Patent ID: 6312250
Filing Date: 2001-11-06
Classification: F23D,F23K,F23N

Abstract:
A premix burner apparatus for heating a process chamber, said apparatus comprising:a burner structure defining a premix reaction zone configured to communicate with the process chamber, said burner structure further defining a plurality of separate entrances to said reaction zone, and a corresponding plurality of separate premix flow paths, each of which is configured to direct both oxidant and fuel to a respective one of said separate entrances to said reaction zone; anda firing rate control system operative to control flows of oxidant and fuel along at least one of said flow paths separately from flows of oxidant and fuel along at least one other of said flow paths;said firing rate control system being further operative to interrupt a combined flow of oxidant and fuel along at least one of said flow paths while oxidant and fuel continue to flow along at least one other of said flow paths;said firing rate control system including a plurality of separately shiftable valve assemblies, each of which is shiftable between a closed condition blocking a combined flow of oxidant and fuel along a single corresponding one of said flow paths and an open condition not blocking said flow;said firing rate control system further including a controller having a mode of operation comprising consecutive cycles in which said controller shifts only one of said valve assemblies into and out of its closed condition.