Burner apparatus for providing adjustable flame geometry

Claim 1

A burner such as for use in a rotary kiln or the like and capable of supplying air and gaseous or liquid fuel along a burner axis from an end of the burner to a flame in a combustion zone, comprising: first and second hollow members, said first member surrounding the other, said members being sized to form an air supply conduit therebetween which terminates at the burner end, said second member being sized to provide fuel to said zone; one of the hollow members having first and second portions with respectively differently sized cross sections and with a transition section therebetween; a flow control baffle disposed within the air supply conduit opposite the transition section and having a front segment that extends forwardly between the first and second hollow members to separate the air supply conduit into inner and outer air channels that are open towards said combustion zone; said flow control baffle being mounted to move axially so as to control air flow through the air channel that borders the transition section and correspondingly adjust the burner flame wherein the cross section of said air channels comprises frustoconical surfaces on said transition section and a complementary frustoconical surface on said flow control baffle, said complementary frustoconical surface being coaxially-positioned with and axially-movable relative to said frustoconical surface on said transition section; means for imparting said axial movement to the flow control baffle; and a plurality of flame stabilizing gas jets positioned radially of said channels at said burner end nearest the combustion zone.