Freezer evaporator apparatus

Abstract

An ultra low temperature freezer evaporator (ULT) apparatus that has a triple feed capillary tube system. The ULT apparatus prevents the low stage compressor from running in a vacuum. The invention significantly reduces the “pull down” time. Further, the ULT freezer evaporator apparatus significantly increases the transfer area between the evaporator tubing and the contact surface on the unit to assist the transfer of heat from the refrigerated unit through the condenser to the surrounding room.

What is claimed is: 
     
         1 . An ultra low temperature freezer evaporator apparatus having a low stage compressor, said apparatus comprising;
 a triple feed evaporator system having three predetermined equal lengths of capillary tubing within three predetermined equal lengths of evaporator tubing thus providing three evaporator sections, each evaporator section having a compressor end and a raceway end;   a freezer cabinet with five freezer liner walls having a top wall, left side wall, right side wall, back side wall, and bottom wall wherein said triple feed evaporator system is attached thereto with one evaporator section attached to the back freezer liner wall, another evaporator section attached to top and left side freezer liner walls, and the third evaporator section attached to the right and bottom side freezer liner walls, wherein said triple feed capillary system prevents the low stage compressor from running in a substantial vacuum and said apparatus having a significantly reduced “pull down” time.   
     
     
         2 . The ultra low temperature freezer evaporator apparatus of  claim 1  wherein said evaporator tubing is approximately ⅜ inch copper tubing and the capillary tubing has a diameter of approximately 0.036 inches. 
     
     
         3 . The ultra low temperature freezer evaporator apparatus of  claim 1  wherein said triple feed evaporator system is attached to said freezer liner walls using aluminum tape. 
     
     
         4 . The ultra low temperature freezer evaporator apparatus of  claim 1  wherein said triple feed evaporator system is attached to said freezer liner walls such that each of said three sections is attached either level or slightly sloping downhill to aid in a refrigerant/oil that is filled from the top of said apparatus to flow downhill thereby facilitating the return of the refrigerant/oil to return to the low stage compressor thus resulting in a down feed design. 
     
     
         5 . The ultra low temperature freezer evaporator apparatus of  claim 1  wherein two evaporator sections are mirror images of one another. 
     
     
         6 . The ultra low temperature freezer evaporator apparatus of  claim 1  further comprising a manifold wherein each compressor end of said three evaporator sections are connected thereto and wherein said manifold leads back to the low stage compressor. 
     
     
         7 . The ultra low temperature freezer evaporator apparatus of  claim 1  further comprising:
 a raceway wherein each raceway end of said three evaporator sections are connected thereto: 
 a distributor connected to said raceway which delivers refrigerant/oil to said raceway. 
 
     
     
         8 . The ultra low temperature freezer evaporator apparatus of  claim 1  wherein the triple feed capillary system increases the contact area between the freezer liner wall and the evaporator tubing by eliminating the necessity of rounding evaporator tubing around the corners of said freezer liner walls when using a single length of evaporator tubing.