US2604760A

US2604760A - Moisture collecting and removing arrangement

Info

Publication number: US2604760A
Application number: US158995A
Authority: US
Inventors: Raymond L Southern
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1950-04-29
Filing date: 1950-04-29
Publication date: 1952-07-29
Anticipated expiration: 1969-07-29

Description

July 29, 1952 R. L. SOUTHERN MOISTURE COLLECTING'AND REMOVING ARRANGEMENT Filed April 29, 1950 2 Sl-IEETS-SHEET l Inventor".

1M His Abbov n ey.

n w e h .D u o L d n o w a R July 29, 19 R. L. SOUTHERN MOISTURE COLLECTING AND REMOVING ARRANGEMENT Filed April 29, 1950 2 Sl-IEETS-SI-IEET 2 South ern Inventor Raymond L by ax. HisAttorney.

Patented July 29, 1952 MOISTURE COLLECTING AND REMOVING ARRANGEMENT Raymond L. Southern, Erie, Pa., assignor to General Electric Company. a corporation of New York A plication April 29, 1950, Serial No. 158,995

9 Claims.

My invention relates torefrigerator cabinets and thelike and, more particularly, to breathing ments therefor. 1

Refrigerator cabinets tend to breathe as the air within the cabinet expands and contracts because of changes in the temperature ofv this air during the cycling of the refrigerating unit. Where even a small opening or leak occurs in the outer wall of the usual double-walled refrigerator cabinet, this breathing may cause moisture-laden outside air to be drawn into the insulation space between the outer and inner walls of the cabinet during the time when the air within-the cabinet is contracting. This corresponds, of course, to the time when the condensing unit is operating and, hence, when the air within the refrigerator cabinet is being cooled. Moisture thus reaching the insulation reduces the insulating value thereof and may actually damage the insulation itself. To counteract this possible adverse efiect on insulation, arrangements have previously been employed wherein a breathing passage was specifically provided for conducting the air between the atmosphere outside the cabinet and the storage compartment within the cabinet without coming in contact with the insulation itself. Thus, a preferential'path was provided for the passage of air from the exterior of the cabinet to the storage compartment. However, such arrangements may result in a substantial collection of frost within the storage compartment and this may prove objectionable. To minimize this latter tendency, I have provided arrangements wherein heating of the passage is coordinated with the direction of air flow so that the passage is relatively cool for the condensation of moisture from the air when the air is passing inwardly toward the storage compartment, but conversely the air is heated when the movement of the air is in a direction outwardly from the storage compartment to the outside atmosphere.

Accordingly, it is an object ofpmy. invention to provide a refrigerator cabinet of the spaced wall type including an improved arrangement for minimizing entrance of moisture into the insulation between the spaced walls. I

' It is another object of my invention to provide a breathing passage including an improved arrangement for'collecting moisture therein during one portion of the operating cycle of the refrigerating unit and disposing of this moisture during and moisture collecting and removing arrangeanotherportion of the cycle. a It is a further object of-my invention to provide 2 a breathing passage including an arrangement for heating the passage dependent upon the operation of the refrigerating unit.

Further objects and advantages of my invention will become apparent as the following description proceeds and the features of novelty which characterize my invention will be pointed out with particularity in the claims annexed to and forming part of this specification.

In carrying out the objects of my invention, I provide a breathing passage and a heating element therefor. The heating element is coordinated with the operation of the. condensing unit so that the heating element is energized only when the condensing unit is deenergized. In one form of my invention, a moisture absorbing material, such as silica gel, is placed within the breathing passage and the heating element is used to drive out the moisture and reactivate the silica gel during the time when the air flow is outwardly from the storage compartment. In another form of my invention, the heat is used for melting any frost collecting in the passage so that the resultant water may be easily drained from the passage and disposed of during the time air flow is outwardly from the storage compartment.

