US1791964A

US1791964A - Refrigerating apparatus

Info

Publication number: US1791964A
Application number: US193830A
Authority: US
Inventors: Kleinhans Francis Joseph; Herman A Brandt
Original assignee: ARCO VACUUM CORP
Current assignee: ARCO VACUUM Corp
Priority date: 1927-05-24
Filing date: 1927-05-24
Publication date: 1931-02-10
Anticipated expiration: 1948-02-10

Description

Feb. All?, 1931. F. JJKLEINHANS ET AL 1,791,964

REFRIGERATING APPARATUS Filed May 24, 1927 5 Sheets-Sheet 2 mmm/"WWW l Feb. l0, 1931. F. J. KLEINHANs ET AL 1,791,964

REFRIGERATING APPARATUS 5 Sheets-.Sheet 5 Filed May 24. 1927 Feb. l0, 1931. F. .1. KLEINHANS ET AL 1,791,964

REFRIGERATING APPARATUS 5 'Sheets-Sheet 4 Filed May 24, 1927 W 00 3 4/ Z QJ 9 a W M 9M a, @y 05W/ @n 00 Feb. 10, 1931. F. J. KLEINHANS ET AL REFRIGERATING APPARATUS Fned May 24, 1927 5 Sheets-Sheet 5 awww/lions Sz/Lam. ula JV Patented Feb. 1U, i931 UNITED s-rATEs PATENT OFFICE FRANCI'S JOSEPH KLENHANS AND HERMAN A. BRANDT, OF BUFFALO, YORK, ASSIGNORS TO ARCO VACUUM CORPORATION,'OF YORK, N. Y., A CORPORATION OF DELAWARE Application led May 24,

Our invention relates to new and useful REFRIGERATING APPARATUS 1927. serial N6. 193,830.

1, with the closure panels for a lower comimprovements in refrigerating apparatus, Dartment in place;

and while it embodies features which render it useful and applicable for refrigeration gen- 5 erally, it will be found especially applicable and useful in a structure o r system for domestic refrigeration, that is, for installation in a refrigerator box or cabinet for domestic use in the refrigeration and preservation of foods. The invention relates particularly to that type of refrigeration in which rapid evaporation of water or an aqueous liquid body is employed as the agency for veecting the production of temperatures low enough to produce a refrigerating effect, and in which the rapid evaporation to produce low temperatures is effected by creating a sulfi- Vciently low sub-atmospheric pressure over the body of water or aqueous liquid and withdrawing the water vapors at such rate thatl the temperature of the liquid body is reduced to a point satisfactory for the desired or determined cooling or refrigerating effect.

An object of this invention is to produce an improved refrigerating apparatus which will operate efficiently to produce the desired low temperature by the eiiicient use of low sub-atmospheric pressures over a body of water, or, if desired; over a mixture of water and a lower freezing point medium, and thus rendering the apparatus available for cihcient and practical use in a system operating on the evaporation principle above stated.

The invention consists in the improvements to be more fullydescribed hereinafter, and the novelty of which will be particularly pointed out and distinctly claimed.

We have fully and clearly illustrated a preferred embodiment of our invention in the accompanying drawings to be taken as a part of this specification and wherein- Figure 1 is a view in front elevationof our invention as embodied in a refrigerator box or cabinet for domestic refrigeration, the door of the cooling chamber jor food compartment and the space for the cooling element being shown open and in edge elevation; y

Fig. 2 is a section on the line 2`2 of Fig.

Fig. 3, is an enlarged sectional view through the cooling element and freezing chamber, taken on the line 3--3 of Fig. 1, with the door of the food chamber closed;

Fig. 4 is a sectional view on the line 4 4 of Fig. 3 with the central freezing pan removed; Fig. 5 is a top plan view of the exhausting means and drivlng motor, and means for separatin water and lubricant discharged from the ex austing means, parts being broken away, and partly in section;

Fig. 6 is a rear elevation of the water and lubricant separating means shown in Fig.

5parts being broken away, andpartly inI section Fig. z7 is a view'in end elevation, with parts roken away and partly in section of the housing for the exhausting means, and showinglin section a separator for air and vapors, and also showing an automatic control means for lubricant;

Fig. 8 is a vertical central section through one form of automatic vvalve forming one of the elementsl of our5w invention, having its cap member"removed to show the lead terminals;

. Fi 9 is a section on the line 9--9 of Fig. l

10 o one form of pump which may be employed as the exhausting means for the embodiment of our invention herein shown and described;

Fig. 10 isa section on the line 10-10 of Fig. 9;

Fig. 11 is a diagram of a circuit system for supplying and controlling electric current to the several electrically driven and controlled elements, the same being shown in the condition when the system is being operated to perform refrigerating functions;

Fig. 12 is a View ofthe circuit system shown in Fig. 11, but in the condition when the system is at rest, that is, not operating to createrefrigerating conditions or functions;

Fig. 13 is a det-ail of part of the circuit system showing the control switch when moved to another position controlling operation of the machine, and

full lines the switch blades at an intermediate of? position when rotated from position shown in Fig. 11 to position of Fig. 13, and showing in dotted lines the blades at a second intermediate off position when rotated from position of Fig. 13 to position of Fig. 11.

Referring to the drawings by characters of reference,1 designates generally a refrigerator box or cabinet of any design and construction suitable for domestic refrigeration. lln the embodiment shown, this box or cabinet may comprise a front wall 2, rear Wall 3, side walls 4, 5, a top wall 6, and a bottom or floor 6a. The walls mentioned preferably consist lof outer sheathing or panels 7 and inner walls 8 s aced therefrom to receive suitable intermediate heat insulating packing 9 (see Fig. 2) of any suitable material serving to insulate the interior ofthe cabinet from the higher external temperature, and maintain the desired low temperature conditions created in the cabinet. The cabinet is divided at a point intermediate its upper and lower portions by means of a horizontal floor or partition 10, into a lower compartment 11 and an upper compartment 12. The compartment 11 constitutes a space or chamber to receive certain apparatus, to be hereinafter described, forming part of our refrigeration system, and the upper compartment 12 forms a space to serve as a food compartment, above which is a space 12 to receive a cooling element by which the desired cooling effect is produced for cooling the food compartment. The front wall 2 is provided with a suitable door opening 13, through which access may be had to the chamber 12, said opening being controlled by a closure door 14 hinged to the front wall, as at 15, and being of any construction suitable for the urpose for which it is employed. The food) chamber 12 may contain suitable shelf grids 121? to support food or other substances to be preserved or cooled.

