Abstract: A gas-solids heat/exchanger apparatus particularly designed for cooling the particulate material such as calcined limestone or cement clinker, but may also be used as a dryer and/or material heater. The apparatus includes a casing having an upper particulate material inlet and a lower particulate material outlet. Upper and lower grates extend on an angle or a slant from the inlet to the outlet for holding a bed of material. Gas is supplied to an inlet plenum chamber on one side of the lower grate for passage through the grates and the bed of material to an outlet plenum chamber. The lower grate is perforated to permit gas to pass therethrough while supporting the bed of material. The upper grate includes a plurality of spaced apart, vertically oriented, perforated slats. Various parameters or gas flow rates, pressure drops and positioning of the upper grate slats are disclosed.

Abstract: A method and apparatus for roasting fine grained ores such as cement raw meal, lime, dolomite, gypsum, phosphate rock and the like. A suspension preheater consisting of a plurality of serially connected cyclone separators is utilized to preheat the raw material. A suspension type roasting furnace follows the suspension preheater which is, depending upon the material being treated, followed by either a rotary kiln for further heat treatment of the material or by a cooler for cooling the product. The apparatus includes an arrangement for recirculating a portion of the material which has passed through the roasting furnace back into the roasting furnace to increase the degree of roasting. An existing preheater, suspension type calciner, rotary kiln cement clinker producing plant can be converted to the method and apparatus by the addition of an appropriately located splash plate.

Abstract: A method for converting existing long rotary kiln wet or dry process cement making plants to a more energy efficient operation including removing a central section of an existing rotary kiln and replacing it with a furnace and associated material separator for calcining material received from a first beginning section of the existing kiln which functions as a preheater and for supplying the calcined material to an end portion of the existing kiln which serves as a clinkering device.

Abstract: An apparatus for burning cement raw meal to produce cement clinker which includes a pair of parallel suspension preheaters each adapted to receive cement raw meal and hot spent combustion gas for preheating the cement raw meal. Each of the suspension preheaters discharges preheated raw meal into a single calcining furnace. Combustion takes place in the calcining furnace to produce a calcined raw meal. The spent combustion gases from the calcining furnace are supplied in proportional quantities to each of the parallel suspension preheaters. From the calcining furnace, the calcined raw meal is supplied to a rotary kiln for clinkering the calcined raw meal. Hot cement clinker is discharged into a cooler where the clinker is cooled by passing cooling air upwardly therethrough. The cooling air is heated by the hot clinker and the hottest portion is supplied to the rotary kiln and to the calcining furnace to serve as combustion air.