Abstract: A roller mill for grinding particulate material such as cement raw materials, cement clinker and the like includes a grinding table and a set of rollers rotatable about a vertical shaft. The set of rollers include a number of rollers rotating about separate roller shafts, which are connected to the vertical shaft. A nozzle ring for directing gases into the roller mill is also included. The nozzle ring encloses the grinding table. Means for regulating the gas flow through the nozzle ring is also provided. At least some of the regulation means are arranged to rotate together with the rollers. Preferably, the position of at least some of the regulation means for regulating gas flow through the nozzle ring relative to the rollers may remain the same so that the gases introduced into the mill via the nozzle ring may exhibit the same flow pattern in relation to the rollers.

Abstract: A roller mill for grinding particulate material comprises a grinding table which by means of a drive mechanism is rotatable about a vertical axis, at least one roller rotatably mounted on a shaft and being maintained in tangential direction relative to the grinding table by means of a guide mechanism and a support. The roller mill also comprises a vibration-compensating device that is arranged in connection with the guide mechanism to ensure in interaction therewith that the roller is maintained in tangential direction relative to the grinding table.

Abstract: A roller mill for grinding particulate material such as cement raw materials, cement clinker and the like includes a grinding table and a set of rollers rotatable about a vertical shaft. The set of rollers include a number of rollers rotating about separate roller shafts, which are connected to the vertical shaft. A nozzle ring for directing gases into the roller mill is also included. The nozzle ring encloses the grinding table. Means for regulating the gas flow through the nozzle ring is also provided. At least some of the regulation means are arranged to rotate together with the rollers. Preferably, the position of at least some of the regulation means for regulating gas flow through the nozzle ring relative to the rollers may remain the same so that the gases introduced into the mill via the nozzle ring may exhibit the same flow pattern in relation to the rollers.

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: The present invention relates to a ring roller mill which, among other things, can be used in connection with the manufacture of cement for grinding of mineral clinker materials, slags, and similar materials. The mill has a grinding ring 1 and a roller 2. Between the roller 2 and the grinding ring 1, the partially crushed material forms a grinding bed 4 and on each side of the grinding ring 1 dam rings 5 are fitted. On the outer side of the dam rings 5 are fitted collecting jackets 6, to which scoop plates 7 are fixed. The jacket collects the material which flows over the dam ring and by means of the scoop plates the material is lifted round with the collecting jacket. Since the speed of the jacket is lower than the critical speed, the material will drop off from the uppermost part of the jacket, being dispersed towards the bottom of the latter, and is subsequently returned to the grinding path.

Abstract: The present invention relates to a ring roller mill which, among other things, can be used in connection with the manufacture of cement for grinding of mineral clinker materials, slags, and similar materials. The mill has a grinding ring 1 and a roller 2. Between the roller 2 and the grinding ring 1, the partially crushed material forms a grinding bed 4 and on each side of the grinding ring 1 dam rings 5 are fitted. On the outer side of the dam rings 5 are fitted collecting jackets 6, to which scoop plates 7 are fixed. The jacket collects the material which flows over the dam ring and by means of the scoop plates the material is lifted round with the collecting jacket. Since the speed of the jacket is lower than the critical speed, the material will drop off from the uppermost part of the jacket, being dispersed towards the bottom of the latter, and is subsequently returned to the grinding path.

Abstract: A ring roller mill for grinding mineral clinker materials and the like comprises at least one grinding ring, at least one roller and at least one air outlet opening within the outer circumference of the grinding ring and air inlet openings on each side of the air outlet opening in the rotating direction of the grinding ring. The location of the air inlet and outlet openings, and respectively, relative to each other ensure that substantially lower flow rates occur in the mill at a certain volume flow rate compared to hitherto known mills. At the same time a more stable operation of the mill is ensured.

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: For controlling the material feed to a roller press, a method is described, whereby the difference between the operating values of a roller press before and after a forced change in the material feed is used to establish whether the material feed should be increased, reduced or maintained unchanged in order to optimize the operation of the roller press. By this method it is obtained that the roller press, regardless of the homogeneity of the feed material, will constantly be operating within the transition range between starve and shaft feeding and that, consequently, the roller press can be utilized to optimum extent, while simultaneously avoiding the fluidization problems associated with shaft feeding.

Abstract: A method for manufacturing cement is described, by which gypsum is added to the clinker in the clinker cooler (3). Hereby it is obtained that the gypsum is dried in a safe, simple and inexpensive manner without substantial additional costs for establishment and operation.

