DE1119774B - Pusher centrifuge with washing device for the spun material - Google Patents

Description

GERMAN

PATENT OFFICE

K 41585ΙΠ / 82 b

REGISTRATION DATE: AUGUST 31, 1960

NOTICE THE REGISTRATION AND ISSUE OF THE EDITORIAL: DECEMBER 14, 1961

For the continuous separation of liquid-solid mixtures, both single-stage and multi-stage pusher centrifuges known.

In the case of a single-stage pusher centrifuge, the sieve-filled cylindrical or conical centrifugal drum along part of the inner surface of which a push floor axially and moved and thereby the solid cake deposited on the inner jacket in batches at the Discharge of the centrifugal drum promoted, from where it is thrown into the solids trap chamber.

In a multi-stage pusher centrifuge, several cylindrical or conical sieve drum parts are telescopic nested into one another and into two axially reciprocating systems in this way connected that each two immediately adjacent drum parts belong to different systems. The end faces of all inner drum parts each act as push members for discharging the settling on the inner surface of the outwardly adjacent drum part.

It has now been shown that hard, granular or crystalline goods are spun in one stage Pusher centrifuges with a cylindrical screen part the multi-stage pusher centrifuges with cylindrical Sieve parts and pusher centrifuges with conical sieve parts with regard to low and high residual moisture Solids output are superior. This advantage can be explained by the fact that single-stage pusher centrifuges With a cylindrical sieve part, the solid cake is built up only once, i.e. not circulated several times and, due to the formation of bridges in its particles, it also retains fines.

Multi-stage pusher centrifuges are advantageously used when the solids cake has to be washed or when viscous, viscous or thixotropic goods are to be centrifuged. The better effect of the multi-stage centrifuges for these goods is to be sought in the repeated layering and loosening of the solid cake with each transition from one drum part to the next with a larger diameter. The loosening promotes the penetration of the washing liquid or the drainage of the initially bound gusset liquid. Since the spatial extent of the respective loosening and circulation is relatively small, several washing stages, ie drum stages, have to be arranged one behind the other when larger amounts of washing liquid are throughput. So centrifuges are known with a total of eight thrust stages, which are burdened with high manufacturing costs due to their intricate construction. Because of the new push-on centrifuge with washing device
for the thrown good

Applicant:
Krupp-Dolberg G. mb H., Essen

Fritz W. Schneider, Dortmund,
has been named as the inventor

construction of the solid cake after the transition from one drum part to the next as well because of the large number of annular gaps between the thrust rings and the sieves, the multistage centrifuge must a high loss of solids in the filtrate and therefore poorer dye yield be taken.

The multi-stage pusher centrifuges with conical sieve drum parts are likely to have the highest solids losses have, since with this construction the loss of solids not only in the annular gaps between the thrust rings and the drum parts, but also because of the constant loosening of the cake occurs to a very large extent on the conical screen lining itself. The flinging of fine fabrics is in these Centrifuges are only possible to a limited extent, even with modest requirements for solids discharge.

The invention is based on the object of eliminating the disadvantages of the multistage centrifuge in terms of washing possibility, Eliminate filtrate loss and construction. According to the invention, this is done in that the shell of the centrifugal drum consists of a cylindrical screen part, one adjoining in the discharge direction, conically widening full jacket part, to which the washing liquid is fed, and a subsequent, correspondingly further cylindrical sieve part.

The design of the washing zone as a conical full-walled part causes the solids cake to loosen up and thus a better washing option without additional loss of filtrate. This can Full jacket part firmly connected to the two adjacent cylindrical screen parts or opposite one or both of these parts can be axially displaced, resulting in a one-, two- or at most three-stage Pusher centrifuge, so a relatively simple construction results.

The described and other features of the invention are shown in the drawing on the basis of four

109 749/216

management examples shown schematically and with regard to Structure and mode of operation explained.

Fig. 1 shows a single-stage,

Fig. 2 and 3 each show a three-stage and

Fig. 4 shows a two-stage pusher centrifuge, in partial axial sections.