The floor 10 is also formed of inner and outer sheathings 7a with intermediate heat insulating material 9 in the same manner as described with reference to the outer walls of the cabinet. t

The bottom, side, rear and top walls of the upper chamber 12 and theinside of door 14 may be lined witha suitable sheet-metal, as at 16.

The lower compartment 11 is preferably provided at the front and rear of the cabinet with openings 11E, normally closed by removable perforate panels 11b which conceal the elements in said com artment, but which may be readily detac ed for access to the com artment and said elements.

'l e upper compartment 12 contains a horizontal baiiie or partition 17 which divides the 'interior of the chamber 12 to form the food compartment at the lower portion thereof, and to form the refrigeration space 12a at the merece upper portion thereof, in which the cooling element to be hereinafter described is located.

From the front edge portion of the partition 17 rises a vertical front wall 18 which extends upward to the top wall 6, and also 7 extends entirely across the front of the compartment to thereby form the front wall of the space 12a. The side edges of the wall 18 are provided with forwardly projecting side plates or flanges 19 which are adapted to be secured by suitable fastening devices 2O to the vertical sides of the opening 13, to there by support said partition 17 and Wall 13.

The side edges of the partition 17 do not extend horizontally entirely across the space 12, but terminate short thereof', as shown at 21 in Fig. 4, and from these side edges rise vertical side walls 22 which are spaced from the adjacent side walls of the compartment to form vertical air ducts 23. The upper horizontal edges 24 of the walls 22 terminate, a-s at 25, at a distance short of the upper wall of the compartment 12a to provide passages 26, through which air flowing upward through the ducts 23 may pass into the space bounded by partition 17,

walls

18, 22, and the top of the compartment 12a. The Vspace formed in the manner just described is provided to receive the cooling element of the system.

rlhe partition 17 isprovided with an opening 27 above which is supported a suitable air delector plate 28, the arrangement beingl such that the warmer air which passes from the food compartment 12 up through ducts 23 and passa es 26, will be cooled in the space containing t e cooling element, and then return through opening 27 into compartment,

12 to maintain the same at the desired low temperature. The side edges of the deflector plate 28 overlie or extend laterally beyond the edges of the opening 27, for a purpose to be presentl described.

The

various walls

17, 18, 19 and 22 are preferably of sheet-metal and may be made integral either by stamping from a single sheet, or may be made separately and welded together to form the structure described.

Within the cooling space above described is located a cooling element 29, in which the desired lower temperature is produced so as to extract the heat from the air currents flowing in contact with `the walls thereof. This element in its preferred embodiment consists of a rectangular metal container which is liquid and air tight, except as hereinafter setr forth, and includes a vertical front wall 29, rear wall 30, bottom wall 31, top wall and side walls 33, all preferably of sheetmetal and formed or united to provide a substantially rectangular hollow or chambered element. This element 29 is of such vertical. and transverse dimensions and is so supported that the side walls are spaced from the walls A22 to form vertical side air duct-s 34 comtrainee municating with passages 26, and the bottom wall 31 is spaced above the l.Epartition 17. By this arrangement the air rom chamber 12 passes up the ducts 23, through passages 26, down through ducts 34 and under thecooling element to the opening 27, and is cooled by contact with side and bottom walls of the element. rlhe cooling element is of such front to rear dimension that the front and rear walls thereof are spaced from the wall 18 and the rear wall of compartment 12a to form additional air How

ducts

35, 36, and the top wall is spaced from the top wall of the compartment to form an air flow space 37. By the arrangement of the cooling element in the manner described, the warmer air rising from. the food compartment is caused to circulate efliciently in contact with the cooling element, be reduced in temperature, and returned by gravity to the food compartment to maintain the desired low temperature therein. rll`he deflector plate 28 is so located beneath the cooling element that any dew formed thereon will be deflected on to the plate 17 and prevented from dropping through the opening 27' into the food compartment. Moisture lcollected on plate 17 may be drained 0E through a pipe 17a to any suitable receptacle (not shown).

'lhe cooling element described is adapted to contain an aqueous body which may be water entirely, or a mixture of water with some other fluid having a lower freezing point than water, for example, glycerine, which freezes at approximately minus 40 F.,vso as to reduce the freezino` point of said body below that of water. advantageous because of its low freezing point, but also becauseof its high boiling point of approximately 338 F., which insures against evaporation of the glycerine along with the water. The overall dimensions of this cooling element may vary within the scope of our invention, but in one embodiment built according to the disclosure herein, the dimensions are 14" wide by 14" long by 9 high, providing a cooling'surface of 6.2 square feet exposed to the air" currents circulating as above described in the box. j

The cooling element may be supported in the relation described by any suitable means, for example, by underlyingtransverse supporting bars 38, supported by the lower ends of hanger rods 39, the upper ends of which are headed and held by slotted clips or brackets 40 bolted, as at 41, to thertop wall of the cabinet. lBy this means the element may be readily applied in and detached from operative position.

Within the liquid containing space of the cooling element is located a freezing compartment 42, which is preferably in the form of a horizontally disposed fluid-tight shell comp'osed of a bottom wall 43,' side walls 44, top wall and rear wall 46. The front portion lycerine is particularly*- of the shell is leftiopen to provide a door i opening to the interior thereof, and projects through registering openings 47, 48, respectively, in the

walls

29a and 18, so that access may be had to the freezing compartment from the front of the refrigerator cabinet. rlhe door opening is adapted to be closed by a drop door 49 hinged, as at 50, to keepers 49a fixed on wall 29a and extending through slots in wall 18, as at 50a, the door having a packing facing 51 of rubber or equivalent material adapted to make an airtight seal with the front projecting edge of the freezing compartment, as will be presently described.

rlhe freezing compartment is supported in the cooling element by suitable vertical spacer bars 52, in such manner that the compartment is spaced from the walls of the element and is surrounded on all sides, except at the front, by the liquid refrigerating medium in the cooling element.

The freezing compartment is divided by apertured partitions 52a into pigeon holes 52h, and is adapted to receive suitable removable receptacles, such as trays 53, adapted to con- (tain water or other material to be frozen or cooled, said partitions being shown in full and dotted lines in Fig. 3 and in section in Fig. 4.

