Abstract: The invention relates to a cooler and to a method for cooling hot bulk material. The hot bulk material is fed on a stationary aerating base through which cooling gas can flow and is transported by means of reciprocating conveyor elements disposed above the aerating base. In the cooler and cooling method, at least two groups of conveyor elements are used which are actuated jointly in the transport direction and separately from one another against the transport direction.

Abstract: The invention relates to a cooler and to a method for cooling hot bulk material (2), wherein the hot bulk material is fed on a stationary aerating base through which cooling gas can flow and is transported by means of reciprocating conveyor elements disposed above the aerating base. In this case at least two groups of conveyor elements are used which are actuated jointly in the transport direction and separately from one another against the transport direction.

Abstract: The invention relates to the production of cement clinker from cement raw material using a preheating zone, a calcination zone, a heating zone in which the calcined material is further heated whilst avoiding the formation of a molten phase, as well as a clinker burning zone and cooling zone from which part-quantities of the hot exhaust air are delivered as combustion air together with proportions of fuel to the clinker burning zone, the heating zone and the calcination zone. A reliable further heating while avoiding incrustations is achieved in the heating zone by constructing this zone in the manner of a flue stream reactor to which calcined material, fuel and combustion air are delivered in the lower end region of a rising first treatment zone at one point in each case and from which the heated material is precipitated essentially by the effect of gravity overlaid with centrifugal action.

Abstract: The invention relates to the heat treatment of fine-grained material which is first of all preheated in a multi-stage cyclone preheater, then further heated in a calcination zone, next finally burnt in a kiln and then cooled. Preheated material and tertiary air are delivered to the reaction chamber of the calcination zone in order to maintain therein a reducing atmosphere for reduction of the NO.sub.X content in the kiln exhaust gases. For the purpose of good adjustability of the reaction temperature in the reaction chamber and for the purpose of a space-saving construction, the preheated material from the second-lowest preheating stage as well as tertiary air are introduced at the bottom into the reaction chamber and an adjustable part-quantity of the preheated material from the third-lowest preheating stage is introduced into an upper region of the calcination zone.

Abstract: The invention relates to a method of producing cement clinker from fine-grained cement raw material which after preheating and calcining is burnt in a clinker burning zone divided into two stages and is then cooled. Optimum process conditions, particularly in the clinker burning zone, are achieved in that the calcined material is first of all heated to a temperature up to the region of the sintering temperature in a stage formed by a fluidized bed or spouted bed so that a build-up granulation of the material is brought about, whereupon the material thus heated is heated to the sintering temperature in a second stage of the clinker burning zone which acts as the finish-burning stage and tempered to the finishing burn.

Abstract: The invention relates to a method of purifying the exhaust gases from plants for the production of cement clinker, in which the filter zone through which the exhaust gases flow contains at least one adsorption stage in which an adsorbent is provided which is suitable for fixing NH.sub.x compounds, heavy metals and/or trace pollutants, at least a proportion of the adsorbent being removed from the adsorption stage at specific intervals of time and introduced into the final burning zone and/or preheating zone. By such a method the NO.sub.x content of the exhaust gases is significantly reduced, and at the same time heavy metals and trace pollutants are eliminated from the exhaust gases.

Abstract: The invention relates to a method and apparatus for purifying the exhaust gases from plants for the production of cement clinker, in which in a multi-stage filter zone hot exhaust gases coming from a preheating zone are first of all cleaned of dust in a first filter stage and then in a further stage are purified of NH.sub.x compounds, heavy metals and trace pollutants, SO.sub.z and NO.sub.x. In order to achieve a particularly efficient and economic purification, the exhaust gases from the preheating zone are set before the first filter stage to such a filter zone inlet temperature that in this first filter stage at least a proportion of the easily volatile pollutant elements and pollutant compounds are precipitated out of the exhaust gases in addition to the dust.

Abstract: The invention relates to a method and to apparatus for the heat treatment of fine-grained material using a calcination zone which is arranged between a preheating zone and a final combustion zone, and after passing through the calcination zone a proportion of the material is introduced into exhaust air from the cooling zone and delivered therewith back to the calcination zone for the purpose of recirculation. In this way a good burn-out of the fuel used in the calcination zone and a high degree of deacidification of the material are achieved.

Abstract: The invention relates to a suspension heat exchanger for heat exchange between gas and fines. It contains a plurality of cyclone separators which lie one above another with their axes aligned vertically and in which the cover walls and the inlet pipe connections of the substantially straight upper parts of the cyclones are inclined at an acute angle with respect to the horizontal. This contributes to a particularly simple and space-saving overall construction and to a favourable material separation with relatively low pressure loss.

Abstract: The invention relates to apparatus and to a method for the heat treatment of fine-grained material using a multi-stage cyclone preheater and a combustion chamber supplied with tertiary air from the cooler, in which the branched part of the tertiary air pipe extends upwards and the material discharged from the second-lowest stage of the cyclone preheater is introduced into one branch pipe at a point which lies lower than the point at which this branch pipe is connected to the combustion chamber. In this way good dispersal of the material which is delivered pneumatically to the combusion chamber and excellent combustion conditions are achieved at the same time as a considerable reduction in the overall height of the entire cyclone preheater.

Abstract: The heat treatment of fine-grained material wherein two quantities of fuel are delivered to a precalcination zone at two different levels. The first quantity of fuel is delivered at a lower level nearer the combustion zone and the oxygen content of the gases passing through this region of the precalcination zone are such that in this region a substoichiometric combustion takes place and a CO content between 0.05% and 1% is established. As a result a reducing decomposition of the NO.sub.x content of the exhaust gases from the combustion zone takes place.

Abstract: Apparatus for the heat treatment of fine material comprises a multi-stage cyclone preheater, a rotary kiln and a calciner supplied with tertiary air from a cooler for precalcination of the preheated fine material. The tertiary air pipe is narrowed at the point where it joins into the calciner. In this way an intensification of the mixing together of material, fuel and gas is achieved as well as an improved combustion, particularly fuels which are slow to react.

Abstract: The invention relates to a multiple-stage heat exchanger 1 in which at least one of the lower heat exchange stages contains a deflector/separator with a horizontal gas inlet pipe and a gas outlet, and at least the upper heat exchange stage has a conventional cyclone. This results in a considerable reduction in the energy requirement, the size and height of the construction.

Abstract: A process for the heat-treatment of fine-grained material using a multistage cyclone preheater and a revolving tubular kiln, additional fuel being introduced into a stage of the preheater which is selected according to the grain size, reactivity, moisture content, and incombustible constituent content of the fuel so that most of the fuel is almost completely burnt in the lowermost stage of the preheater. In this way, it is possible to obtain a high degree of calcination of the material before it enters the revolving tubular kiln with low preparation costs.

Abstract: Fine-grained material such as raw ground cement adapted to be fired in a rotary tube furnace is introduced to a vertical preheater and falls through a heating zone located at a level below the level at which the material enters the preheater. A stream of air enters the preheater at a level below the heating zone and passes upwardly at sufficient velocity to entrain the material that has passed through the heating zone, thereby causing such material to pass again through the heating zone. From the preheater the material is delivered to the furnace for final firing.

Abstract: Fine-grained material such as raw ground cement adapted to be fired in a rotary tube furnace is introduced to a vertical perheater and falls through a heating zone located at a level below the level at which the material enters the preheater. A stream of air enters the preheater at a level below the heating zone and passes upwardly at sufficient velocity to entrain the material that has passed through the heating zone, thereby causing such material to pass again through the heating zone. From the preheater the material is delivered to the furnace for final firing.