US2289728A - Refrigerator with humidity control - Google Patents

Description

Patented July 14,` 1942 UNITED? STATI-:s

PATENT OFFICE n 2,289,728 l aaraleanaroa Wrrn nUMmrrY ooNrnoL Clyde Malin Rees, White Plains, N. Y., assignor to George A. Rees, White Plains, N. Y.

tApplication April 25, 1939, Serial No. 269,831

6 Claims.

air in food storage compartments in a positive and efficient manner, simulating the advantages of the ice-boxes already known to the art.

More specifically, the object is to provide refrigerating compartments of refrigerators having systems for circulating refrigerant -with means for positively introducing and controlling `the water. vapor of'therefrigerating air-in such compartments, as well as the temperature thereof, so that meats, vegetables, and similar articles will not be dehydrated while being kept therein. Another object of the invention is to provide a simple and positive means in association with the cooling elements of refrigerators for the controllable introduction of water vapor directly into the refrigerating air.)

Another object is to provide humidifying means for'refrigerators which is adapted to maintain a relatively large amount of grains of moisture in the air which is circulated in a refrigerating compartment, irrespective ofbatmospheric conditions. y Still another object is toprovide a refrigerator having'a plurality of refrigeratlng compartments I Ycooled by' a common system with'temperature tempering means associated with the cooling elel.ment in a selected compartment in such a way as to modify the temperature gradient of the circulated air to get a desired cooling effect without changing the system, for example, reducingy the vgradient so asto avoid undue moisture precipitation on the cooling element.

Other objects of the invention will in part be obvious and will in part appear hereinafter,`

The invention accordingly comprisesthe fea-l ,tures of construction', combination of elements and arrangement of parts, which willbe exemplified in the construction hereinafter set forth-and the scope of the invention will -be indicated in the claims.

For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawings, in

- which:v

Fig. l shows a front elevation of a typical domestic refrigerator of a type to which the present invention'is applicable;

Fig. 2 is a vertical section, taken on the line 2,2 of Fig. 1,' showing a refrigerating compart-u ment with means for cooling and humidifying the same in accordance with the invention;

Fig. 3 is a schematic diagram showing' means 60 (on cs2-3)' for maintaining automatically desiredtemperatures in the-compartments of the refrigerator shown in Fig.- 2; l Fig. 4 is afragmentary sectional view, similar to Fig. 2, illustrating a modified form of the invention:

l Fig.'5 is a fragmentary sectional view, taken on the line 5-5 of Fig. 4, illustrating certain constructional details thereof;

Fig. 6 is a fragmentary vertical sectional view,

illustrating still another modified-form of the invention: andl Fig, 7 isa fragmentary view showing -details of a control element lthat may be employed in the practice of the invention.

Referring now to the drawings, and particularly to Figs. 1 and 2,- a refrigerator of the domestic type is shown generally at I0. provided with upper and lower compartments denoted re spectlvely Il and `i2, to 'which access is'had. by

doors opening at the front in the usual mannen The compartments Il and IZ are 'here shown as of the cold wall type, i. e., they are double-walled vessels in the enclosed space of which a refrigerant is contained or circulated. The refrigerant contained in the enclosed spaces may be a secondary refrigerant or brine that is cooled by a primary refrigerant admitted to the respective en-` closed spaces of the compartments by an expan- 34') sion valve, as shown at I3 and at Il fonthe compartments il and vi2' respectively. Such primary refrigerant is arranged to circulate in coils I3' and Il' disposed in the enclosed spaces of the respective compartments and connected` to 35 the respective expansion valves. These coils. have outletconnections shown respectively at i5 and. I6. The primary refrigerant for compartments il and l2 may be any suitable refrigerant, for ex'- 0 ample, ethyl chloride, which is supplied from a common system having a compressor shown` generally at 20, disposed in an unin'sulated compartment inthe base' of the refrigerator l0. [Such compressor is arranged to discharge compressed refrigerant into condenser coils indicated sym- `bolically at 2l, from the base of which the cooled refrigerant is led by a conduit 22 tothe enclosed spaces, in which are located the cooling coils conducting the primary refrigerant. It is 5'0 to be understood that these cooling coils are immersed in the secondary refrigerant and aretapped into the conduit leadingrespectively'from the expansion valves I3 and il. The advantage of using botli'primary and secondary refrigerants is readily seen in that it permits the use of a low boiling point refrigerant without lowering the surface temperature of the walln of the enclosed spaces to the `point where the circulating air will be dehumidiied. A return conduit 23 is similarly connected to the outlets I5 and it of the coolingcoils and led to an inlet of the compressor 20. The system preferably has a power-driven ventilating fan, shown at 24, for cooling the coils 2|, the power being advantageously had from that which drives the `compressor,here shown as an electric motor 25.

