Duoflex ™¢ burner

Duoflex ™¢ burner

The Duoflex™¢ burner fires rotary kilns with pulverised coal or coke, oil, natural gas or any mixture of these fuels. The burner may be fitted with extra ducts for secondary fuels such as plastic chips, wood chips, sewage sludge, etc. Standard types are available for any fuel combination and a maximum capacity ranging from 20 to 250 MW, catering for even the largest of rotary cement kilns.


The burner is based on a novel concept featuring a central duct for gaseous and liquid fuels placed inside an annular coal duct which is surrounded by two concentric ducts that form two primary air channels, one for radial air and one for axial air. The two air flows are mixed before being injected via the conical air nozzle. The two outer ducts form a very rigid supporting structure, minimising deflection of the burner pipe and ensuring long refractory life.

The primary air is supplied by a high pressure fan that yields a maximum pressure of 250 mbar as standard, but on request pressures up to 400 mbar can be delivered. The air nozzle area can be adjusted within the range 1:2. The axial/radial air ratio - and consequently the degree of swirl - is also adjustable. These adjustments offer wide scope of shaping the flame.

Burner: Flsmidth.com

Related Stories

Indian Cement Review