Horizontal Extraction and Return Extensions in liquid storage tanks

Abstract

This invention is an improvement to the shape of liquid storage tanks, in particular to unpressurized molded polymer tanks used for thermal storage in solar systems. All aspects of this invention are well suited to solar storage tanks, and individual aspects are suited to other liquid tank applications. This invention provides a formed horizontal extension at the bottom of the tank. From the top of this lower extension, a hollow vertical stub provides a reliable connection to a circulator pump. Thermal performance is enhanced by ensuring the lowest and coolest water is delivered to the array of rooftop solar collectors without entraining debris from the bottom of the tank. At the top of the tank, a similar horizontal extension is used to distribute hot water returning from the solar collectors. Flow velocity is eliminated and a curving lower edge allows return water to find the matching thermocline to avoid de-stratifying.

1 . A molded storage tank that incorporates an essentially horizontal and hollow foot-like extension at the tank bottom, whose outer extremity includes an upwardly-directed tank outlet. 
     
     
         2 . Claim  1  where the tank shape is a vertical-axis cylinder. 
     
     
         3 . Claim  1  where the tank shape is a rectangular prism. 
     
     
         4 . Claim  1  with the outlet designed to support a circulating pump. 
     
     
         5 . Claim  4  where the outlet is vertical. 
     
     
         6 . Claim  1  with the extension having two essentially vertical outer edges that form a 90 degree angle and which extend tangentially from a cylindrical tank. 
     
     
         7 . Claim  1  where the underside of the extension is coplanar with the tank bottom. 
     
     
         8 . A molded storage tank that incorporates an essentially horizontal and hollow extension at the tank top, whose outer extremity includes an upwardly-directed tank inlet. 
     
     
         9 . Claim  8  where the tank is a vertical-axis cylinder. 
     
     
         10 . Claim  8  where the tank shape is a rectangular prism. 
     
     
         11 . Claim  8  with the extension having two essentially vertical outer edges that form a 90 degree angle and which extend tangentially from a cylindrical tank. 
     
     
         12 . Claim  8  where the top side of the extension is coplanar with the tank top. 
     
     
         13 . Claim  8  where there is a large radius fillet at the intersection of the lower surface of the extension and the tank wall. 
     
     
         14 . Claim  8  where the top extension includes holding means for a pipe extending vertically from the circulating pump. 
     
     
         15 . Claim  14  where the holding means is a molded hole through the top extension. 
     
     
         16 . Claim  14  where the holding means is a molded slot recess in an edge of the extension.