US2330917A - Refrigerating apparatus - Google Patents

Description

1943. L.- A. PHILIPP REFRIGERAIING APPARA S Original Filed Au 8 1940 INVENTOR. Lawlezucz Ii. PHILIP? RTTORNJEY WLAWM' 0a. 5, 1943. L, A. PHlLll P 2,330,917

REFRIGERATING APPARATUS Original Filed Aug. 8, 1940' 3 Sheets-Sheet 5 Fig. i

INVENTOR. Lqwesqcz. FI-(ILIPP BY WZM Patented Oct. 5, 1943 REFBIGERATING APPARATUS Lawrence A. Philipp, Detroit, Mich., assignor to Nash-Kelvlnator Corporation, Detroit, Mich., a corporation of Maryland Original application August 8, 1940, Serial No.

Divided and this application August s, 1941, Serial No. 405,900

(or. s2-4) 2 Claims.

This invention relates to refrigerating apparatus, and more particularly to refrigerating apparatus of the multiple temperature type.

The present application is a division of my pending application, Serial No. 351,834, filed August ,8, 1940, for Refrigerating apparatus.

One of the objects of my invention is to provide an improved system of control for a re-. frigerating system.

Another object of my invention is to provide an improved control device for the aforementioned refrigerating system' which includes thermo-sensitive means having a portion extending into the freezing zone and another portion extending into an air cooling zone, and arranged so that each of said portions cooperate to control a power device for the control element.

1 Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings, wherein a preferred form ,of the present invention is clearly shown.

In the drawings: Fig. 1 is a front view in elevation of my improved refrigerator showing a portion broken away;

Fig. 2 is a diagrammatic illustration of the refrigerating system utilized for refrigerating the refrigerator shown in Fig. 1;

Fig. 3 is a view taken along the line 3-3 of F 1;

Fig. 4 is a view taken along the line 4-4 of Fig. 3; and

Fig. 5 is a view in elevation showing a portion broken away of a switch element used for controlling the operation of my refrigerating system.

Referring to the drawings, Fig. 1 discloses my improved refrigerator cabinet, designated in gen-,

eral by the numeral 20. Within this refrigerator cabinet I have disposed the refrigerating system disclosed in Fig. 2.-

Referring to Fig. 2, my improved refrigerating system includes a motor compressor unit 24, condenser 26, high temperature heat absorbing sections 28 and 30, low temperature'refrigerating sections 32, 34, 36 and 38, and an accumulator 40. Evaporated refrigerant is withdrawn from the accumulator 40 through a vapor return conduit 42 whence it passes to the motor compressor unit 24 wherein it is compressed and from which it is delivered through conduit 46 to condenser 26. In the condenser it is liquified and from which it is delivered to heat absorbing section 28 through a small diameter tube 46 after first passing through a strainer device 50. The refrigerant passes from the section 28 through conduit 52 to the section 30. Before passing to the section 32 from section 30, the refrigerant must pass through a fixed restriction, or small diameter tube 56. This reduces the pressure of refrigerant flowing to the sections 32, 34, 36 and 38 so as to maintain a higher temperaturein the sections 28 and 30 than. in sections 32, 34, 36 and 38. This system is of the non-flooded type wherein droplets of liquid refrigerant are passed into the heat absorbing sections, but due to the absorptionof lieat very little, if any, liquid refrigerant passes into the accumulator 40. Thus, the refrigerant passing through conduit 42 is gaseous refrigerant and, asdisclosed, I have arranged the conduit 42 in thermal heat exchange relation with the small diameter tube 48 so as to cool the liquid refrigerant passing through the tube 48. These two conduits may be secured together by solder if desired.

Referring more specifically to the drawings,

. and more particularly'to Figs. 3 and 4, the refrigerator cabinet includes an outer casing and an inner liner 62. Insulation 64 is interposed between the walls 66 and 62 to insulate a food storage compartment 66 formed by the inner walls of theliner 62. The outer casing extends downwardly to provide a machine compartment 68. A base 10 is provided for the cabinet and is open as at 12 to provide for thefree circulation of air through the machine compartment.

