Abstract: There is provided a cement plant including a chlorine bypass apparatus capable of efficiently reducing the chlorine concentration in a cement kiln due to exhaust gas extraction by a small amount, by preventing calciner exhaust gas low in chlorine concentration from contamination and extracting a part of kiln exhaust gas high in chlorine concentration. In the invention, a baffle wall 20 which protrudes, on a lower face 16a of an exhaust duct 16 of a calciner connected to the pipe inclination part 14 of an exhaust gas pipe 9 rising from a kiln inlet part 2 of a cement kiln 1, toward a pipe inclination part 14 side at an inclination angle ? within a range of 20 to 60° relative to the horizontal plane, and a spacing between a lower end edge 20a of the baffle wall and an opposite wall plane 14a of the pipe inclination part is configured such that an average flow rate of the exhaust gas between the both falls within a range of 15 to 35 m/s.

Abstract: The invention relates to a cement production system with a preheater for preheating the cement raw meal, a calciner for pre-calcining the preheated cement raw meal, and a rotary kiln for firing the pre-calcined cement raw meal, wherein the calciner has a riser pipe through which exhaust gases from the rotary kiln flow. The gas offtake probe is arranged in a calciner nozzle, which is formed by a nozzle-like constricted section of the riser pipe, wherein the gas offtake probe is arranged flush on the calciner nozzle of the riser pipe.

Abstract: In a process for utilizing organic waste materials, in particular cellulose-containing, moist, organic waste materials, in a clinker production process in which the waste materials are introduced as fuel and burnt in the clinker production process, the waste materials are brought into contact with the hot exhaust gases of the clinker production process and dried in a drying step flowing in parallel therewith before they are introduced into the clinker production process. The drying step is carried out in a drying reactor in which the moist waste materials are passed together with the hot exhaust gases through a series of concentrically arranged tubes, with multiple changes in flow direction about 180°, and the temperature of the hot exhaust gases is set to a maximum value of 400° C. by mixing in of ambient air and/or air from the clinker production process before the drying step.

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: A method and plant for burning sludge or filter cakes during the cement clinker manufacture where the cement is manufactured in known manner by the cement raw meal being preheated, calcined and burned into clinker with subsequent cooling of the clinker and where the sludge is dried and finely divided prior to burning. The drying heat is provided by feeding hot raw meal from either the preheater or a separating cyclone installed in connection with the calciner to the drier unit, which may be a drier crusher. Applicable types of sludge include sewage sludge, beaching earth, paper sludge, fibre rejects, combustible chemical residues, e.g. waste derived from the manufacture of nylons and pesticides, and drill sludge resulting from oil exploration.

Abstract: With the present invention, a feed preparation system for producing cement includes mixing raw materials with a source of potassium. The mixture is conveyed to feed preparation system where it is placed in condition for treatment in a fluidized bed reactor for thermal processing to produce cement clinker. The potassium combines with the SO.sub.2 generated in the process to form potassium sulfate solids that are filtered from the process gas stream before emission to the atmosphere to thereby reduce sulfur emissions from the fluid bed cement process. The starting material may include white cement raw meal, grey cement raw meal and cement kiln dusts.

Abstract: A suspension shaft furnace and process for producing clinkers from discrete pellets of cement-forming batch materials, the furnace having a top vertical shaft section comprising a pellet-feeding and preheating zone, an intermediate fluidized bed section containing fuel inlet conduits for clinkering of the pellets in a fluidized bed, an air-permeable clinker-impermeable support for supporting the pellets as a fluidized bed, and a lower clinker-cooling section beneath the fluidized bed section. Clinker-discharge means permit the gravity flow of clinkers from the top of the fluidized bed down into a cooling zone in the cooling section. Air inlet means supply a combustion-supporting cooling gas up through the cooling zone, to cool the clinkers therein, and upstream through the fluidized bed section to support the combustion of fuel at the fuel inlet conduits.

Abstract: This invention isolates in separate furnaces the three thermochemical processes required in manufacturing Portland cement and sulphur dioxide from a calcium sulfate source so as to yield improved pyrometallurgical treatment for each individual process. Separating these processes facilitates selection of the most kinetically suitable reactions by enabling the maintenance of optimum conditions for each process without compromising the thermal or kinetic efficiencies of the other processes.Only one fourth of the calcium sulfate is reduced to calcium sulfide in a separate ad hoc reduction furnace specifically designed for achieving enhanced reduction parameters which results in minimized reduction equipment size. Treating most of the calcium sulfate elsewhere works to avoid side reactions and allows Portland cement raw mix components to have an enhanced synergistic catalytic effect on reduction kinetics.