`We will now proceed to describe the means for producing the desired cooperative effect in the cooling element, and in the freezing compartment to produce refrigeration and cooling or freezing. rear portion of the cooling element above the liquid level therein is an exhaust or suction conduit 54, which communicates with the interior ofthe element. The conduit adjacent its point of connection with the cooling element passes through the rear wall of the cabinet and ythence downward on the exterior thereof, and is then directed into the chamber 11 where it communicates through a union 55 with the inlet port 55a of a suitable exhausting or evacuating means 56 capable of producing the required sub-atmospheric pressure in the cooling element to result in the necessary rapid evaporation of the water to lower the temperature thereof to the degree desired. The evacuator should have sufficient volumetric capacity to remove thevapors with sufficient rapidity to facilitate rapid evaporation with consequent eliicient lowering of the water temperature. In Figs. 9 and 10 of the drawings, we have illustra-ted one form of pump or evacuator capable of achieving the results sought, said pump not'v being of our invention either jointly or severally, the same being merely by way of example. The exhaust from the exhausting means is discharged through an exhaust port 57.

The pump or exhauster shown comprises in general a casing'` 58 containing a cylindri- Connected to the upper v.

shown herein cal chamber 59 from which projects a hollow boss 60, to which the inlet *L opens. In thel chamber is a cylindrical member 61 eccentrically mounted on a shaft 62, mounted in suitable bearings in the end walls of the casing, and one end of which projects external of 1the casing, as at 63. Rotatable on the cylindrical part 61 is a. cylindrical piston sleeve 64, the circumference of which at one point closely approaches and rolls on the wall of the chamber 59, a`s at 65, to make a seal contact. The sleeve 64 carries a rigid, radial abutment 66 which slides in a rocking bearing member 67 between the chamber 59 and the chamber of boss 60, and projects into the latter chamber. The abutment 66 is hollow as at 66;` and at its base is provided with ports 68, whereby the vapors exhausted from the cooling element entering boss flow through abutment passages 66a and ports 68 into the inlet side a of the pump chamber. Then as the piston rotates in the direction of the arrow the v apbr drawn into the pump is forced on the next revolution to the exhaust side and is discharged through the exhaust 57. ln the discharge duct 57 is arranged an inwardly closing check valve 57, of any suitable construction, which opens to permit expulsion from the exhaust side of the piston, but which is urged to closed position by a bow-spring 575 to prevent any liquid in the housing being drawn into the pump chamber. Fixed on the projecting end 63 of the piston shaft, is a belt pulley-69, which is driven by a power belt 70, in turn driven by a pulley 71 on the shaft 72 of a. suitable prime mover, preferably in the form of an electric motor 7 3, mounted on the same base as the pump. The pulley 69 may be equipped with fan blades 69a to cool the Working elements.

In operating this system, we `have found that a pump of the character illustrated having a chamber, the internal dimensions of which are 7 by 7, and in` which the rotor or piston is of such diameter that the greatest radial distance between its circumference and the wall of the chamber is 21/2, and,

therefore, having a displacement or volumetric capacity of 158 cubic inches per revolution, will, act to produce satisfactory cooling and freezing when driven at the rate of 305 revolutions per minute. When a pump of the capacity stated is. driven at this speed, it will produce temperatures corresponding to the freezing point of water, and in so doing will produce a low sub-atmospheric pressure of about .1806 inches mercury absolute, and will also produce temperatures below the freezing point of water with correspondingly lower sub-atmospheric pressures. 1t will be understood, however, by those skilled in the art, that the area of the surface of the liquid in the cooling element may be properly Y proportioned relative to the pump capacity to produce the .desired rate .of evaporation, and, consequently, the desired refrigeration effect. i

lt will also be understood that the volumetric capacity of the pump in operation is directly related to the temperature of the vapor evolved and to the refrigerating effeet desired. lt is known that at 32 F. a pound of water vapor occupies 3296 cu. ft. and the evaporation of a pound of water is equivalent to 1073 B. t. u.s, while at 20O ll'. one pound of water vapor occupies 5650 cu. ft. and theevaporation of a pound of water at this temperature is equivalent to 1223 B. t. u.s, from which it will be seen that if a refrigerating effect of 500 B. t. u.s per hour is desired, so as not to produce a temperature below 32 F., a pump capable of displacing 28 cu. ft. per minute or 1600 cu. ft. per hour, would be sufficient For lower degrees of temperature, pumps of greater capacity would be required. From this it will be apparent that the greater the volumetric capacity of the pump the greater will be the refrigerating effect produced per hour at the same lt. P. M. rlhe motor is supplied with electric current from any suitable source, but we prefer to employ a control circuit-to be described hereinafter.

The freezing conditions in the freezing l compartment are preferably achieved by connecting the interior thereof by an exhaust connection 74 with the pipe 54, so that in the embodiment shown, the exhausting means or pump will simultaneously create a low sub-atmospheric pressure in the freezing compartment as Well as in the cooling element. By this arrangement thefood compartment is cooled, and at the same time water may be frozen in the trays in the freezing compartment. This provision also enhances the freezing action because of the external cooling effect of the cold liquid in the cooling element and the direct effect of the low sub-atmospheric pressure in the freezing chamber. lt will be noted that the low pressure or approximate vacuum in the freezing chamber will serve to maintain the door 4:9l in air-tight, sealed engagement with the front edge of the freezing' chamber so long as such low pressure exists.

