Hot Gas Defrost Condensate Pan
A hot gas defrost condensate pan for collecting condensation from a refrigerator evaporator system is disclosed and claimed. In an embodiment, the condensate pan includes a heat exchanger with a header forming a closed loop and a tube bank disposed within the closed loop. The upper plane of the tube bank sits below the upper plane of the header, forming a recess in which an inner pan section sits. The header and tube bank collectively define a frame for the condensate pan. Further, the header surrounds the perimeter of the inner pan section, providing defrost heat in ice-prone areas. An outer pan section is provided on the underside of the heat exchanger. The inner pan section and the outer pan section are preferably seam welded to the heat exchanger, to protect the internal components of the condensate pan, and to prevent the ingress of dirt and bacteria.
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BACKGROUND OF THE INVENTIONS1. Technical Field
The embodiments described and claimed herein relate generally to a hot gas defrost condensate pan for a refrigerating evaporator. The hot gas defrost condensate pan includes a hot gas defrost heat exchanger with an improved configuration. More specifically, at least some of the embodiments described herein relate to a hot gas defrost heat exchanger that forms a frame for the condensate pan and/or provides improved defrost characteristics in ice-prone areas of the condensate pan.
2. Background Art
It is well known in the refrigeration art to use “hot gas” refrigerant to melt ice and slush that accumulate in an evaporator condensate pan. In a typical application, the “hot gas” refrigerant is drawn from the compressor outlet or from the liquid receiver, and directed into a heat exchanger placed in or adjacent to the condensate pan. See, for example, U.S. Pat. Nos. 3,451,226, 3,664,150, 4,474,029, and 5,315,836, which are all incorporated herein by reference. Typical prior art hot gas defrost condensate pans lack a frame and are generally constructed using heat exchanger tubes disposed between two thin gauge sheets that are brought together and welded at their perimeter. In these prior art pans, it has been found that ice tends to accumulate at the perimeter and in the corners of condensate pans. The prior art condensate pans have attempted to solve this problem by locating heat exchange tubes near, but inside of, the perimeter of the pan. While these prior art hot gas defrost condensate pans may provide satisfactory defrost characteristics, they do not present the optimal solution to the aforementioned icing problem. Accordingly, there is still a need in the art for a hot gas defrost condensate pan that is effective at melting ice in ice-prone areas.
BRIEF SUMMARY OF THE INVENTIONSThe embodiments described and claimed herein solve at least some of the problems of the prior art.
In one particular embodiment described and claimed herein, a condensate pan for a refrigeration unit is provided with an inner pan section for condensate collection and a heat exchanger that is thermally connected to the inner pan section. The heat exchanger includes at least a first tube extending along a length of the inner pan section, wherein the first tube is positioned and extends outside a perimeter of and along a first side of the inner pan section.
In another particular embodiment, a condensate pan for a refrigeration unit is provided with an inner pan section for condensate collection and a heat exchanger that is thermally connected to the inner pan section. The heat exchanger has a header and a tube bank. The header forms a closed loop and the tube bank is disposed inside of the closed loop and below an upper plane of the header to define a recess in the closed loop. The inner pan section sitting in the recess, whereby the heat exchanger defines a frame for the inner pan section.
In yet another particular embodiment, a condensate pan is provided with an inner pan section thermally connected to a heat exchanger. The heat exchanger has at least one tube extending adjacent to substantially the entire perimeter of the inner pan section, wherein the at least one tube is in thermal contact with the perimeter of the inner pan section. The heat exchanger also includes a tube bank extending underneath and being in thermal contact with the inner pan section.
In each of the three embodiments described above, the edge of the inner pan section is kept warm to prevent or reduce ice accumulation at the perimeter and in the corners of the pan.
Other embodiments, which include some combination of the features discussed above and below and other features which are known in the art, are contemplated as falling within the claims even if such embodiments are not specifically identified or discussed herein.
These and other features, aspects, objects, and advantages of the embodiments described and claimed herein will become better understood upon consideration of the following detailed description, appended claims, and accompanying drawings where:
It should be understood that the drawings are not necessarily to scale and that the embodiments are sometimes illustrated by graphic symbols, phantom lines, diagrammatic representations and fragmentary views. In certain instances, details which are not necessary for an understanding of the embodiments described and claimed herein or which render other details difficult to perceive may have been omitted. It should be understood, of course, that the inventions described herein are not necessarily limited to the particular embodiments illustrated. Indeed, it is expected that persons of ordinary skill in the art may devise a number of alternative configurations that are similar and equivalent to the embodiments shown and described herein without departing from the spirit and scope of the claims.
