摘要:
A method and apparatus whereby flameless combustion may be precipitated and sustained within the essentially oval combustion chamber of an integrated heater/burner apparatus. The invention provides for an air inlet and fuel source in combination with recirculating flue gas within the apparatus combustion chamber to precipitate and maintain flameless combustion of the combined gases along, and within, a narrowly defined boundary. Air is introduced to the oval combustion chamber via an air inlet. Fuel gas is combined with recirculating flue gases with continued heating of the recirculating flue gas, introduced air or both flue gas and air, until the temperature at the boundary interface between the air and inerted fuel gas exceeds an auto ignition temperature of the boundary interface components. A fuel gas stream absent a flamed portion thereof is combined with the recirculating flue gas and then allowed to diffuse with the air stream in a measure sufficient to sustain flameless combustion and chamber operational temperature of generally between 1500° F. and 1900° F. The essentially oval configuration of the integrated heater/burner allows for increased mass and circulation rates beyond that possible with heaters of the contemporary art and as a consequence thereof provides for uniform, complete and cooler combustion resulting in low NOx emissions.
摘要:
A high temperature air heater including a heat transfer conduit located in higher temperature gas. The heat transfer conduit is made up of a heat transfer pipe through which the air to be heated flows and a refractory protective pipe covering the heat transfer pipe. A clearance is provided between the heat transfer pipe and the refractory protective pipe. The clearance makes it possible to accommodate the differences in thermal expansion between the heat transfer pipe and the refractory protective pipe to prevent damaging the refractory protective pipe, thus extending the service life of the high temperature air heater.