The pump constituting the exhausting means is arranged in a suitable housing 74, which serves as a receiver for the discharge from the pump and a container for a body of water and oil which submerges the pump to a point above the discharge 57, and seals the pump against any ingress of air thereto which ,might interfere with its vacuum producing capabilities. The housing-74 is provided with a suitable inlet connection and hand valve 7 4 by which the housing may be supplied with an initial quantity of oil and water, preferably equal parts, necessary for operation ofthe device. The water and oil may also be replenished through the said connection and valve. The housing is also supplied with a drain c ck 7 4l (Fig. 7) by which the contents of the ousing may be drained, if desired. In this arrangement the discharge from the pump takes place directly into the interior of the housing, and inasmuch as the matter discharged may comprise air, water, water vapor and lubricating oil, we provide means for separating oil and water from the air and discharging the latter from the housing. This means comprises a closure wall for the top of the casing, which includes an inwardly cupped plate 7 5 having distributingperforations 76, and over which is placed a layer of suitable fibrous packing material 77 coveroutlet opening 81.

ing the perforations 76, through the interstices of which fibrous material air alone may pass. Over the sheet 77 of fibrous material, is arranged a metal plate 78, said plate and the sheet of fibrous material being of such dimensional area as to leave a marginal air passage space 79 about the periphery thereof. Overlying the plate 78 and spaced therefrom, and of such area as to cover the marginal space 79, is a top plate 80 having a central air The exhaust from the pump passes through the liquid in the housing and strikesr the underside of plate 75, any oil and water carried by the air being thrown back into the housing, and the. air passing through perforations 76, fibrous material 77, space 79 and the space between plates 78 and 80 emerging through outlet 8l. By this arrangement only airis thrown out of the housing. Any water vapor present condenses and together with oil straties in the housing, as indicated by the level llines marked Oil and Water in Fig. 7 of the drawings. Incidently, this arrangement may to some extent act as a mufier of any noise arising from operation of the pump.

l/Ve will now describe means, also of our invention, for separating the water from the body of oil in thehousing and returning it to the cooling element so that the supply of water therein necessary to produce the cooling effect will not become prematurely depleted to such an extent as to require too frequent replenishment from an outside source.

82 designates an oil and water separator, 'preferably in the form of a tank having. a primary receiving chamber 83. The receiving chamber` has communicating therewith at its upper portion, as at 84, one. end of a pipe A85, the other end of which enters the housing 7 4, and is directed downwardly therein so that the open end of said pipe will be located in the Vbody of water in the housing, preferably close to but just .above the bottom of the housing. y It will be apparent that due to the weight of the liquid body in the'housing,

water with some. oil from the bottom of the housing-Wi1l iow through pipe 85 into the primary receiving chamber 83. The separator 82 in addition to the chamber 83, has a plurality of separating chambers, indicated at 86, 87, formed by vertical partitions 86, 87, segregating the chambers, and these chambers are connected in sequence by

Howpipes

88, 89, the pipe 88 having an inlet end adjacent the bottom of chamber 83, and a discharge end delivering through partition 86a into the top portion of chamber 86, while the pipe 89 is arranged similarly in chamber 86 and delivers through partition 87 a into the top portion of chamber 87. It will be seen that by this arrangement water, together with some oil, will flow from the housing 74 through pipe 85 into the primary separating chamber 83,- wherein the water and oil will separate in part and stratify in said chamber, the,

water being at the bottom of the chamber. The water so separated out will flow successively through

pipes

88 and 89 to the chambers 86, 87 where further separation takes place until the final chamber 87 contains water free or substantially free of oil. It will be understood that the separator may contain as many separating chambers as may be required to produce satisfactory separation. We have shown this separator as located on the base and external to the housing, but it may be located within the housing, if desired, without changing its construction or principle of operation( Each of the

pipes

88, 89 may be provided at the inlet ends thereof vwith any suitable form of straining or ilteringdevice 88EL to pass water but eliminate oil and dirt particles from the water to be returned to the cooling element. A

Eachof the

chambers

83, 86 and 87 may be provided with a drain cock 83a, by which the contents of said chambers may/be withdrawn when desired. Leading from the chamber 87 tothe cooling element, is a water return pipe 89, which may also have a ltering device 88a, and through which lwater may be returned from said chamber to the cooling element byy virtue of the vacuum or low sub-atmospheric pressure existing in the latter. This conduit 89 may include a flexible connection 89b having a slip or telescoping connection 89c with a metallic section, so as to be detachable therefrom for a purpose to be presently set forth. Return flow through the return pipe is controlled by an automatic valve 90, which is constructed and controlled-so as to-be closed while the exhausting means is operating to create sub-atmospheric pressure, in the cool ing element, and to be opened tb lpermit water to return to the cooling .element when the exhausting means comesuto rest. Bythis arrangement the water return pipe is closed to permit creationofl the desired low pressure in the cooling element during operation ofthe may be a magnet or solenoid operated valve, as shown in Fig. 8. The. valve illustrated includes a body 91 having inlet and

outlet passages

92, 93, connected in the pipe 89a and separated by a partition 94 having a port 95 and seat 96. Cooperating with the seat 96 to open and close the port 95, is a valve head 97 carried on the lower end'of a vertically movable valve stem or plunger 98.

Mounted on the valve body 91 is a casing 99 enclosing a hollow magnet or solenoid winding 100, in the hollow portion of which is arranged a sleeve 101 in which is housed the upper end of the valve stem 98. The upper end of the tube 101 is closed by a head 102 between which and the top of the stem is arranged a spring 103 which normally exerts its force to move the valve stem and the valve head 98 so that the latter will he seated on the seat 96 to close the port 95. The arrangement is such that when the magnet or solenoid is energized, it will raise the valve stem or plunger to lift the valve from its seat and permit How through the port 95, but when the magnet is deenergized the spring 103 will move the valve to closed position. The magnet or solenoid winding is arranged in a circuit system to`be hereinafter described, which in the embodiment shown may be so controlled that the magnet will be deenergized for closing the valve whenever current is suppliedto the motor 73 to drive the exhaustin means, but will be energized to move the valve to open position when current to the motor 7 3 is discontinued. 'Lead terminals for the winding are shown at 100B.

We-will now proceed to describe means for supplying lubricating oil to the pump or eX- hausting means 56, and for maintaining the supply of lubricant thereto forproperlubrication andv sealing thereof. As heretofore stated, the housin 74 contains a body of liquid, consisting o a lower stratum of water and an upper stratum of oil. Leading from the housing at a point high enough so as to always be in position to receive oil from the oil stratum, is the inlet end of an oil feed pipe 104, which is led through the wall of the housing to a point external thereof, and is then returned within the housing and connected to one of the bearings for the pump Yshaft 62, which bearing communicates withtheinterior of the pump chamber. The arrangement is such that when flow is permitted through t-he pipe 104, the suction or low sub-atmospheric pressure in the pump chamber will operate to draw lubricant from the stratum of oil in the housing and deliver such oil through the shaft 105 adapted to` establish iiow of lubricant through the pipe 104 while the pump is in op` eration and requires lubrication and sealing, and to cut off supply of lubricant when the pump is at rest. This valve 105 is preferably electrically and automatically operated so as to open when ever current .is supplied to the motor to drive the pump, and to close to cut off supply of lubricant when current to the motor is discontinued. rllhe valve may take a number of forms available for the purpose, without departing from the spirit and scope of our invention, and may be of the form illustrated in Fig. 8 and heretofore described. In the pipe 104 may be arranged a manually controlled valve 104 which may be of any suitable type permitting manual adjustment to regulate the rate of flow of lubricant passed from the housing and through the automatic valve to the pump bearing and piston or rotor chamber.