In the single-stage pusher centrifuge according to FIG. 1, the jacket of the centrifugal drum 1 consists of the cylindrical screen part 2, the conical widening full jacket part 3, which follows in the discharge direction, and the subsequent, correspondingly further cylindrical screen part 4. The inlet pipe 5 for the centrifuged material opens into the Acceleration funnel 6, which is connected to the moving floor 7 by means of webs and rotates with this and with the centrifugal drum. The solid cake that forms on the sieve part 2 is moved in batches to the right by the axially reciprocating pusher bottom, which is sealed on the circumference by piston ring-like members 8 made of elastic materials against the sieve part 2, and thereby reaches the conical full-walled part 3. There it is loosened by the constant enlargement of the diameter, whereby the penetration of the washing liquid applied simultaneously by means of the pipe 9 and the nozzle 10 is promoted. Because the conical part is designed as a full-jacket drum, neither solid breakdown nor loss of filtrate occurs in the loosening and washing zone. The washing liquid runs along the inner jacket of the full jacket part 3 into the cylindrical sieve part 4, in which the cake no longer experiences any circulating movements that could initiate and promote the escape of solid particles through the sieve openings. The solid cake is spun dry in the sieve part 4, the spun off liquid is collected in the filtrate trap and the solid discharged at the right-hand end is finally thrown into the solids trap 11.

The multi-stage pusher centrifuges according to Fig. 2 to 4 are used to dewater goods that are under the Exposure to the washing liquid begin to flow, e.g. B. are fine-grained, amorphous in nature. Such goods are not capable of the axial thrust pressures required for ejection in the area transferred to the washing zone.

In the centrifuge according to FIG. 2, the centrifugal drum is divided into two axially stationary cylindrical screen parts 12 and 13, as well as in a conical solid jacket part 15 that moves back and forth with the push floor 14 divided. In this embodiment, the solid is comparatively after passing through the first sieve part 12 and the long washing zone on the full jacket part 15 of the end faces acting as a thrust ring the sieve part 12 and the full jacket part 15 detected and further promoted.

Basically the same effect is achieved in the centrifuge shown in FIG. 3. In deviation of the embodiment described, however, the conical full jacket part 16 by radial webs 17 is on Acceleration funnel 18, which in turn is hinged to the push floor 14. The washing liquid is introduced via the pipe 19 into the drum 20 connected to the acceleration funnel 18. The jacket of this drum is provided with spray nozzles 21 which evenly act on the washing zone. In order to prevent the drum 20 from flooding, there are radial bores 17 in the webs provided, through which the washing liquid in the event of an excessively large inflow or when the nozzles 21 are clogged can overflow. The arrangement of rotating washing nozzles is advantageous if the Dusts that are unavoidable when the nozzles are at a standstill and that affect the solids collecting chamber 11 can be prevented.

ίο In the two-stage centrifuge according to Fig. 4 is the conical full jacket part 23 connected directly to the first screen part 24, while the second screen part 25 is connected to the reciprocating moving floor 26. In this arrangement, too, is preferable a comparatively long washing zone is available.

Claims (7)

PATENT CLAIMS: 1. Pusher centrifuge with washing device for the centrifuged material, characterized in that the jacket of the centrifugal drum (1) consists of a cylindrical screen part (2), a conically widening full jacket part in the discharge direction, to which the washing liquid is fed, and a subsequent, correspondingly further cylindrical screen part (4) consists. 2. Multi-stage pusher centrifuge according to claim 1, characterized in that the conically widening full jacket part (15) of the centrifugal drum (1) with the axially reciprocating Moving floor (14) is connected. 3. Multi-stage pusher centrifuge according to claim 2, characterized in that the washing device consisting of a rotating with the centrifugal drum (1) with the acceleration funnel (18) for the drum (20) connected to the material to be thrown, the jacket of which is provided with spray nozzles (21) is provided and the interior of which the washing liquid is supplied. 4. Multi-stage pusher centrifuge according to claim 3, characterized in that the drum (20) for the washing liquid with the conically widening full jacket part (15) of the Centrifugal drum (1) is connected by radial webs (17), the radial bores (22) for have an overflow of the washing liquid. 5. Multi-stage pusher centrifuge according to claim 1, characterized in that the narrower cylindrical sieve part (24) with the adjoining, conically widening volhnantelpart (23) and the further cylindrical sieve part (25) is connected to the push floor (26). 6. pusher centrifuge according to claims 1 to 5, characterized in that the conically widening full jacket part (3, 15) of the centrifugal drum (1) against the drum axis for single-stage centrifuges by 10 to 20 ° and for multi-stage centrifuges - by 20 to 40 ° is. 7. pusher centrifuge according to claims 1 to 6, characterized in that the annular gaps on the end faces of the axially reciprocating parts serving as thrust ring through elastic Substances existing piston ring-like members (8) is sealed. 1 sheet of drawings