Abstract: A method and apparatus for removing purifying vaporizable contaminants such as mercury from a particulate material. Particulate material is first contacted with heated gases to vaporize the contaminants and entrain the material in the gases. The gases are directed to a first dust collector to remove the entrained particulates, after which a sorbent or chemical reagent is injected in the gases to interact with the contaminants and form a contaminant containing product that is entrained in the gases. The product is then separated from the gases in a second collector.

Abstract: Described is a method as well as a plant for preheating particulate or pulverulent material such as cement raw meal or similar material in a cyclone preheater (1), comprising at least two cyclone stages, each comprising a riser duct (2a, 2b, 2c, 2d) and a cyclone (1a, 1b, 1c, 1d). The method is peculiar in that a portion of the material which is fed to at least one cyclone stage is introduced to the first part of the riser duct, viewed in the direction of travel of the exhaust gases, and is heated from a temperature of maximum 450° C. to a temperature of at least 550° C., and in that the remaining material which is fed to the same cyclone stage is introduced into the last part of the said riser duct. As a result, there will be a reduction in the amount of SO2 which is discharged from the cement plant preheater as emission, without a simultaneous increase in energy consumption.

Abstract: The invention Described is a device (1) for dividing a stream of particulate or pulverulent material into at least two substreams. The device has a housing (2) with a substantially vertical inlet duct (3) and two or more outlet ducts (4, 5, 6, 7) emanating from separate openings, and being separated by partition walls (9) extending radially relative to the centreline of the inlet duct (3). The device also has a rotor 11) which is located in immediate extension of the inlet duct (3), with its axis of rotation coinciding with the centreline (10) of the inlet duct. The rotor (11) has a radially configured surface (11a) for directing the falling material stream radially outwards into the free space (12) above the outlet ducts. The device is peculiar in that the radial partition walls (9) can be adjusted in the circumferential direction. The result will be a freely variable ratio between an arbitrary number of outlet substreams.

Abstract: A method and plant for manufacturing cement clinker are disclosed, in which cement raw meal is calcined in a calciner. The calciner comprises an upper zone and a lower zone, where fuel, combustion gas and raw meal are introduced into the upper zone of the calciner and directed downward through the calciner. The combustion gas and raw meal are introduced tangentially into the calciner and subject to rotation follow a spiral-shaped flow path, and, under the action of gravity, the raw meal is primarily directed down along the wall of the calciner. The rotation of the combustion gas in at least the lower zone of the calciner is subjected to braking and approximately simultaneously or subsequently at least some of the combustion gas and at least some of the raw meal in the lower zone of the calciner is directed in the direction towards the center-line of the calciner.

Abstract: An accumulator assembly comprising at least two accumulators that are hydraulically interconnected to the same source of hydraulic fluid. Each accumulator containing an energy absorbing medium which is compressible when a movable barrier which separates the hydraulic fluid from the energy absorbing medium is acted upon by an increase in pressure of the hydraulic fluid. When the assembly contains two accumulators, one accumulator contains a compressibility limiter which interrupts the compressibility of the energy absorbing medium within the accumulator and the other accumulators does not contain a compressibility limiter so that the energy absorbing media therein may be fully compressed by the hydraulic fluid. The accumulator assembly is favorably utilized in a vertical roller mill.

Abstract: Provided is a method and plant for reducing SO2 emissions in which a catalyst for catalyzing the formation of cement clinker is extracted from kiln exhaust gas and recycled.

Abstract: A description is given of a method as well as a plant for manufacturing cement clinker by which method cement raw meal is preheated in a preheater (1), calcined in a calciner (3) comprising an upper end (3a) and a lower end (3b), burned into clinker in a kiln (5) and cooled in a subsequent clinker cooler (7).

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.