US2550165A

US2550165A - Refrigerator having a secondary cooling means

Info

Publication number: US2550165A
Application number: US643642A
Authority: US
Inventors: William E Richard
Original assignee: Seeger Refrigerator Co
Current assignee: Seeger Refrigerator Co
Priority date: 1946-01-26
Filing date: 1946-01-26
Publication date: 1951-04-24
Anticipated expiration: 1968-04-24

Description

prifl 24, 1951 w. E. RICHARD 2,550,155

REFRIGERATOR HAVING A SECONDARY COOLING MEANS ll Sheets-Sheet 1 Filed Jan. 26, 1946 \N. E. RICHARD April 24, 1951 REFRIGERATOR HAVING A SECONDARY COOLING MEANS l1 Sheets-Sheet 2 11 IIIII IIIHHIIH Filed Jan. 26, 1946 April 24, 1951 w. E. RICHARD REFRIGERATOR HAVING A SECONDARY COOLING MEANS Filed Jan. 26, 1946 11 Sheets-Sheet 3 Jkderzibf (Unis 4 April 1951 w. E. RICHARD REFRIGERATOR HAVING A SECONDARY COOLING MEANS 11 Sheets-Sheet 4 Filed Jan. 26, 1946 April 1951 w. E. RICHARD 2,550,165

REFRIGERATOR HAVING A SECONDARY COOLING MEANS Filed Jan. 26, 1946 11 Sheets-Sheet 5 Aprifi 24, 1951 w. E. RICHARD REFRIGERATOR HAVING A SECONDARY COOLING MEANS ll Sheets-Sheet 6 Filed Jan. 26, 1946 April 24, 1951 w. E. RICHARD 0,

' REFRIGERATOR HAVING A SECONDARY COOLING MEANS Filed Jan. 26, 1946 ll Sheets-Sheet 7 IN VEN T 02 William 8. Richard April 24, 1951 w. E. RICHARD 2,550,165

REFRIGERATOR HAVING A SECONDARY COOLING MEANS Filed Jan. 26, 1946 i1 Sheets-Sheet a r INVENTOR.

William @Rz'c/mrd W. E. RICHARD REFRIGERATOR HAVING A SECONDARY COOLING MEANS April 24, 1951 ll Sheets-Sheet 9 Filed Jan. 26, 1946 m WM %W F. m b M M April 24, 1951 w. E. RICHARD REFRIGERATOR HAVING A SECONDARY COOLING MEANS Filed Jan. 26, 1946 ll Sheets-Sheet l0 I N VEN TOR'.

Wz'llzhgn /Pz'cizard Y WM 3 W fills Q'Zforney Patented Apr. 24, 1951 REFRIGERATOR HAVING A SECONDARY l COOLING MEANS William E.

Richard, Evansville, Ind., assignor to Seeger Refrigerator Company, a corporation of Minnesota Application January 26,1946, Serial No. 643,642

The present invention relates to refrigerators, and is particularly concerned with a refrigerator of the type employed for preserving, cooling or freezing foodstuffs in the household.

One of the objects of the invention is the prow vision of an improved refrigerator of the class described, which may be provided with suitable compartments for freezing ice or food products,

and for maintaining them in a frozen condition, and other suitable compartments for preserving food at another suitable higher temperature un- V der suitable humidity conditions, so that the foodstufis will not be dried out in the latter compartment by the removal of the moisture from the air, which would otherwise result in removal of moisture from the food.

Another object of the invention is the provision of a refrigerator of the class described including a primary evaporator system and a closed secondary system, but in which the secondary I system is not in'heat exchange contact with the primary evaporator but the secondary system radiates heat fromits condenser to the air in one compartment of the refrigerator, thereby providing a more moderate cooling effect in that compartment of the refrigerator which is to be operated at higher temperature and higher humidity than the freezing compartment.

Another object of the invention is the pro vision of an improved secondary systemarrangement which simplifies the installation and removal of the primary refrigeration unit, and which simplifies the manufacture because there is no mechanical connection between the primary evaporator and the condenser coil of the secondary system. Another object of the invention is the provision of an improved secondary system arrangement for cooling the food storage compartment of a refrigerator which is adapted to raise the temperature of the liner walls of the cabinet at the cold sections of the liner which surround the evaporator, and,'consequently, adapted to reduce sweating on the outside of the liner so as to substantially eliminatethe sweatingwhich causes wet insulation at this point.

