Device for continuously pressing liquid out of a suspension

Abstract

A device is described for continuously pressing liquid out of a suspension, in particular a screw press, which may have a rotationally-driven rotor, which may rotate in a tubular screw housing and support a conveyor screw. The screw housing may be at least partially formed as a first filter jacket, which may at least partially interact with the conveyor screw and which may have radial passages for discharging the filtered liquid and which may supply a filter cake, made of retained solids, in the conveyance direction of the conveyor screw to a discharge. To provide advantageous filter conditions, a ring-shaped first sleeve, which coaxially encloses the rotor, for peeling off an outer filter cake layer from the filter cake may be associated with the rotor, downstream from the conveyor screw. A conveyance channel for the remaining inner filter cake layer may be provided between sleeve and rotor.

Claims

1. A device for continuously pressing liquid out of a suspension, comprising: a conveyer screw; a tubular screw housing that includes a first filter that at least partially interacts with the conveyor screw and has radial passages for discharging filtered liquid, the first filter supplying a filter cake including retained solids in a conveyance direction of the conveyor screw to a discharge; a rotationally-driven rotor that rotates in the tubular screw housing and supports the conveyor screw; a ring-shaped first sleeve coaxially enclosing the rotor and disposed in the conveyance direction of the conveyor screw, that peels off an outer filter cake layer from the filter cake; a conveyance channel disposed between the first sleeve and the rotor for an inner filter cake layer that remains after the outer filter cake layer is peeled off, wherein the rotor includes a second filter for discharging the filtered liquid through the rotor in a region of the conveyance channel; and at least one scraper fastened on the first sleeve in the conveyance channel and protruding radially from the first sleeve toward the second filter for cleaning a portion of the filter cake off of the second filter.

2. The device according to claim 1, wherein the first sleeve is displaceable parallel to an axis of rotation of the rotor using a drive.

3. The device according to claim 1, wherein the first sleeve has at least one cone on an intake side of the first sleeve.

4. The device according to claim 1, further comprising: a washing lance having cleaning nozzles oriented toward the second filter, the washing lance arranged inside the rotor between the second filter and an axis of the rotor.

5. The device according to claim 1, wherein the second filter includes a fine screen, a filter cloth, or a filter made of porous filter materials.

6. The device according to claim 5, wherein the porous filter materials include plastics or ceramics drawn onto a screen support.

7. The device of claim 1, wherein the device comprises a screw press.

8. The device according to claim 1, further comprising: a second sleeve disposed in the conveyance direction from the first sleeve, wherein the second sleeve is displaceable using a drive in a direction of an axis of the rotor, has a smaller internal diameter than an internal diameter of the first sleeve, and encloses the rotor with a clearance.

9. The device according to claim 8, wherein the second sleeve has a cone which lifts the filter cake radially off of the rotor on an intake side of the second sleeve.

10. The device according to claim 8, wherein the first sleeve and the second sleeve are displaceable parallel to the axis of the rotor.

11. A device for continuously pressing liquid out of a suspension, comprising: a conveyer screw; a tubular screw housing that includes a first filter that at least partially interacts with the conveyor screw and has radial passages for discharging filtered liquid, the first filter supplying a filter cake including retained solids in a conveyance direction of the conveyor screw to a discharge; a rotationally-driven rotor that rotates in the tubular screw housing and supports the conveyor screw; a ring-shaped first sleeve coaxially enclosing the rotor and disposed in the conveyance direction of the conveyor screw, that peels off an outer filter cake layer from the filter cake; a conveyance channel disposed between the first sleeve and the rotor for an inner filter cake layer that remains after the outer filter cake layer is peeled off, wherein the rotor includes a second filter for discharging the filtered liquid through the rotor in a region of the conveyance channel; and a second sleeve disposed in the conveyance direction from the first sleeve, wherein the second sleeve is displaceable using a drive in a direction of an axis of the rotor, has a smaller internal diameter than an internal diameter of the first sleeve, and encloses the rotor with a clearance.

12. The device according to claim 11, wherein the second sleeve has a cone which lifts the filter cake radially off of the rotor on an intake side of the second sleeve.

13. The device according to claim 11, wherein the first sleeve and the second sleeve are displaceable parallel to the axis of the rotor.

