Baffle design for a gas-fired unit heater

Abstract

A gas-fired unit heater ( 10 ) is provided and includes a burner ( 20 ), a heat exchanger tube ( 18 ) located to receive a flow of the combustion products from the burner ( 20 ), the tube ( 18 ) including at least one linear tube run ( 30 ) extending along a longitudinal axis ( 18 ), and a corrugated baffle ( 40 ) received in the tube run ( 30 ).

1 . A gas-fired unit heater comprising: 
 a burner;    a heat exchanger tube located to receive a combustion gas flow from the burner, the tube including at least one linear tube run extending along a longitudinal axis, the tube run having an inner wall;    a corrugated baffle received in the tube run, the baffle comprising a corrugated strip of material having a length extending parallel to the longitudinal axis, and alternating peaks and valleys joined by side walls defining corrugations along the length with each of the peaks and valleys being non-parallel to longitudinal axis.    
   
   
       2 . The unit heater of  claim 1  wherein opposite edges of the strip engaging the inner wall at at least one of the peaks and at at least one of the valleys.  
   
   
       3 . The unit heater of  claim 1  wherein: 
 the inner wall is cylindrical with an inside diameter D;    the corrugations having a height dimension H from the peaks to the valleys perpendicular to the longitudinal axis and a width dimension W perpendicular to both the height dimension and the longitudinal axis; and    the ratio of (W*H)/D is in the range of 0.60 to 0.80.    
   
   
       4 . A corrugated baffle for use in a linear tube run of a gas-fired unit heater: the baffle comprising a corrugated strip of material having a length extending parallel to the longitudinal axis, and alternating peaks and valleys joined by side walls defining corrugations along the length with each of the peaks and valleys being non-parallel to longitudinal axis.  
   
   
       5 . The baffle of  claim 4  wherein opposite edges of the strip engaging the inner wall at at least one of the peaks and at at least one of the valleys.  
   
   
       6 . The baffle of  claim 4  wherein: 
 the inner wall is cylindrical with an inside diameter D;    the corrugations having a height dimension H from the peaks to the valleys perpendicular to the longitudinal axis and a width dimension W perpendicular to both the height dimension and the longitudinal axis; and    the ratio of (W*H)/D is in the range of 0.60 to 0.80.