Another object of the invention is the provision of an improved refrigeration system including a primary and a secondary in which the primary evaporator is so arranged in the uppermost insulated compartment adjacent the liner, but out of contact therewith, so that the temperature of that part of the liner is reduced to a temperature substantially equal to the tempera- 11 Claims. (Cl. 62-89) ture of the primary evaporator, by the transmission of heat from the liner to the primary evaporator by radiation ofheat from the liner across the spaces between the liner and the primary evaporator and by convection air currents circulating through said spaces and transferring" heat from the liner to the primary evaporator.

'A further object of the invention is the provision of an improved refrigerator construction which is simple, adapted to be manufactured economically, adapted to be serviced readily, and adapted to be used for a long period of time without necessity for repair or replacement of any of its parts.

Other objects and advantages of the invention will be apparent from the following description and the accompanying drawings, in which similar characters of reference indicate similar parts throughout the several views.

Referring to the drawings, of which there are six sheets,

Fig. 1 is a view in perspective of a household refrigerator embodying the invention.

Fig; 2 is a fragmentary perspective view of the upper part of the cabinet of Fig. 1 with the freezing compartment door open.

Fig. 3 is a top plan view of'the liner of the" cabinet.

7 Fig. 4 is a side elevational view of the exterior of the liner of the cabinet. shown apart from the insulation and outer shell.

Fig. 5 is a rear elevational view of the liner with the outlineof the outer shell shown in dot-dash lines.

Fig. 6 isa side elevational view of a liner, similar to Fig. 4, except that the lower header, and coils are shown as located on the bottom of the liner instead of on the back of the liner. 7

Fig. 7 is a view similar to Fig. 6, of another modification in which the evaporator coils are arrangednot only on the bottom but also on the back of the liner at its lower portion. 7

Fig; 8 is a fragmentary horizontal sectional view, taken on a plane below the upper shelf and above the partition or shelf 36, showing the contour of the rear edge of the shelf and its engagement with the insulating plug;

Fig. 9 is a rear elevational view of the evaporator; v l

Fig..10 is aside elevational view of the evap orator, taken from the "left side of Fig. 9.

I Fig. 11 is a diagrammatic developed'plan view of the evaporator, shown in conjunction with theshelfi l 3 Fig. 12 is a diagrammatic vertical sectional view taken on a plane parallel with the door at a point behind the front edge of the evaporator; Fig. 13 is a diagrammatic side elevational view showing the arrangement of the compartments and evaporator, taken on a vertical plane parallel to the side wall of the cabinet on the plane of the line I3-|3 of Figure 12.

Referring to Fig. 1, I indicates, in its entirety, a refrigerator of the household type which comprises a cabinet I I having an outer shell I2 and an inner shell or liner I3 which is provided with a forward opening closed by a door I5.

The outer shell may be made of metal, such as sheet metal, suitably ornamented 'or' covered by paint or enamel, and the inner shell or liner I3 may also consist of a suitable sheet metal member, its walls being preferably covered with a coating of vitreous enamel on the inside and outside for the purpose of promoting sanitation and preventing rusting.

The liner I3 is supported from the outer shell I2 by means of insulating breaker strips I6 of conventional construction, and any suitable form of insulation may be placed between the outside of the liner and the inside of the outer shell I2.

The door it may be of similar construction, with a pair of shells spaced from each other and filled with insulation, such as rock wool, the shells being secured together by suitable breaker strips I6.

At the lower end of the cabinet H there is an insulating wall, the forward edge of which is indicated at H, formed by the bottom of the liner and a transverse plate of the shell and insulation between them, and the space below the insulating wall Il may be occupied by a drawer I3 mounted upon suitable guides. v

V The liner I3 comprises a top wall I9, a pair 'of side walls 20, 2|, a bottom wall 22, and a rear wall 23, the latter being preferably provided with a rectangular opening 24 adjacent the top of the liner for insertion of a removable primary evaporator unit. I

The primary refrigeration system of the cabinet is preferably of. the type disclosed in the prior application of Russell W. Ayres, Serial No. 494,600, filed July 14, 1943, now Patent No. 2,445,988, granted July 27, 1948, entitled Refrigerator Construction With Removable Refrigerator Unit, in that this unit is preferably mounted upon an insulating plug 25 which supp'ortsthe evaporator on the inside of the cabinet and is insertable into the opening 24 of the liner, and carries upon its rear side suitable mechanism-of the motor compressor-condenser type, the details of the latter being substantially as disclosed in the application above mentioned. The primary evaporator is indicated'in its entiretyby the numeral 26, and it preferably -includes an evaporator of the two-sheet type, one of the sheets being embossed to provide suitable groovesforming conduits for the passage of refrigerant both in 'the bottom wall 21 of the evaporator and the side wall 28.

