US 6,805,550 B2 · Method of operating a furnace

Abstract

The method of the invention concerns operation of a furnace utilizing a hydrogen-rich gas as furnace fuel. The furnace has multiplicity of burners for burning fuel supplied thereto. The method comprises providing ignition means for lighting a flame at at least one burner of the multiplicity of burners. An oxygen-containing gas and a combustible gas comprising a hydrocarbon gas are supplied to each of the multiplicity of burners in amounts capable of forming an ignitable mixture. A flame is ignited at the predetermined one burner which is then allowed to propagate from the at least one predetermined burner to the other burners of the multiplicity of burners. Then the composition of the combustible gas is altered over a period of time so as to replace at least a major part of the hydrocarbon gas by a hydrogen-rich gas until a hydrogen flame is established at each of the multiplicity of burners.

Claims21

Dependent claims

A method of operating a furnace utilising a hydrogen-rich gas as furnace fuel, the furnace having a multiplicity of burners for burning fuel supplied thereto, which method comprises:

(a) providing ignition means for lighting a flame at at least one predetermined burner selected from the multiplicity of burners;
(b) supplying to each of the multiplicity of burners an oxygen-containing gas and a combustible gas comprising a hydrocarbon gas in amounts capable of forming an ignitable mixture;
(c) igniting a flame at the at least one predetermined burner;
(d) allowing a flame to propagate from the at least one predetermined burner to the other burners of the multiplicity of burners;
and
(e) altering the composition of the combustible gas over a period of time so as to replace at least a major part of the hydrocarbon gas by a hydrogen-rich gas until an at least predominantly hydrogen flame is established at each of the multiplicity of burners.

3 more elements

A method of operating a furnace utilising a hydrogen-rich gas as furnace fuel, the furnace having a multiplicity of burners for burning fuel supplied thereto, the multiplicity of burners being arranged in an array in the furnace such that a flame ignited at at least one predetermined burner can propagate to each of the other burners of the array, which method comprises:

(a) providing ignition means for lighting a flame at at least one predetermined burner selected from the multiplicity of burners;
(b) supplying to each of the multiplicity of burners air and natural gas as fuel in amounts sufficient to provide a mixture comprising about 4% by volume of natural gas and about 96% by volume of air;
(c) igniting a flame at the at least one predetermined burner;
(d) allowing a flame to propagate from the at least one predetermined burner to the other burners of the multiplicity of burners;
(e) after a flame has been established at each of the multiplicity of burners, increasing the amount of natural gas supplied to the multiplicity of burners, incrementally or continuously, so as to provide a mixture comprising about 8% by volume of natural gas and about 92% by volume of air;
(f) supplying hydrogen-rich gas to the multiplicity of burners in increasing amount while reducing the amount of natural gas supplied to the multiplicity of burners over a period of from about 5 seconds to about 1 minute so as to replace at least a major part of the natural gas as fuel by a hydrogen-rich gas until an at least predominantly hydrogen flame is established at each of the multiplicity of burners;
(g) maintaining the flow rate of hydrogen-rich gas during step (f) at a reduced flow rate compared with a design flow rate of hydrogen-rich gas for use during subsequent operation of the furnace;
and
(h) thereafter increasing the flow rate of hydrogen-rich gas to the multiplicity of burners to the design flow rate.

6 more elements

Dependencies are inferred from the claim text.

Method of operating a furnace

Life of this patent

Method of operating a furnace

Life of this patent

Abstract

Claims21