The compartment may be describedl as a freezing compartment, inasmuch as it is adapted to have means disposed therein for supporting ice-cube -trays and the like. The compartment I2, however, is intended for the preservation of articles of food, and may be described as the refrlgerating compartment. The temperatures desired in these compartments' are preferably different-and are hence independently controlled. An arrangement for achieving th'is is shown in Fig. 3 whereA I1 and i3 denote the sensitive elements of the thermostatic means which are disposed respectively in thecompartments and I2. These sensitive elements may be of any suitable type, for example, of the expanding uid type, in which a heat sensitive fluid operates an expansible element for doing the Workof oper- I ating the primaryrefrlgerant controlling valves and the like, such mechanism being diagrammatically indicated in Fig. 3 by the blocks I9 and I9'. e

The control elements I9 and I9 are shown arranged for moving the -valves I3 and I4 independently through valve rods |3| andMI. By

such means, refrigerant may be admitted selectively whenever the temperatures of the respective compartments rise above predetermined values. These control elements are. also preferably arranged 'to set the compressor 20 into operwith an overflow connection V39 in order that a predeterminedl water level may not be exceeded at any time in the pan 35.

The body of water introduced through the nozzle 36 into the panl 35 is invariably at a higher temperature than that desired to be main# tained in the refrigerating compartment I2. In consequence, the amount of water admitted is' adjusted so that the water in the pan has a desired temperature tempering effect which substantially raises the temperature of theair being circulated by gravity Nabove its dew point and prevents its otherwise being too rapidly cooled. This higher temperature is also seen to be of advantage in accelerating the evaporation of water from the surface of the pan to a point approach` ing Isaturation during the period when the walls of the compartment are being cooled.

The evaporation of water into the air circulate V ing in the compartment I2 may be further accelerated by introducing a porous body containing a number of capillary passages, for example, a body of moist clay, hardwood charcoal, or activated carbon. Such block of porous material is indicated at 39 and provides a relatively large l upper or exposed surface that is always moist, and

, quickly humidifles the air circulating in the com` s compartments I properly setting the automatic devices |9 and I9',

ation whenever an expansion valve is opened.'

Accordingly, the elements I9 and |9 are arranged to actuate suitable motor control means. To this end, they are connected in parallel to each other but in series with thev source of current. This latter is symbolically shown as a pair of alternating current bus bars 26. The wiring arrangement connecting this source to motor 25 comprises amainconductor leading -from onerside of the buses 26 and provided with parallel taps 3| and 32 leading to each of the control elements |9 and I9'. From the other side ofy the elements |9 and I9 conductors 29 and 29' lead in parallel to the conductor 28 which'is connected to a motor terminal. The circuit is completed by another con- V ductor 21 leading from the other motor terminal to the other'side of the bus bars. The food compartment I2 of the refrigerator here shown is thus provided through its cold walls with cooling means that lowers the temperature of the air circulated in the compartment to a desired low value, which is preferably above the dew point for the atmospheric conditions to which the refrigerator is subjected. l

Positive means for humidifying the compartment are, in accordance with the invention, associated with the refrigerating compartment I2,Y

the means in this instance comprising a pan= 35, located in the compartment at .a point relatively remote from its side walls in a region of relatively high temperature, into which pan water is discharged from a nozzle 36 that is cooperatively disposed above the pan and connected through the wall of the refrigerator to a water main 31; the latter being advantageously connected with the city water-supply. The water supplied to pan 35 by nozzle 36 is provided with a positive control in the form of a-valve 38 introduced in the connection leading from the pipe 31 to the nozzle 36. The pan 35 is also provided partment I2.

