scale.

Figure 9, which is drawn to a small scale, illustrat'es the manner in which various parts of the refrigerating system are arranged in a cabinet.

Referring now to the drawing and first to Figure 1 thereof, it will be seen that I have disclosed my invention as it is applied to a continuous absorption refrigerating system comprising a boiler B, an analyzer D, a' rectifierR, a pair of condensers C and C, an evaporator E, a gas heat exchanger G, ari absorber A, a liquid heat exchanger L, and a circulating fan F driven by a motor M, all of which are connected by various conduits to form a plurality of gas and liquid circuits constituting a complete refrigerating system. w i

The refrigerating system is charged with a suitable refrigerant such as ammonia, and an absorbent such as water, and an inert gas such as nitrogen or hydrogen.

The boiler B is heated by a burner H of any desired construction which is provided with a suitable flame failure cut-off mechanism. The burner H is supplied with gas through a conduit l2, solenoid valve II, and a conduit l4. A

suitable by-pass i5 is provided around the valve l3 to permit a small amount of gas to by-pass the valve it when it is closed in order to maintain a pilot or igniting flame at the burner; The

burner ll andthe motor M for the fan 1? are controlled by a thermostatic switch mechanism H which is preferably mounted in the food storage compartment. Electrical energy is supplied through the wires 20 and 2|. The wire 2| connects directly to the motor M and to the sole-- noid valve It. The line 20 connects to one termi- -nal of the thermostatic switch mechanism l1, the other terminal of which is connected by the line 22 t0,the solenoid valve and the motor M. The arrangement is such that a rising temperature in the food storage compartment, evidencing a demand for refrigeration, causes the thermostatic switch to close the circuits to the line 22 and 20, and thereby to energize the circulating motor M and th solenoid valve It.

The boiler B normally contains the solution of a refrigerant in the absorbent which liberates refrigerant vapor when heated. The refrigerant vapor generated in the boiler B passes upwardly through the analyzer D in-counterflow relationship to strong absorption solution flowing downwardly therethrough. vapor is generated in the analyzer from the strong solution by the heat of condensation of the vapor of the absorbent which passes into the analyzer. Therefrigerant vapor is conveyed from the analyzer D through the condensers C and C by a conduit 24 which includes the air Additional refrigerant cooled rectifier R. The rectifier R causes condensation of any vapor of absorption which may pass through the analyzer.

i The weak solution formed in the boiler by the generation of refrigerant vapor i s conveyed therefrom into the upper portion of the air cooled absorber A through a conduit 28, the liquid heat exchanger L, and a conduit 21. It is apparent that the absorber is at an elevation above the liquid surface level normally prevailing in the boiler analyzer system; therefore, it is necessary to provide some means to elevate weak solution from the boiler into the absorber. For this purpose, a conduit 28 is connected between the gas discharge conduit 29. and the conduit 11 below the liquid surface level therein,

whereby the weak solution is elevated into the.

'is absorbed by the absorption solution and the heat of absorption is rejected to the medium surrounding the absorber which is preferably provided with a plurality of air cooling nns. The strong solution formed in the absorber is conveyed from the bottom portion thereof into the upperportion of the analyzer D through a conduit 3|, the liquid heat exchanger L, and a conduit 32.

The lean pressure equalizing medium is conveyed from the upper end of the absorber into the suction inlet of the fan F by a conduit 34." The pressure equalizing medium is placed under pressure by the circulating fan and is conveyed therefrom into the lower portion of the evaporator E through the conduit 29, the outer part of the gas heat exchanger G, and a conduit 35. The evaporator-condenser structure will be dedescribed more fully hereinafter; for the present, it'is suiiicient to note that the lean pressure equalizing medium circulates upwardly through the evaporator in counterflow relation to refrigerant liquid flowing downwardly therethrough. The refrigerant evaporates into the inert gas to produce refrigeration and the resulting rich pressure equalizing medium refri'gerant vapor mixture is conveyed from the upper portion of the evaporator to the lower portion of the absorber A through a conduit 31, the irmer path of the gas heat exchanger G, and theconduit 38. The rich gas flows upwardly through the absorber in counterflow relationship to the absorption solution thereby to remove the refrigerant vapor contents therefrom in the manner previously described.

The evaporator E comprises the lower coil section 40 which connects toa superimposed rectangular evaporator conduit 4| through a riser conduit 42. The evaporator section 4| is provided with a plurality of spaced-apart freezing pads 43 which are inclined to the horizontal for a purpose to be described hereinafter. The inert gas conduits l5 and 31 connect to the evaporator sections '40 and 4|, respectively.

