Flameless combustion heater

Abstract

A flameless combustion heater is described, that comprises an oxidation conduit and a fuel conduit positioned within the oxidation conduit to form an oxidation zone having an inlet and an outlet, said fuel conduit having a plurality of openings that provide fluid communication from within the fuel conduit to the oxidation conduit wherein the longitudinal axis of at least one opening forms an oblique angle with the inner surface of the oxidation conduit. A method for providing heat to a process conduit is described, that comprises providing an oxidation conduit; providing a fuel conduit having a plurality of openings that provide fluid communication from within the fuel conduit to the oxidation conduit wherein the longitudinal axis of at least one opening forms an oblique angle with the inner surface of the oxidation conduit; providing a process conduit in a heat exchange relationship with the oxidation conduit; introducing fuel into the fuel conduit; introducing an oxidant into the oxidation conduit; and introducing the fuel into the oxidation conduit through the plurality of openings such that flameless combustion occurs in the oxidation conduit.

1 . A flameless combustion heater comprising an oxidation conduit and a fuel conduit having a plurality of openings that provide fluid communication from within the fuel conduit to the oxidation conduit wherein the longitudinal axis of at least one opening forms an oblique angle with the inner surface of the oxidation conduit. 
   
   
       2 . A heater as claimed in  claim 1  wherein the longitudinal axis of the at least one opening forms an acute angle with the inner surface of the oxidation conduit, as measured from the inlet end of the fuel conduit. 
   
   
       3 . A heater as claimed in  claim 2  wherein the angle is less than about 80 degrees. 
   
   
       4 . A heater as claimed in  claim 2  wherein the angle is greater than about 20 degrees. 
   
   
       5 . A heater as claimed in  claim 2  wherein the angle is from about 35 to about 75 degrees. 
   
   
       6 . A heater as claimed in  claim 2  wherein the angle is from about 50 to about 70 degrees. 
   
   
       7 . A heater as claimed in  claim 1  wherein the longitudinal axis of the at least one opening forms an obtuse angle with the inner surface of the oxidation conduit, as measured from the inlet end of the fuel conduit. 
   
   
       8 . A heater as claimed in  claim 7  wherein the angle is greater than about 100 degrees. 
   
   
       9 . A heater as claimed in  claim 7  wherein the angle is less than about 160 degrees. 
   
   
       10 . A heater as claimed in  claim 7  wherein the angle is from about 105 to about 145 degrees. 
   
   
       11 . A heater as claimed in  claim 7  wherein the angle is from about 110 to about 130 degrees. 
   
   
       12 . A heater as claimed in  claim 1  wherein a majority of the openings form oblique angles with the inner surface of the oxidation conduit. 
   
   
       13 . A heater as claimed in  claim 1  wherein all of the openings form oblique angles with the inner surface of the oxidation conduit. 
   
   
       14 . A heater as claimed in  claim 1  wherein the longitudinal axis of the at least one opening does not intersect the longitudinal axis of the fuel conduit. 
   
   
       15 . A heater as claimed in  claim 14  wherein the distance between the longitudinal axis of the opening and the longitudinal axis of the fuel conduit is greater than one-fourth of the internal radius of the fuel conduit. 
   
   
       16 . A heater as claimed in  claim 14  wherein the distance between the longitudinal axis of the opening and the longitudinal axis of the fuel conduit is greater than one-half of the internal radius of the fuel conduit. 
   
   
       17 . A heater as claimed in  claim 1  wherein the longitudinal axis of one opening forms a first angle with the inner surface of the oxidation conduit and the longitudinal axis of another opening forms a second angle with the inner surface of the oxidation conduit that is not equal to the first angle. 
   
   
       18 . A heater as claimed in  claim 1  wherein at least one opening has a circular cross-section. 
   
   
       19 . A heater as claimed in  claim 1  wherein one opening has a cross-sectional area that is greater than the cross-sectional area of another opening. 
   
   
       20 . A heater as claimed in  claim 1  further comprising an oxidant conduit, the oxidant conduit having an inlet for oxidant and an outlet for preheated oxidant that is in fluid communication with the inlet of the oxidation conduit. 
   
   
       21 . A heater as claimed in  claim 1  further comprising a process conduit in a heat exchange relationship with the oxidation conduit. 
   
   
       22 . A heater as claimed in  claim 21  wherein the process conduit is adapted for carrying out an endothermic chemical reaction. 
   
   
       23 . A heater as claimed in  claim 1  further comprising a preheater in fluid communication with the flameless combustion heater, wherein the preheater is capable of preheating the oxidant to a temperature at which when the oxidant and fuel are mixed in the oxidation conduit, the temperature of the mixture exceeds the auto-ignition temperature of the mixture. 
   
   
       24 . A heater as claimed in  claim 21  wherein the oxidant conduit is in heat exchange relationship with the process conduit. 
   
   
       25 . A heater as claimed in  claim 1  wherein the heater further comprises an oxidation catalyst. 
   
   
       26 . A heater as claimed in  claim 25  wherein the oxidation catalyst is selected from the group consisting of palladium, platinum and mixtures thereof. 
   
   
       27 . A method for providing heat to a process conduit comprising:
 providing an oxidation conduit;   providing a fuel conduit having a plurality of openings that provide fluid communication from within the fuel conduit to the oxidation conduit wherein the longitudinal axis of at least one opening forms an oblique angle with the inner surface of the oxidation conduit;   providing a process conduit in a heat exchange relationship with the oxidation conduit;   introducing fuel into the fuel conduit;   introducing an oxidant into the oxidation conduit; and   introducing the fuel into the oxidation conduit through the plurality of openings such that flameless combustion occurs in the oxidation conduit.