'Ihe operation of the refrigerator is believed to be sulciently indicated in th above, it being Aapparent that the temperatures desired in the and I2, are maintained by exemplary details of which are shown in Fig. 7.

Referring to Fig. '7, a valve stem I3| is seen'to be extended into an enclosed compartment |3a which may be a small iron receptacle with removable cover, the receptacle being arranged to house an expansible' bellows |30 to which is connected a fluid conduit |13: that communicates with the sensitive element I1. By such arrangement, the lower wall of the bellows |30 is free to move up and down, and has an actuating column |32 connected thereto, on which an adjustable follower |33'is secured for engaging with one arm of a lever |34 that actuates the Valve rod |3I, the lever and the column |32 being resiliently held in operative engagement by means of a spring- |35. The column |32 is also provided with an adjustably positioned arm |36 for engaging with one end of a pivoted lever |39 which trips the contact making element |40 of an enclosed arc type of make-and-break ldevice, such as a mercury switch, that is connected at one end with conductor 3| through a pigtail |31, the other end being connected to conductor 29 through a pigtail |38. Thus, by suitably adjusting the follower |33 and the arm |36 on the column 32, a control maintaining substantially any desired operating condition o of its associated expansion valve and the motor 25 may be had.

I' compressor"`2|l""'is .tapped by a connection I3 which has an expansion valve therein at M and Here, the refrigerator has leads to a cooling coil 45 inan open tank r pan 46 that 'contains a suitable. temperature tempering liquid, such as brine, and is dis-.

- posed inthe upper part of compartmentj'42. The coil 45 has an outlet connection 41 thatileads to .y the return connection 23.

'y In order that the secondary refrigerant or e brine in pan 46 mayinot only lower the temperhas an outlet connection 49 provided .with a plu-'- rality ofnozzles 56 distributed over the top of the pan 46.y 'Ihearrangement of these nozzles `is preferablysuch as to spray the .brine upwardlyinto the air in the compartment, any unevaporated spray falling back into the body of liquid in the pan 46. In order that this brine may becirculated to an extent which lowers the temperaturethe pan 46 is provided with a sump 5I at its bottom from vwhich a pump inlet connection 52 leads to the inlet endof pump 48. Autovmatic control for the circulation'of the brine is also preferably provided.v To this end, a temperature controlling means is employed, comprising a sensitive element 53, arranged toactuate acontrol element 54, which may .be similar to that shownin Fig. 7 and arranged to actuate both aasavaa 5 this motion, and is hence bothcool'edand humidifled by the4 secondary refrigerant or brine circulated and sprayed in compartment 42.' In this manner, the tempered cold wall effect-is achieved `by the forced circulation of a secondary refrig-` erant. 1 -A third form of the invention is shown in Fig.'

.6,1m which 6I denotes an upper freezing compartment of the refrigerator, while 62 denotes a lower refrigerating compartment. vin which cold walls are not directly employed, but a cold wall eilect is achievedby the use of both secondary and tertiary refrigerants. Here, the primary the expansion valve 44 and a makeand break forl the circuits supplying'power to a motor 55 coupled to drive the pump 48.

The brine thus circulated is seen toV serve as a secondary refrigerant. at a Ahigher temperature than the primary refrigerant circulated `in the coil 45 and is adaptedin its circulation to introduce a relatively large number of grains of moisture directly into the air circulated in the cornpartment 42.

