Abstract: An apparatus for the calcination of fine grained material, particularly material used to produce cement clinker employing at least two separate, essentially parallel preheater lines, one of which is treated with exhaust gases from a clinker-forming zone and the other is equipped with a calcination zone which itself is fed by hot combustion air from the clinker cooler. In the area of the preheater line which is attached to the exhaust gas conduit of the clinker-forming zone, a divider device is arranged for dividing the stream of material. A first conduit directs a portion of the material into the exhaust gas conduit of the clinker-forming zone and a second conduit directs material into the calcination zone. The calcination zone is in the form of a vertical reaction duct having a downwardly bent pipe at its upper end. There is also provided a conduit which connects the vertical reaction duct with the exhaust means for hot gases in the clinker-forming zone.

Abstract: A method and apparatus for calcining lime, dolomite or similar materials in which the raw material to be calcined is preheated in a preheating zone by exhaust gases from a calcining zone, cooled by means of combustion air in a cooling zone, the combustion air passing from said cooling zone into said calcining zone and then into the preheating zone. A specific improvement of the invention resides in adding fuel in the calcining zone at a plurality of spaced locations along the calcining zone in the direction of flow of the combustion air therethrough.

Abstract: A method and mechanism for heat treating a pulverulent comminuted raw material in the process of making cement including preheating the material, passing the material through a first reaction zone, supplying a first fuel supply to the first zone for supplying thermal energy for carrying out the calcination reaction, separating the material from the hot gases received from the first reaction zone and delivering the material to a second reaction zone to which is supplied a second fuel supply for supplying thermal energy for the calcination reaction in the second zone and separating the material from the hot gases from the second zone and delivering the material to a sintering kiln and then passing it to a cooler with the air from the cooler supplied to support combustion in the first zone, and with the arrangement preferably arranged in two parallel flows with each flow path containing the preheater, and the reaction zones and separators with the material flows combining just as they enter the sintering zone.

Abstract: A method and apparatus for reducing the sulfur content and/or the SO.sub.2 emission in a system for calcining fine grained materials such as in the manufacture of cement utilizing a pre-calcining and a final calcining stage. The sulfur content of a process gas or of a material stream is determined and then is mixed with appropriate amounts of a dust or a raw meal in a reaction zone, the dust or raw meal containing sulfur bonding substances such as alkaline earth carbonates. The exhaust gas from which the sulfur compounds are removed by the sulfur bonding is separated from the sulfur containing solids and the exhaust gas and solids are removed from the calcining system.

Abstract: A method for the production of low alkali-cement clinker from alkali-containing raw material comprising a preheating step, a deacidification step and a sintering step utilizes a portion of the alkali-containing exhaust gases from the sintering step which are mixed with deacidified combustion gases from the deacidification step and reintroduced into the system in contact with the raw material to preheat and precalcity the raw material in a plurality of cyclones.

Abstract: A method for burning fine-grained material particularly for the manufacture of cement clinker wherein a stream of the raw cement meal is sequentially treated at progressively increasing temperatures in a preheating stage, a pre-calcining stage, a calcining stage, and a sintering stage. The improvements involve introducing one or more deacidified raw meal fractions into the stream at one of a variety of possible locations so that recarbonation does not occur.

Abstract: A method and apparatus for the production of coal dust includes a connection between a pulverizing mill's exhaust gas output port and a transition region between a preheater region and a calcination region of a related calcination installation which uses the coal dust as a fuel.

Abstract: A method and apparatus for the production of cement clinker low in sulphur from a calcium carbonate containing particulate raw material in an installation containing a multi-stage suspension gas preheater, a sintering furnace and a material cooler. A portion of the sulphur-containing exhaust gases issuing from the sintering furnace is separated, and the separated portion is preheated in the gas preheater. The material is heated in the hottest stage of the preheater to a temperature below the deacidification temperature. A reducing medium is added to the thus heated material. The remaining portion of the sulphur-containing exhaust gases is removed from the system for disposition.

Abstract: A method for the production of low alkali-cement clinker from alkali-containing raw material comprising a preheating step, a deacidification step and a sintering step utilizes a portion of the alkali-containing exhaust gases from the sintering step which are mixed with deacidified combustion gases from the deacidification step and reintroduced into the system in contact with the raw material to preheat and precalcity the raw material in a plurality of cyclones.

Abstract: Method and apparatus for the thermal treatment of moist, granular materials utilizing at least two superposed cyclone separators, with a relatively long gas conduit connecting the lower cyclone separator to the upper one. Charging means are provided in the conduit for introducing material to be treated near the lower cyclone separator, and a venturi-type constriction is provided in the conduit below the charging means, the constriction having its lower end projecting into the lower cyclone separator and serving to break up lumps of material which might otherwise be deposited in the cyclone separator and transfer the particulate material to the upper cyclone separator.

Abstract: Method and apparatus for the thermal treatment of moist raw pulverulent material, particularly slurries of raw cement material, wherein a plurality of gas and material separators are connected in series, the material to be treated is introduced between the last separator and the next-to-the-last separator and penetration of infiltrated air into the gas stream is prevented by a blower in advance of the zone of introduction of the raw material.The blower prevents a large pressure differential at the point of material supply and at the same time accommodates maintenance of a high vacuum and rate of flow of gas for the transporting of the material. The gas conduit leading to the last separator has an elongated riser so that the moist material introduced into the gas stream is maintained in contact with the hot gases for a long period to effect efficient pre-drying of the material.