Within the machine compartment I have disposed my motor compressor unit 24- and condenser 26. The motor compressor unitjs mounted upon an angle iron 16 which is supported by 'the base I0. At the rear of. the cabinet I have provided a flue 60 for aiding and setting up a natural draft of air over the motor compressor unit and condenser to take the heat of condensation out of the machine compartment 68. It will be noted that on the inner side of the flue 881 have provided insulating material 84, which may preferably be of sound absorbing characteristics. As indicated, the insulation is formed of sheet cork. It may, however, be of any suitable fibrous material which has characteristics for sound absorbing. The front of the cabinet is cut away as at 96 so as to provide an opening for gaining access to the machine compartment. This opening is closed by a door 92 which is formed of double walled sheet metal having ends 94.and 96.

which carry'gasket'material 98. These ends are turned in toward each other and are spaced apart so as to receive an angle member I carried by the base 10. .By this arrangement it is possible to tilt the door outwardly away from the machine compartment at its upper edge. The angle member I00 may extend from one side of the machine compartment to the other if desired or part way so that it will be sufilcient for supporting the weight of the door. On the rear side of. the door I have provided a vegetable bin I04 which is secured to the door in any suitabl manner and is tiltable with the door. Thus when the upper part of the door 92 is tilted outwardly away from the machine compartment, access may be had to the interior of the vegetable bin. The bin includes bottom wall I06, side walls I08 and rear wall III). Secured to the rear wall is a slab of insulating material II2, which, as indicated, is formed of sheet cork. This insulating material II2 like insulating material 84 may be of any suitable material so long as it has heat absorbing characteristics as well as insulation qualities so as to insulate the vegetables from the heat of condensation as well as absorb noises created by the motor compressor unit. This vegetable bin may extend from one side of the machine compartment to the other. As will be noted, the condenser is placed on an incline, with the lower portion being directly over the lowermost portion of flue 80 while the upper'portion of the condenser is positioned slightly within the machine compartment 68. As will be noted in Fig. 2, 'the condenser is formed of a serpentine coil having spaced apart fins therein so as to be very effective in the dissipation of heat while rmitting the free flow of air thereabout. Since the lower part of the cabinet is open at 12 and the lower part of the flue 80 is open to the atmosphere, air may freely pass up through the machine compartment and the fine and over the motor compressor unit and condenser and out through the fiue to thus remove the heat of condensation. By placing the inner wall IIO of the vegetable bin at an angle it tends to guide the flow of air toward the motor compressor unit as the air travels upwardly due to the natural draft flow of air. Also, as air passes upwardly through the flue over a the lower portion of the condenser, it tends to create an aspirating effect to draw air through the machine compartment over the motor compressor unit at the upper portion of the condenser.

The insulation 64 includes slab I20 in the. botment while the other sections of the heat absorbing means are utilized for freezing ice in an ice freezing zone within the interior of the metal casing I46. The casing I46 is formed preferably of stainless steel or steel having a coating of vitreous enamel in the general shape of a U and includes upright walls I48 and bottom wall I50. The upright walls have their ends secured to the top wall of the liner 62 and the rear edges of the upright walls are in engagement with the rear wall of the liner 62. The rear wall of the liner 62 is provided with an opening I54 which is closed by the removable panel I40. The upright walls I48 extend vertically across such opening. This opening I54 is provided for the ready insertion or removability of the heat absorbing sections of the system. The bottom wall I50 of the casing I46 is provided with upwardly directed corrugations I60 upon which may be inserted receptacle I62. The bottom wall is also provided with an opening I64 to permit drip water from the refrigerating sections in the casing to fiow from the casing when such sections are defrosted.

' The casing I46 has secured thereto guideways I10 for receiving lips I12 of drip pan I14. This en ables the drip pan to slide on the guideways I10 so that it may be readily removed from beneath the casing. Drip collectors I16 are also carried by the casing I46 to collect any moisture that may drip from the casing and conduct such moisture to the drip receptacle. The drip collectors I16 and the guideways I10 are secured to the casing by means of bolts (not shown).

