Operation of a pulse-fired burner
AssigneesBritish Gas Corporation, Hotwork Developments Ltd.
InventorsJames H. Goodfellow, Trevor Ward
Life of this patent
Estimating the term…
Abstract
A pulse-fired burner is operated by modulating a fuel supply rate between a pilot level and a main level to provide a flame the level of which modulates respectively between a pilot level during a non-firing phase and a main flame level during a firing phase. Air supplied at a pilot rate is premixed with the fuel before ignition, the pilot air level being sufficient to support combustion of the fuel at the pilot rate but not at the main rate. The supply of fuel is terminated if no flame is sensed.
Claims17
A method of operating a pulse-fired burner of the type comprising:
- (a) a combustion chamber having an inlet to receive air during a firing phase of the burner for the combustion of fuel;
- (b) an outlet for discharging the combusted fuel;
- and
- (c) a fuel injector having an outlet arranged to inject fuel into the combustion chamber,
- said method comprising the steps of:
- (d) supplying fuel to the injector;
- (e) modulating the rate at which the fuel is supplied to the injector between a first lower rate during a non-firing phase of the burner and a second higher rate during a firing phase of the burner;
- (f) supplying air for premix with the fuel before ignition at a rate which is sufficient only to support combustion of the fuel at the lower rate of supply;
- (g) premixing the air with the fuel before ignition;
- (h) igniting the fuel during a non-firing phase;
- (i) sensing the presence of a flame at the injector outlet;
- and
- (j) terminating the supply fuel to the injector if no flame is sensed.
A pulse-fired burner comprising:
- (a) a combustion chamber having an inlet to receive air during a firing phase of the burner for combustion of fuel;
- (b) an outlet for discharging the combusted fuel;
- (c) a fuel injector having an outlet arranged to inject fuel into said combustion chamber;
- (d) first means for supplying fuel to said fuel injector;
- (e) second means for modulating the rate at which the fuel is supplied to said fuel injector between a first lower rate during a non-firing phase of the burner and a second higher rate during a firing phase of the burner;
- (f) third means for supplying air for premix with the fuel before ignition at a rate which is sufficient only to support combustion of the fuel at the lower rate of supply;
- (g) fourth means for premixing the air with the fuel before ignition;
- (h) fifth means for igniting the fuel during a non-firing phase;
- (i) sixth means for sensing the presence of a flame at said outlet of said fuel injector;
- and
- (j) seventh means for terminating the supply of fuel to said injector if no flame is sensed.
Dependencies are inferred from the claim text.