For a better understanding of my invention, reference may be had to the accompanying drawings in which Fig. 1 is a sectional elevation view of a portion of a refrigerated cabinet illustrating an embodiment of my invention; Fig. 2 is a sectional elevation view of a portion of a refrigerated cabinet showing a modified form of my invention; and Fig. 3 is a sectional plan view taken along, the line 3 3 in Fig. 2. a

I have illustratedmy invention as applied to a home freezer type of refrigerated cabinet, since the breathing and the frost and'moisture collection problem is particularly acute in this type of cabinet because of the relatively low temperatures maintained Within the food storage compartment. However, it will be apparent that my invention is alsoapplicable to any-type of refrigerated cabinet employing spaced outer and inner walls. Referring to, Fig. 1, there is shown a portion of a refrigerated cabinet or freezer-l which includes an outer wall 2 andaspaced inner wall 3 which defines a food storage compartment 4. The space between the inner and outer walls is filled with a suitable heat-insulating material 5. The ,refrigerated cabinet illustrated is of the top opening or chest type,-and a lid 6 ispro-i vided for closing the access'op'ening.

.The: food storage compartment 4 Y is refrigerwhen the condensing unit 8 is idle.

ated by a suitable evaporator l, which may consist of tubing secured to the inner wall 3, and refrigerant is pumped through the evaporator I by a condensin unit 8. The condensing unit 8 is intermittently energized, the condensing unit being started when the temperature. within the food storage compartment reaches a predetermined maximum, for example, F. and the condensing unit being stopped when the temperature reaches a predetermined minimum, for example, 5 F. Power is applied to the condensing unit 8 from the lines 9, In through a snapacting swit'ch II. The position of the switch H is controlled by a bellows l2 under the influence of a bulb l3 which is positioned against the inner wall 3 and i connected to the bellows by a tube l4.. It can be seen that, on the basis of the temperature range chosen by way of example, the temperature within the food storage compartment 4 decreases from 5 F. to 5 F. durin the time when the condensing unit is operating, and, conversely, the temperature within the food storage compartment rises from the minimum of 5 F. to the maximum of 5 F. during the time This change in temperature of the air within the food storage compartment 4 causes an expansion of the air within the food storage compartment when the condensing unit 8 is not operating and a contraction of the air within the food storage compartment when the condensing unit 8 is operating.

Thus, when the condensing unit 8 is not operating, air tends to move outwardly from the food storage compartment to the outside atmosphere, and when the condensing unit 8 is operating, air

- tends to move inwardly from the outside atmosphere to the food storage compartment. Since small openings or leaks may occur in the outer wall 2, moisture-laden air from the outside atmosphere tends to move inwardly through said small openings or leaks toward the food storage compartment 4, passing into the heat-insulating material 5. Moisture may condense and be deposited within the heat-insulating material 5,

particularly in the region adjacent the inner wall 3. This moisture, at best, reduces the insulating value of the heat-insulating material and, in the case of some insulations, it may have a definitely deleterious effect on the insulating material itself. In order to minimize the amount of moisture reaching the heat insulatin material 5 in this manner, I provide a definite passage extending from an opening through the outer wall 2 to an opening through the inner wall 3 through which air ma readily move during the expansion and contraction described above.

This breathing passage includes a conduit IS, a receptacle l6, and a second conduit H. The conduit l5 includes three sections l8, l9 and 20. The metal section l8 extends through an opening 2| in the outer wall 2 and is welded to a plate 22 which is secured to the outer wall 2 by screws 23 or other suitable fastening devices. The metal section 20 is secured to and extends into the upper end of the receptacle IS. The intermediate section I! is formed of some material of relatively low thermal conductivity, such as a suitable plastic material. so as to minimize transfer of heat through the conduit. The metal conduit I1 is secured in any suitable manner, as by welding, to a plate 24 which is secured by screws 25 or other suitable fastening devices to the inner wall 3. The conduit ll extends into the lower end of the receptacle l6 and is secured to the receptacle. The receptacle l8 includes a hollow cylindrical element 26 and two closure members 21 and 28 for closing the open ends of the element 28.

In order to absorb moisture under proper conditions from air passing through the receptacle, a mass of moisture-absorbing material 28a, such as silica gel, is disposed within the receptacle IS. A plurality of perforations 28b are provided in the conduits l5 and I! for permitting passage of air and, at the same time, excluding silicagel from the interior of these conduits. For drivin off moisture from the silica gel 28a and reactivating this silica gel under proper conditions, a heating element 28 is mounted centrally within the receptacle l8 and extends between the two end closure members 21 and 28. The recaptacle I6 is supported from the inner wall 3 by a bracket 38 which is secured to the tubular element 26 and is mounted On the inner wall 3 by a bolt and nut 3|, 32 or other suitable fastening device.