We will now describe an electric circuit system for controlling supply of current to the motor 73 and the

valves

90 and 105, in order to accomplish the refrigerating action and the operation of said valves, as heretofore described, reference being particularly had to Figs. 11 and 12 of the drawing. Located at any suitable point in the system where best subject to variations in temperature which may be employed as the agent to control the system, is a thermostat 106, the same being preferably located .in the food compartment 12, and for the purposes of this application being shown as of the type including a double pole mercury switch 107. embodying a tube or vessel, which is adapted to be tilted by thermostatically responsive means, not shown, to shift the mercury to establish the circuit at one pair of poles, and break the circuit at the other pair of poles. rThe switch 107 contains at each of its opposite ends a pair of

contacts

108, 109, respectively, and also contains a body of mercury 110 adapted to immerse either pair of contacts to establish current therethrough according to the direction in which the switchY tube is tilted. Such switches are readily available on the market, and, therefore, a specific description of the structure thereof need not be set forth herein, except in so far as may be necessary for a disclosure and understanding of the manner of controlling the circuit system.

The source of current may be from any suitable point, for example, a commercial line circuit,`and is indicated by the leads 111 112, which connect to protective fuses 113. The lead 111 is connected to the innermost of the pair of contacts 108, and the lead 112 connects to one of the contactsof a threepole cord connector or socket 114, which'may be of any of the well known commercial types. The other or outer contact 108 is connected by a lead 115 with a contact L of a :merece rotary hand switch, of a type known en the market as a Perkins doublepnle, doublethrow snap switch,-tlie same being indicated at 116. The innermost of the other pair of switch contacts 109 is connected by a lead 117 to the lead 111. The outermost contact 109 is connected by a lead 118 with the other point L2 on the switch 116.' Tntermediate the switch points L', L2, are

contacts

119, 119a and 120, 1202, and the switch includes a pair of rotary contacts or blades 1152, 1182, shown diagrammatically in Figs. 11 to 14, by which the circuit may be completed from the points L", L2 to said contacts and bridge across from contact 119 to 1202, or from 119a to 120, added jumper leads 1191), 119C, as indicated, connecting these contacts. Contact 120 is connected by a lead 121 to a second of the contacts of the connector 114, and contact 1202 is connected to the third contact ot connector 114 by a lead 122. The contact to which lead 121 is connected in the connector 114 is connected by a lead 123 to the motor circuit or windings 124 of the motor 73, the return lead oit' the motor being shown at 125 and connecting to the connector 114 at the point to make circuit with the line lead 112. The winding or core 100 for the control valve 105 heretofore described, is bridged across the

leads

123 and 125 through suitable connections 126 and a two-pole plug connection 1262, if desired. To the third contact of the connector 114 is electrically connected a circuit lead 127, which is in circuit through the lead 122 with the contact 1202. This lead 127 connects to one end ot the wire for the coil 100, which operates the water valve 90, the other end of said coil winding being connected to the lead 125. The coil for the water valve may be connected into the lead 127 by a two pole plug 1272. It will be seen that with the parts in the position shown in Fig. 11, with the contacts 108 in the switch tube immersed in the mercury and the hand switch 116 operated to cause the blade 115* thereof to connect the switch points L, 119a and 120. the motor circuit will be energized to drive the exhauster pumpL' and simultaneouslv' therewith the winding 100 f the magnet for operating the oil control valve 105 will be energized to cause the valve to open to permit 'low of oil from the pump housing 74 to the pump bearing and the piston chamber of the pump. The conditions just described are those which exist when the thermostat has been a'ected bv higher temperatures to throw the mercury switch to immerse the contacts 108 in the mercury. This condition continues so longas the temperature is high enough to cause the thermostat to tilt the mercurv, switch to the position described.

When the temperature produced and controlling the thermostat falls low enough to actuate the thermostat to throw the mercury switch to the position shownin Fig. 12,5the

from the lead 111 the current Hows to the innermost of the tube contacts 109, through the mercury to the outermost Contact and throjugl the lead 118 to the contact L2 at the rightifo' lthe double pole switch 116, thence through blade 118a to the contact 1202, and by way of the lead '122 and lead 127 through the winding 100 of the water valve to lead 125. By way of lead 125 the current passes through the connector 114 to the line lead 112. 1n this condition of the circuit it will be seen that the water valve is opened to permit flow of water from the separator to the cooling element whenever the motor and pump are at rest, and thereby adds an increment of water to the body in the cooling element to maintain the desired quantity therein. It will lbe seen that when the circuit is in the condition shown in Fig. 11, current to the lead 127 and the coil `for the water valve. will be cut off so that the valve plunger will be released from the magnet and the spring 103 will seat the valve and thereby prevent flow of water from the separator to the cooling element.

