Method and apparatus for burning a pollutants contained in a carrier flow

Claim 1

A method for controlling an operating temperature in an apparatus for burning pollutants out of a carrier gas flow to be cleaned, said carrier gas flow containing varying proportions of oxidizable components, said apparatus including a gas flow path extending from an inlet port (4) to an outlet port (20), said gas flow path including an inlet chamber (9) connected to said inlet port (4) for receiving said carrier gas flow (4b), heat exchanger pipes (10) mounted in a ring space (19) for receiving said carrier gas flow from said inlet chamber (9), a first combustion chamber (12) with a burner (14) receiving said carrier gas flow out of said heat exchanger pipes (10), a flue gas mixing pipe (15) receiving a gas flow from said first combustion chamber (12), a second combustion chamber (18) receiving gas from said flue gas mixing pipe (15), said ring space (19) receiving hot gasses at one end (18a) from said second combustion chamber (18), said ring space (19) leading to said exit port (20) at an opposite end thus completing said gas flow path with a flow direction from said inlet port (4) to said exit port (20); said method comprising the following steps: a) feeding said carrier gas flow to be cleaned through said gas flow path; b) diverting a controllable portion of gas in said inlet chamber from flowing directly into said heat exchanger pipes (10); c) admixing said controllable portion of gas into said carrier gas flow at a location near an exit end of said flue gas mixing pipe (15) and near an inlet end of said second combustion chamber (18); d) causing gas flowing out of said flue gas mixing pipe (15) and said controllable portion of gas to flow along the length of said flue gas mixing pipe (15) as said gasses flow through said second combustion chamber (18); and e) controlling the volume of said controllable gas portion for said admixing so that said operating temperature in said second combustion chamber (18) remains substantially constant even if variations occur in said proportions of oxidizable components in said carrier gas flow to be cleaned.

Claim 2

A method for controlling an operating temperature in an apparatus for burning pollutants out of a carrier gas flow to be cleaned, said carrier gas flow containing varying proportions of oxidizable components, said apparatus including a gas flow path extending from an inlet port (4) to an outlet port (20), said gas flow path including an inlet chamber (9) connected to said inlet port (4) for receiving said carrier gas flow (4b), heat exchanger pipes (10) mounted in a ring space (19) for receiving said carrier gas flow from said inlet chamber (9), a first combustion chamber (12) with a burner (14) receiving said carrier gas flow out of said heat exchanger pipes (10), a flue gas mixing pipe (15) receiving a gas flow from said first combustion chamber (12), a second combustion chamber (18) receiving gas from said flue gas mixing pipe (15), said ring space (19) receiving hot gasses at one end (18a) from said second combustion chamber (18), said ring space (19) leading to said exit port (20) at an opposite end thus completing said gas flow path with a flow direction from said inlet port (4) to said exit port (20); said method comprising the following steps: a) feeding said carrier gas flow to be cleaned through said gas flow path; b) diverting a controllable portion of gas in said inlet chamber from flowing directly into said heat exchanger pipes (10); c) admixing said controllable portion of gas into said carrier gas flow at a location near an exit end of said flue gas mixing pipe (15) and near an inlet end of said second combustion chamber (18); d) causing gas flowing out of said flue gas mixing pipe (15) and said controllable portion of gas to flow along the length of said flue gas mixing pipe (15) as said gasses flow through said second combustion chamber (18); and e) controlling the volume of said controllable gas portion for said admixing so that said operating temperature in said second combustion chamber (18) remains substantially constant even if variations occur in said proportions of oxidizable components in said carrier gas flow to be cleaned.

Claim 4

An apparatus for controlling an operating temperature while burning pollutants out of a carrier gas flow to be cleaned, said carrier gas flow containing varying proportions of oxidizable components, said apparatus comprising a housing (2) with an inlet port (4) for said carrier gas flow (4b) and an outlet port (20) for cleaned gas, a gas flow path arranged in said housing (2), said gas flow path including an inlet chamber (9) connected to said inlet port, open ended heat exchanger pipes (10) connected at one end to said inlet chamber (9) for receiving gas from said inlet chamber, a first combustion chamber (12) connected to an opposite end of said heat exchanger pipes (10) for receiving preheated gas through said heat exchanger pipes (10), a burner (14) in said first combustion chamber (12), a flue gas mixing pipe (15) arranged coaxially with said burner for receiving gasses from said first combustion chamber (12), said flue gas mixing pipe having an inlet end facing said burner (14), a second combustion chamber (18) surrounding said flue gas mixing pipe (15) substantially along the entire length of said flue gas mixing pipe (15), said second combustion chamber (18) having an inlet zone (15a) communicating with an exit end of said flue gas mixing pipe (15), a ring space (19) surrounding said second combustion chamber (18), said heat exchanger pipes (10) being arranged in said ring space (19), one end of said ring space (19) communicating with said second combustion chamber (18), an opposite end of said ring space (19) communicating with said outlet port (20) for discharging cleaned gas, by-pass means (11) leading from said inlet chamber (9) into said exit end of said flue gas mixing pipe (15) for diverting a proportion of gas from said inlet chamber (9) into a space near said exit end of said flue gas mixing pipe (15) communicating with said inlet zone (15a) of said second combustion chamber (18), and control means in said by-pass means (11) for controlling a volume of by-pass gas flow and thereby the operating temperature inside said second combustion chamber (18) so that said operating temperature is maintained substantially constant even if variations in said proportions of oxidizable components in said carrier gas flow to be cleaned occur.

Claim 5

An apparatus for controlling an operating temperature while burning pollutants out of a carrier gas flow to be cleaned, said carrier gas flow containing varying proportions of oxidizable components, said apparatus comprising a housing (2) with an inlet port (4) for said carrier gas flow (4b) and an outlet port (20) for cleaned gas, a gas flow path arranged in said housing (2), said gas flow path including an inlet chamber (9) connected to said inlet port, open ended heat exchanger pipes (10) connected at one end to said inlet chamber (9) for receiving gas from said inlet chamber, a first combustion chamber (12) connected to an opposite end of said heat exchanger pipes (10) for receiving preheated gas through said heat exchanger pipes (10), a burner (14) in said first combustion chamber (12), a flue gas mixing pipe (15) arranged coaxially with said burner for receiving gasses from said first combustion chamber (12), said flue gas mixing pipe having an inlet end facing said burner (14), a second combustion chamber (18) surrounding said flue gas mixing pipe (15) substantially along the entire length of said flue gas mixing pipe (15), said second combustion chamber (18) having an inlet zone (15a) communicating with an exit end of said flue gas mixing pipe (15), a ring space (19) surrounding said second combustion chamber (18), said heat exchanger pipes (10) being arranged in said ring space (19), one end of said ring space (19) communicating with said second combustion chamber (18), an opposite end of said ring space (19) communicating with said outlet port (20) for discharging cleaned gas, by-pass means (11) leading from said inlet chamber (9) into said exit end of said flue gas mixing pipe (15) for diverting a proportion of gas from said inlet chamber (9) into a space near said exit end of said flue gas mixing pipe (15) communicating with said inlet zone (15a) of said second combustion chamber (18), and control means in said by-pass means (11) for controlling a volume of by-pass gas flow and thereby the operating temperature inside said second combustion chamber (18) so that said operating temperature is maintained substantially constant even if variations in said proportions of oxidizable components in said carrier gas flow to be cleaned occur.