EP1585599B1 - Solid bowl helical conveyor centrifuge comprising an adjustable outlet for solids - Google Patents

Abstract

A solid bowl helical conveyor centrifuge, including a rotatable drum having a horizontally-oriented axis of rotation and a rotatable screw arranged in the rotatable drum. Also included is at least one discharge opening oriented at an angle with respect to the horizontally-oriented axis of rotation. The at least one discharge opening is configured to discharge solids from the rotatable drum. An adjusting device is assigned to the at least one discharge opening and by which adjusting device an outlet cross-section of the at least one discharge opening is changeable. The adjusting device includes a movable adjusting disk arranged in the rotatable drum as an extension of the rotatable screw, and which movable adjusting disk is non-rotatably connected with one or more of the following: a) the rotatable drum, b) the rotatable screw, and c) a screw body. At least one connecting rod is fastened to the movable adjusting disk.

Description

The invention relates to a solid bowl screw centrifuge according to the preamble of claim 1.

From DE 43 20 265 A1 a solid bowl screw centrifuge is known, which is provided at the liquid outlet side with a weir, which has a passage which is associated with a stationary during rotation of the drum relative to this stationary throttle plate, which in turn via a threaded bushing axially is displaceable. By turning the threaded bush, the distance between the weir and the throttle plate can be changed. The concomitant change in the discharge cross section causes a change in the liquid level in the centrifugal drum, so that a continuous adjustment of this liquid level by moving the throttle plate is possible. A setting of the solids discharge, however, is not possible.

From EP 0 747 127 B1, it is known to arrange a particular radially adjustable Durchlußregulierelement between flights in the conical region of the screw. In this case, a relatively long adjustment path must be bridged in order to realize a change in the outlet cross-section for the solid.

In contrast, DE 41 19 003 A1 again shows a type of adjustable disk at the transition between the cone and the cylindrical region of the drum and the screw. The adjustment is made through the screw. The function is that of a baffle plate, which also affects the liquid level in the drum.

From EP 0565 268 A1 it is known to provide only screw flights in the cylindrical part of a screw body and to set a kind of retaining disc at the axial end of the screw body. The problem is, inter alia, that a screw design must be selected, which differs in principle from conventional Scheckenkonstruktionen.

From EP 0 798 045 A1 it is known to associate the solids discharge opening with a flow rate control device. This device is arranged on the outside of the drum shell, which should allow easy optical inspection of the flow control device. Relatively problematic, however, is the realization of the adjustability of the throughput control device on the outside of the rotating drum in operation, because this does not have to be close to the center, but must be realized on a relatively large diameter, where the peripheral speed is relatively large.

The prior art still JP2002153771A and JP2002153772A and DE 41 19 003 A1 and DE 39 21 327 A1 are called.

A generic centrifuge is known from DE 1 823 269. The disadvantage here in some embodiments, the non-given adjustability of the adjusting cone and the structurally very complex and relatively complicated adjustment of FIG. 2 from the outside. It is also disclosed an automatic adjustment of the adjusting cone against a spring, but in practice does not lead to satisfactory results.

The invention has the object to remedy this problem.

The invention solves this problem by the subject matter of claim 1.

In this case, at least one or more drawbar (s) are attached to the adjusting disc, which allow a simple construction of an uncomplicated operation or adjustment of the adjusting disc from the outside.

Further, the remote from the adjusting disk end of the tie rod is connected directly or indirectly with a rod or pipe, which centrally passes through an inlet pipe in the axis of rotation of the solid bowl screw centrifuge. Here, the pull rod can be designed as nicht initdrehendes part and housed particularly uncomplicated.

The rotationally fixed connection of the adjusting disc with the worm or its worm body and the arrangement in the axial extension of the worm and the selected actuation make it possible in a surprisingly simple manner, e.g. an adjustability of the cross section of the at least one (or more) Feststoffaustragsöffnung (s) to realize "through the screw body" (or possibly through the drum). The screw body can continue both in the cylindrical and in itself. conically tapered section having worm threads.