In Order to remove the maximum moisture from air passing from the outside atmosphere through the passage into the food storage compartment 4, it is desirable that the silica gel or other moisture-absorbing material within the passage be at a relatively low temperature when the air is passing inwardly tothe food storage compartment. Conversely, it is desirable that any heating of the silica gel and resultant driving off of moisture therefrom should occur only when air is passing outwardly from the food storage compartment to the outside atmosphere. In accordance with my invention, these objectives are accomplished by coordinating the energization of the heating element 29 with the de-energization of the condensing unit 8. The electrical circuit includes a stationary contact 33 and a movable contact 34 which is mounted on a movable arm of the switch ll. One line 35 from the heating element 29 is connected to a line 36 extending from the power line 8 to the movable contact 34. The other line 31 from the heating element 29 is connected directly to the stationary contact 33 and also to one terminal 38 of the condensing unit 8, and the other terminal 39 of the condensing unit is connected to the other power line I8 through a line 40. In the position of the elements shown in Fig. 1, the switch II is in its closed position with the

contacts

33, 34 in engagement and power is being supplied to the condensing unit 8 through lines 38,

contacts

33, 34 and line 40. At the same time, it can be seen that the engagement of the

contacts

33, 34 provides a short across the heating element 29, so that the heating element is de-energized. Since the condensing unit 8 is operating, the air within the food storage compartment 4 is being cooled and is, therefore, contracting; hence, air tends to move in through the passage from the outside atmosphere to the food storage compartment 4 and passes over the silica gel 28a in so doing. Since the heating element 29 is de-energized, the silica gel 280 is relatively cool and is readily able to absorb moisture contained in the air passing therethrough. Hence, the amount of moisture passing through the conduit ll into the food storage compartment 4 is minimized. When a predetermined low temperature, for example 5 F., is. reached within the food storage compartment 4, the contraction of the bellows shifts the switch ll over center, interrupting the circuit at the

contacts

33, 34. This removes the previous short circuit across the heating element 29. Under these circumstances, a circuit is provided from the power line 8 through lines 36 nals 33 and 39, and line 44 to the power line I4, energizing the heating element 29. Current also flows through the motor of the condensing element during this time but. because of the high resistance of the heating element 29, the amount of this currr nt is small and does not cause operationof the condensing unit. Since th condensing u it now th t m rature of the airwithln the food storage compartment 4 begins to rise from a'predetermined mum and, hence, the air tends to expand outs wardly through the Passage to the outside at! mosphere. Because of the arrangement provided, the silica gel is being heated by the heating element 29 at this same time, with a resultant driving off of moisture from the silica gel and the reactivating thereof, and this moisture, so removed from the silica gel, is carried to the outside atmosphere in the air moving from the food storage compartment through the passage to the outside atmosphere. It can be seen, therefore, that I have provided a correlated arrangement wherein the silica gel is in condition for ready absorption of moisture from air passing inwardly toward the food storage compartment, and, at the same time. provision is made for intermittent reactivation of the silica gel so that it will be able to absorb moisture indefinitely without at any time becoming saturated therewith.

In Figs. 2 and 3 there is shown a modified form of my invention which also includes a specific passage for the fiow of air between the outside atmosphere and the food storage compart ment 4, but which omits the moisture-absorbing silica gel employed in the modification of Fig. 1. Instead, provision is made for insuring condensation and freezing of any moisture contained in the air passing inwardly through the passage and for melting and disposing of this condensed and frozen moisture when the air passes outwardly.

Referring to Figs. 2 and 3, the breathing passage includes a conduit 4|, a vertically-mounted receptacle 42 and a conduit 43. Similar to the form previously described, the conduit 4| includes a metal section 44 which is secured within an opening 45 in the outer wall 2, a metal section 46 which extends through the top of the receptacle 42, and a section 41 of a material of relatively low thermal conductivity intermediate the

sections

44 and 46 to minimize heat conduction through the conduit. As indicated at 43, the end of the section 46 terminates within the receptacle 42 near the top thereof. One end of the conduit 43 is secured within an opening 49 in the inner wall 3, and the conduit extends through an opening in the top of the receptacle 42 and downwardly to a point near the bottom of the receptacle, as indicated at 50.