Like reference numerals will be used to refer to like or similar parts from Figure to Figure in the following detailed description of the inventions.
DETAILED DESCRIPTION OF THE INVENTIONSA first embodiment of a hot gas defrost condensate pan 10 is shown in
In that regard, the condensate pan 10 comprises five main components: an inner pan section 20, a heat exchanger 40, an outer pan section 60, an internal reinforcement member 80, and insulation 100. It is contemplated that the inner pan section 20, the heat exchanger 40, the outer pan section 60, and the internal reinforcement member 80 will be constructed from stainless steel, although other materials can be used.
The inner pan section 20 sits at the top of the condensate pan 10 and includes a bottom wall 21 with a drain pipe 22, a side wall 23 extending upward from the bottom wall 21, and a lip 24 extending outward from a top edge of the side wall 23. The drain pipe extends through and is fully seam welded to both the inner pan section 20 and the outer pan section 60.
The inner pan section 20, as shown, is rectangular with four sides, although the shape of the inner pan section 20 can be varied depending upon the application without departing from the intended scope of the inventions. The side wall 23 is comprised of a first side wall 25, a second side wall 26, a third side wall 27, and a fourth side wall 28. Each of the first, second, third, and fourth side walls 25, 26, 27, and 28 extend upward from the bottom wall 21 at each respective side of the inner pan section 20. The first side wall 25 is opposite from the second side wall 26, and the third side wall 27 is opposite from the fourth side wall 28. The lip 24 is comprised of a first lip 29, a second lip 30, a third lip 31, and a fourth lip 32. The first, second, third, and fourth lips 29, 30, 31, and 32 extend outward from the respective side wall 25, 26, 27, and 28 of the inner pan section 20.
As best shown in
The tube bank 46 is positioned inside the closed loop of the header 40, and extends from the first pipe 42 to the second pipe 43. The tube bank 46 is comprised of a set of first pass tubes 47 and a set of second pass tubes 48. The first pass tubes 47 extend from the inlet side of the first pipe 42 to the same side of the second pipe 43. The second pass tubes 48 extend from the outlet side of the first pipe 42 to the same side of the second pipe 43. In the shown embodiment, the tube bank 46 comprises a total of four tubes, although any number of tubes can be used. Typically, the quantity will range from four to twenty tubes depending upon the application and size of the heat exchanger 40.
During a hot gas defrost cycle, hot refrigerant enters the inlet side of the first pipe 42 through the inlet tube in direction D1. The first pipe 42 of the header 41 directs refrigerant flow into the first pass tubes 47 and the third pipe 44. A first metered opening or orifice plate 50 is provided in the inlet side of the first pipe 42 to distribute refrigerant flow between the first pass tubes 47 and the third pipe 44, to prevent refrigerant from bypassing the first pass tubes 47 through the path of least resistance (i.e., the third pipe 44). The orifice plate 50 could alternatively be disposed in the third pipe 44, or the inlet side of the second pipe 43. After leaving the inlet side of the first pipe 42, refrigerant travels through the third pipe 44 and the first pass tubes 47 in the directions D2, D3, and D4, and enters the inlet side of the second pipe 43. The second pipe 43 directs refrigerant flow into the second pass tubes 48 and the fourth pipe 45. Refrigerant travels in directions D5, D6, and D7 through the second pass tubes 48 and the fourth pipe 45, and into the outlet side of the first pipe 42. A second metered opening or orifice plate 51 is provided in the outlet side of the first pipe 42 to distribute refrigerant flow between the second pass tubes 48 and the fourth pipe 45, to prevent refrigerant from bypassing the second pass tubes 48 through the path of least resistance (i.e., the fourth pipe 45). The orifice plate 51 could alternatively be disposed in the fourth pipe 45, or the outlet side of the second pipe 43. Flow leaves the outlet side of the first pipe 42 through the outlet tube 53 in direction D8. As reflected in
The header 41 of the heat exchanger 40 serves multiple purposes, including: to support and provide rigidity for the condensate pan 10, to distribute refrigerant to the tube bank 46, and to provide defrost heat to the perimeter of the bottom wall 21 and the side walls 23 of the inner pan section 20, both being ice-prone areas of the condensate pan 10, to ensure that the outer portion of the frame is warm during defrost cycles.
