Heat recovery device with standoff heat exchanger mount

Abstract

A heat recovery device comprises a gas flow conduit, a gas/liquid heat exchanger and a gas diverter valve provided in the gas flow conduit, the valve being movable between a bypass position and a heat exchange position. The gas flow conduit includes a divergent branch point at which it is divided into a bypass branch conduit and a heat exchange branch conduit. The bypass branch conduit bypasses the heat exchanger, and the heat exchange branch conduit includes an upstream conduit portion and a downstream conduit portion. The gas flow direction from the upstream conduit portion into the gas inlet opening of the heat exchanger diverges in a direction away from the overall gas flow direction, permitting the heat exchanger to be spaced away from the exhaust gas conduit.

What is claimed is: 
     
         1 . A heat recovery device, comprising:
 a gas flow conduit having an inlet and an outlet, wherein an overall gas flow direction through the gas flow conduit is defined between the inlet and the outlet thereof;   a gas/liquid heat exchanger having a gas inlet opening and a gas outlet opening;   a gas diverter valve provided in the gas flow conduit, wherein the valve is movable between a bypass position and a heat exchange position;   wherein the gas flow conduit includes a divergent branch point at which the gas flow conduit is divided into a bypass branch conduit and a heat exchange branch conduit;   wherein the bypass branch conduit bypasses the heat exchanger, and the heat exchange branch conduit includes an upstream conduit portion and a downstream conduit portion;   wherein the upstream conduit portion has a first end in flow communication with said gas flow conduit at said divergent branch point, and a second end in flow communication with the gas inlet opening of the heat exchanger;   wherein the downstream conduit portion has a first end in flow communication with the gas outlet opening of the heat exchanger; and   wherein a gas flow direction into the gas inlet opening of the heat exchanger diverges in a direction away from the overall gas flow direction through the gas flow conduit.   
     
     
         2 . The heat recovery device of  claim 1 , further comprising a convergent branch point at which the bypass branch conduit and the heat exchange branch conduit converge, the convergent branch point being located upstream of the outlet of the gas flow conduit. 
     
     
         3 . The heat recovery device of  claim 2 , wherein the downstream conduit portion has a second end in flow communication with the gas flow conduit at the convergent branch point. 
     
     
         4 . The heat recovery device of  claim 1 , wherein a first plane passes through the inlet and outlet of the gas flow conduit, the first branch point and the bypass branch conduit. 
     
     
         5 . The heat recovery device of  claim 4 , wherein a second plane passes through the second end of the upstream conduit portion and the first end of the downstream conduit portion, and wherein portions of the first and second planes passing through heat recovery device are spaced apart from one another. 
     
     
         6 . The heat recovery device of  claim 5 , wherein the second end of the upstream conduit portion and the first end of the downstream conduit portion are secured to the heat exchanger at the respective gas inlet opening and gas outlet opening, in said second plane. 
     
     
         7 . The heat recovery device of  claim 4 , wherein the upstream conduit portion and the downstream conduit portion curve away from the first plane toward the second plane. 
     
     
         8 . The heat recovery device of  claim 1 , wherein the second end of the upstream conduit portion and the first end of the downstream conduit portion are free from connection to each other or to other portions of the gas flow conduit. 
     
     
         9 . The heat recovery device of  claim 1 , wherein the gas flow direction at the gas inlet opening of the heat exchanger is at an angle of about 90 degrees to the overall gas flow direction through the gas flow conduit. 
     
     
         10 . The heat recovery device of  claim 1 , wherein the gas flow direction at the gas outlet opening of the heat exchanger is at an angle of about 90 degrees to the overall gas flow direction through the gas flow conduit. 
     
     
         11 . The heat recovery device of  claim 1 , wherein the gas flow direction at the second end of the upstream conduit portion and the first end of the downstream conduit portion is at an angle of about 90 degrees to the overall gas flow direction through the gas flow conduit. 
     
     
         12 . The heat recovery device of  claim 1 , wherein the heat exchanger is constructed from a stack of plates defining alternating gas flow passages and liquid flow passages extending substantially parallel to the overall gas flow direction through the gas flow conduit. 
     
     
         13 . The heat recovery device of  claim 1 , wherein the heat exchanger further comprises a gas inlet manifold communicating with the gas inlet opening and a gas outlet manifold communicating with the gas outlet opening, and wherein a gas flow direction through each of the gas inlet manifold and the gas outlet manifold is at an angle to the overall gas flow direction through the gas flow conduit. 
     
     
         14 . The heat recovery device of  claim 1 , wherein the gas diverter valve is located at the divergent branch point. 
     
     
         15 . The heat recovery device of  claim 14 , wherein,
 with the gas diverter valve in the bypass position, gas flow to the heat exchange branch conduit is substantially completely blocked; and   with the gas diverter valve in the heat exchange position, gas flow to the bypass branch conduit is substantially completely blocked.   
     
     
         16 . The heat recovery device of  claim 1 , wherein the heat exchanger further comprises a bottom plate in which the gas inlet opening and the gas outlet opening are provided, and wherein the second end of the upstream conduit portion and the first end of the downstream conduit portion are secured to the bottom plate. 
     
     
         17 . The heat recovery device of  claim 16 , wherein the bottom plate is reinforced or thickened, at least in areas proximate to the gas inlet opening and the gas outlet opening. 
     
     
         18 . The heat recovery device of  claim 1 , wherein the second end of the upstream conduit portion and the first end of the downstream conduit portion are aligned with one another along the overall gas flow direction. 
     
     
         19 . The heat recovery device of  claim 1 , wherein the second end of the upstream conduit portion and the first end of the downstream conduit portion are aligned with one another along a direction which is substantially perpendicular to the overall gas flow direction.