The condenser sections C and C areidentical and only one need be described. The condenser 0 comprises a finned conduit designed to be aira conduit 46 to which the vapor supply conduit 24 is connected. l

The condenser C is connected to the inert gas discharge end of the lefthand side of the evaporator coil section 4|, as viewed in Figure 1,

through a conduit ill containing a U -shaped section. The condenser C' is similarly connected to the righthandside of the evaporator section through a conduit 5|. The flow of cooling air over the condenser C is under the control of a plate valve 53 which is rigidly attached to a con trol shaft .54. The flow of cooling air over the condenser C' is under the control of a plate valve 50 which is rigidly mounted upona control shaft 51. The control shafts 54 and 61' are provided which are pivotally connected to an actuating connecting rod 6|. The connecting rod is provided with an extension 62 which is connected to an overcenter snap-acting mechanism 64 carried within a control box 65.

Referring now to Figure 2, the condenser and control arrangement will be described in detail.-

The condensers extend longitudinally between the rear panel 61 of the refrigerator compartment and the rear wall 68 which define an air cooling flue for the condensers and the absorber of the refrigerating system. A dividing panel 69' is supported between the walls 61 and 68 and between the condensers C and C. It will be seen from Figure 2 that the arrangement is such that the flap valves 53 and 56 are positioned to control the air flow across the condensers C andC; furthermore, it will be seen that the flap valves 53 and 56 are mounted 90 apart, whereby one will be in full closed position while the other is in a full open position. J

Referring now to Figures 2 and 3, it will be seen that the evaporator is completely encased in an insulated compartment 10 which is provided with an inner chamber 1|. The insulated compartment 10 will be provided with a suitable insulated hingedly mounted door and seal. The evaporator sections 40 are mounted in heat exchange relationship with the bottom portion of the chamber II and the connecting conduit 42 is in heat exchange relationship with the rearand top portions of the compartment II. The ice freezing evaporator'sectionsfl are housed in the installation forming the outer wall of the casing I6 with the freezing pads 43 lying slightly above the installation in the top portion of the compartment 70 which is formed to provide a U-shaped channel to receive the U-shaped bottom portion 13 of a water tank I4.

A pair of thermostatic bulb elements 15 and 16 are mounted in the bottom portion of the tank 14 and in position to be frozen into ice blocks formed within the tank 14 above certain of the freezing pads 43 and positioned at opposite sides of said tank. The bulb I5 is connected by a conduit 11 the bellows I8 is positioned to actuate the overcenter snap-acting mechanism '64. The bulb I6 is connected by conduit 19 to a bellows 66 also in the interior of the tank 14 over the freezing pads 43 on the left hand section of the evaporator melt therefrom. As the ice blocks melt, the

18 will begin to warm up and expand. If the' bulb 16 has been frozen into an ice block sufficiently to collapse the bellows 80, the bellows 16 will move the mechanism 64 over-center and will cause the plate valves 53 and 56 to reverse position; that is, the condenser C will no longer be swept by cooling air, and the condenser C will be swept by cooling air wherefore all condensation will occur in the condenser C. However, if the bulb 16 has not been frozen into an ice block, the bellows 'I8 .will expand and be opposed by the bellows 86 without altering the position of the mechanism 64-until the bellows 80 collapses when the 'bulb I6 is frozen into an ice block.

The condensers C and C are connected at their discharge ends by a slightly curved conduit 82 to which is connected a vent 8| at the high point thereof. The vent 8| opens into the inert gas discharge conduit 31 of the evaporator. This apparatus provides a means for purging the condensers of any non-condensible gases that might find their way thereinto. The refrigerant vapor does not discharge through thes conduits for the reason that they are very'restricted in crosssectional area and any refrigerant vapor finding its way thereinto condenses and flows backwardly into one or the other of the condensers.