Therefrige'rant conduits in the sidewall may communicate with a transverselyextending larger header 29, also formed by embossing grooves in both of the sheets which form the evaporator, and the header 29 may communicate with another upper header 30 through "a plurality-of embossed conduits between the plates of the side wall 28.

Referring to Fig. 11, this is a diagrammatic bend at the bottom of the developed plan view of the shelf and the external walls of the evaporator 26, showing the course of the refrigerant. The refrigerant is brought in at the point 33a and introduced into the sinuous coils 35 of the shelf 33, which extend back and forth under the shelf, and thereafter communicate at 331 2,1with additional sinuous coils 3|a formed in the wall "3| and part of the bottom of the evaporator 26.

The line AA, Fig. 11, indicates the point of I side wall 3 I. The line BB, Figure 11, indicates the point of the bend at the bottom of the side wall 28 of the evaporator 2B.

The sinuous coils visible in Figure 2,

3Ia, in side wall 3|, are not because they are on the outinside sheet fiat. From the series coils 3Ia the refrigerant goes to a distributing header I02, which has a multiplicity 'of distributing conduits |Il| communicating with the parallel conduits I03, at the U-shaped ends of the conduits I03.

The conduits I03 are formed in one or the other of the sheets which constitute the wall 28, and they extend upward and communicate with the header 29-, which in turn communicates through a multiplicity ofconduits I04, with the header 30.

The take-off from the header 30 is shown at I05, and the supporting tabs 32, which support the front end of the evaporator from the ceiling of the liner, areshown in Figure ll.

The side walls 28 and 3| of'the evaporator 26 may be secured to the top 'wall I9 of the liner by inwardly turned attaching flanges 32 'and suitable screw-bolts threaded into threaded members carried by the liner wall I9, so that, in addition to being supported by the plug 25, the evaporator is supported at its forward upper edges from the top liner wall I9.

The evaporator '26 is also preferably provided with a freezing shelf 33 which may consist of a sheet metal member presenting an' upper plain surface for engagement with the ice trays 34 and having on its lower side a plurality of transversely extending tubular copper coils 35 which are soldered to the shell 33 for intimate heat exchange contact therewith.

The refrigerant from the compressor may be brought first to the coils 35 of the shelf 33 and thence to the embossed conduits in the bottom 21 of the evaporator, which terminate in the header 29 which .communicates with the header 30, the latter avoiding all possibilityof turbulence of liquid in the uppermost header which is connected to the inlet side of the compressor.

The back of the evaporator unit 26 is adjacent to the forward metal wall of the plug 25, while the front of the evaporator unit may 'be provided with a suitable metal door 3.6 pivotally mounted on the hinges at its lower edge and provided with a main body .3! and attransverse border flange 38 which is adapted, when the door is closed, to overlap the. outer forward edge of the evaporator walls 21, 38, 3|. The door 36 may be. supported in horizontal position when open by pairs of links 39, liL'pivoted together and each pair having its ends pivotally secured to the door 36 and to each side wall 28or=3| at 4|.

The door 35 may be held in closed position by the friction-of its hinges and-links for engagement of its border flange with the side walls, and it :iS held inopen-position, asshown in Fig. .2,

, from each other by the ing only relatively

narrow spaces

42, 43 between the side walls 26, 3| of the evaporator and the,

walls 26 and 2| of the liner, to which the air in the uppermost compartment has access. The space inside the liner is preferably divided into an upper compartment 44 and a lower compartment 45 by an insulating partition or shelf 46.

