Abstract: A limestone preheater which segregates material according to particle size and further provides for material bed depth adjustment, preferably during operation.

Abstract: A method for removing sulfur containing dust particles from particulate material exiting a material preheater in which the particulate material is heated by kiln off gases may include a number of steps. Off gases from the kiln are directed through a gas conduit to the preheater to preheat particulate material traveling through the preheater in a direction countercurrent to the direction of off gas flow through the preheater. Material exiting the preheater is directed to a material bypass conduit that is separated from the gas conduit and is flow connected to a material inlet to the kiln. A stripping gas is directed through the conduit to entrain dust particles in the preheated material and to carry said dust particles away from the preheated material.

Abstract: Disclosed is a method for calcining a natural chalk powder within a rotary kiln. The powder is inserted into the kiln accompanied by an additive that promotes nodulization of the powder to thereby facilitate the treatment of the chalk powder within the rotary kiln. The nodulization takes place at temperatures less than the calcining temperatures of the chalk and prior to the nodulized chalk being calcined within the kiln.

Abstract: A method for removing sulfur containing dust particles from particulate material exiting a material preheater in which the particulate material is heated by kiln off gases may include a number of steps. Off gases from the kiln are directed through a gas conduit to the preheater to preheat particulate material traveling through the preheater in a direction countercurrent to the direction of off gas flow through the preheater. Material exiting the preheater is directed to a material bypass conduit that is separated from the gas conduit and is flow connected to a material inlet to the kiln. A stripping gas is directed through the conduit to entrain dust particles in the preheated material and to carry said dust particles away from the preheated material.

Abstract: An apparatus for preheating particulate material in which the particulate material is transferred from one or more upper storage bins to a circular lower chamber that has an outer, essentially annular, portion which serves as a gas flow passage. The particulate material is directed from the feed bin or bins into a plurality of essentially vertical cylindrical feed cassettes via intermediate feed ducts. The lower chamber has a flat roof which is in contact with the bottom portion of the vertical feed cassettes. The vertical feed cassettes are approximately evenly spaced on top of the outer perimeter of the flat roof. The particulate material is preheated in the annular flow passage by hot kiln gases flowing in countercurrent heat exchange relationship with the particulate material.