The apparatus just described causes the refrigerating effect to be shifted alternately to the right-and the left hand side of the ice freezing coil, and this is accomplished by alternately al- -lowing and preventing rejection of heat from fixedly mounted within the control box 65 and having its free end positioned to actuate the mechanism 64. The arrangement is such that the bellows I8 and 80 positively operate the over-center mechanism 64 to change'the position of the plate valves 53 and 56 thereby to alter the condensing area of the refrigerating system. In the position shown in Figure 2, the condenser C is being swept by cooling air, but no air can flow over the condenser C by reason of the horizontal position of the plate 53. Therefore, the refrigerant vapor is condensed by air cooling in the condenserC', and is discharged through the conduit 5| into the right hand portion of the coil 4|, as viewed in Figure I. The refrigerant vapor in the condenser section C does not condense therein because there is no air flow over the condenser section,'and it does not flow therethrough because of liquid contained in the u-shaped portion of the various portions of the refrigerating system. Each side of the ice freezing coil is directly associated with one of the condenser elements whereforerefrigeration will be produced only in that side of the evaporator freezing coil which is associated with a condenser element which is permitted to perform its normal function; that is, when the respective valve plates 53 or 56 are in a position not to obstruct air flow over their associated condenser sections. The control mechanism is so arranged that it tends to operate to produce refrigeration in the evaporator section from which previously formed ice blocks have just melted free and floated to the surface of the water within the tank 14; however, the control. mechanism will not so function unless ice is formed on the opposite side of the evaporator section to the depth desired or determined by the control mechanism. The large exposed surfaceof the tank 14 in the storage compartment serves as an ideal boxcooling element by reason of the fact that the temperature of the walls of the water tank is not low enough to cause frost to deposit thereon, v and the area of these walls is sufficiently large to permit efficient cooling of the box air without the use of a large temperature differential. By reason of this construction, the humidity within the refrigerating compartment is maintained at a very high value. The air striking the walls of the water tank will be cooled to a temperature approximating that of the water tank and its humidity will be lowered substantially to a hundred percent relative humidity. As the air warms up by absorbing heat from foodstuffs in the storage compartment, it will not have its humidity lowered to a verygreatdegree for the reason that thetemperature diflerential between the air leaving the walls of the water tank and warm air flowing upwardly to be re-cooled by such walls is not great. If extremely dry air finds its way into the box when the door is open to remove foodstuffs, it will pick up moisture from the water contained in the freezing tank and will thereafter operate at a relatively high humidity. If desired, or necessary, a suitable trough may be secured to the lower portion of the walls of a the water tank in order to catch any moisture which may. condense thereon.

Referring now to Figures 4-to 6, there is disclosed a modifled form of the invention. This form of the invention is designed to be utilized with a refrigerating system exactlyas disclosed in connection with Figure 1; therefor a repeated disclosure of that system is deemed unnecessary. Certain portions of this apparatus are identical with portions of that disclosed in connection with Figure 1 and are therefore given the same reference characters primed.

The refrigerant vapor is discharged by a conduit 24' into a condenser 90 of the tubular air cooled type. The condenser 90 connects to a liquid pre-cooler 9| which discharges into a diversion chamber 92. The diversion chamber 92 is provided with an upstanding bi-metallic thermostatic diverter 99 which in its neutral or unflexed position would exactly divide the stream of liquid issuing from the pre-cooler 9|. A precooler 94 opens into the bottom of the chamber 92 on the right hand side of the diverter 99, as viewed in Figures 4 and 6. A conduit 99 is connected between the bottom of the chamber, 92 on the left hand side of the diverter 99 and the left hand side ofthe evaporator freezing element 4|.

of the bell crank IIO not connected to the connecting rod I09 is connected to an actuating lever III which connectsto an actuating crank II2 rigidly carried by the plate valve I09. The arrangement is such that the valves I05 and III are always positioned 90 apart whereby one of the pre-coolers is always being swept by cooling.

air.

This form of the invention operates as follows:

'The thermostat I09|09 functions to maintain a constant discharge temperature of the air leaving the condenser 90 whereby the liquid refrigerant discharging into the pie-cooler 9| from the condenser 90 is always maintained at a constant temperature.

i The position of the plate valves I05 and I09 will be determined by the demand for refrigeration in the evaporator; that is, one or the other of the bulbs 15' and I9 will not be frozen into an ice block and the associated bellows will be expanded to operate the over-center mechanism 64" to shift the plate valves into position to permit cooling air to circulate over the pre-cooler associated with the evaporator section which is demanding refrigeration. Assuming that the thermostatic bulb I6 has been freed of contact with the ice and that its associated bellows has expanded,

* the over-center mechanism 04' will be shifted to The pre-cooler 94 is connected to the right hand side of the evaporator freezing elements 4| by means of a conduit 91.

The arrangementof the condenser 90 and the pre-cooler' elements 9| and 94 is clearly depicted in Figure 5. The condenser 90 is at the top rear portion of the cooling air flue formed by the panel 68' and the rear panel 01' of the refrigerating cabinet. The pre-cooler 9| is placed centrally of the air flue, and the pre-cooler 94 and the diversion chamber 92 are placed adjacent the panel 61'. A pair of vertically positioned plates IM and I02 divide the air flue into three separate passageways, each. of which contains one of the elements 90, 9|, and 94.

The cooling elements are arranged in the cooling air flue with the condenser 90, which i the warmest element, adjacent the rear panel 98',