The shelf 46 may consist of a pair of complementary telescoping metal shells, each of which has a

main body plate

41, 48 and a border flange 49, 56. The border flange 56 of the upper member of shelf 46 may be separated from the border flange 49 and insulated therefrom by a fibre breaker strip which is frictionally heldbetween the telescoping flanges 4-9 and 56, and the interior of the shelf 46 may be filled with suitable insulation, such as rock wool.

Referring to Fig. 8, 25 indicates in its entirety the insulating plug, which isinsertable in the rear opening 24 in the liner, and. which carries the evaporator 26. This plug maybe made of a pair of pressed metal shells 25a and 25b joined together by insulating breaker strips 250.

As the lower part of the plug is located substantially at the shelf 46, the rear edge of the shelf 46 has a curved outline, as indicated at 46a in Fig. 8, thus separating the

compartments

44 and 45 and preventing air communication between them at the back of the shelf.

Thewidth of the shelf 46 may be such that its lateral edges engage the inside of the liner walls 26, 2 I, and its rear edge engages the rear wall 23 of the liner, while its front edge extends into a position which has a clearance with respect to the rear side of the door [5. The shelf 46 may be supported in its position shown in Fig. 2 by a plurality of metal studs threaded into suitable threaded members carried on the outside of the liner walls 26 and 2 Land having threaded bores, registering with apertures in the lined walls.

The partition 46 may also be provided with guides for supporting a porcelain enamel covered drawer 52 for storage of foodstuffs which are to be kept separate from the rest of the food in'the compartment l4.

The two compartments 44 and :4 are separated fact that the partition 46 engages the lower edge of the door 36 when the door is closed, and the major portion of the air from the lower compartment is thus excluded from the upper compartment, although there may be some leakage between the

spaces

42 and 43=adjacent the primaryevaporator 26 and the lower compartment, since the insulated partition .46 is not provided with sealing means for engagingthe door [5. This access of the air fromthe' lower compartment to the upper compartment and to part of the primary evaporator may-be utilized for removing, from the lower compart ment l4 a predetermined'amount of the moisture in the air for reducing the relative humidityi While it is desirable that the air of the food ture conditions in the storage compartment l4.

Thus the access of air from the lower food storage compartment to the

limited spaces

42, 43, at the sides of the evaporator, may be predetermined to reduce the relative humidity of the air of the,

lower compartment by the condensation of a predetermined amountof the moisture.

Referring to Figs. 3, 4 and 5, these are diagrammatic illustrations of the liner, which show the arrangement of the secondary system for facilitating the cooling of the compartment 45. The liner is preferably provided on its top with a top header 55 which may extend forwardly and backwardly across the top wall IQ for the purpose of charging and purging the system, and this header is preferably provided with a suitable fitting 56 at one end for communicating with a charging pipe 51 which may be removed when the system has been charged.

The top header 55 comprises a relatively large copper tube which communicates with a plurality of laterally extending refrigerant conduits comprising the copper tubes 586| on the left, Fig; 3, and 62-65 on the right. The conduits 58-65 may also consist of copper tubes which are brazed or soldered to the top header 55 and communicate therewith, andconduits 58-6I ex-. tend laterally on the top Wall l6 of the liner to its lateral edge where they are? all bent downwardly to extend downwardly along the side wall2l. 5 a

The downwardly extending portions of these pipes are indicated by the numerals 66-69. The

conduits 68-65 and their extensions are preferably uniformly spaced from each other, and prefthe liner wall. Thus the first conduit 58 is spaced from the back wall by approximately the same distance as the spacing between the conduits, and the same is true of the spacing of the conduits 6 land from the front wall or door opening.

In order to cool the back wall 23 of the liner adjacent the lower compartment 45, the conduit portions 66-69 are bent with an easy bend at their lower ends, but these conduit portions 6669 are made successively shorter so that the substantially horizontally extending portions 10-13 are also spaced substantially equally from each other on the side wall 26 and the back wall 23. The easy bends are indicated by the numeral 14.

At the rear wall 23 of the liner the conduit portions 16-73 are bent laterally in such manner that they extend laterally across the rear wall 23 and in contact therewith, as shown in I Fig. 5. It should be noted that the rearwardly storage compartment 45 be maintained at a higher humidity than the air in the freezingcompartment 44, it is also true that excessive humidity may result in the lower compartment, unless someof themoisture is removed as the reduction in the temperature of the air which comes infrom the outside increases its relative humidity.

when this air has beenreduced to. :thete'mperae;

extending portions 1013 slope downwardly toward the back, and the rear wall portions 14-Tl also slopedownwardly toward the bottom header 18, with which the conduit portions i i- 11 communicate on both sides of the bottom header 18.