While the circuit is in the condition shown in Fig. 11, if for any reason it should be desired to stop the motor and pump, the double pole switch 116 may be moved to the position shown in Fig. 13 to make Contact at L, blade 1182, 119, jumper. lead 119c andcontact 120,

thereby cutting ofi' the current to the motor and establishing the current to the coil for operating the water valve. This arrangement provides for a manual control independently of the thermostatic automatic control. The flow of. current when the parts are in this condition is from lead 111 through the contacts 108, lead 115, switch point L', contact- 119, contact 120% to lead122, and thence A through the water valve magnet, as heretofore described. It for any reason it should be desired t0 start operation of the pump when the same is at rest, and independently of the thermostatic control, and when the mercury switch is in the position shown in Fig. 12, the switch 116 is operated to cause blade 115EL to bridge the contacts4 L2, 120, under which conditions the current flow is as follows: from lead lllthrough the lead 117 to the innermost contact 109, thence to the 'outermost contact 109 and lead 118 to the switch contact L2, thence to contact 120, and` by

leads

121, 123 to the motor and oilvalve coil. Under these conditions the water valve magnet is cut out of the circuit system and the water valve closed.

rlhe parts being constructed and arranged as above set forth, the operation of a preferred embodiment of our invention is as follows: The cooling element 29 is supplied with either a body of water, or a mixture compris ing a liquid body of glycerine and Water, preferably in the proportions by Weight of about seventy per cent-of water to thirty (30) per cent. of glycerine, the total quantity of liquid being such that the level thereof will be below the inlet to the suction duct 54, so that an air or vapor space will be left above the liquid, and the latter will not be drawn as liquid through the suction duct. ln a. system of given capacity the liquid may amount to three and one half (3l/2) gallons, and the proportions of the element 29 being such that with the liquid quantity mentioned there will be about 1.36 square feet of evaporative surface. The trays or other receptacles in the freezing chamber may be supplied with zvater or other ingredients to be frozen or cooled. The cooling velement 29 may be charged with the water or aqueous mixture by disconnecting the flexible pipe connection 891 from the section 89a and connecting said connection to a vessel (not shown) containing the desired quantity of water or aqueous mixture, and then operating the hand switch 116 to cause the exhauster to create a low enough sub-atmospheric pressure in the cooling element 29 to draw the charge from the vessel into the element 29. `When charging, the amount of water or aqueous mixture placed in the vessel may substantially approximate that desired to form the charge in the cooling element. The housing 7 4 will also be supplied with a quantity of water and suitable lubricating oil, as indicated in llig. 7 of the drawings. For initial starting, the motor and pump will be at rest, the oil valve closed and the water valve open, the circuit being in the condition shown in Fig. 11, due 'to-the fact that the food compartment is relatively warm and the thermostat has assumed a position to hold the mercury switch in the position shown in Fig. 11. The switch 116 is then operated to throw the current on to the system, whereby the motor 73 is'energized and the oil valve magnet also energized to open the oil supply connection 104. At the same time the circuit to the magnet of the water valve is interrupted and the water valve moves to closed position. The motor when energized drives the pump, and the latter operates to evacuate' or exhaust the space above the liquid level in the cooling element, resulting' in rapid evaporationof the liquid 'which causes the temperature of the liquid towbe lowered ata. rate, depending upon the degree .of sub-atmospheric pressure created "avancee in Said space. "When the liquid evaporates, the vapors liberated therefrom are carried out by the pump suction, and passing through the duct 54 enter the pump and are discharged therefrom through the discharge 57. In View of the great affinity of glyc-crine for water., these two elements are intimately mixed in the cooling element, but in View of the difference in boiling points, the water alone will evaporate and be carried over as vapor through the suction line. The glycerine remains in the cooling element. YVth a pump of suficient volumetric capacity to cause a substantial vacuum over the surface of the liquid in the cooling element, the evaporation will take place so rapidly that the temperature of the liquid, and consequentlythat of the cooling element, will be rapidly reduced toward the freezing point of the water, or lower, depending upon the degree of vacuum produced. By employing a mixture of water which freezes at approximately 32 F., yand glycerine, whiclrfreezes at a lower temperature, approximately 40 F., the temperature of the liquid in the cooling element may be carried to a point below that of the freezing point of water, so that low temperatures may be produced, if desired, and suiciently low to create elicient freezing conditions around the freezing chamber Without freezing the mixture in the cooling element. Simultaneous with the suction created in the cooling element, the vacuum or low sub-atmospheric pressure is also produced in the freezing chamber, so that water or other substance therein will be frozen, cooled or congealed, according to the degree of vacuum produced and the characteristics of the material placed in the freezing chamber.

During this operation of the exhausting means or pump, the oil valve 105 will be open and the suction created in the pump chamber will draw in small quantities of oil, but sufficient to properly lubricate the bearings and form a 'seal between the surface of the pump piston or rotor sleeve and the'cylinder wall. The air and' water vapor withdrawn by the pump from the cooling element and the freezing chamber, are expelled from thedischarge VY57 of the pump into and through the-bodyof liquid in the housing, and together'therewith will pass small quantities of oil, some of the water vapor not condensed during compression by the pump being condensed by contact with the liquid in the housing. The airwcarrying any water vapor not condensed, or oil particles not separated out, will pass upward from the liquid bodyand against the oil'and airseparator made up-of the elements 75 7,7V and 78, the water vapor and oilbein'g Septirated out and fallingback into the housing, while .the air is expelled frointhe port', 81. The oilandwater separated out 'remain'n the housing and a portion of 'thejwater'with someta muy@ ,frpugthahtniagthrough pipe 85 to the primary chamber 83 of the oil and water separator, wherein the oil and water will stratify and be separated as described, substantially oil-free water finally reaching the chamber 87. This flow of water willtake place whenever there is a greater level of liquid in the housing thanin the oil separator, and is assisted in part by any pressure which may exist over the surface of the liquid in the housing. This operationcontinues so long as thel thermostat acts to maintain the switch 107 in the position shown in F 11.

When the system has operated long enough to create the desired or determined low tem-Y perature condition in the food compartment,

or other point of control, the thermostat operates to move the switch 107 to the position shown in Fig. 12, under which conditions the circuit to the motor will be discontinued and the pump brought to rest. Simultaneously with stopping of the pump, the current to the oil'valve coil will be discontinued and further flow of oil from the housing 74 to the pump and its bearings will be stopped, even though a sub-atmospheric pressure exists within the pump when brought to rest, although the suction may drawA in the small amount of lubricant between the valve 105 and the pump. The system being air andiuid-tight, the pump piston-being oil-sealed, and the discharge therefrom being provided with an inwardly closing check Valve, the low sub-atmospheric pressures created will be maintained for a considerable time after the pump has come to rest. It will thus be seen that the oil flow to the pump will be established whenever the pump is operating to draw a sub-atmospheric pressure, and will cease whenever the pump is stopped. Simultaneously with the stopping of the pump and theclosing of the oil valve, the current will be thrown upon the coil for the water valve 90, and the latter will be immediately opened, so that the suction existing by reason of the low sub-atmospheric pressure in the cooling element will serve to draw back a certain quantity of water from tank 87 into the cooling element to make up for any water losswhich may have resulted, due to evaporation, while the pump was running. By this provisionwater loss is minimized and replenishment of water in the cooling element from a source outside the system will not be required as often as wouldbe the case if this automatic water return were not provided. The parts remain in this condition until the temperature rises to a point suliicient to actuate the thermostat to again shift the tube 107 to the position shown in Fig. 11, whereupon the operation above-described is repeated until the temperature drops low enough to cause the thermostat to throw the switch, 107 back to the position shown in Fig.r12.

