Abstract: A method of removing sulphur dioxide from exhaust gases generated in the production of cement wherein cement raw meal is preheated, ground, and burned in a kiln to form cement clinker which subsequently is cooled and ground. Grinding of the clinker is performed in the presence of preheater exhaust gases containing sulphur dioxide, the cement particles absorbing sulphur dioxide from such exhaust gases.

Abstract: The invention relates to a separator comprising a separator housing with an inlet spiral for separating air which opens tangentially into an annular separating chamber and is divided into a plurality of delivery channels which lie one above the other, as well as a basket-shaped separator rotor disposed centrally and with a vertical axis in the separator housing and a guide vane ring which surrounds the latter with a radial clearance. In order that this separator on the one hand has a high effectiveness of separation between oversize material and fine material and on the other hand facilitates a sufficiently broad grain size distribution of the fine material, the overall shape of the separator rotor is that of a cone which tapers downwards.

Abstract: Fresh raw material is delivered to a crushing zone for crushing. Beforehand, fine particles are separated from the raw material by means of an airstream and directed into the housing of the crusher where they are entrained by an independent gas stream that conveys crushed fines upwardly to a separator also located within the housing. The separator removes fine particles from the system and returns the remaining, relatively course tailings material to the crushing zone through a tailings return chute. At least a portion of the material exiting the tailings return chute is subjected to a secondary separation treatment to capture additional quantities of fine particles before entering the crushing zone. The captured tailings material may be mixed with the fresh raw material else reintroduced into the top of the separator to receive the secondary separation treatment.

Abstract: The invention relates to a roll mill having at least one pair of grinding rollers bearing against a substantially horizontal surface of a grinding table which is rotatable about a vertical axis. The rollers are mounted at one end of a roller support the opposite end of which is guided by guide lugs slidable vertically in guides and linked to the roller support by a tension rod. In order to achieve particularly smooth running of the grinding rollers on the grinding surface, the guides and the guide lugs lie approximately at the level of the grinding surface.

Abstract: The invention relates to a pneumatic separator for separating relatively coarse and relatively fine particles and in which a material distributor plate is arranged below the rotor and guide unit in such a way that the material thrown off by the rotor passes into the stream of separating air flowing towards the guide unit.

Abstract: The invention relates to apparatus for delivering material to part of a plant, for example to a crushing and grinding machine, in which the fines are separated out of the feed material passing through the material feed chamber by means of an air stream. In this way a substantial increase in the output of the part of the plant can be achieved.

Abstract: The invention relates to a grinding method and to grinding apparatus using a ring mill, in which the air speed in an air ring surrounding the grinding track is chosen to be sufficiently low that a proportion of the material which has already been comminuted to the fineness of the finished product also falls downwards against the air stream and through the air ring, is mechanically elevated and subjected to separation, the resulting tailings being delivered back to the grinding track of the ring mill. Such a solution is distinguished by a substantially reduced pressure loss and accordingly a considerable saving of energy.

Abstract: The invention relates to a roller mill with a mill casing having a vertical axis, a grinding table rotating therein about the casing axis and two grinding rollers which roll on the grinding table and are held stationary by a roller carrier. This roller mill is intended in particular for small throughput capacities, and both grinding rollers are rigidly connected by their spindles to one another and to the roller carrier which passes diametrically through the mill casing and is flexibly and resiliently mounted or supported at its ends. In this way a simple and robust, reliable construction is produced.

Abstract: The invention relates to a method and to apparatus for crushing brittle material for grinding using a roller mill and a material bed roll mill for crushing the material for grinding falling downwards over the edge of the grinding track before it is delivered to the sifter. By the use of a material bed roll mill a considerable increase in the throughput capacity of the apparatus and a significant saving of energy can be achieved.

Abstract: The invention relates to a roller mill with a sifter arranged above it which is provided with a deflecting rotor and an adjustable ring of guide vanes. Such a construction is distinguished by a particularly high degree of separation.

Abstract: The invention relates to a sifter having a dispersing plate which has material passage openings therein. The dispersing plate carries guide elements and distributor elements adjacent such openings which are inclined with respect to the radius of the plate. Such a dispersing plate makes it possible to feed the material to be sifted into the sifting chamber very evenly.

Abstract: The invention relates to grinding apparatus and a method of operating such apparatus in which the gas speed in the nozzle ring of the mill is altered as a function of the power consumption of the bucket conveyor so that the quantity of material conveyed by the bucket conveyor and the gradation of grain sizes thereof are kept constant. A control circuit alters the material supply to the mill when the gas speed in the nozzle ring exceeds a predetermined maximum value or falls below a predetermined minimum value.

Abstract: Apparatus for lubricating the sealing rings of grinding roll bearings comprises an oil-containing vessel located at a level higher than that of the grinding roll bearings and connected via an oil conduit to an annular gap between the sealing rings. The oil conduit is disp osed within an air line which delivers air to the gap.

Abstract: The invention relates to a process for regulating a grinding installation using four automatic control systems, of which one control system keeps the material level of the storage silo for the ground material constant by altering the grinding force of the roller mill. In this way, the mill throughput is altered in the event of variations in consumption in such a way that the differential mill pressure and hence the quality of the end product are kept constant.

Abstract: A method of processing abrasive material, the material being comminuted by means of a roller mill, thereafter sifted in an air separator, and the course material which is collected in the air separation again being comminuted in the roller mill. Furthermore, the invention relates to an apparatus for carrying out said method.

Abstract: A roll crushing mill comprises rollers rollable in concentric, trough-like grinding tracks. Material to be crushed is delivered to the innermost track in the path of the associated rollers. Crushed material passes from the innermost track over a vertically adjustable barrier ring into the outer track in the path of the associated rollers. Crushed material passes out of the outer track over a further barrier ring which also may be vertically adjustable.

Abstract: The invention concerns an apparatus for crushing, by means of a rotary mill, material containing particles that are difficult to pulverize. The mill has an air-sifter with pneumatic supply of ground material, where the coarse-material discharge of the air-sifter is connected to the intake side of the mill, and has a mechanical conveyor whose intake side is connected to the coarse-particle discharge of the mill and whose discharge is connected to the intake side of the mill.