Firing system and burner for rotary kiln

A burner for use with a rotary kiln and having an elongated cylindrical coal pipe adapted to receive at its inlet a stream of pulverized coal and primary air for discharge from its outlet, means for supplying said coal and air to said inlet, another cylindrical pipe disposed about and coaxial with said coal pipe and of a diameter to form an annular secondary air chamber between the two pipes, a secondary air inlet to said chamber, means for supplying air to said air inlet, a plurality of gas pipes disposed in said chamber, uniformly distributed about the coal pipe and axially parallel with said coal pipe, a gas manifold, means connecting each of said pipes to the manifold, air straightening vanes mounted in the secondary air chamber near the coal pipe outlet end, and an oil gun adapted to be mounted in said coal pipe for easy insertion and removal therefrom, support means on said oil gun for positioning the same generally coaxial of the coal pipe, the ratio of the area in square feet of the coal pipe at its discharge end to volume flow rate of the primary air stream in cubic feet/sec being about 1 to 340.