Abstract: A tube mill for dry grinding of a granular material, the mill being formed with one or more grinding compartments charged with grinding bodies and, downstream of the first or sole grinding compartment, a relatively short compartment bounded downstream by a dam ring having a central opening and upstream by a sieving diaphragm for holding back the grinding bodies, but permitting fluidized ground material to flow from the upstream grinding compartment to the short compartment and vice versa, the short compartment being adapted to serve as a reservoir of fluidized ground material.

Abstract: A method of heat treating a preheated, pulverous, raw material consisting of or containing lime, such as cement raw meal. By mixing at least part of the preheated raw material intimately with a fuel capable of carrying out at least a partial calcination, a suspension of raw material in a combustible gas is provided. Upon providing a flow of oxygen-containing gas in contacting relation with the suspension of gas/material, at least a partial calcination takes place according to an endothermic process in which calcium carbonate is dissociated into calcium oxide and carbon dioxide. A finishing calcination and/or other heat treatment may follow the calcination process. When the raw material is cement raw meal, the aforesaid finishing heat treatment following the calcination is a sintering by which cement clinker is produced according to an exothermic process.

Abstract: This invention relates to arrangements for supporting rotary drums such as tube mills and rotary kilns of the type which rotate about a horizontal or slightly inclined axis and are provided with at least one running surface on the circumferential surface thereof and corresponding with one or more supporting means for supporting the drum on a foundation. The supporting means is mounted on the foundation and an endless member is positioned on the supporting means with the running surface of the drum in contacting relation with the endless member such that part of the weight of the drum is thereby transmitted to the supporting means. The endless member follows an endless path substantially perpendicular to the axis of the drum while moving in running contact with the corresponding running surface of the drum during rotation thereof. The running surface may be a belt-like, machined surface of the drum proper, but it is preferably a special, machined live ring encircling the drum.

Abstract: An air-swept tube mill having at least two grinding chambers and a discharge chamber, an internal by-pass means in the last grinding chamber in communication at one end with the grinding chamber immediately preceding the last grinding chamber and at the other end, with the discharge chamber, whereby material ground in the first chamber is transferred through the by-pass directly to the discharge chamber and oversize material is transferred from the discharge chamber to the last grinding chamber for further grinding. A unique method is disclosed in which grinding of material takes place in a first grinding chamber of a tube mill and by-passed into a discharge chamber. The method further comprises feeding oversize materials from the discharge chamber into a last grinding chamber for additional grinding thereof.

Abstract: A rotary kiln plant for calcining and sintering mineral materials such as cement raw materials, comprising a separate unit for preheating and at least partially calcining the raw materials, a rotary kiln for sintering the preheated and calcined raw materials, a separate inside airswept rotary cooler means for cooling the materials burnt in the kiln, and a stationary chamber positioned intermediate the outlet of the rotary kiln and the inlet of the rotary cooler means and forming a passage for the burnt kiln product from the kiln to the rotary cooler means in countercurrent with heated cooling air passing to the rotary kiln. Air inlet and outlet means on the chamber make it possible to introduce additional cooling air and to utilize cooling air from the chamber for the preheating and calcining unit while by-passing the rotary kiln.

Abstract: A method and apparatus is disclosed for burning pulverous or granular material, particularly cement raw material to cement clinker. Burning of the pulverous material is accomplished in a plant which includes a suspension preheater, a rotary kiln and a separate rotary cooler unit having an inlet end and an outlet end, for cooling the burnt material exiting from the kiln by means of air which is subsequently used for combustion and preheating purposes. The method comprises dividing the heated cooling air into at least two streams, directing the divided heat cooling air out of both ends of the rotary cooler unit in its divided streams, directing at least one stream to the rotary kiln to be used as combustion air, directing exhaust gases from the rotary kiln to the preheater to preheat the material, and directing the other stream of heated cooling air to the preheater to preheat the material prior to being burnt in the rotary kiln.

Abstract: A method of burning pulverous or granular material in a plant including a suspension preheater and a rotary kiln having an integrally mounted planetary cooler for cooling the burnt material exiting from the kiln by means of air subsequently used for combustion and preheating in the plant.