In order to achieve direct impingement by the spray from nozzles 50 of substantially all the air being circmted in compartment 42,. bamlng.

means are preferably employed, ofv a character adapted to direct the impingement and assist in inducing circulation. An arrangement'of bailles 'of this character is shown in` Fig. 5,'where a main baffle 56 is disposed horizontally across the main -space in the upper portion of the compartment 42 but whose ends clear the side walls of the compartment by a substantial distance.` Superior auxiliary bailles 51 are disposed above the nozzles andto one side, such bailies clearing the side walls of the compartment by a less distance than the main bailles 56. Inferior bailles 56 are also preferably disposed below the main baille 56 in substantially the same position asthe bailles 51. "To assist in inducing circulation, a thin metallic plate 59, which maybe described as a vertical baille, is disposed adjacent each or the side walls but clearing thesame in all directions by small distances, the clearances being such that eachl plate `5!! fits snugly against the adjacent edges of baiiles 51 and 58. In this manner, the circulation of air which may have been .warmed by absorbing heat from an article or articles being refrigerated in compartment 42, rises in the space between the vertical bailies 59 and the side walls of compartment 42, land moves horizontally over the baiiies 51 and thence downwardly through the spray from nozzles 50 and then about the sides of the brine pan 45 to descend centrally into the cooling compartment through the space between the baffles 56. Substantially-the whole body of air in the compartment 42 partakes of Vrefrigerant circulated achieves itsl refrigerating eilect in'accordance withl the so-called absorption principle, the compartment 6| being shown provided with a cooling element 63,. the front endl of which is adapted to house ice ltrays for making ice-cubes, while the rear portion 63' is adapted for cooling the secondary refrigerant. The cooled secondary refrigerant is led from this portion of the cooling element through a conduit 64 to a cooling coil 65 in a closed brine tank or vessel 66, the connection 64 advantageously having an automatically controlled expansion -valve 64a: disposed therein, the secondary refrigerant when warmed by the brine in vessel 66- -passing out through the connection 61 back to an upper portion loi! the coolingv element at 63'. Here, the cooling of the air -circulating in the compartment 62 is accelerated by the provision of a plurality of cooling fins 68 on the vessel 66,

these operating in conjunction with oneor more haines. as .shown at 69, which may be similar to those shown in Fig. 5. The circulation of thel `primary refrigerant for thecooling element68 is insured by the provision of, an exteriorelement, shown symbolically at 10, the power supply for which `may be throughgas for heating. In this form of the invention, the air is humidiiled `by evaporating water from the surface of a water pan 1I, which is disposed in the upper part of the compartmentv 62 on a shelf 12, the pan having a detachable overflow connection 13 leading directly through the wall of the refrigerator for discharge into a sewer or other sink. The f supply of water' for tho pan 1| is had from a connection 14 leading from the city water-supply to a door-actuated valve controlled device, shown generally at 15. To this end, the valve devicer 15 comprises ava1ve casing-16 having a spring-lifted valve element 11, the stem of which is prolonged as a valve rod 16 having a button 18 on its outer end in engagement with the inner surface of a door 8,0 that .affords access to the compartment 62.

By this arrangement, the valve element 11 is normally seated when the door is closed, and

the air circulating in the compartment 62 passes downwardly over the brine tank 66where, if it be dehumidiiled.I it is rehuinidiiied by evaporating water from the surface of the pan 1I. 'I'he air circulating is thus substantially saturated by evaporation at the water'surface in pan 1l, as long as equilibrium conditions obtain with the door -86 closed. When, however, the door is temperature gradient between the air circulated 4 Y aaeaves ing being positively accomplished in each of the l forms of the invention here illustrated. There is thus substantially no tendency for the air cirs culating to dehydrate food or other hydrated articles stored in the refrigerating compaent.

Since certain changes lmay be made in the i5 above construction and diderent embodiments of the invention could be made without departf ing from the scope thereof, it is intended that all mattercontained in the above description or shown in the accompanying drawings shall be 2g interpreted as illustrative and not in a limiting sense. r v

Having described my invention, what I claim as new and desire to secure by Letters Patent is:

1. In a refrigerator the combination comprising, a food storage compartment containing air, a system for circulating primary refrigerant in'- cluding a cooling element, a vessel in the upper part of said compartment containing a body of liquid adapted to be cooled by said cooling ele- 3o ment and to cool the air which is freely circulated substantially solely by gravity, humidity ycontrolling means for introducing water Vapor directly into-gravity circulated air including a relatively low pressure nozzle associated with the body of liquid in said vessel, said means being' located in said compartment at a point remote from the side walls thereof in a region ofrelatively high temperature, means forv circulating primary refrigerant in said system to cool the 4o body of liquid whereby it serves as secondary refrigerant, and thermostatic means' lcontrolling the circulation of said primary refrigerant so as to 4maintain a desired temperature of the liquid.