The tie rods (in the sense of slidable pressure and tension rods) allow in a structurally simplest way to operate the adjusting disc, without it being necessary to realize a Verstelldrehbewegung.

By the arrangement "in extension" of the screw - in particular in extension of the conical section of the screw - it is also possible in turn possible to arrange the adjusting disc and its actuator particularly close to the center. It is also conceivable to guide the actuating forces, for example by means of the tie rods close to the center through the drum, although the arrangement in the worm or its drive shaft is particularly advantageous and allows a particularly close to the center arrangement.

With the invention, relatively short adjustment paths for changing the outlet cross section can be realized. The adjustment is e.g. depending on the TS content (dry matter) of the solid made (the determination of which is known per se and need not be explained in detail here).

Preferably, the adjusting disc (which in turn may be preferably "flat" or formed as a flat disc, but need not necessarily be) arranged axially displaceably in the drum. You can also be swiveled.

Preferably, the adjusting disc is completely perpendicular or radially aligned with the axis of rotation.

The axial displaceability can be realized by means of an electric motor actuable actuator or drive unit or a hydraulic or pneumatic device through the screw body, especially if they act on the tie rod which is attached to the adjusting disc and the axial end the screw body of the screw passes through, which connects axially to the manifold. The actuator may also be located inside the screw body (e.g., an electric motor).

Preferably, the adjusting device in the axial extension of the drum end is structurally simple and space-saving arranged in a subsequent axially to the screw discharge chamber.

The adjusting disc may also have recesses in various applications, which always allow a defined solid "minimum passage". The recesses may be distributed on the outer circumference, but they may, for example, also in the manner of holes, slots or the like. Or, for example, formed segment-like be. Preferably, the disc is flat, but it can be formed in different cases, for example, curved.

The invention is complemented in a meaningful way by a computer-controlled control device for controlling the adjusting disk, in particular as a function of the solids content of the solids. For this purpose, the numerical control or the centrifuge today often associated control computer of the machine can be used. This control can then act on the actuator.

Further advantageous embodiments can be found in the dependent claims.

Fig. 1

einen Schnitt durch einen Teil einer ersten erfindungsgemäßen Vollmantel-Schneckenzentrifuge;

Fig. 2

einen zu Fig. 1 analogen Schnitt durch eine zweite erfindungsgemäße Vollmantel-Schneckenzentrifuge;

Fig. 3

einen zu Fig. 1 analogen Schnitt durch eine dritte Vollmantel-Schneckenzentrifuge, die keine erfindungsgemäß Vollmantel-Schneckenzentrifuge darstellt;

Fig. 4

einen weiteren Schnitt durch das axiale Ende der Vollmantel-Schneckenzentrifuge aus Fig. 1; und

Fig. 5

einen zu Fig. 1 analogen Schnitt durch eine vierte erfindungsgemäße Vollmantel-Schneckenzentrifuge.

The invention will be explained in more detail by means of exemplary embodiments with reference to the drawing. It shows:

Fig. 1

a section through a portion of a first solid bowl screw centrifuge according to the invention;

Fig. 2

a similar to Figure 1 section through a second solid bowl screw centrifuge according to the invention;

Fig. 3

a similar to Figure 1 section through a third solid bowl screw centrifuge, which does not represent a full-bowl screw centrifuge according to the invention;

Fig. 4

a further section through the axial end of the solid bowl screw centrifuge of Fig. 1; and

Fig. 5

a similar to Fig. 1 section through a fourth inventive solid bowl screw centrifuge.

Fig. 1 shows a solid bowl screw centrifuge with a machine housing 1, is arranged in the drum 3, which has a horizontal axis of rotation. In the drum 3, a screw 5 is arranged.

