Abstract: The present invention relates to a kiln plant and a method for manufacturing cement. The kiln plant comprises a kiln for burning clinker, a cooler, a calciner followed by a separation cyclone and a burning compartment which is fed tangentially with tertiary air from the cooler. Completely or partially calcined material is routed from the bottom of the burning compartment to the calciner to which exhaust gases from kiln are also vented. The object of the invention is to provide a kiln plant and a method for manufacturing cement. The kiln plant is of a relatively simplified construction and it may advantageously burn fuel with a low reactivity, such as petcoke, anthracite and other grades of coal with a low gas content in the calcining zone.

Abstract: A method and apparatus for introducing solid, liquid or gaseous fuel into a burning zone of a rotary kiln for manufacturing cement clinker. Fuel is conducted through a duct or ducts and primary air is conducted through at least two annular ducts arranged substantially concentrically with, and around, the fuel duct(s), the portion of air in one of the air ducts flowing substantially axially, whereas the portion of air in the second of the air ducts comprises air which has a rotary component about the center axis of the burner, and wherein the amount of primary air in the two portions is independently controlled, such that the two portions of primary air are mixed at a lower velocity in a collecting duct into a single primary mixed airstream having a desired axial/rotary flow characteristic, and wherein this airstream is subsequently accelerated up to a desired, higher discharge velocity.

Abstract: A bed (6; 78) of particulate material, which is supported by a gas distribution bottom (9; 75), is located utilizing a treatment gas, which via ducts (19; 35; 77) is conducted in sectionalized manner to and directed up through the gas distribution bottom and the bed of material from one or several underlying compartments (15; 76). The flow of the treatment gas through each duct (19; 35; 77) is self regulated by means of a flow regulator (21) provided in each duct. It is thereby obtained that the total pressure loss across the gas distribution bottom can be reduced, that the flow of the treatment gas through the material bed is distributed in a desirable and well-defined manner across the entire gas distribution bottom regardless of the composition of the material bed and the distribution thereon, and that tunnel formations are avoided.

Abstract: A method for the continuous treatment of particulate material, such as cement raw meal, in an apparatus comprising a stationary reactor (6) configured as a conical spouted bed, to which the material is fed and treated in a suspended bed by means of gas which, via a centrally arranged gas inlet (21), is injected at the bottom of the reactor (6) and flows upwards through the reactor (6), and wherefrom the material is discharged via an opening (21) at the bottom of the reactor (6).

Abstract: There is disclosed a method for reducing the NOx emission from a kiln plant for heat treatment of raw materials, in which kiln plant fuel can be fired in at least three zones an amount c of fuel is burned, in a second of these zones an amount b of fuel is burned and to this second zone the NO containing exhaust gases from the other at least two zones are also fed. In the rest of these at least three zones an amount a of fuel is burned and at least a part of the raw materials are fed to these zones together with an oxygen containing gas. The total amount of fuel, b+a, burned in the second and in the last zones is determined by the need for treatment of the raw materials. When the kiln plant is used for manufacturing cement clinker the heat treatment consists of preheating, calcining, sintering and cooling of the mineral raw materials.

Abstract: The present invention relates to a plant for manufacturing cement clinker. The plant consists of a preheater, a calciner in which the raw material is calcined at a temperature of more than 800.degree. C. and where fuel and oxygen-containing gas are fed to the lowermost zone of the calciner, and a kiln. The object of the invention is to provide a plant for manufacturing cement in which it is possible to bum lumpy fuel in a calciner, while simultaneously maintaining the possibility of increasing the time of retention and possibly the temperature of the material being fed to the lowermost zone in the calciner. This object is achieved according to the invention in that the calciner is provided with a fixed bottom (27) allowing combustible material fed to the calciner to be deposited on the bottom and in that oxygen-containing gas is fed horizontally to the calciner through openings in the lowermost zone of the calciner.

Abstract: A method for grinding of material in a ring roller mill having at least one grinding ring, at least one roller fitted in the grinding ring and at least one unit fitted between the roller and the grinding ring. The method includes the steps of operating the mill at a subcritical speed and at a grinding pressure above 40 MPa, placing the unit in the path where compacted material is released from the ring at a certain distance from a point P, which is the point on the ring where the material is released, in such a way that the unit is hit by agglomerates formed during operation at an angle between 60.degree. and 120.degree., said angle being between the surface of the unit and the direction of incidence of the material, after the latter is released from the grinding ring, and that the loosened material is distributed over the draw-in-zone in front of the roller and over the roller.

Abstract: A cooler (1) for cooling particulate material from a kiln, wherein the material upon entry into the cooler (1) is distributed to a material bed on a stationary supporting surface (11) in the form of a tray, while cooling gas, such as atmospheric air, is blown up through the material bed from injectors in the tray in a uniform and evenly distributed manner. The material is conveyed forward across the supporting surface (1) and through the cooler (1) by means of a separate mechanical conveying device (17). It is thus possible to split the three functions of such a cooler, viz. to support the material, to distribute the cooling gas across the supporting surface and to convey the material forward across the supporting surface, into functions which are independent of one another, so that each function can be optimized.

Abstract: A grate element (1) for a grate surface, e.g. in a clinker cooler, is shaped in the form of a box between the walls (3, 4) of which a number of surface-defining grate bars (5, 6) are mutually arranged so that, between them, they form fine gas channels (7). The grate bars (5, 6) alternately consist of bars (5) having a substantially rectangular cross section and bars (6) having a cross section substantially of the form of an inverted T. The rectangular bars (5) overlap the transverse sections (6a) of the T-bars, each of which is provided at the free end with a projecting, longitudinal bead (17), whereas each of the rectangular bars (5) at the sides facing the T-bars (6) are correspondingly configured with depending, longitudinal beads (15).