The entire heat absorbing means is carried by the removable wall I40 and includes portions for ice making and air cooling. The portion utilized for ice making includes a U shaped sheet metal member I84 of single thickness which has secured thereto an upper shelf I86 and a shelf I88 positioned therebelow. The shelf I88 is removably mounted to the U shaped member I84 so that it may be readily removed from the said tom wall, I 22 in the rear wall, I24 in the top wall and I26 and I28 in the side walls. As indicated in the drawings, this insulation is shown as slabs provided in the rear wall so that it may be readily removed. Conduits 42 and48 enter the rear wall of the refrigerator and pass into the food compartment through insulation I30. If the insulation is made of cork, such cork may be slotted to receive the conduits and to permit removal of the insulation from each side of the conduits or if it is loose fibrous material such insulation may be readily removed by simply removing rear panel I34 of 'the cabinet by removing nuts I36 from bolts I38. On the inner side of the insulation I30 is a removable panel I40 which may be readily removed by removal of nuts I42 from bolts I44. The panel I40 carries the heat absorbing portion of the refrigerating system and includes sections 28, 30, 32, 34, 36, 38 and accumulator 40.

e sections 28. and 30 are utilized for cooling circulating air within the food storage CQIDDBl-tr member. The removable shelf .is carried by lugs I30 and is provided with slots I92 so-that the removable shelf may be lifted upwardly and then removed through the open-front of the U shaped member I84. To the U shaped member is secured the heat absorbing sections 32, 34, 36 and 38. The sections 32 and 36 are secured to the side walls of the member I84 and the section 34 is secured to the bottom wall thereof while the section 38 is secured to the upper shelf of the member I84. On each side of the U shaped member are located heat absorbing sections 30 and 28. These sections are the same and so only'one will be described. The sections include vertically extending fins 200 through which a refrigerant conduit 202 extends. This conduit is arranged so that parallel runs extend through the upper portions of the fins in a horizontal plane and parallel runs extend through the lower portion of the fins on a vertical plane. This provides for more refrigerating coil in the upper portion of the fins per fin area than in the lower portion. The reason for this arrangement is that warm circulating air in the food storage compartment 62 comes in contact with the uppermost portion of the fins first and tends to warm up the fins at that point. Consequently the fins may be cooled to a lower temperature at that point than at the lower portion of the fins where the air is somewhat cooled before it reaches that point. By thisarrangement it is possible to have a small compact fin area and at the same time direct the warm air over such fin surfaces so that when the refrigerating system is in operation the collection of frost and moisture on the fins will be evenly distributed so that during periods when the compressor is not operating the frost and ice accumulated on the fins will entirely melt off before the compressor again resumes operation. As will be noted, the U shaped member I84 and the ice making sections 32, 34, 36 and 38 are disposed within the casing I46 in spaced relation thereto. The accumulator 40 is also positioned within the casing I46. A will be noted in Figure 3, the accumulator is ellipticalshape in cross section and includes an inlet pipe 220 near the lower portion of the accumulator and an outlet conduit 222 adjacent the upper portion of the accumulator. By this arrangement any liquid that may get into the accumulator 40 would enter near the bottom thereof while the gaseous refrigerant would leave by the outlet 222 from the upper part of the ac-' cumulator. The bottom wall of the U shaped member, shelf 188 andshelf I86 are all provided ior supporting ice making receptacles 224. It will be noted that when the U shaped member I84 is positioned. within the casing I46 that it is posit oned somewhat above the bottom wall I50, of the casing. This provides ample space for the receptacle I62.v The receptacle I62 is provided with a lid 228 which may be loosely fitted on the receptacle I62 to provide ventilation therebetween or may tightly engage the upper edge of the re-' ceptacle and have one or' more small, holes (not shown) positioned in the lid so as to give ventilation to the foodstuff stored therein. .Preferably the receptacle I62 is provided for the storage of meats and at, for example, slightly above the freezing point of water. This is accomplished by operating the refrigerating sections 32, 34, 36 and 38 sufficiently low enough for freezing substances but due to a removable panel 230 carried by flanges, 234 on the bottom of the U shaped member I84 the temperature therebelow is above the freezing point of water. This panel acts to insulate the direct effect of the cooling of the section 34 and maintains the temperature therebelow approximately at 34 degrees F. When it is desired to refrigerate the space below the panel '230 to a lower temperature, such panel is removed and for example, placed under the receptacle I62. At this time the receptacle will be refrigerated to 'a temperature below the freezing point of water and if it is desired meats may be stored in the receptacle at this time and frozen. Also if des red the removable shelf I88 may be removed and the receptacle I62 maybe inserted upon the bottom wall of the U shaped member directly below the shelf I86 where the receptacle will be cooled to somewhat below the freezing point of water. Thus it is possible to shift the receptacle I62 to various positions within the casing and provide large storage spaces for the freezing of meats or the preservation of foods below the freezing point of water or slightly above the freezing point of water as desired. The sections perforate portions 242 and slotted portions 244.

