Abstract: A method of grinding cement clinkers and a cement clinker grinding apparatus having a vertical roller mill are provided. In the method, feed material is ground by a table and rollers. Next, substantially all the resultant ground material is taken out from an underside of the table and then converted to a separator for classifying the ground material by a bucket elevator. The resultant coarse powder provided by the separator is returned to a center of the table. In grinding, an pressing force of each of the rollers onto the table is selected so that a roller pressure per full sectional area of the roller ranges from 10 to 15 kg/cm2. Further, a circulation quantity of the coarse powder to be returned to the vertical roller mill is selected from 100 to 300% of the feed material charged into the center of the table. And the liquid of 0.

Abstract: The grinding efficiency can be improved by use of a vertical roller mill, while reducing the energy consumption and improving the product quality. The disclosed cement clinker grinding apparatus comprises a closed circuit for conveying the ground material from the vertical roller mill (21) to the external separator (28) by the bucket elevator (29), for classifying the conveyed material into coarse powder and fine powder, and further for returning the classified coarse powder into the vertical roller mill (21). That is, a part of the ground material conveyed by the bucket elevator (29) is divided by the distributing damper (32) and then directly returned to the vertical roller mill (21). Since the ground material are not conveyed by air flow conveyance (i.e., air sweep), it is possible to prevent an increase of power consumption of the suction fan (31).

Abstract: A fluidized-bed classifier has a vessel defining a space divided into an upper fluidized-bed chamber and a lower gas chamber by a perforated dispersion plate having the shape of a funnel. Rising currents of a gas, such as air, are blown through the dispersion plate into the upper fluidized-bed chamber to produce a fluidized bed of a particulate material over the dispersion plate. The lower gas chamber is divided into a first gas chamber and a second gas chamber by a partition plate. The gas is supplied into the first air chamber so that rising gas currents of a velocity necessary for fluidizing coarse particles contained in the particulate material fed into the vessel are blown from the first air chamber through the dispersion plate into the fluidized-bed chamber.

Abstract: In the processing of exhaust gases by a chlorine bypass system, a portion of kiln exhaust gases G is extracted from a kiln 1, after the extracted exhaust gases G are instantly cooled to 600.degree. C. to 700.degree. C. or less, the dust W in the cooled exhaust gases is separated to rough powder and fine powder by a separator, the separated rough powder is returned to the kiln 1 and the separated fine powder is discharged to a cement system, wherein extracting means extracts the kiln exhaust gases at the ratio more than 0% to equal to or less than 5% and the separating point of the separator is set to 5 .mu.m to 7 .mu.m.

Abstract: A clinker cooler (3) comprises a plurality of grates (5) arranged in adjacent and overlapping relation to each other for conveying hot cement clinker (11) supplied from a kiln (1). The grate (5) is formed with an air hole (20) through which air from a fan (8) is jetted toward the cement clinker via a compartment (16) to cool the cement clinker. A distribution chamber (13) is equipped to a part of the grate corresponding to a part of cement clinker which is not cooled sufficiently, and the air from the fan (14) is jetted to such part of cement clinker which is not cooled sufficiently. The quantity of air jetted from the distribution chamber is adjusted by varying a degree of opening of a damper (15).

Abstract: Materials such as cement clinker are crushed by utilizing a crushing apparatus including a vertical roller mill provided with a rotatable table and a plurality of rollers and a distributing device for distributing materials preliminarily crushed by the vertical roller mill. The materials to be crushed is fed into the vertical roller mill, the materials are crushed between the table and the rollers by a pressing force applied to the rollers and substantially the whole amount of the crushed materials is then taken out from the vertical roller mill and conveyed to the distributing device. The crushed materials once conveyed to the distributing device is returned partially as they are to the vertical roller mill and again crushed together with the materials newly fed into the vertical roller mill. The materials are returned to the vertical roller mill by about 20% or more in weight ratio with respect to the newly fed materials when cement clinker is utilized as the materials to be crushed.