The purpose of the bottom header is to equalize the refrigerant level in all of the conduits of the secondary system, and it may be closed at both ends.

The conduits forming an extension of top conduits 62-65 on the right side of the liner, Fig. 3, may be arranged exactly as described with respect to the left side, the whole system being a closed container for refrigerant.

All of the conduits of the secondary are prefarably in heat conducting contact with the Walls of the liner, and they may be held in engage-' ment with the walls of the liner by a'plurality of channeled

metal cross-bars

19, 80, 8| and 82,

7 on each side of the liner. The cross-bars are. provided with apertures for receiving the screw-bolts 83 which pass through the crossbars, and are threaded into threaded members carried by the liner Wall, such as, for example, nuts soldered to the liner wall.

The cross-bars are provided with partially circular grooves 84, Fig. 5, for receiving the outer side of the conduits and for holding the conduits in definite spaced relation while the crossbars clamp the conduits into engagement with the exterior of the liner.

In order to further assure the heat conducting contact between the conduits and the liner at points between the cross-bars, the conduits are preferably cemented to the liner by an initially plastic, adhesive compound 85, 'such as asphaltum or a bituminous composition, which;

holds the conduits uniformly in contacting engagement with the walls of the liner. This cementitious compound is used because the liner is covered with porcelain.

The heat conductivity of the cementitious compound may be increased by incorporating in it a multiplicity of metallic particles, such as aluminum filings, whichaid in conducting the heat from the liner to th sideportions of the copper conduits and increase the effective heat transfer between the conduits and the liner.

In some embodiments of the invention the liner might be made of a metal, suchas stainless steel, which need not be coated with porcelain enamel, and in such case the copper coils would be soldered to the exterior walls of the liner. a The closed secondary system on the exterior of the liner hasits air and other non-condensible gases evacuated from it, and after being dehydrated by successive evacuation and heating, the secondary system is charged with a predetermined amount of suitable refrigerant, such as dichloro-difluoromethane (CC12F2).

The operation of the refrigerator system is as follows:

The primary evaporator 26 is supplied with liquid'refrigerant in the usual manner, the vaporized refrigerant being pumped off by the rotary compressor and condensed by the condenser for return to the primary evaporator.

The major part of the upper compartment space 54 is occupied by the primary evaporator, the interior of which provides an upper freezing shelf for ice trays and a lower freezing space for. freezing food or storing it at below-freezing temperatures.

' The upper wall portions of

liner walls

20 and 21 adjacent the

air spaces

42 and 43 are cooled by radiation from the liner walls to the evaporator and by convection of heat by theadjacent air, so that these portions of the liner walls are at a temperature which closely approximates that of the primary evaporator.

In the operation of the secondary system, the food and air in the lower compartment 45 transmit heat to the lower portions of the side walls 20 and 2! and to the back wall 23, which heat is conducted to the secondary refrigerant conduits, causing the refrigerant to vaporize and topass upward in the conduits to the upper ends of the conduit portions E-B9 and to the conduits 58-65 and header E on the top wall 19.

The vaporized refrigerant in the secondary system is condensed .to liquid which runs back down the conduits to the bottom of the secondary system through the. same conduits, but in some embodiments of the invention separate return pipes might be used.

At the same time, heat is conducted upwardly in the liner walls 20 and 2! from the warmer lower portions of these walls to the upper colder portions of the walls adjacent the

air spaces

42 and 43. This increases the cooling effect of the secondary system, in particular, at the upper part ofthe compartment 45, where the warmer air tends to accumulate.

vIt should be understood that the specific location and construction of the secondary coils may be Varied, as the coils may be placed on the bottom of the liner instead of the rack, or they may be S-shaped coils extending around as many sidesof the.liner as desired.

.As distinguished from the secondary systems of the prior art, condensation takes place in the present secondary system over a larger surface, at higher temperatures, instead of on the smaller contact surface on the primary evaporator at a lower temperature, as is the case where the secondary is in direct thermal contact or direct heat exchanging relation with the primary.