-whereby. the rear wall 01' of the refrigerating within the housing 95' are connected to bothelements 15' and I6 by capillery conduits l1 and 19', which correspond exactlyto the conduits I1 and I9. The over-center mechanism 94' is connected to an actuating connecting rod I09 which in turn is connected to a bell crank IIO the position shown in Figure 5 and will move the plate valves I09 and I06 to the position shown in Figure 5. Cooling air will now circuate over the pre-cooler 9| but will not be permitted to circulate across the pre-cooler 94; due to this action, the liquid refrigerant discharging from the pre-cooler 9| will..be at a relatively low temperature and will flex the bimetallic element 99 i to the position shown in Figures 4 and 8 with the result that all the liquid refrigerant discharges through the conduit 99 into the left hand evaporator section 4| as shown in Figure 4. This action will continue until the bellows associated with the thermostatic bulb I9 is contracted by reason of said bulb being frozen into an ice block,

and the bellows associated with the bulb I9 has 5 expanded after being released from ice contact. When this condition has been reached, the position of the plate valves I09 and I09 will be reversed and the liquid refrigerant will'discharge through the conduit 9| which will be warm because the plate valve III! will prevent circulation thereoviix. The warm liquid refrigerant will flex the bi-metallic diverter element 99 into the position shown in dotted lines in Figure '6 with the result that the warm liquid will discharge into the pre-cooler 94 where its temperature will be substantially lowered by air cooling. This liquid refrigerant will then discharge through the conduit 91 into the right hand side of the evaporator sections 4|, as viewed in Figure 4.

It is necessary to maintain the liquid discharged by the condenser 90 at a substantially constant temperature; otherwise, the temperature of the liquid ultimately discharging into the diversion chamber 92 might'be'so high or so low as to cause the thermostatic diverter 99 to operate improperly. For example, if the ambient temperrigidly attached to the platevalve I09. The arm ature were to be very low, the liquid refrigerant discharged by the condenser might be at a temperature approaching that of liquid normally discharged from the first pre-cooling element 9| when that element was being swept by cooling 'air. Wherefore, the diverter element 99 would be flexed to discharge the liquid into the conduit 99 when the control mechanism had operated the plate valves to permit operation of the pre-coolen 94 in which event, liquid refrigerant should be diverted in the chamber 92 into the conduit 94.

This difliculty is obviated by the condenser temcause of the large air contact area provided by condenser is maintained substantially constant.

From the description above, it will be seen that this form of the invention operates by discharging the liquid refrigerant from the condenser at a constant relatively elevated temperature and that the temperature conditions of the liquid refrigerant leaving the first pre-cooler section determines its ultimate destination. The temperature at which the liquid is permitted to leave the first pre-cooler section is determined by the demand for refrigeration in the evaporator; therefore, refrigeration is produced alternately in opposite sides of the evaporator section: 4|. The evaporator as a whole operates and is controlled in the manner explained in connection with Figures 1 to 3.

Referring now to Figures 7 and 8, there is disclosed a third modification of the invention. The condenser, the precooler, the plate valves, and the evaporator structures. are identical with; those disclosed in connection with Figures 4 and 5, and will not be described in detail herein.

These elements are given the same reference characters primed as identical parts in Figures 4 and 5.- The pre-cooler 9I' discharges into a diversion chamber I25 which communicates with the conduit 96' and the pre-cooler 94'. A bimetallic diversion element I21 is pivotally mounted at I28 at the bottom portion of the chamber I25 and between the conduits 96' and 94'. In the neutral position thebi-metallic element I21 would equally divide the stream of liquid refrigerant discharging into the diversion chamber from the-pre-cooler 9|. In the form of the invention described in connection with Figures' i and variations in atmospheric temperature are compensated by the thermostatic mechanism I08 and I09 and the plate valve I04 in order that the diversion thermostat 93 may be actuated solely in response to a condition induced by adjustment of the various plate valves and not by conditions induced by an extreme variation in atmospheric temperature conditions. In the form of the invention disclosed in Figures '1 and 8, there is no plate valve governing the flow ofair across the condenser 90' wherefore other means must be provided to compensate the changes in air temperature in order that the diversion thermostatic element I21 will operate correctly at all times. the diversion chamber I25 is provided on one side thereof with a thermostat chamber I30 which is lined with insulation I3I and communicates with the chamber containing the diversion element I21 by means of a hole I33. The hole I33 is closed by a flexible element I34 which'is secured to an actuating link I35 whereby the link means may be shifted backwardly and forwardly in the opening I33 without permitting communication between the chamber I30 and the chamber containing the liquid refrigerant.

The link I35 is pivotally connected to thediversion element I21 and to a thermostat I31. The thermostat I31 is carried by a rod I40 which is preferably constructed from material, having a high heat conductivity. The heat conductor I40 is provided with a portion which extends through the wall of the chamber I30 and carries For this purpose,

a plurality of heat conducting fins MI. The

thermostat I31 responds quickly and accurately to temperature changes in the cooling air be- 'the fins MI.