Abstract: A description is given of a plant for heat treatment of lumpy material, such as limestone, other carbonate materials, cement raw materials, or the like. The plant comprises a preheating zone, a burning zone, and connecting means which connect the material outlet of the preheating zone to the material inlet of the burning zone. A separating device is provided as a part of the connecting means and consists of a duct through which a gas stream can be induced to flow from below and upwards. On entry into the separating duct at the top of the duct, the preheated material will be dispersed in the counterflowing gas stream, whereby the material is divided into a fine fraction which suspended in the gas can be discharged via the discharge means provided at the upper end of the duct, and a fall-through coarse fraction which is normal manner can be fed via a connecting means to the material inlet of the burning zone.

Abstract: A grate element for a grate surface, e.g. in clinker cooler, comprises a top plate which is shaped in the form of a box having a surface which is plane at one end, whereas at the other end it consists of in cross section downwardly curved slats which, between them, form slots. The grate element further comprises a corrugated bottom plate which is provided with longitudinal rows of slots and projections rising into the slots of the top plate, and gas channels which are defined by the underside of the slats of the top plate and the upper side of the bottom plate, and open at the slots in the two plates. Accordingly, the top plate of the grate element is effectively cooled, the pressure loss through the grate element is appropriately large, the grate element is protected against falling-through of material and maintenance work in connection with the replacement of grate elements is facilitated.

Abstract: A method and plant for heat treatment of lime sludge (CaCO.sub.3) formed by the causticizing process during the manufacture of paper pulp. The lime sludge is dried and pulverized in a first process stage and preheated in a second process stage by means of hot exhaust gas coming from a kiln. In order to ensure that the temperature in the second process stage does not exceed a predetermined temperature lying within the range from 400.degree.-600.degree. C., the relationship between the amount of energy available in the exhaust gas for preheating in the second process stage and the amount of accumulated energy in the material which is to be preheated is regulated.

Abstract: A method and apparatus for controlling the temperature in a kiln in which cement clinker is manufactured. The temperature is controlled by controlling the fuel rate to the kiln. The fuel rate is adjusted according to a calculation that is made of the sulphur evaporation in the kiln, thereby obtaining a measure of the instantaneous temperature in the burning zone. The evaporation factor is calculated on the basis of measurements of the sulphur content in the cyclone material which passes to the kiln or a measurement of the sulphur content in the exit gases out of the kiln.

Abstract: A cooler (1) for cooling particulate material from a kiln, wherein the material upon entry into the cooler (1) is distributed to a material bed on a stationary supporting surface (11) in the form of a tray, while cooling gas, such as atmospheric air, is blown up through the material bed from injectors in the tray in a uniform and evenly distributed manner. The material is conveyed forward across the supporting surface (1) and through the cooler (1) by means of a separate mechanical conveying device (17). It is thus possible to split the three functions of such a cooler, viz. to support the material, to distribute the cooling gas across the supporting surface and to convey the material forward across the supporting surface, into functions which are independent of one another, so that each function can be optimized.

Abstract: The invention relates to a method and a plant for manufacturing mineralized portland cement clinker. The method and plant provides for preheating, calcining, burning and finally cooling the clinker. The mineralizer may e.g. be gypsum, fluorine, or a waste product containing these or other mineralizers. The mineralizer is added to the feedstock after the feedstock has been fed to the process, preferably after the cyclone which handles the feed to the calciner, i.e. the last cyclone in the preheater, or the lowermost preheater stage in a plant which does not incorporate a calciner.

Abstract: A separator for sorting of particulate material suspended in a conveying gas into a fine fraction and a coarse fraction, which separator comprises a rotor with a shaft, a housing, which encases the rotor and has an inlet for the material/gas suspension and outlets for fine and coarse fractions, respectively. Regulating means are associated with the shaft for adjusting the axial position of the shaft, and hence of the rotor, relative to the housing, thereby adjusting the amount of unseparated material that bypasses the rotor and passes directly to the fine fraction outlet.

Abstract: A roller press (1; 11) for grinding of granular material and comprising two or more rollers (3, 5; 13, 14, 15) alternately rotating in opposite directions, of which at least one is displaceable in a guideway (7; 16, 17) and where only some of the rollers (5; 14) are connected to a driving means. According to the invention the guideway for each of the displaceable rollers is provided so that it is substantially parallel to the resultant force on that roller. As a result, virtually all of the resultant force acting on the displaceable roller will be acting substantially eliminating the reaction force at right angles to the guideway.

Abstract: A flexible connection for supplying cooling air to a movable grate element in a grate cooler. A rigid pipe has two end sections each having a wall thickness exceeding that of the pipe. The end sections are rounded on their outer sides and are each mounted in a displaceable and tiltable manner in separate pipe sockets. One of the sockets is fixed to the movable grate element while the other is fixed to the stationary frame of the cooler.

Abstract: A cooler (6) for cooling of particulate material which is subjected to heat treatment in the rotary kiln is mounted at the material outlet end (1) of a rotary kiln. The cooler is provided with annular chambers (7, 8, 9) disposed around each other, and which are successively passed by the material from the outlet (5) of the kiln to a material outlet (20) in the stationary housing (15) of the cooler in countercurrent with the cooling air which flows from an air inlet (18) and through the annular chambers to the kiln in which the air thus heated is utilized as combustion air.

Abstract: A roller press comprising two rollers which rotate in opposite rotational directions, the rollers being driven via two gear units mounted on the roller shafts and having means for counterbalancing the oppositely-directed torques arising in the gear units in the form of a torque reaction system, eliminating the need for a torque absorption mechanism attached to the machine frame of the roller press.