Gaseous fuel burners

Claim 2

A mixer device for mixing first and second fluids, the device comprising a hollow vessel having two open ends and a longitudinal axis and comprising in combination first and second tubular members nested together to form the vessel, one of said members having a surface with a plurality of grooves each of which lies in a direction that is both tangential to a cylinder drawn about said axis and inclined towards one end of said vessel, the other of said members having a surface that coacts with said grooved surface to form a plurality of inlets into said cylinder for said first fluid whereby said first fluid is directed into said vessel with a helical motion about said axis and directed towards said one end of said vessel whereby a low pressure zone is created within the helix to draw said second fluid into said vessel via the other end thereof.

Claim 3

A mixer device as claimed in claim 1 in which said inlets are linear and lie along lines inclined to the generatrix of said cylinder.

Claim 4

A mixer device as claimed in claim 2 in which the angle between each said inlet and said generatrix lies in the range of from 35°-60°.

Claim 5

A mixer device as claimed in claim 3 in which said angle is 45°.

Claim 6

A mixer device as claimed in claim 1 in which the said tubular members together form an annular supply chamber from which said grooves extend, said chamber having an inlet for said first fluid.

Claim 7

A mixer device as claimed in claim 1 in which said one member has a bore that is flared outwardly towards said other end.

Claim 8

A mixer device as claimed in claim 1 in which said other tubular member has a bore of venturi configuration.

Claim 9

A gaseous fuel burner comprising a burner head with an inlet and a mixer device as claimed in claim 1 for mixing a gaseous fuel and air for supply as a combustible gaseous fuel mixture to said burner inlet.

Claim 10

A gaseous fuel burner as claimed in claim 8 and comprising a plurality of gaseous fuel mixture inlets each supplied, in use, with gaseous fuel mixture from a different mixer device.

Claim 11

A gaseous fuel burner as claimed in claim 9 in which each mixer device is separated from the respective gaseous fuel inlet of the burner via an air gap for permitting the entrainment of air into the gaseous fuel mixture.

Claim 12

A gaseous fuel burner as claimed in claim 8 in which there is located in the mouth of the burner head a gaseous fuel mixture diffuser having a flow path therethrough for the passage of a cooling fluid, said diffuser being in heat exchanging relationship with the gaseous fuel mixture before ignition.

Claim 13

A gaseous fuel burner as claimed in claim 11 in which the diffuser comprises a plurality of finned pipes.

Claim 14

A gaseous fuel burner as claimed in claim 12 in conjunction with a heat exchanger having a fluid flow path therethrough, said heat exchanger being located in close proximity to said diffuser so as to be heated by flames seated upon said diffuser but spaced therefrom whereby to define a combustion zone for said flames.

Claim 15

An assembly as claimed in claim 13 and further comprising an interconnection from said fluid flow path in said heat exchanger to said flow path through said diffuser to permit fluid to flow through both said fluid flow paths.

Claim 16

A mixer device for mixing first and second fluids comprising an open-ended tubular mixing chamber and means at or adjacent one end of the chamber for inspirating the second fluid into the chamber, the means including a supply header for the first fluid, the header comprising inner and outer members forming a header of generally annular form and having a surface generally coaxial with the longitudinal axis of the chamber, and a series of orifices in the surface formed between cooperating surfaces on the inner and outer members, the orifices being disposed radially inwardly with respect to the inner surface of the chamber to form a passage to allow second fluid to enter the chamber between the orifices and said inner surface, said orifices being orientated in such manner that first fluid entering the chamber via the orifices has imparted to it a helical motion about the longitudinal axis and directed towards the other end of the chamber whereby second fluid is inspirated into the chamber through the supply header and from outside the header into the chamber at points adjacent said orifices.

Claim 17

A mixer device for mixing first and second fluids comprising an open-ended tubular mixing chamber and means at or adjacent one end of the chamber for inspirating the second fluid into the chamber, the means including a supply header for the first fluid, the header comprising inner and outer members forming a header of generally annular form and having a surface generally coaxial with the longitudinal axis of the chamber, and a series of orifices in the surface formed between cooperating surfaces on the inner and outer members, the orifices being disposed radially inwardly with respect to the inner surface of the chamber to form a passage to allow second fluid to enter the chamber between the orifices and said inner surface, said orifices being orientated in such manner that first fluid entering the chamber via the orifices has imparted to it a helical motion about the longitudinal axis and directed towards the other end of the chamber whereby second fluid is inspirated into the chamber through the supply header and from outside the header into the chamber at points adjacent said orifices.

Claim 18

A mixer device as claimed in claim 15, in which the supply header is located at the one end of the mixing chamber and in which the mixing chamber is gapped or formed with holes at locations close to the orifices to permit entry into the chamber of second fluid between the apertures and the inner surface of the chamber.

Claim 19

A mixer device mounted at the inlet of a diffuser of a burner element for mixing first and second fluids comprising an open-ended tubular mixing chamber and means for inspirating the second fluid into the chamber, the means including a supply header for the first fluid, the header being of generally annular form and having a surface coaxial with the longitudinal axis of the chamber and facing one of the open ends thereof, and a series of orifices in the surface and in communication with the interior of the header, the latter being positioned coaxially within the chamber in such manner that there is an annular passageway between the header and the chamber for the entry into the latter of second fluid, the orifices being spaced radially inwardly with respect to the inner surface of the chamber and being orientated in such manner that first fluid entering the chamber from the orifices has imparted to it a helical motion about said longitudinal axis and directed towards said one open end whereby second fluid is inspirated into the chamber through the supply header and through said annular passageway.

Claim 20

A mixer device mounted at the inlet of a diffuser of a burner element for mixing first and second fluids comprising an open-ended tubular mixing chamber and means for inspirating the second fluid into the chamber, the means including a supply header for the first fluid, the header being of generally annular form and having a surface coaxial with the longitudinal axis of the chamber and facing one of the open ends thereof, and a series of orifices in the surface and in communication with the interior of the header, the latter being positioned coaxially within the chamber in such manner that there is an annular passageway between the header and the chamber for the entry into the latter of second fluid, the orifices being spaced radially inwardly with respect to the inner surface of the chamber and being orientated in such manner that first fluid entering the chamber from the orifices has imparted to it a helical motion about said longitudinal axis and directed towards said one open end whereby second fluid is inspirated into the chamber through the supply header and through said annular passageway.

Claim 21

A mixer device as claimed in claim 1, in which the vessel formed by said nested tubular members is an open-ended tube, and in which said open-ended tube is coaxially housed in a further open-ended tube, said members being spaced from said further tube to provide an annular passageway between the members and the further tube for the entry into the latter of second fluid.

Claim 22

A mixer device as claimed in claim 1, in which said nested components form a tubular mixing chamber that is attached to a second tubular mixing chamber at one end thereof, the second mixing chamber having inlets to permit entry of second fluid into the said second chamber between the latter and said inlets for said first fluid.