The operation of this form of the invention is identical with that disclosed in connection .with Figures 4 and 5 except with respect to the air temperature compensating mechanism, the operation of which will now be described.-

It was explained with reference to the mechanism disclosed in Figures 4 and 5 that liquid refrigerant would discharge through the conduit 96' when the plate valves I05 and I06 are in position to permit the pre-cooling section 9| to be swept by cooling air; that is, the relatively cool liquid refrigerant discharging through the conduit 9I' should deflect the bi-metallic element I21 to such position that the liquid will be discharged into the conduit 96 in the diversion chamber I25. Now, if the temperature of the air'is very low, the temperature at which the liquid will be discharged from the pre-cooler 9I' is relatively low and no difiiculty will. beencountered; however, if the temperature of the cooling air is very high, the temperature of the liquid discharged through the pre-cooler 9I may not be sufliciently low to deflect the bimetallic element I21 sufllciently far to the right, as viewed in Figure 8, in order to direct all the liquid into the conduit 96; however, under these conditions, the thermostat I31 has responded to the high ambient temperature and has shifted the thermostat I21 to the right as viewed in Figure 8 about the,-pivot I28. In the event that the pre-cooler SIR is not operating and the temperature of the cooling air is very low, it Will be evident that the liquid refrigerant discharged through the pre-cooler 9| will beat a low temperature even though not cooled in the pre-cooler, and that this low temperature might for ambient temperature changes in order that it may properly divert the liquid refrigerant into or away from the pre-cooler,94'.

Figure 9 illustrates the arrangement of the apparatus in a cabinet. The cooling air which enters the bottom portion I03 of the refrigerator cabinet I00 containing the absorber, liquidheat exchanger, boiler, and analyzer passes upwardly over the absorber and then in contact with the various condenser sections. This cooling passes upwardlythrough a flue formed by the rear wall 61 of the refrigerating compartment and a panel 68 spaced from such rear wall. The air which passes overthe condensers C and C was previously passed over the absorber A butits temperature is still low enough to cause condensation of the refrigerant at all air temperatures normally encountered. Therefore, it is apparent that the cooling air passes first across one heat rejecting element, .the absorber, and

then across either of two or more heat rejecting elements, namely, the condensers. In the modifications disclosed in Figures 4 to 8., the cooling air also traverses a pre-cooler element.

Each of the three forms of the invention disclosed herein is provided with an evaporator having a constantly operating insulated low temperature freezing or low temperature storage compartment and a plurality of ice-freezing evaporator sections which are alternately operated. The control of the alternately operated ice-freezing evaporator sections is achieved slmambient temperature. This follows from the fact that a high ambient temperature will in-' crease heat loss through the walls of the refrigerator compartment thereby causing the apparatus to cycle more frequently, but. more frequent cycling of the apparatus produces a greater quantity of ice whereby the production of ice will normally be at its maximum durin the hot months of the year when the demand for ice is also at a maximum value.

If desired, the water tank may be provided with a spigot'to permit cold water to be drawn there-' from for drinking purposes at any desired time.

Normally, the water contained within the tank will be at a temperature close to the freezin point of water and will contain a number of blocks of ice floating freely on the surface of the water. be removed simplyby ladling the desired number out of the water tank.

The control mechanism disclosed in connection with the form of the invention illustrated in Figures 1 to 3 is simpler. than that disclosed in connection with the other modifications disclosed. However, the modifications disclosed in Figures 4 to 8 possess the advantage that it is not necessary to duplicate the condenser as a' whole butonly to duplicate the last or pre-cooling section thereof.

The very large exposed walls of the water tank are continually swept by the air within the food contained in the ice-freezing tank which may be exposed directly to'the air circulating in the storage compartment or which may be covered by a substantially non-sealing cover which will prevent accidental deposit of impurities into the water tank.

While I have illustrated and described several forms'of my invention it is notlimited thereto but maybe embodied in other variations and conventional forms without departing from the Any number of ice blocks desired may spirit thereof of the scope of the appended claims. I

I claim:

1. That improvement in the art of refrigeration which includes the steps of expelling re frigerant vapor from solution, selectively condensing the vapor in a plurality of condensing zones, selectively evaporating the liquid in a plu rality of evaporating zones, freezing ice by heat absorbed in said evaporating zones, discontinuing condensation and evaporation in associated con-.

(lensing and evaporating zones after a predetermined quantity of heat has been absorbed, and absorbing the vapor in solution.

2. Refrigerating apparatus comprising an evaporator having a plurality of freezing sections, a cooling *medium heat rejecting element connected to each section, means for supplying cooling medium to said elements, and means for controlling heat rejection from said elements selectively to produce refrigeration in individual sections of said evaporator.

3. A cooling unit comprising an insulated compartment, an evaporating conduit having a plurality of sections mounted in the insulation of said compartment, some of said sections being in'heat exchange relationship with-the interior of said compartment and others of said sections being insulated from said compartment and having a plurality, of freezing elements projecting from said insulation, a water container mounted in heat exchange relationship with such projecting elements, and means constructedand arranged to cause refrigeration to be produced substantially continuously in those sections of said evaporator in heat exchange relationship with said compartment, and sequentially in those sections of said evaporator in heat exchange relationship with said container.

