Method and burner for introducing solid, liquid, or gaseous fuel to a kiln burning zone

摘要

In the present invention there is disclosed a method for introducing solid, liquid or gaseous fuel into a burning zone of a rotary kiln for manufacturing cement clinker or the like products, wherein the method is characterized in that fuel is conducted through a an oil burner nozzle /1/ and through a fuel duct /6/ wherein primary air is conducted through at least a first and a second annular ducts /8, 9/ arranged substantially concentrically with, and around, the fuel duct( /6/, wherein primary air supplied through the second annular duct /9/ flows substantially in axial direction, whereas primary air conveyed through the rotates about the center axis of the burner, and wherein the amount of primary air in both the annular ducts /8, 9/ can be independently controlled, such that the primary air conveyed through the first annular duct /8/ and that conveyed through the second annular duct /9/ are mixed at a lower velocity in a collecting duct /15/ into a single primary mixed air stream having a desired axial/rotary flow characteristic, and wherein this air stream is subsequently accelerated up to a desired, higher discharge velocity. A burner according to the present invention has annular ducts /8, 9/ arranged at a joint annular collecting duct /15/ for directing air therein, and said annular collecting duct /15/ is followed up with an annular nozzle /14/ being supplied with the mixed primary air from the annular collecting duct /15/, whereby flow surface of the collecting duct /15/ is gradually decreasing in axial direction of air flow.