F. L. Smidth & Co., A/s

F. L. Smidth & Co.

F. L. Smith & Co. A/s

Jan Folsberg

Ring roller mill

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. Effective internal conveyance is achieved with the mill according to the invention, hence eliminating the need for any external conveyance of overflow material.

Separator for sorting of particular material

Method for controlling the material feed to a roller press for grinding

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.

Method for manufacturing cement

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.

Method for manufacturing of normal as well as ultra-fine cement

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.

Method for grinding of material

Double separator for sorting particulate material

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.

Vertical roller mill

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.

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.

Separator for sorting particulate material

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.

Separator for sorting particulate material, with a plurality of

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).

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Copenhagen, Denmark

Jan Folsberg