4. Refrigerating apparatus comprising a cabinet, an evaporator moun' in said cabinet having a low temperature lcompartment insulated from the air in said cabinet, a watertcontainer havingcertain walls thereof exposed to the'air within said cabinet,-a.nd a heat abstracting element insulated from the air in said cabinet having means to refrigerate said compartment and to freeze ice in said container, the exposed portions of said container serving to refrigerate the air within said compartment.

5. Refrigerating apparatus comprising a cabi- -net, as water tank mounted within said cabinet andhavingaportionthereofexposedtotheair within said cabinet, an evaporator having a plurality of heat exchange contacts with said tank to freeze ice blocks therein, and means preventing said evaporator from contacting air in said cabinet, the arrangement being such that the exposed portion of said tank is maintained at temperatures above the freezing temperature of water and serves to cool the air in said cabinet.

6. An air cooled absorption refrigerating apparatus including a cabinet, a cooling air passage formed adjacent one wall of said cabinet, a plurality of evaporator elements mounted within said cabinet, a plurality of refrigerant heat reiecting elements mounted in said passage, each of said evaporator elements being connected to one of said heat rejecting elements, an air cooled absorber mounted to be cooled by air passing through said passage. and means overning the flow of air across said heat rel ifl l elements in response. to refrigeration demands.

I. An air cooled absorption refrigerating apparatus including a cabinet, a cooling air passage formed adjacent one wall of said cabinet, a plurality of evaporator elements mounted within said cabinet, a plurality of refrigerant heat rejecting elements mounted in said passage, each of said evaporator elements being connected to one of said heat rejecting elements, an air cooled absorber mounted to be cooled by air passing through said passage, and means governing the flow of air across said heat rejecting elements in sage formed adjacent one wall of said cabinet, a plurality of evaporator elements mounted within I paratus including a cabinet, a cooling air passaid cabinet, a plurality of refrigerant heat're- .iecting elements mounted in said passage, each of said evaporator elements being connected to one of said heat rejecting elements, an air cooled absorber mounted to be cooled by air passing through said passage, and means governing the flow of air-across said heat rejecting elements inresponse to refrigeration" demands, a condenser in said passage, and means preventing cooling air which has passed over one of said elements from flowing over another of said elements or said condenser, said condenser being positioned adjacent the wall of said passage remote from said cabinet.

9. Refrigerating apparatus comprising a low temperature freezing compartment having insulating walls, a water tank mounted on said compartment, an evaporator embedded in the insulated walls of said compartment having portions thereof positioned to refrigerate the interior of said compartment and portions thereof positioned to refrigerate said tank.

10. Refrigerating apparatus comprising a condenser, a first pre-cooling element connected to receive liquid from said condenser, a diversion chamber connected to receive'liquid from said first precooling element, a second pre-cooling element connected to receive liquid from said diversion chamber, a container forwater, a pair of evaporating elements in heat transfer relationship with said container, means connecting one of said evaporator elements to said diversion ing element to said second precooling element,

' control means for permitting cooling air to flow over only one of said precooling elements at a. time, means responsive to the formation of a predetermined quantity of ice in said container for operating said control means to' change the flow of cooling air from one of said precooling elements to the other, and means in said diversion chamber for diverting liquid supplied thereto into said second precooling element or into the evaporator section connected to said diversion chamber in accordance with the operation of said control means, said diversion element including a thermostat which is responsive to the temperature of the liquid supplied to said diversion chamber, and means for compensating said diversion thermostat for variations in cooling air temperature.

12. Refrigerating apparatus comprising a condenser, a first precooling element. connected to receive liquid from said condenser, a diversion chamber connected to receive liquid from said first precooling element, a second precooling elechamber, means connecting the other eVaDorating element to said second pre-cooling element, control means for permitting cooling air to fiow over only one of said pre-cooling elements at a time, means responsive to the formation of a predetermined quantity of ice in said container for operating said control means to change the flow of cooling air from one of said precooling elements to the other, and means in said-diversion chamber for diverting liquid supplied thereto into said second precooling element or into the evaporator section connected to said diversion chamber in accordance with the operation of ment connected to receive liquid from said diversion chamber, a container for water, apair of -evaporating elements in heat transfer relationfor operating said control means to change the flow of cooling air from one of said precooling elements to the other, and means in said diversion chamber for diverting liquid supplied thereto into said second precooling element or into the evaporator section connected to saiddiversion chamber in accordance with the operation of said control means, said diversion element including a thermostat which is responsive to the temperature of the liquid supplied ,to 'said diversion chamber, and means for compensating said diversion thermostat for' variations in cooling airtemperature, said compensating means including means for regulating the flow of cooling air over said condenser and means responsive to air temperature for actuating said last mentioned air flow control means.