The receptacle 42 is formed of a material of relatively high thermal conductivity, and, in order to insure the maintenance of the properly low temperature within thereceptacle 42 when desired, the walls 5| and 52 of the receptacle are secured to brackets 53' and 54, respectively, which are mounted in heat exchange relationship with the relatively low temperature inner wall 3. The

brackets

53 and 54, which are composed of a material of high thermal conductivity, may be held against the inner wall 3.,by nuts and

bolts

55, 56 or other suitable fastening devices.

and 60, respectively, of the receptacle 42, The

heating elements

51 and 53 are'supplied through ,a a circuit identical withlthat employed in the forrn illustrated'in 1; ,In order tofprovide In order to provide for raising'the tempera;

ture within the receptacle42 when desired, heating elements 51 and 5-8 are mounted immediately adjacent and secured to wall portions 53 for the disposition of any water collecting within the receptacle 42, a drain conduit Si is provided extending from the slopingbottom 62 of the receptacle '42 through an opening 53' in the outer wall 2 of the cabinet. A'trap 64 is provided in the conduit iii to prevent new of air through the conduit. at. The conduitil is formed similarly t o duit 4| in that an intermediate section 65 of a material of relatively low thermal conductivity, such as plastic, is provided.

Since the refrigerated cabinet described maintains a temperature within the food storage compartment in the range of from about 5 F. to 5- F. and, since relatively good thermal conductivity is provided between the inner wall 3, which is at this relatively low temperature, andv the receptacle 42, a temperature well below the freezing point of water is maintained within the receptacle 42. Accordingly, as air passes inwardly through the elongated passage to the food storage compartment, moisture is condensed and frozen within the receptacle 42 and within the portion of the conduit 43 extending within the receptacle 42. Accordingly, the passage of moisture into the food storage compartment 4 is minimized. As in the form previously described, the

heating elements

51 and 58 are energized when the condensing unit 8 is de-energized. Accordingly, as the air passes outwardly from the food storage compartment during the period of rising temperature within the food storage compartment, heat is supplied to raise the temperature within the receptacle '42. This melts any frost which may have collected therein, and the resultant water flows down to the bottom of the receptacle and into the conduit El, from whence it is discharged to the exterior of the cabinet. Thus, moisture which passes inwardly through the passage during the time when temperature is decreasing in the food storage compartment 4 is condensed and frozen within the receptacle 42, and this frost is melted and disposed of during the time when the temperature is rising within the food storage compartment 4 and, hence, when any air flow is outwardly from the food storage compartment to the outside atmosphere.

While I have shown and described specific embodiments of my invention as applied specifically to a home freezer type of refrigerated cabinet, I do not desire my invention to be limited to the particular construction shown and described and I intend, by the appended claims, to cover all modifications within the spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. A refrigerated cabinet comprising an outer wall, an inner wall spaced from said outer wall and defining a food storage compartment, heatinsulating material in the space betweensaid walls, said inner wall having an opening therein, said outer wall having an opening therein, means defining a passage extending between said openings, a condensing unit intermittently energized 2. A refrigerated cabinet comprising an outer wall, an inner wall spaced from said outer wall and defining a food storage compartment, heatinsulating material in the space between said walls, said inner wall having an opening therein, said outer wall having an opening therein, means defining an elongated passage extending between said openings, a condensing unit intermittently energized for supplying refrigerant to cool said compartment, a heating element disposed adjacent said passage for supplying heat to said passage, and means for energizing said heating unit at all times that said condensing unit is deenergized and for deenergizing said heating element all times that said condensing unit is energized.

3. A refrigerated cabinet comprising an outer wall, an inner wall spaced from said outer wall and defining the food storage compartment, heatinsulating material in the space between said walls, said inner wall having an opening therein, said outer wall having an opening therein, means defining a passage extending between said openings, a condensing unit intermittently energized for supplying refrigerant to cool said compartment, moisture-absorbing material within said passage, a heating element for supplying heat to said passage to remove moisture from said mois ture-absorbing material for reactivating said-material and means dependent on de-energization of said condensing unit for energizing said heater.

4. A refrigerated cabinet comprising an outer wall, an inner wall spaced from said outer wall and defining a food storage compartment, heatinsulating material in the space between said walls, said inner wall having an opening therein, said outer wall having an opening therein, means defining a passage extending between said openings, a condensing unit intermittently energized for supplying refrigerant to cool said compartment, silica gel within said passage, a heating element for supplying heat to said passage to remove moisture from said silica gel for reactivating said silica gel, and means dependent on de-energization of said condensing unit for energizin said heater.

