Voest-alpine Aktiengesellschaft

Voest-alpine Aktiengesellschaaft

Alois Janusch

Franz W Mayer

Walter Lugscheider

Gero Tessmer

Vilim Cvitas

Karl Faltejsek

Reinhart Hanke

Gerhard Larch

Fritz Ludewig

The solid jacket centrifuge is a plural chamber centrifuge (1). A housing (2) is, together with the centrifuge, stationarily supported, noting that a carrier (6) for cylindrical mantle surfaces (7 and 8) is provided within the housing (2). The cylindrical mantle surfaces (7 and 8) delimit annular chambers (9 and 10) and are shiftable in the direction of the axis of the shaft (3). There is further provided a screw conveyor (12) for introducing the material to be dewatered. The material to be dewatered enters the first annular chamber (9) via radial channels (15). By shifting the cylindrical mantle surface (7) in the axial direction, the material is discharged in a radial direction into the concentric greater annular chamber (10). When subsequently the mantle surface (8) is moved in the axial direction, discharge is again effected in the radial direction.

Solid jacket centrifuge

For dehydrating peat, centrifuges (5) being pressurized by saturated steam having a pressure of 2 to 35 bar are used, the heat of the discharged condensate as well as of the removed water being recovered.

Process for dehydrating peat

In a process for the disposal of settled sludge derived from a biological sewage-disposal plant, in which the thickened sludge is further dewatered and at least partially thermically decomposed within a centrifuge (15) by using separated steam, preferably at a pressure within the range of 1 to 15 bar and at a temperature of 100.degree. C. to 200.degree. C., the centrifugate of the centrifuge (15) subjected to the action of saturated steam is discharged via a lock (18) and is immediately subsequently subjected to a sulfidic precipitation (19) of heavy metals. The solid matter separated within the centrifuge (15) is simultaneously discharged via locks (28) and optionally is subjected to a post-drying step (33) and at least partially to a combustion, for example a fluidized bed combustion (23), for steam production (17) for the centrifuge (15), noting that the steam is completely circulated along a closed circuit and the waste steam of the locks is used for air-heating (30), whereupon condensate formed is supplied to the pre-settling basin (5) of the sewage-disposal plant, whereby the energy requirement is reduced and the environmental load is equally reduced.

Process for the disposal of settled sludge derived from a biological

A drying plant for brown coals of high water content comprises, as seen in flow direction of the coal and one behind the other, a conveyor means (2) equipped with a means (3) for spraying hot waste water onto the coal, a wet sieve (4) equipped with a means (5) for supplying residual steam, a conveyor means (6) for conveying the sieved material to a pressure lock (7), a preheating means (8) equipped with a pressure lock (7) at the charging location and with connections for steam conduits (11), a further pressure lock (13) for discharging the coal from the preheating means (8) and for charging the coal into an autoclave (14) being adapted for being supplied with steam, preferably saturated steam, and having connected thereto waste water conduits (12), a sieve drum (15) arranged within the autoclave (14) and being equipped with a variable rotational drive means (16) and with conveyor elements, in particular screw conveyor elements, a further pressure lock (19) for discharging the steamed material into a subsequent drying means (20), a subsequent drying means (20) having a connection (22) for preheated gases such as steam, air or inert gases, and a means (23) for transporting away the dry coal.

Drying plant for brown coals of high water content

A sieve drum (2) for drying solid materials such as, for example, brown coal is rotatably supported for being rotated around its axis (8). A conveying screw (3) is arranged within the interior of the sieve drum and can be rotated independent from the rotation of the sieve drum (2). The sieve drum (2) is designed as a slot-sieve drum, the slots (26) of which extend within the mantle of the drum from one front end (7) of the drum to its other front end (5). The sieve drum (2) and the conveying screw (3) are arranged within a tightly closable pressure resistant housing (1), steam supply openings (22) being connected to the housing (1) outside of the sieve drum.

Device for drying of solid materials

For drying organic solid materials, such as brown coals, the solid materials are, particularly for the purpose of immediately subsequent briquetting or refinement or gasification, respectively, preheated and introduced into an atmosphere of saturated steam at super-atmospheric pressure and increased temperature. After such a first drying stage (1, 2) operated with saturated steam, the process water formed in this drying stage is separated and the solid materials are at least partially pressure-released and subsequently further dried within an atmosphere of superheated steam at a temperature of at least 200.degree. C. of this steam atmosphere. The steam of this further drying stage (7) is passed along a closed circuit via heat exchangers (10, 11) and brought to or maintained at the required temperature. A portion of the steam passed along a closed circuit, that portion approximately corresponding to the amount of steam having its origin in the water content of the solid materials, is tapped via conduit (12) and used for preheating purposes (FIG. 1).

Process for drying of organic solid materials, particularly brown coals

For drying organic solid materials such as, for example, brown coals, these materials are, after preheating, treated with saturated steam under a pressure of 5 to 45 bar and at a temperature of 150.degree. to 260.degree. C. Prior to the subsequent upgrading step, the water content can further be reduced by introducing superheated steam and/or a pressure relief, whereupon immediately subsequently an upgrading treatment, particularly a gasification under pressure, a briquetting or a coal liquification, is effected with the sensible or intrinsic heat from the drying stage. Preferably the dried organic solid materials are introduced into the upgrading stage while still being under a residual pressure of the drying stage.

Process for continuously drying and upgrading of organic solid materials

For the purpose of briquetting organic solid materials, such as brown coal or bituminous coal, the materials are heated by hot water and/or steam and under super-atmospheric pressure to temperatures exceeding 160.degree. C. After discharging the organic solid materials, which have become dried to a great extent, the generated steam is separated by sucking off the steam without substantially cooling effect, bitumen-forming substances present within the organic solid materials thereby rapidly becoming homogeneously distributed. These homogeneously distributed binding agents give the compressed briquettes obtained a high strength and good mechanical properties when using substantially reduced compacting pressures as compared with known briquetting processes.

Process for hot briquetting of organic solid materials

The apparatus for drying organic materials such as for example brown coal has a space (5) maintained under a pressure exceeding atmospheric pressure, the material to be dried being supplied to the upper end (12) of said space and the dried material being discharged from the lower end (20) of said space. Between the supply opening (12) and the discharge opening (20) there are provided obliquely arranged sieves (2, 6) and water-impermeable collecting spaces for the water separated on the sieves. The collecting spaces (3, 7) for the water separated on the sieves are connected with drain channels (9, 10), and several sieves (2, 6) are arranged one above the other in the manner of cascades, the lower edge of one sieve being located above an uppermost area of the following sieve (2, 6) as seen in flow direction (FIG. 1).

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Leoben, Austria

Alois Janusch