13. Refrigerating apparatus comprising a con-' denser, a first precooling element connected to receive liquid from said condenser, a diversion chamber connected to receive liquid from said first precooling element, a second precooling element connected to receive liquid from said diversion chamber, a container for water, a pair of evaporating elements in heat transfer relationship with said container, means connecting one of said evaporator elements to said diversion chamber, means connecting the other evaporating element to said second precooling element, con trol means for permitting cooling air to flow over only one of said precooling elements at a time.

means responsive to the formation of a predetermined quantity of ice in said container for operating said control means to change the flow of cooling air from one of said precooling elements to the "other, andmeans in said diversion chamber for diverting liquid supplied thereto into said second precooling element or into the evaporator section connected to said diversion chamher in accordance with the operation of said control means, said diversion element including a thermostat which is responsive to the temperature of the liquid supplied to said diversion cham- 14. Refrigerating apparatus comprising a pair of air cooled heat rejecting elements, means for supplying refrigerant to said elements, an evaporator having a pair of sections, means connecting each of said heat rejecting elements to an' evaporator section, a water container mounted in heat exchange relationship with each of said sections, means controlling the flow of cooling air over said elements, temperature responsive means for actuating said air flow control means, said temperature responsive means including temperature reponsive elements positioned to be frozen into ice formed in said container adjacent each of said evaporator sections, the arrangement being such that said temperature responsive means operates said air flow control means to allow new of cooling air' over the heat rejecting element connected to the evaporator section adjacent that portion of the tank from which an ice block has just melted away from one of said temperature responsive elements and to prevent flow of cooling air over the other heat rejecting element.

' 15. Refrigerating apparatus comprising a pluralityof condensers, an evaporator having sections connected to receive refrigerant liquid discharged by each of said condensers, an ice freezing chamber in heat transfer relation with each of said'sections, means for governing the flow of cooling medium over said condensers, and means forrendering said governing means operativeto allow air flow over said condensers alterplurality of points, a compartment housing'said evaporator and water container whereby the air in said compartment is refrigerated by the exposed walls of said container.

19. Absorption refrigerating apparatus comprising a solution circuit including a boiler and an absorber, an inert gas circuit including an evaporator and said absorber, means for supplying refrigerant liberated from solution in said boiler to said evaporator in liquid phase, a water container having exposed walls positioned in heat transfer relationship with said evaporator at a plurality of points, a compartment housing said evaporator and water container whereby the air in said compartment is refrigerated by the exposed walls of said container, andmeans responsive to the temperature of'the air in said compartment for governing the production. of refrigeration in said evaporator.

20. Absorption refrigerating apparatus comprising a solution circuit including a boiler and an absorber, an inert gas circuit including an evaporator and said absorber, means for supplying refrigerant liberated from solution in said boiler to said evaporator in liquid phase, a cabinet housing said evaporator, means shielding said evaporator from contact with the air in said I cabinet, and a water container having certain of the walls thereof exposed to the air in said cabinet mounted in heat transfer relationship with said evaporator at a plurality of points.

21. Absorption refrigerating apparatus comprising a solution circuit including a boiler and an absorber, an inert gas circuit including an evaporator and said absorber, means for supplying refrigerant liberated ,from solution in said nately whereby refrigeration is produced in said evaporator sections alternately.

16. Refrigerating apparatus comprising a cooling unit having a plurality of branches encased in insulating material, heat conducting elements extending from said branches to the surface of said insulating material, a water tank mounted on saidelements, a source of supply of cooling medium, and control means for directing cooling medium from said source of supply to aselected one of said branches.

1'7. Refrigerating apparatus comprising a cab inet, an insulated low temperature storage chamber mounted within said cabinet, a cooling unit mounted in the insulation of said chamber and arranged to refrigerate the interior of said chamber, a water container mounted adjacent said chamber, a second cooling unit having a pair of sections mounted in the insulation of said chamber and arranged to refrigerate said container, a source of supply of cooling medium, control means arranged to direct the cooling medium from said source d supply into a selected one'of said sections of said second mentioned cooling unit, and means for draining cooling medium from each of said. sections into said first mentioned cooling unit. f

18. Absorption refrigerating apparatus com-. prising a solution circuit including a boiler and an absorber, an inert gas circuit including an evaporator and said absorber, means for supplying refrigerant liberated from solution in said boiler to said evaporator in liquid phase, a water container having exposed walls positioned in heat transfer relationship with said evaporator at-a 7.5

boiler to said evaporator in liquid phase, a water container having exposed walls positioned in heat transfer relationship with said evaporator at a plurality of points, a compartment housing said evaporator and water container whereby the air in said compartment is refrigerated by the exposed walls of said container, and means responsive to the production of ice in said container for confining the production of refrigeration to selected portions of said evaporator.