5. A refrigerated cabinet comprising an outer wall, an inner wall spaced from said outer wall and defining a food storage compartment, heatinsulating material in the space between said walls, said inner wall having an opening therein, said outer wall having an opening therein, means defining a passage extending between said openings, said passage-defining means including a receptacle, a heating element centrally disposed within said receptacle, moisture-absorbing material within said receptacle surrounding said heating element, a conduit extending from said opening in said outer wall and into said receptacle at one end thereof, a second conduit extending from said opening in said inner wall and into said receptacle at the other end thereof, a condensing unit intermittently energized for supplying refrigerant to cool said compartment, a heating element for supplying heat to said receptacle to remove moisture from said moisture-absorbing material for reactivating said material, and means dependent on de-energization of said condensing unit for energizing said heating element,

6. A refrigerated cabinet comprising an outer wall, an inner wall spaced from said outer wall and defining a food storage compartment, heatinsulating material in the space between said walls, said inner wall having an opening therein, said outer wall having an opening therein, means defining a passage extending between said openings, a condensing unit intermittently energized for supplying refrigerant to cool said compartment, at least a portion of said inner wall being maintained at a temperature below the freezing point of water, at least a portion of said passagedefining means being arranged in heat exchange relationship with said portion of said inner wall whereby moisture is condensed and frozen within said passage, a heating element disposed adjacent said portion of said passage for supplying heat to said passage, and means dependent on the deenergization of said condensing unit for energizing said heating element to melt frost collected within said passage.

7. A refrigerated cabinet comprising an outer wall, an inner wall spaced from said outer wall and defining a food storage compartment, heatinsulating material in the space between said walls, said inner wall having an opening therein, said outer wall having an opening therein, means defining a passage extending between said openings, a condensing unit intermittently energized for supplying refrigerant to cool said compartment, at least a portion of said inner wall being maintained at a temperature below the freezing point of water, at least a portion of said passagedefining means being arranged in heat exchange relationship with said portion of said inner wall whereby moisture is condensed and frozen within said passage, a heating element disposed adjacent said portion of said passage for supplying heat to saidpassage, means dependent on the deenergization of said condensing unit for energizing said heating element to melt frost collected within said passage, and means for effecting removal of melted frost from said passagedefining means. I

8. A refrigerated cabinet comprising an outer wall, an inner wall spaced from said outer wall and defining a food storage compartment, heat-insulating material in the space between said walls, said inner wall having an opening therein, said outer wall having an opening therein, means defining a passage extending between said openings, said passage-defining means including a receptacle disposed between said walls, a condensing unit intermittently energized for supplying refrigerant to cool said compartment, said inner wall being maintained at a temperature at a temperature below the freezing point of water. said receptacle being arranged in heat exchange relationship with said inner wall whereby moisture is condensed and frozen within said receptacle, a conduit extending from said opening in said outer wall and into the top portion of said receptacle, said conduit including a section of low heat conductivity, a second conduit extending from said opening in said inner wall and into the bottom of said receptacle, a heating element disposed adjacent said receptacle for supplying heat thereto, and means dependent on the deenergization of said condensing unit for energizing said heating element to melt frost collected within said receptacle.

9. A refrigerated cabinet comprising an outer wall, an inner wall spaced from said outer wall and defining a food storage compartment, heat-insulating material in the space between said walls,

=said inner wall having an opening therein, said outer wall having an opening therein, means defining a passage extending between said openings, said passage-defining means including a receptacle disposed between said walls, a condensing unit intermittently energized for supplying refrigerant to cool said compartment, said inner wall being maintained at a temperature below the freezing point of water, a bracket secured to said inner wall and to said receptacle, said bracket being composed of a material of high thermal conductivity for providing a heat transfer path between said inner wall and said receptacle whereby sald receptacle is maintained at a temperature below the freezing point of water and moisture is condensed and frozen within said receptacle, a conduit extending from said opening in said outer wall and into said receptacle, a second conduit extending from said opening in said inner wall and into said receptacle, a heating element secured to said receptacle for supplying heat thereto, and means dependent on the de-ener- 15 2, 85, 30

gizatlon of said condensing unit for energizing said heat element to melt frost within said receptacle.

RAYMOND L. SOUTHERN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,857,086 Keith May 3, 1932 1,908,248 Hull May 9, 1937 2,124,268 Williams July 19, 1938 Munters Oct. 25, 1949