Inorder to relieve, any excessive starting load onsthe pump land motor, which might .exist when the pump is started from a posi- -cause the resistance of such air to be reduced by relieving the pressure through the by-pass into the inlet side of the pump when the latter starts. It will be understood that during normal operation of the pump, the relief valve is seated and held shut, and that it opens to relieve the pressure only at starting.

It willbe noted that the'pump when running operates to evacuate the interior of the cooling element and simultaneously therewith the interior of the. freezing chamber. By this operation not only is the freezing chamber evacuated at a rate to produce rapid freezing conditions therein, but the liquid in the cooling element is cooled down to a point which will rapidly lower the temperature of the wall of the freezing chamber and thereby facilitate freezing in the freezing chamber. This is true whether the liquid in the cooling element be water or an aqueous mixture, such, for example, as water and glycerine, as described. It will beunderstood that by employing a mixture of water and glycerine (which freezes at a temperature much lower than water), the mixture will have a lower freezing point than that of water, and therefore higher vacuums may be employed with resulting lower temperatures than is possible with the use of water alone. This permits low temperature (below the freezing point of water, if desired) of the liquid in the cooling element, and also facilitates freezing It will be understood that while the pumpy is running and creating the low sub-atmospheric pressure in the freezing chamber, the door or closure 49 will be held closed to seal the opening to the freezing chamber, due to the preponderance o'f external atmospheric pressure, However, when it is desired to obtain access to the freezing chamber, it is only necessary to operate the switch 116 to bring the system to rest,-whereupon the pressures within and external to the freezing chamber will become balanced suiciently to permit the door to be readily opened.

What we claim and desire to secure by Letters Patent of the United States is:

1. In an apparatus of the character described, a cooling chamber adapted to cont-ain an aqueous liquid, a freezing chamber within `said cooling chamber, and evacuating means to produce simultaneously a low sub-atmospheric pressure in said chambers.

2. In an apparatus of the character described, a cooling chamber adapted to contain an aqueous liquid, a freezing chamber housed within said cooling chamber 'and sealed with relation thereto, evacuating means, and connections between said evacuating means and said chambers whereby a low sub-atmospheric,pressure may be produced simultaneously 1n said chambers by said evacuating means.

3. In an apparatus of the character described, a cooling chamber adapted to contain an aqueous liquid, a freezing chamber housed within said cooling element and sealed with respect thereto, evacuating means for simultaneously producing a sub-atmospheric pressure in said chambers, said freezing chamber having an opening through a wall of the cooling chamber, and a sealing closure for said opening.

4. In an apparatus of the character described, a cooling chamber adapted to contain an aqueous liquid, a freezing chamber housed within said cooling chamber and sealed with relation thereto, said freezing chamber being surrounded by the liquid in the cooling chamber, evacuating means, and connections between said evacuating means and said chambers respectively whereby a low sub-atmospheric pressure may be produced simultaneously in said chambers by said evacuating means, whereby the freezing chamber is cooled interiorly by the low pressure produced therein and is cooled externally by the surrounding liquid in the cooling element.

5. In an apparatus of the'character described, a cooling chamber adapted to contain an aqueous mixture of water and another liquid of a lower freezing point than water, a freezing chamber housed within said cooling chamber and sealed with relation thereto, and immersed in said liquid mixture, evacuating means, and connections between said evacuating means and said chambers whereby a low sub-atmospheric pressure may be produced in said chambers 'by said evacuating means.

6. In an apparatus of the character described, a cooling element adapted to contain an aqueous liquid, means for evacuating the interior of said element to evaporate said liquid to cool the same, a receptacle, said evacuating means having a discharge opening into said receptacle, an air outlet from said receptacle, and means between said discharge opening and said air outlet for separating moisture from air before passage from said outlet.

7. In an apparatus of the character described, a cooling element adapted to contain an aqueous liquid, means for evacuating the interior of said .element to evaporate said,

liquid to cool the same, a housing enclosing said evacuating means, said evacuating means having a discharge opening into said housing, an air outlet from the housing, and means between said discharge opening and said air outlet for separating moisture from air before passage of the air from said outlet.

8. In an apparatus vof the character de scribed, a cooling element adapted to contain an aqueous liquid, means for evacuating the interior of said element to evaporate said liquid to cool the same, a housing enclosing said evacuating means, said evacuating means having a discharge opening into said hous ing, an air outlet from the housing, and means between said discharge opening and said air outlet for separating moisture from the air before passage of the air from said outlet, said last-named means including air passages and moisture-eliminating means intercepting said passages.

9. In an apparatus of the character described, a cooling element adapted to contain an aqueous liquid, means for evacuating the interior of said element to evaporate said liquid tocool the same, a housing enclosing said evacuating means, said evacuating means having a discharge opening into said housing, an air outlet from the housing, and means between said discharge opening and said air outlet for separating moisture from the air before passage from said outlet, said last-named means comprising a closure for said housing and including a' perforated plate, and fibrous material overlying the perforations of said plate.

l0. In an apparatus of the character described a cooling element adapted to contain an aqueous liquid, means for evacuating the interior of said element to evaporate said liquid to cool the sa`me,a housing enclosing said evacuating means, said evacuating means having a discharge opening into said housing, an air outlet from the housing, means between said discharge and air outlets for separating moisture from the air before passage from said outlet, said last-named means comprising a closure for said housing and including a perforated plate, fibrous material overlying the perforations of said plate, and a cover-plate overlying said fibrous material.

ll. In an apparatus of the character described, a cooling element adapted to contain an aqueous liquid, means for evacuating the interior of said element to evaporate said liquid to cool the same, a housing receptacle enclosing said evacuating means, means for lubricating said evacuating means, said evacuating means having an exhaust discharge into said housing receptacle which constitutes a separator for oil and aqueous liquid, an oil and water separator connected to said housing receptacle, and means for returning sa-id aqueous liquid rator to said cooling element.