22. That improvement in the art of refrigeration which includes the steps of flowing an inert gas between an absorbing zone and a plurality of evaporating zones each of which is associated with one of a plurality of heat rejecting zones arranged to supply refrigerantliquid thereto, applying heat to a solution of 'a refrigerant in an absorbent to expel refrigerant therefrom, conducting the refrigerant to said heat rejecting zones, and governing the production of refrigeration in said evaporating zones by regulating the rejection of heat from said heat rejecting zones. 23. That improvement in the art of refrigeration which includes the steps of flowing an inert gas between an absorbing zone and a plurality. of evaporating zones each of which is associated with one of a plurality of heat rejecting zones arranged to supply refrigerant liquid thereto, applying heat to a solution of a refrigerant in an absorbent to expel refrigerant therefrom, conducting the refrigerant to said heat rejecting zones, supplying liquid refrigerant to one of saidevaporating zones from its associated heat rejecting zone by preventing rejection of heat from all of said heat rejecting zones except that heat 4 rejecting zone associated with said one evaporating zone, and selecting said one evaporating zone 24. That improvement in the art of refrigeration which includes the steps of flowing an inert pressure equalizing medium between a Place of absorption and a place of evaporation, applying heat to a solution of a refrigerant in an absorbent to expel refrigerant vapor therefrom,

conducting the vapor expelled from solution to a place of condensation which is in heat exchange evaporation when a predetermined quantity of ice has been formed in said body of water by preventing the flow of cooling medium in heat exchange relationship with said place of condensation, and resuming production of refrigerant in said place of evaporation when said predetermined quantity of ice has floated to the surface of said body of water by restoring the flow of cooling medium in heat exchange relationship with said place of condensation.

25. In a refrigerating apparatus, a plurality of heat absorbing elements, means for circulating a cooling medium through said heat absorbing elements including a plurality of heat rejecting elements each of which is associated with one of said heat absorbing elements, and means for governing the production of refrigeration in each of said heat absorbing elements including means arranged to govern the rejection of heat by said heat rejecting elements.

26. In a refrigerating apparatus, a source of refrigerant vapor, a liquefying means connected to receive refrigerant vapor from said source, a

plurality of evaporators, a. plurality of serially connected air cooled elements, each of said air cooled elements being connected to one of said evaporators, means arranged to conduct liquid refrigerant from said liquefying means to one of said air cooled elements, and means for selectively directing refrigerant liquid from said one air cooled element into its associated evaporator or into another of said air cooled elements in accordance with refrigeration demand.

27. Absorption refrigerating apparatus including a plurality of evaporators, a generator, means arranged to supply liquid refrigerant to said evaporators, to remove refrigerant vapor from said evaporators, to absorb the vapor removed from said evaporators in solution and to return the solution to said-generator, said means including a plurality of air cooled heat rejecting devices so constructed and arranged that the operation of said evaporators is directly dependent upon the rejection of heat from said heat rejecting devices, each of said heat rejecting derefrigerant vapor, a liquefying means connected to receive refrigerant vapor from said source, a plurality of evaporators, a plurality of serially connected air cooled elements, each of said aircooled elements being connected to one of said evaporators, means arranged to conduct liquid refrigerant from said iiquefying means to one of said air cooled elements, means for selectively directing refrigerant liquid from said one air cooled element into its associated evaporator or into another'of said air cooled elements in accordance with refrigeration demand, and means for compensating said last mentioned means for variations in the temperature of the cooling air.

29. In a device of the character described, a cabinet having an insulated refrigerating chamber and a machinery chamber arranged for flow I of cooling air therethrough, refrigerating mechanism associated with said cabinet comprising a cooling unit positioned within said refrigerating chamber, a water container positioned in said refrigerating chamber and in heat exchange relationship with said cooling unit at a plurality of points, means positioned in said machinery chamber arranged to supply a cooling medium to said cooling unit, said means including an air cooled heat rejecting eiementpositioned to be cooled by air flowing through said machinery chamber and so related to said cooling unit that the operation of said cooling unit is dependent upon the rejection of heat by said heat rejecting element, and means for controlling the production of refrigeration by said cooling unit including a device for governing the flow of cooling air in heat exchange relationship with said heat rejecting element whereby alternately to freeze ice in said container and to allow previously frozen ice to float to the surface of the water in said container.

30. In a refrigerating apparatus, a source of refrigerant vapor, a liquefying means connected to receive refrigerant vapor from said source. a

plurality of evaporators, a plurality of serially connected air cooled elements, each of said air cooled elements being connected to one of said evaporators, means arranged'to conduct liquid refrigerant from said liquefying means to one of said air cooled elements, means for selectively directing refrigerant liquid from said one air cooled element into its associated evaporator or into another of said air cooled elements in accordance with refrigeration demand, and means for compensating said last mentioned means for variations in the temperature of the cooling air, including means for regulating the temperature of said liquefying means.

DONALD G. SMELLIE.

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