Abstract: The aim of the invention is to provide grinding rolls in particular for high-pressure roller mills or rolling presses for pressure grinding a granular material not only with a wear-resistant coating but also with a face armour plating in the area of the roller annular edge, which has a long service life due to the high wear resistance thereof and whose production and repair are, in general, relatively simple and inexpensive. For this purpose, the inventive face armour plating consists of a plurality of prefabricated hard bodies which are circularly arranged side by side in such a way that the circular face edge of the roller is formed, said hard bodies are disposed on said circular shoulder of a roll shell such that said hard bodies are placed axially and radially against said circular shoulder of the roll shell and are movably assembled with the roll shell.

Abstract: The aim of the invention is to create a compact circulating grinding plant comprising a product bed comminution roller mill or roller press and a sifter device, in which the problem of mechanically transporting the grinding product that is directed through the circuit is minimized. Said aim is achieved by a circulating grinding plant in which a static cascade sifter is disposed below the gap of the roller press while a subsequent sifter, particularly a dynamic rod basket sifter, is disposed above said roller press. The sifting product discharge area of the static cascade sifter is connected to the sifting air and sifting product inlet of the subsequent sifter via an ascending duct which pneumatically conveys the product.

Abstract: The aim of the invention is to provide grinding rolls in particular for high-pressure roller mills or rolling presses for pressure grinding a granular material not only with a wear-resistant coating but also with a face armour plating in the area of the roller annular edge, which has a long service life due to the high wear resistance thereof and whose production and repair are, in general, relatively simple and inexpensive. For this purpose, the inventive face armour plating consists of a plurality of prefabricated hard bodies which are circularly arranged side by side in such a way that the circular face edge of the roller is formed, said hard bodies are disposed on said circular shoulder of a roll shell such that said hard bodies are placed axially and radially against said circular shoulder of the roll shell and are movably assembled with the roll shell.

Abstract: The aim of the invention is to create a compact circulating grinding plant comprising a product bed comminution roller mill or roller press and a sifter device, in which the problem of mechanically transporting the grinding product that is directed through the circuit is minimized. Said aim is achieved by a circulating grinding plant in which a static cascade sifter is disposed below the gap of the roller press while a subsequent sifter, particularly a dynamic rod basket sifter, is disposed above said roller press. The sifting product discharge area of the static cascade sifter is connected to the sifting air and sifting product inlet of the subsequent sifter via an ascending duct which pneumatically conveys the product.

Abstract: The rolls of high-pressure roll presses for the compressive size reduction of granular material are hard surfaced with nub pins which are wear-resistant and suitable for autogenous wear protection. The nub pins, which have a long potential service life even under the action of high compressive loads, have a radially inner pin part (13) which is easily welded to the roll surface (12) and a radially outer harder pin part (14) protectively covering the radially inner pin part.

Abstract: In order to create a wear-resistant hard-surfacing for the rolls of high-pressure roll presses for the compressive size reduction of granular material, which is suitable for autogenous wear protection and which is simple from the fabrication standpoint and also exhibits a long potential surface life with minimized danger of cracking, even under the action of high pressing compressive loads, it is proposed in accordance with the invention that a multitude of profiles, such as, in particular, nub pins (17), arranged at intervals from one another, be welded onto the roll surface by mold welding, specifically with the assistance of a mold (11) laid on the roll body (10), which mold is provided with radial through openings (12, 13, 14), which are filled with surface weld metal, after which, after solidification of the weld metal, the preferably water-cooled mold (11) is lifted off the roll (10).

Abstract: A rotary sifter for separating different fractions of particulate material having a cylindrical outer housing and three rotary cages with vertical bars through which material and air pass inwardly with the cages independently rotary mounted, and channels communicating with the spaces below the rotors for collecting the separate fractions of separated material, and additional air delivery means to each of the channels which collect the separated fractions.