The header 41 and tube bank 46 are rigidly constructed to define a frame for the condensate pan 10, and more particularly, for the inner pan section 20. As shown, the header 41 is constructed from larger diameter pipe (or tube) than the tube bank 46. In one embodiment, the header is formed from 1¼″ NPS schedule 40 stainless steel pipe and the tube bank 46 is formed from 15 mm (0.59″) OD stainless steel tubing. To be clear, other sizes of pipe and tube may be used depending upon the application and the overall dimensions of the pan. For example, some embodiments may use 2″ NPS schedule 10 stainless steel pipe and 22 mm (0.866″) OD stainless steel tubing. It has been found that construction and assembly of the heat exchanger 40 may be simplified by using rectangular tube for the header 41. Of course, because rectangular tube can withstand less pressure, the walls of the rectangular tube will need to be thicker than corresponding round tube.
As best shown in
Collectively, the header 41 and tube bank 46 of the heat exchanger 40 provide defrost heat to the inner pan section 20, to melt ice and slush. The header 41 and tube bank 46 also serve a dual purpose: providing support for the inner pan section 20. As best shown in
The shown embodiment utilizes four hangers 56 for supporting the condensate pan 10 in a refrigeration unit, although any number may be used. The hangers 56 extend through the inner pan section 20 and are welded to the header 41 of the heat exchanger 40. The hangers 56 are also fully seam welded to the inner pan section 20.
As best shown in
As best shown in
The inner pan section 20 and the outer pan section 60 collectively provide a housing for the tube bank 46 of the heat exchanger 40, the internal reinforcement member 80, and the insulation 100, to protect those components during, for example, operation, cleaning, and maintenance. Because the inner pan section 20 and the outer pan section 60 are fully seam welded to the header 41 of the heat exchanger 10, to the drain pipe 22, and to the hangers 56 the condensate pan 10 is fully sealed to prevent ingress of dirt and bacteria.
Although the inventions described and claimed herein have been described in considerable detail with reference to certain embodiments, one skilled in the art will appreciate that the inventions described and claimed herein can be practiced by other than those embodiments, which have been presented for purposes of illustration and not of limitation. Therefore, the spirit and scope of the appended claims should not be limited to the description of the embodiments contained herein.
Claims
1. A condensate pan for a refrigeration unit comprising:
- an inner pan section for condensate collection, the inner pan section being thermally connected to a heat exchanger;
- the heat exchanger comprising at least a first tube extending along a length of the inner pan section, wherein the first tube is positioned and extends outside a perimeter of and along a first side of the inner pan section.
2. The condensate pan of claim 1, wherein the inner pan section comprises a bottom wall; the heat exchanger comprises a tube bank; and, the tube bank is thermally connected and disposed adjacent to an underside of the bottom wall.
3. The condensate pan of claim 2, wherein the inner pan section comprises a first wall extending upward from the bottom wall at the first side; and, the first wall is thermally connected and disposed adjacent to the first tube.
4. The condensate pan of claim 3, wherein the inner pan section comprises a first lip extending outward from a top of the first wall; and, the first lip is thermally connected and disposed adjacent to the first tube.
5. The condensate pan of claim 2, wherein the inner pan section comprises a second side, a third side, and a fourth side; the heat exchanger also comprises a second tube being positioned and extending along the second side of the inner pan section, a third tube being positioned and extending along the third side of the inner pan section, and a fourth tube being positioned and extending along the fourth side of the inner pan section; and, the first tube, the second tube, the third tube, and the fourth tube are interconnected to form a closed loop with at least a portion of the inner pan section resting inside of the closed loop.
6. The condensate pan of claim 5, wherein the first tube, the second tube, the third tube, and the fourth tube collectively form a header for the heat exchanger to distribute refrigerant to the tube bank.
7. The condensate pan of claim 6, wherein the tube bank is disposed below an upper plane of the header to form a recess, and the bottom wall of the inner pan section is supported by the tube bank within the recess.
8. The condensate pan of claim 7, wherein the inner pan section comprises a first wall extending upward from the bottom wall at the first side, a second wall extending upward from the bottom wall at the second side, a third wall extending upward from the bottom wall at the third side, and a fourth wall extending upward from the bottom wall at the fourth side; the first wall is thermally connected and disposed adjacent to the first tube, the second wall is thermally connected and disposed adjacent to the second tube, the third wall is thermally connected and disposed adjacent to the third tube, and the fourth wall is thermally connected and disposed adjacent to the fourth tube.
