Abstract: A calcining system is operated in a substoichiometric mode for reducing nitrogen oxide generation and removing sulfur from materials to be processed by creating an oxygen deficient atmosphere. The calcining system includes a rotary kiln rotating on a slightly inclined horizontal axis. The rotary kiln has a feed end introducing material to be processed and a discharge end. A preheating/precalcining device is positioned adjacent the feed end such that the material passes through the device prior to entering the rotary kiln. A stationary hood surrounds the discharge end. A burner is supported by the stationary hood. The burner introduces combustible fuel and combustion air into the rotary kiln through the discharge end and operates in a substoichiometric mode. At least one air nozzle is located along the length of the rotary kiln. The air nozzle injects combustion air into the rotary kiln.

Abstract: A calcining system is operated in a substoichiometric mode for reducing nitrogen oxide generation and removing sulfur from materials to be processed by creating an oxygen deficient atmosphere. The calcining system includes a rotary kiln rotating on a slightly inclined horizontal axis. The rotary kiln has a feed end introducing material to be processed and a discharge end. A preheating/precalcining device is positioned adjacent the feed end such that the material passes through the device prior to entering the rotary kiln. A stationary hood surrounds the discharge end. A burner is supported by the stationary hood. The burner introduces combustible fuel and combustion air into the rotary kiln through the discharge end and operates in a substoichiometric mode. At least one air nozzle is located along the length of the rotary kiln. The air nozzle injects combustion air into the rotary kiln.

Abstract: An apparatus and method for feeding pulverized solid fuel to one or more burners of a kiln in which batches of the pulverized fuel are weighed and metered into air conduits at a rate controlled by the weight of the batch for the supply of an air-fuel mixture to the burners.

Abstract: An apparatus for preheating particulate material in which the particulate material is transferred from an upper storage bin to a lower annular flow passage by a plurality of connecting chutes and the particulate material is preheated in the annular flow passage by hot kiln gases flowing in countercurrent heat exchange relationship with the particulate material and, in addition, by hot kiln gases introduced into the annular flow passage from the lower regions of radially extending ducts.

Abstract: Apparatus for cooling calcined or sintered particulate material discharged from a rotary kiln or other pyro-processing system. The apparatus includes an upright shell adapted to contain the material to be cooled, a mixing hopper arranged within the upper portion of the shell for mixing together particles of the material of different size and air distributing means arranged within the lower portion of the shell for releasing cooling air into the material. The apparatus is configured so that the cooling air moves counter to the direction of material flow.