In the present systemthe larger condensing surface is provided by the close proximity of the wider evaporator to the upper liner wallswhich conduct heat from the adjacent secondary coils.

The present secondary system greatly simplifies the installation and removal of the primary refrigeration system through the opening 24, as there are no mechanical connections whatever between the primary system and the secondary system.

The manufacture-of the secondary and the primary systems is simplified and made more economical because there is no mechanical connection between the primary evaporator and the secondary coil. The temperature of the liner walls at the cold sections surrounding the evaporator is raised, and this consequently reduces sweating on the outside of the liner, which sweating would be undesirable, as it causes wet insulation.

Referring to Fig. 6, this is a modificationin which the secondary refrigerant conduits are connected with a header at the top similar to the header 55, previously described. The conduits 66B9 are arranged to pass across the top of the liner 19 in substantially the same way as described with respect to Fig. 4, and. are clamped to the sides by clamping

members

19 and 80, in the same way.

In this modification, however, instead of these conduits being bent laterally at 14, they extend straight down to the bottom 22 of the liner and are bent at substantially right angles at the lower corners and extend across the bottom to the centrally located manifold 90. This manifold extends from front to back of the liner and is preferably centrally located on the bottom.

7 Referring to Fig. 7, thisis another modification in which the upper part of the secondary and liner are arranged in the same way as described with respect to Fig. 4. This modification is provided with an angular manifold 91 which extends rearwardly across the bottom 22 to the back of the liner, where it is bent upwardly at 92 and is provided with a vertical portion 93 on the back of the liner.

82 again indicates one of the clamping members. In this case the two foremost refrigerant conduits 66, 61 extend downwardly into communication with the bottom portion of the manifold 9f in the same manner as described with respect to these conduits in Fig. 6.

The two

conduits

68, 69 on each side of the box are bent rearwardly at 14 with an easy bend,

andextend to the back of the box where they that a l of the conduits tend to drain into the manifold 9|. v

With regard to the proper level of liquid reifrigerant in the secondary conduits, the liquid level should preferably be as high as, or higher t than, the highest connection between any of the laterally located conduits and the lowermost header. The level of the liquid refrigerant determines, at least approximately, the cooling area below which evaporation takes place, although some evaporation may take place above the normal level due to the bubbling and boiling. The operation of these modifications is substantially similar to that of the preferred embodiment of the invention.

While I have illustrated a preferred embodiment of my invention, many modifications may be made without departing from the spirit of the invention, and I do not wish to be limited to the precise details of construction set forth, but desire to avail myself of all changes within the scope of the appended claims.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States, is:

1. In a refrigerator, the combination of an insulated cabinethaving an outer shell and a liner of heat conducting characteristics, said liner forming an interior cabinet space which is divided b an insulated partition into upper and lower compartments, a primary evaporator unit located in the upper one of said compartments spaced from the walls of the liner, but closely adjacent to said walls, said evaporator being adapted to provide a freezing temperature in said upper one of said compartments and by radiation and convection of heat from the liner to the evaporator by the adjacent air to cool the adjacent walls of the liner, a secondary refrigeration system comprising a closed system having a plurality of refrigerant passages, said refrigerant passages extending along predetermined walls of the liner from points adjacent the primary evaporator to the lower parts of the liner wall for cooling the side walls and rear wall of the liner at a higher temperature than that existing in the other compartment of the refrigerator, said refrigerant passages extending upwardly and downwardly on the side walls of the liner and being curved to extend across the back of the liner to cool that portion of the back of the liner at a point remote from the primary evaporator, said passages being provided with a manifold joining the passages at the lowermost point of said secondary system.

2. In a refrigerator, the combination of an insulated cabinet having an outer shell and a liner of heat conducting characteristics, said liner forming an interior cabinet space which is divided by an insulated partition into upper and lower compartments, a primary evaporator unit located in the upper one of said compartments spaced from the walls of the liner, but closely adjacent to said walls, said evaporator being adapted to provide a freezing temperature in said upper one of said compartments and by radiation and convection of heat fromthe' liner to the evaporator by the adjacent air to cool the adjacent walls of the liner, a secondary refrigeration system comprising a closed system having a plurality of refrigerant passages, said refrigerant passages extending along predetermined walls of the liner from points adjacent the primary evaporator to the lower parts of the liner wall for cooling the side walls and rear wall of the liner at a higher temperature than that existing in the other compartment "of the refrigerator, said refrigerant passages extending upwardly and downwardly on the sidewalls'of the liner and being curved to extend across the back of the liner 'to cool that portion of theback of the liner at a point remote from the primary evaporator, said passages being provided with a manifold joining the passages at the lowermost point of said secondary system, and havinglanother manifold joining said passages at the uppermost point of said secondarysystem.