12. In an apparatus of the character described, a cooling element adapted to contain an aqueous liquid, means for evacuating the interior of said element to evaporate said liquid to cool the' same, a receptacle, means for lubricating said evacuating means, said evacuating means having an exhaust discharge into said receptacle which constitutes a separator for o-il and aqueous liquid, an oil and water separator connected to said receptacle, and means for returning aqueous liquid from said separator to said cooling element, said last-named means including provisions whereby the return of aqueous liquid to said cooling element is established when the exhausting means is at rest and cut off when the evacuating means operates.

13. An apparatus of the character described, comprising a hollow cooling element adapted to hold an aqueous liquid, evacuating means communicating with said element above the liquid level therein for creating a sub-atmospheric pressure over said liquid and removing vapor of said liquid, lubricating means for the evacuating means, means from said sepafor receiving the exhaust from said evacuating means and separating aqueous vapor and entrained lubricant from the exhaust, means to receive condensed aqueous vapor and the lubricant, conduit connections for feedingcondensed aqueous vapor to the cooling element and feeding lubricant to the evacuating means respectively, a valve controlling each of said conduit connections, and means whereby the valve in the aqueous liquid conduit opens automatically when the evacuating means is at rest and closes when the evacuating means operates, and the valve in the lubricant conduit opens when the evacuating means operates and closes when the evacuating means is at rest. y

14. An apparatus of the character described, comprising a hollow cooling element adapted to hold an aqueous liquid, evacuating means communicating with said element above the liquid level therein for creating a sub-atmospheric pressure over .said liquid and removing vapor of said liquid, 4means for returning tlubricant to said evacuating means and including a receptacle for receiving lubricant from said evacuating means, and means acting automatically to feed lubricant from saidv receptacle to said evacuating means when the latter is operating, and to stop said feed when the evacuating means istat rest.

l5. An apparatus of the character described, comprising a hollow cooling element adapted to hold an aqueous liquid, evacuating means communicating with said element above the liquid level therein for creating a sub-atmospheric pressure over said liquid and removing vapor of said liquid, an electric motor for driving said evacuating means, means for furnishing lubricant to said evacuating means and including a receptacle for receiving lubricant from said evacuating means, and having a conduit connection with said evacuating means, an electrically operated valve in said conduit co-nnection, and a circuit system including said motor and valve whereby the valve is energized to open said conduit connection when the motor is running and the valve is deenergized to close said conduit connection when the motor is at rest. y

16. An apparatus of the character described, comprising a hollow cooling element adapted to hold an aqueous liquid,evacuat ing means communicating with said element above the liquid level therein for creating a'subatmospheric pressure over said liquid and removing vapor of said liquid, means for receiving the exhaust from` said`evacuating means and separating from theeXhaust the aqueous vapor and entrained lubricant, means to receive condensed aqueous vapor and lubricant, conduit connections for returning condensed aqueous vapor to the cooling element and lubricant to the evacuating means respectively, and automatic means acting whenthe evacuating means operates to cut oil' feed of the aqueous liquid to the cooling element and establish flow of lubricant to the evacuating means, and acting when the evacuating means is at rest to establish fiow of aqueous liquid to the cooling element to cut off the flow of lubricant to the evacuating means.

17. An apparatus of the character,` described, comprising a hollow cooling element adapted to hold an aqueous liquid, evacuating means communicating with said element above the liquid level therein for creating a sub-atmospheric pressure over saidI liquid and removing vapor of said liquid, means for receiving. the exhaust from said evacuat ing means and separatingV from the exhaust the aqueous vapor and entrained lubricant, means to receive condensed aqueous vapor and lubricant, conduit connections for'returning condensed aqueous vapor to the cooling element Aand lubricant' to the evacuating means respectively, a valve controlling each of said conduit connections, and means Whereby the valve in the aqueous liquid conduit opens automatically when the evacuating means is at rest' and closes when the evacuating means operates, and the valve in the lubricant conduit opens when the evacuating means operates and closes when the evacuating means is at rest.

18. An apparatus of the character described, comprising a hollow cooling element adapted to hold an aqueous liquid, evacuat-q ing means communicating with said element above the liquid level therein for creating a sub-atmospheric pressure over said liquid and removing vapor of said liquid, means for receiving the` exhaust from said evacuat ing means and separating from the-exhaust the aqueous vapor and entrained lubricant,

means to receive condensed aqueous vapor and lubricant, conduit connectlons for returning condensed aqueous lvapor to the cooling element and lubricant to the evacuating means respectively, -an electrically operated valve for controlling each of said conduit connections and circuit connections for said valves whereby the valve in the aqueous liquid conduit opens automatically When the evacuating means is at rest,l and closes when the evacuating means operates, and the valve in the lubricant conduit opens when 'the evacuating means operates and closes when the evacuating means is at rest.

19. In a apparatus of the character described, a cooling chamber containing a liquid comprising a mixture of Water and a liquid having a lower freezing point than water, a freezing chamber Within said cooling chamber, and means to produce simultaneously a sub-atmospheric pressure in said chambers.

20. In an apparatus. of the character described, a cooling chamber containing a liquid comprising a mixture of Water and glycerine, a freezing chamber within said cooling chamber, and means to produce. simultaneously a sub-atmospheric pressure in said chambers.

21. In an apparatus of the character described, a cooling chamber containing a liquid comprising a mixture of substantially seventy per cent. water and thirty per cent. glycerine, a freezing chamber Within said cooling chamber, and means to produce simultaneously a sub-atmospheric pressure in said chambers.

22. lAn apparatus of the character described, comprising a hollow cooling element adapted to hold an aqueous liquid, evacuating -means communicating with said element above the liquid level therein for creating a sub-atmospheric pressure over said liquid .and removing vapor of said liquid, an electric motor for driving said evacuating means, means for furnishing lubricant Y,

to said evacuating means and including a receptacle for receiving lubricant from said evacuating means, and having a conduit connection with said evacuating means, and a valve in said conduit connection, said valve acting automatically to open said conduit connectionwhen the 'motor is running and to close said conduit connection when the motor is at rest.

' In testimony whereof signed our names.

FRANCIS JOSEPH KLEINHANS. HERMAN A. BRANDT.

We have hereunto