2. Ina refrigerator the combination, comprising, a food storage compartment containing air,

. a ,system for circulating primary refrigerant including a cooling element, humiditycontroliing -means for introducing water vapor directly into gravity circulated air including aA plurality of relatively low pressure spraying nozzles, said means being located in said-compartment at a point remote from the side walls thereof in a region of relatively high temperature, a vessel holding asecondary refrigerant comprising a body of brine D each of saidcompartments connectedin parallel connected to supply spray to said nozzles and to collect that which issues therefrom, means forA forcing the circulationv of said brine, said cooling element being arranged for cooling thefbrineyz'ith the latter being adapted for cooling theair'which -60 is freely circulated substantially solely; bygr'avity, and thermostatic means for controlling 'both the circulation and the temperatureof--the brine.

3. In a refrigerator the combination comprising, a food storage compartment containing air,

a system 'for circulating; primary' refrigerant including a cooling element, humidity controlling means for introducing water vapor; directly into gravity circulated air including a plurality of relatively low pressure spraying nozzles, said holding a secondary refrigerant comprising a body of brine associated with said humidity controlling means and adaptedfor cooling the' air which is freely circulated substantially solely by gravity, said cooling element having atleast a portion immersed in the body of brine to permit the circulation of primary refrigerant therethrough, thermostatic means for maintaining the temperature of the brine at a desired value, and

baille means for causing the gravity circulated air to be tempered by passage about the body of brine.

4. In a refrigerator having a plurality of com# partments one of which contains air to be refrigerated, the combination with asystem com'- rnon to said compartments for circulating primary refrigerant and including cooling elements one for each of said compartments, of means in saidl air-containing compartment at a point remote from the side walls thereof in a region of relatively high temperature for holding a body of liquid adapted for cooling the air which is freely circulated substantially solelyv by gravity with the cooling element 'for said compartment being ar-l ranged for cooling the body of liquid, a plurality of spraying nozzles for humidifying air disposed in said compartment, means connected to said liquid holdingv means to supply spray to said nozzles, means for collecting and returning to said liquid holding means spray which is unevaporated `by gravity circulated air, and means for directing gravity circulated air into contact with said.-

spray.

5. In a refrigerator having a plurality of coin-l partments one of which contains air to be refrigerated, the combination with a system common to said compartments for circulating primary refrigerant and including cooling elements one for l .each of said compartments, of means in saidaircontaining compartment at a point remote from the side walls thereof in a region of relatively high temperature Afor holding a body of liquid adapted to be cooled by one of said cooling elements and to cool the air which isA freely circulated substantiallyHy solely by gravity, baiiies for directing gravity circulated air to pass over the body of liquid, xmeans associated with the body ofV liquid for introducing grains of moisture directly.`

into gravity circulated air and means for controlling the temperature of the body of liquid.

(i.4 In a refrigerator having a plurality of segregated compartments one of which contains air to .be refrigerated, the combination with a system common to said compartments for circulating refrigerant and including cooling elementsone for of said air-containing compartment containing secondary refrigerant adapted for cooling the air which is freely circulated substantially solely by gravity with one of said cooling elements' im? mersed in the secondary refrigerant, humidity" 4controlling means comprising a relatively low pressure spraying nozzle located above said vessel, means to circulate secondary refrigerant from saidV vessel to said nozzle, baiiles for directing gravity circulated air over said vessel, and ther-l mostatic means for controlling both the circulation of said secondary 'refrigerant and saidV primary refrigerant flow control means.

' CLYDE MALIN REES.

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