3. In a refrigerator, a secondary cooling system comprising a liner and a plurality of con duits for refrigerant extending across the top of the liner and downwardly on each of the side walls of the liner, said conduits being turned backwardly and extending across the back of th liner at the lower part of said liner.

4. In a refrigerator, a secondary cooling system comprising a liner and a plurality of conduits for refrigerant extending across the top of the liner and downwardly on each of the side walls of the liner, said conduits being turned backwardly and extending across the back of the liner at the lower part of said liner, said conduits being clamped to the outer wall of the liner by a plurality of transversely extending clamping members.

5. In a refrigerator, a secondary cooling system comprising a liner and a plurality of conduits for refrigerant extending across the top of the liner and downwardly on each of the side walls of the liner, said conduits being turned backwardly and extending across the back of the liner at the lower part ofsaid liner, said conduits being clamped to the outer wall of the liner by a plurality of transversely extending cla'nping members, and being also held in heat conducting contact with the liner by an init ally plastic adhesive compound.

6. In a refrigerator, a secondary cooling system comprising a liner and a plurality of conduits for-refrigerant extending across the top of the liner and downwardly on each of the side walls of the liner, said conduits being turned backwardly and extending across the back of the liner at the lower part of said liner, said conduits being joined by an upper header conduit located between the side walls and extending across the top wall of said liner.

7. In a refrigerator, a secondary cooling sys tem comprising a liner and a plurality of conduits for refrigerant xtending across the top of the liner and downwardly on each of the side walls of the liner, said conduits being turned backwardly and extending across the back of the liner at the lower part of said liner, said conduits'being provided with a header conduit located on the'back wall and extending upwardly and downwardly to communicate with all of said conduits which extend across the backwall.

8. In a refrigerator, a secondary cooling system comprising a liner and a plurality of conduits for refrigerant extending across the top of th liner and downwardly on each of the side apron-e5 tem comprisinga" liner and a'pluralityzof conduits for refrigerant extending, across the topof: the liner and*downwardly= on; each of the side walls off th liner, said conduits being turned backwardly and lextendingiacross the-back- -of the liner at the lower part of-said liner, ,saidi conduits .being providedv "with. a: header. conduit located; on the back wall and extending upwardlyanddown- I wardlyto -communicate with. all of said conduits which extendacross'the backwall', and saidconduits also being joined by a: top header extending across the top wall and: communicating-1 with the conduitsata point betweenthe sidewalls.

.10. In a refrigerator, a secondary cooling-system comprising -a-- liner and a plurality of. conduits for refrigerant, the said conduits communieating with: a" header at the: top of the-? liner and extending laterally across the: top and=-downwardlyon' each of theesidewalls- -of the liner, predetermined of said" conduits on each side extending downwardly to the: bottom of Y the liner and extending. transversely of said bottom into communication with. similar conduits from: the other side of'theliner, and: others of said conduitsJbeingbent backwardly andlextending toi-the rear of, said-liner where the..1atter:=conduits extend into communicationwith each-other.

11.. In..a refrigerator, alsecondary cooling systemcomprising a liner and aplurality of conduits for. refrigerant, the said conduits communicating with arheader at the top of. the liner and extending, laterally across the top and downwardly on each of the side walls oflthe liner, predetermined of saidrconduitson. each side extending downwardly to. the bottom of the liner and extending transversely of said bottom into communication with similar conduits-from the-other side of the liner, and others of said-conduits being bent backwardly and. extending to the rear of said.1iner where t-he'latter conduits: extend into communication with each other, and a header extending, rearwardly across the: bottom of. the linerv and upwardly onthebacleof the liner. and communicating withall of. saidconduits at their lowermost. end portions.

WIILIAME. RICHARD.

REFERENCES CITED:

The following references are of record in the file of this patent UNITED STATES PATENTS