Immediately below the sections 28 and 30 are provided drip troughs 260 which are provided with louvers 262 in each side wall. The drip troughs include a projection 264 which extends over the drip collectors I16 for conducting the drip water from the ections 28 and 30 to the drip pan I14. The drip water first collects in the trough 260 whence it passes over the projection 264 to the drip collector I16 whence it passes into the drip pan I14.

Also within the food storage compartment there is provided slidable shelves 304, which may be of any suitable open work construction. In addition, there is provided sliding receptacles 306, which may be of any suitable construction, and are used primarily for thestorage of vegetables. Supported above the receptacles 306 are transparent glass plates 308. The glass plates removable independent of the receptacles 306. Likewise the receptacles 306 are independently suspended and are slidably removable and independent of glass covers 308. Within the casing I46 and secured to the top wall of the liner 62 is a switch control element 3I0. This switch control element is of the pressure operated type well known in the art and includes a power element in the form of an expansible bellows 3I4 (see Fig. 5). To the bellowsls connected a small diameter conduit 3I6 which is provided with branch 3 I8 and branch 3I9. To the branch 3I8 is connected a thermal bulb 320 and'to branch 3I9 is connected thermal bulb 322. The two thermal bulbs and the two branch conduits as well as conduit 3I6 are connected in open communication with the bellows 3 and with .each other. Preferably, the conduits 3I6, 3I8 and 3 I9 are of very small diameter. Within the bellows 3I4, conduits 3I6, 3I8 and 3I9 and thermal bulbs 320 and 322 is confined a volatile fluid which serves to .control the operation of the switch element by expansion and contraction of i the bellows 3I4 in the well known manner. As 40 shown in the'drawings, the thermal bulb 320 is primarily responsive to the temperature of the 7 heat absorbing section 30, and the thermal bulb compressor unit to control the ,electric circuit,

thereof by electric conduits (not shown). The switch completes such electric circuit when there is a demand for refrigeration and interrupts such circuit when the demand has been satisfied. As the temperature of the U-shaped member I84 and heat absorbing section 36 rises to a predetermined point, the thermalbulb 322 will initiate operation of the switch to start the motor compressor unit.

In the operationv of my refrigerating system, I have arranged so that sections 28 and 30 of the heat absorbing means cools the circulating air in-the food storage compartment. Prefer-' ably, the switch 3I0 is adjusted so that during normal operation sections 28.and 30 collect a slight film of frost on the fins and refrigerant conduit during operation of the motor compressor unit, and this slight film of frost melts off when the compressor unit is not operating. Due to the fixed restriction 56, which is interposed between the section 30 and section 32 of the heat absorbing means, the pressure in sections 28 and 30 is 15 somewhat greater than in the ice making sections are independently suspended and are slidably circulating air in the food storage compartment and defrost the cooling elements by'the cycles of refrigeration while at the same time freeze ice by another portion by the heat absorbing means. Due to the fixed restriction 56, the pressure and temperature in the ice making sections is sufficiently low during operation of the motor compresson unit to provide for the rapid freezing of ice in the receptacles 224. While the sections 34 and 38 re adequate for the rapid freezing of ice in the'receptacles placed thereabove, I have also provided sections 32 and 36 along the side walls of the U-shaped member I84 so as to aid in retaining a low temperature within the confines of the U-shaped member I64 when the motor compressor unit is not operating. This is due to the fact that'with these added sections 32 and 36 the temperature within the confines of the U- shaped member I84 is pulled down sufficiently low as to hold its freezing temperature until during periods when the compressor is not operating so that such freezing temperature is maintained and until the motor compressor unit resumes operation. By arranging the switch 3I0 so that it is responsive both to the high temperature as well as the low temperature heat absorbing units, it

is possible to initiate operation of the motor com-- pressor unit when either the ice making or box cooling sections require refrigeration. In some instances, it may be desirable to omit the conduit 3!!) and thermal bulb. 322. At this time it is desired to point out that the switch 3I0, which includes bellows 3, is positioned part way inside the casing I46 where the low temperature air confined in the casing comes in contact with the bellows 3M. Consequently, the thermal bulb 320 may rise to a temperature which would normally initiate operation of the switch, neverthelessthat operation may be delayed for a brief period of time due to the chilling down of the fluid in the bellows 3I4. The chilling down of the fluid in bellows 3I4 has a tendency to counteract the effectivenes of the rising temperature of the fluid contained within the thermal bulb 320.