14. The device according to claim 11, further comprising: at least one scraper extended toward the rotor for cleaning a portion of the filter cake off of the second filter.

15. The device according to claim 11, wherein the first sleeve is displaceable parallel to the axis of the rotor.

16. The device according to claim 11, wherein the first sleeve has at least one cone on an intake side of the first sleeve.

17. The device according to claim 11, further comprising: a washing lance having cleaning nozzles oriented toward the second filter, the washing lance arranged inside the rotor between the second filter and the axis of the rotor.

18. The device according to claim 11, wherein the second filter includes a fine screen, a filter cloth, or a filter made of porous filter materials.

19. The device according to claim 18, wherein the porous filter materials include plastics or ceramics drawn onto a screen support.

20. The device of claim 11, wherein the device comprises a screw press.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The subject matter of the system described herein is illustrated by way of example in the drawings. In the figures:

(2) FIG. 1 shows a device according to an embodiment of the system described herein in partially cutaway cross-section; and

(3) FIG. 2 shows the left section of the device from FIG. 1 in the region of the second filter in an enlarged scale, according to an embodiment of the system described herein.

DESCRIPTION OF VARIOUS EMBODIMENTS

(4) In some embodiments of the system described herein, a device is provided for continuously pressing liquid out of a suspension, namely a screw press 1, comprises a rotationally-driven rotor 4, which rotates in a tubular screw housing 2 and supports a conveyor screw 3. The screw housing 2 may comprise a first filter jacket 5, which at least partially interacts with the conveyor screw 3 and has radial passages 6 for discharging the filtered liquid and which supplies a filter cake K, made of retained solids, in the conveyance direction 7 of the conveyor screw 3 to a discharge 8.

(5) A fluid to be filtered may be introduced into the space between the conical conveyor screw 3 and the first filter jacket 5 and conveyed by the conveyor screw, which is rotationally driven around the rotor axis R, in the conveyance direction 7 while pressing out the fluid, wherein the solids, which are retained by the first filter jacket 5 and form the filter cake, may be conveyed in the conveyance direction 7 toward the discharge 8, and fluid passing through the passages 6 of the first filter jacket may be discharged from the device via the drain F. Instead of the conical conveyor screw 3, a cylindrical conveyor screw having different pitch could also be used. Combinations thereof are also conceivable. Moreover, the screw can be designed having a single thread or (at least partially) having multiple threads.

(6) According to embodiments of the system described herein, a ring-shaped first sleeve 9, which coaxially encloses the rotor 4, for peeling off an outer filter cake layer 10 from the filter cake K may be associated with the rotor 4, downstream from the conveyor screw 3, wherein a conveyance channel 11 for the inner filter cake layer 12 may be provided between the sleeve 9 and the rotor 4. The rotor 4 may have a second filter 13 for discharging the filtered liquid through the rotor 4 in the region of the conveyance channel 11.

(7) The first sleeve 9 may have at least one scraper 14 extended toward the rotor 4 for cleaning the filter cake 12 off of the second filter 13. In this case, the first sleeve 9 may be displaced parallel to the rotor axis using a drive 15, which may be a hydraulic drive, and may be equipped on the intake side with at least one cone 16.

(8) Moreover, a second sleeve 18 may be disposed downstream from the first sleeve 9. This second sleeve 18 may be displaceable using a drive 17 (which also may be a hydraulic drive) in the direction of the rotor axis R, may have a smaller internal diameter than the internal diameter of the first sleeve 9, may enclose the rotor with clearance, and may have a cone 19 lifting off the filter cake radially from the rotor 4.

(9) In some embodiments, a washing lance 20 having cleaning nozzles 21, which are oriented toward the second filter 13, may be arranged inside the rotor 4, between the second filter 13 and the rotor axis R. The second filter 13 may comprise a fine screen, a filter cloth, or a filter made of porous filter materials, such as plastic or ceramic drawn onto a screen support 22. Liquid discharged through the rotor 4 may be discharged from the device via a discharge 23.

(10) Other embodiments of the invention will be apparent to those skilled in the art from a consideration of the specification and/or an attempt to put into practice the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only, with the true scope and spirit of the invention being indicated by the following claims.