Abstract: A method is described for manufacturing of normal as well as ultra-fine cement on the basis of cement materials, such as cement clinker, gypsum, slag, limestone, pozzolana, flyash etc. in a plant comprising at least a mill (1), a classifying separator (3), a separation cyclone (5) and a dust collector (7). By this method some of the dust-laden conveying gas which is extracted via the cyclone gas outlet duct (11) is diverted to and dedusted in the dust collector (7), and the dust from the dust collector (7) is utilized as the basis for ultra-fine cement, whereas the cyclone material from the material outlet (9) of the cyclone is utilized as normal cement. Hence it is possible to manufacture ultra-fine cement in existing grinding plants in a mechanically simple and operationally inexpensive way, while normal cement is simultaneously manufactured, without having any significant impact on the mill operation.

Abstract: To improve the operation of a roller press, a method is described according to which fluidized material that is discharged from the roller press over and above the sides of the roller press is collected and passed on to the next process stage together with the material which is ground in the roller press and discharged from the centermost section of the roller press. The remaining material which was ground in the roller press and discharged from the roller press through its end sections is returned to the roller press.By practicing the method of the present invention, a depletion of the material in the feed shaft is prevented due to a more stable roller feed, hence obtaining a smooth operation, even for high circulation factors, a higher average power absorption and a higher output level.

Abstract: A double separator for sorting particulate material, e.g. raw materials of cement or cement clinker comminuted in a roller press, and in which the material charge is suspended in a conveying gas, and consisting of a coarse separator (2), on top of which a fine separator (1) is mounted directly. The coarse separator (2) has a material inlet duct (15), a centrifugal pulverizer or rotor with arms (16) forming a disagglomerator, a gas inlet duct (18) and a material outlet duct (21) for a separated coarse fraction. The fine separator (1) has a material gas inlet duct (9), an additional material inlet duct (11), an outlet duct (3) for a fine fraction in suspension and an outlet duct (10) for a separated coarser fraction.

Abstract: A vertical roller mill has a rotatable grinding table (1) which is fed with material to be ground through a feed pipe (14) so that a cone of material is formed between the bottom of the pipe and the table, and scrapers (25) for intercepting the cone and spreading the material over the table and under grinding rollers. In order to avoid the feed pipe running empty so that the cone is not formed, sensors (21) sense the level of material in the pipe and controlling means (19,20) responsive to the sensors adjust the height of the feed pipe and/or the angle of the scrapers.

Abstract: A vertical roller mill has stationary grinding rollers which roll over a grinding path (4) of a rotatable grinding table (1), and a surrounding nozzle ring (7) for conveying and separating air. A coarse fraction of ground material is entrained upwards and radially inwards over an inclined outer wall (19) of a screen (15) and is directed downwards by an overlying guide wall (16) onto an inclined inner wall (20) of the screen (15) and hence back to the grinding table (1) for further grinding.

Abstract: A separator has a rotor (1) with top and bottom plates (2,3). An annular collecting casing (10) is secured to the top plate and is positioned at a radial distance from the material inlets (13). The casing has a concave side which faces the top plate (2) for collecting material (15) which is flung outwards from the top plate (2), and for discharging the material (19) downwards.

Abstract: A separator for sorting particulate material has a rotor (1) with vanes (3); static, separately adjustable guide vanes (8,9); a casing (14) defining an inlet duct for material suspended in a conveying gas; an outlet (7) for a suspended fine fraction; and a hopper (12) for collecting a coarse fraction.

Abstract: A separator for sorting particulate material suspended in a conveying gas into coarse and fine fractions has a rotor (1) with two sets (9,10) of vanes. Dampers (13,14) in outlet ducts for the fine fraction regulate the relative flow through the two vane sets and hence control the cut between the fine fraction and the coarse fraction which is flung centrifugally outwards by the vanes and falls down inside a casing (3).

Abstract: A vertical roller mill has a grinding table (1), rollers (3) and a separator (6) for separating ground material, which is conveyed to the separator in an air stream supplied through an inlet (7), into a fine fraction, which passes out through an outlet (8), and a coarse fraction which is returned for further grinding through an outlet (10). A part of the ground material is conveyed through an outlet (11) to a second separator (13), where it is separated from the air and returned for further grinding via an outlet (14) and an inlet (9) for fresh material to the mill. This provides a flatter grain size distribution curve in the finish ground material.

Abstract: A method for separating particulate material into coarse and fine fractions is disclosed by suspending the material in a conveying gas flow having a radially symmetrical flow pattern, radially surrounding the gas suspension with a band of clean gas containing substantially no particulate and directing the concentric gas flow past a vaned rotating rotor having an axis of rotation axially aligned with the concentric axis of the gases. The rotor vanes fling the coarse fraction in a radially outwardly direction while the remaining fine fraction remains in the conveying gas flow for subsequent separation from the gas. An apparatus in the form of a separator is disclosed for sorting particulate material suspended within a conveying gas into coarse and fine fractions is also disclosed.