This sometimes is advantageous in that when such condition occurs it is evident that the temperature in the casing I46 is such that it retains the frozen substances therein in their frozen condition and that delayedaction of the switch would ing I46 will not cause the cooling of the walls or casing I46 to a very low temperature. By proportioning the ice making sections and spacing them from the walls of the casing, as disclosed herein, it is possible to operate my refrigerating system without the collection of moisture upon the outer surface of the casing I46 during days when the relative humidity is below a certain value and never at sucha temperature so as to collect frost'on the outer surfaces of the casing I46. The casing I46 also includes an inturned flange 325 about its front face which is engaged by a door 321. The door includes panel 323 and 32, 34, 36 and 38. Thus it is possible to cool thecarries a rubber sealing gasket 33I which engages the flange 325'to seal the front of the casing I46. Secured to the panel 323 is a panel 335 arranged in spaced apart relation so as to provide a dead air space for the door. This limits the flow of heat through the door into the interior of the casing I46. The door is hinged as at 340 so as to permit ready access to the interior of the easing. Since the casing I46 is sealed on top, rear and front walls, the circulating air within the food storage compartment cannot enter the interior of the casing and consequently the ice making sections of the heat absorbing means cannot extract moisture from air other than that which is confined within the interior of the casing I46. This small volume of air causes a very slight accumulation of frost upon the ice making sections of the heat absorbing means and U-shaped memher I 84, thus requiring defrosting of such sections and member only after long periods-of operation. In view of the fact that the heat absorbing sections for cooling the circulating air defrost during periods when the compressor is not operating between each cycle of operation, it is unnecessary to shut the system down for defrosting. When the ice making sections of the,

heat absorbing means are defrosting, the drip water drops to the bottom wall I50 of the casing I46 or falls upon the lid-of receptacle I62 whence it flows to the bottom wall I50, and due to the corrugations I60 the drip water may freely flow under the receptacle I62 and pass through opening I64 to drip pan I14.

As will be noted in Figs. 3 and 4, rear panel I40 is provided with openings 350. These openings 350 provide for open communication between the air within the insulation and the interior ,of the casing I 46. Thus if there is any moisture within the air in the insulation, it will not be condensed out upon the rear wall of the panel I40 and cause the insulation to become wetted, but instead the moisture along with the circulating air in the insulation will pass tothe ice making sections of the heat absorbing means and such moisture will readily be frozen out of such air. In cooling the air in the food storage compartment, the circulating air passes upwardly and through the slots 24 3 in baiiies 260. The air is then cooled by sections 28 and 30 and flows downwardly into troughs 260 and through the louvers 262 into the food compartment below the troughs. This gives two distinct circulatory paths of air in the food compartment. The casing I46 also does some cooling of the air in the invention or from the scope of the appended claims.

I claim: 1. Refrigerating apparatus comprising a cabinet having two compartments to be cooled, heat absorbing means for cooling said compartments,

a refrigerant condensing element for operating said heat absorbing means at sufliciently' low temperatures to cool the circulating air in one of sald compartments below the freezing point of water and the air in the other compartment at a higher temperature, a control element for controlling the operation of said condensing element, a thermo-sensitive power member for said control element positioned to be influenced by said cir v culating air cooled below the freezing point of water, a thermal bulb connected to said power member and extending into one of said compartments and a second thermal bulb connected to said power member and extending-into the other of said compartments.

2. Refrigerating apparatus comprising a cabinet having two compartments to be cooled, heat absorbing means for cooling said compartments, a refrigerant condensing element for operating said heat absorbing means at' sumciently low temperatures to cool thecirculating air in one LAWRENCE A. PHILIPP.

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