Hot Gas Defrost Condensate Pan

Abstract

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.

We claim: 
     
         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.