9. The condensate pan of claim 8, wherein the inner pan section comprises a first lip extending outward from a top of the first wall, a second lip extending outward from a top of the second wall, a third lip extending outward from a top of the third wall, and a fourth lip extending outward from a top of the fourth wall; and, the first lip is thermally connected and disposed adjacent to the first tube, the second lip is thermally connected and disposed adjacent to the second tube, the third lip is thermally connected and disposed adjacent to the third tube, and the fourth lip is thermally connected and disposed adjacent to the fourth tube.
10. The condensate pan of claim 9, wherein an underside of the first lip rests atop the first tube, an underside of the second lip rests atop the second tube, an underside of the third lip rests atop the third tube, and an underside of the fourth lip rests atop the fourth tube, whereby the first tube, the second tube, the third tube, and the fourth tube collectively support the inner pan section.
11. The condensate pan of claim 1 further comprising an outer pan section, wherein the inner pan section and the outer pan section collectively define a housing for the condensate pan.
12. The condensate pan of claim 1, wherein the first tube has a rectangular cross-section.
13. A condensate pan for a refrigeration unit comprising:
- an inner pan section for condensate collection, the inner pan section thermally connected to a heat exchanger;
- the heat exchanger having a header and a tube bank;
- the header forming a closed loop;
- the tube bank being disposed inside of the closed loop and below an upper plane of the header to define a recess in the closed loop; and,
- the inner pan section sitting in the recess, whereby the heat exchanger defines a frame for the inner pan section.
14. The condensate pan of claim 13, wherein the inner pan section has a bottom wall with a drain opening and a side wall extending upward from a perimeter of the bottom wall; the bottom wall is positioned adjacent to the tube bank; and, the side wall is positioned adjacent the header.
15. The condensate pan of claim 14, wherein an upper surface of the tube bank is thermally connected to and supports the bottom wall.
16. The condensate pan of claim 15, wherein an inner surface of the header is thermally connected to and supports the side wall.
17. The condensate pan of claim 16, wherein the inner pan section has a lip extending outward from a top of the side wall; and, the lip is positioned adjacent to the header.
18. The condensate pan of claim 17, wherein an upper surface of the header is thermally connected to and supports the lip.
19. The condensate pan of claim 13, wherein the header is rectangular-shaped with a first header tube, a second header tube, a third header tube, and a fourth header tube; the first header tube is opposite the second header tube and the third header tube is opposite the fourth header tube; and, the tube bank extends between the first header tube and the third header tube.
20. The condensate pan of claim 19, wherein an inlet tube and an outlet tube are connected to the first header tube of the header; and, the header includes an internal plug between the inlet tube and the outlet tube to prevent short circuit of refrigerant from the inlet tube to the outlet tube.
21. The condensate pan of claim 20, wherein tube bank includes a plurality of first pass tubes and a plurality of second pass tubes; the header includes a first internal orifice plate positioned downstream of the inlet tube to distribute flow between the third header tube and the plurality of first pass tubes; and, the header includes a second internal orifice plate positioned upstream of the outlet tube to distribute flow between the fourth header tube and the second pass tubes.
22. The condensate pan of claim 20, wherein a cross-sectional area of the header is larger than a cross-sectional area of each of the first pass tubes and the second pass tubes.
23. The condensate pan of claim 13 further comprising an outer pan section attached to an underside of the heat exchanger, wherein the inner pan section and the outer pan section collectively define a housing for the condensate pan.
24. The condensate pan of claim 13, wherein header has a rectangular cross-section.
25. A condensate pan comprising:
- an inner pan section thermally connected to a heat exchanger, the inner pan section having a perimeter;
- the heat exchanger comprising at least one tube extending adjacent to substantially the entire perimeter of the inner pan section, wherein the at least one tube is in thermal contact with the perimeter of the inner pan section;
- the heat exchanger further comprising a tube bank, wherein the tube bank extending underneath and is in thermal contact with the inner pan section.
26. The condensate pan of claim 25, wherein the at least one tube forms a closed loop, surrounds the perimeter of the inner pan section, and defines a frame for the inner pan section.
27. The condensate pan of claim 26, wherein the at least one tube serves as a header for the tube bank; the tube bank being disposed underneath an upper plane of the at least one tube, wherein the at least one tube and the tube bank collectively define a recess in which the inner pan section rests.
28. The condensate pan of claim 25, wherein the at least one tube has a rectangular cross-section.
Type: Application
Filed: Mar 27, 2012
Publication Date: Oct 3, 2013
Applicant: GUNTNER U.S., LLC (Schaumburg, IL)
Inventors: Jorge Antonio Lufin CORREA (Santiago), Ian Neil RUNSEY (Algonquin, IL)
Application Number: 13/431,216
International Classification: F25D 21/14 (20060101);