Radiant Heat Transfer System

Abstract

A radiant heat transfer system has one or more radiant elements inserted in a radiant source. Radiant elements convert the combustion products from burning fuel into radiant energy. A radiant element may be formed from one or more ceramics and may be used in radiant sources, such as radiant tubes, immersion tubes, heat exchanger tubes, boiler walls, and other radiant heat applications. Each radiant element has a core section defining a longitudinal cavity enabling the insertion of a positioning mechanism. Each radiant element may have one or more normal and/or tangential wings attached to the exterior of the core section. Each radiant element may produce a more laminar or less turbulent flow of combustion products within the radiant source.

1 . A radiant heat transfer system, comprising:
 a radiant source; and at least one ceramic radiant element disposed inside the radiant source, where the at least one ceramic radiant element has at least one wing extending from a core section, and where the core section forms a longitudinal cavity.   
   
   
       2 . The radiant heat transfer system of  claim 1 , comprising a positioning mechanism disposed in the longitudinal cavity, where the positioning mechanism is connected to the radiant source. 
   
   
       3 . The radiant heat transfer system of  claim 2 , where the positioning mechanism comprises:
 a positioning rod disposed in the longitudinal cavity;   a stop device connected to one end of the positioning rod; and   a retention device connected to the other end of the positioning rod.   
   
   
       4 . The radiant heat transfer system of  claim 1 , comprising a first ceramic element and a second ceramic radiant element with a spacer therebetween. 
   
   
       5 . The radiant heat transfer system of  claim 1 , where the at least one ceramic radiant element occupies less than about 20% of an axial cross-sectional area of the radiant source. 
   
   
       6 . The radiant heat transfer system of  claim 1 , where the at least one ceramic radiant element occupies from about 5% to about 100% of an axial cross-sectional area of the radiant source. 
   
   
       7 . The radiant heat transfer system of  claim 1 , where the at least one ceramic radiant element has an element surface area, where the radiant source has a source surface area, and where a ratio of the element surface area to the source surface area is greater than about 1.1:1. 
   
   
       8 . The radiant heat transfer system of  claim 7 , where the ratio of the element surface area to the source surface area is about 1.1:1 to about 3:1. 
   
   
       9 . The radiant heat transfer system of  claim 7 , where the ratio of the element surface area to the source surface area is about 1.2:1 to about 1.5:1. 
   
   
       10 . The radiant heat transfer system of  claim 1 , where the at least one ceramic radiant element has an emissivity of about 0.4 to about 0.9. 
   
   
       11 . The radiant heat transfer system of  claim 1 , where the flow of combustion products in the radiant source has a Reynolds Number less than about 4500. 
   
   
       12 . The radiant heat transfer system of  claim 1 , where the flow of combustion products in the radiant source has a Reynolds Number less than about 2300. 
   
   
       13 . The radiant heat transfer system of  claim 1 , where the flow of combustion products in the radiant source has a Reynolds Number of about 1500 to about 2300. 
   
   
       14 . The radiant heat transfer system of  claim 1 , where the radiant source is a radiant tube. 
   
   
       15 . The radiant heat transfer system of  claim 14 , comprising:
 a radiant tube having a first portion and a second portion; a burner connected to the first portion; and the at least one radiant element disposed in the second portion.   
   
   
       16 . The radiant heat transfer system of  claim 15 , comprising a first radiant element and a second radiant element with a spacer therebetween. 
   
   
       17 . The radiant heat transfer system of  claim 15 , where the at least one radiant element occupies greater than about 50% of the second portion. 
   
   
       18 . The radiant heat transfer system of  claim 15 , where the at least one radiant element occupies from about 70% to about 80% of the second portion. 
   
   
       19 . The radiant heat transfer system of  claim 1 , where the ceramic radiant element has at least one wing normal to the core section. 
   
   
       20 . The radiant heat transfer system of  claim 1 , where the ceramic radiant element has at least one wing tangential to the core section. 
   
   
       21 . The radiant heat transfer system of  claim 1 , where the at least one wing has a substantially helical shape defining a helix angle, and where the helix angle is from about 20° to about 90°. 
   
   
       22 . The radiant heat transfer system of  claim 1 , where the at least one wing has a substantially curvilinear shape. 
   
   
       23 . A ceramic radiant element for insertion in a radiant source, comprising: a core section forming a longitudinal cavity; and at least one wing extending from the core section. 
   
   
       24 - 41 . (canceled)