The drum 3 and the screw 5 each have a substantially cylindrical portion 3a, 5a and a tapered at this subsequent thereto Section 3b, 5b on. The worm blade 42 surrounds both the cylindrical and the tapered region of the worm or of the worm body 29.

The drum 3 also has a further cylindrical section 3c adjoining the conically tapering section 3b, which defines a discharge chamber 15 and whose diameter is smaller than the diameter of the cylindrical section 3a and the diameter in the conical section 3b of the drum 3.

An axially extending centric inlet pipe 7 serves to supply the centrifuged material via a distributor 9 into the centrifugal space 11 between the screw 5 and the drum 3.

For example, if a muddy slurry is fed into the centrifuge, solid particles settle on the drum wall. Further inward, a liquid phase forms.

The bearing on a bearing 13 screw 5 rotates at a slightly lower or greater speed than the drum 3 and promotes the ejected solid to the conical section 3b and beyond to a subsequent to the screw in the axial direction cylindrical discharge chamber 15 in the second cylindrical portion 3c of the drum 3, which in turn is provided with at least one radially outwardly from the drum 3 leading discharge opening 17 for solid.

In contrast, the liquid flows to the larger drum diameter at the rear end of the cylindrical section of the drum 3, where it is discharged to overflow openings 19 with an adjustable weir 21.

The at least one solids discharge opening 17 is associated with an adjusting device which is movable in such a way that with it the cross section of the discharge opening 17 is more or less released.

The adjusting device has in the second cylindrical portion 3c of the drum 3 a arranged in the axial extension of the screw and there axially displaceable adjusting disk 25 which rotates with the screw or is arranged rotatably relative thereto.

The adjusting disk 25 is aligned in particular perpendicular to the drum axis and can be moved axially below the discharge opening 17, which changes the available outlet cross section of the discharge opening 17 for the solid. Its outer diameter is adapted to realize the displaceability of the inner diameter of the second cylindrical portion 3 c of the drum.

At the adjusting disc 25 is at least one or more, in particular three to this vertically arranged tie rod (s) 27 attached, which passes through the axial end of the pintail 29 of the screw 5 into a chamber 28 in the interior of the screw body 29 (t) ( en), which connects axially to the manifold 9, but is not connected to this.

The remote from the adjusting plate 25 end of the drawbar 27 is attached to a ring 31 (here by means of screw nuts 23) which is mounted by means of a bearing 33 on a rod 35 which does not work with the screw 5 or drum during operation of the solid bowl centrifuge 3 rotates but stops and which passes through the inlet pipe 7 in the axis of rotation of the solid bowl centrifuge centric.

Due to the bearing 33, the adjusting disk 25 can rotate with the at least one pull rod 27 during operation of the centrifuge together with the screw 5.

If the rod 35 is displaced axially (for example by means of a servomotor, not shown outside the drum 3), with this the bearing 33, the ring 31, the tie rod (s) 27 and thus also the adjusting disk 25 move axially, which in turn the outlet cross section changed for the solid.

According to Fig. 1, the inlet pipe does not rotate with. In constructions with a co-rotating inlet pipe (not shown here), the bearing can also be arranged outside the decanter (rotary feedthrough).

According to FIG. 1, only a relatively small speed difference has to be handled mechanically. Since the transition from the stationary rod 35 (pull rod) to the at least one or more (in particular two or preferably three), preferably with the screw 5 rotating tie rods 27, see Fig. 4, is arranged relatively close to the center, only a relatively small speed difference mechanically be dealt with.

Depending on the design of the decanter, the stationary pull rod 35 of the servomotor (not shown here) can be guided by the feed tube 7 or, for example, in the manner of Fig. 3 by the worm drive shaft 41 to the rotationally fixed ring 31 in the manner of FIG. The tie rods 27 are preferably arranged on the drive (in particular of the worm and drum) opposite end. If the drive, for example, in Fig. 2 left of Fig. 2 or arranged at the tapered end of the drum, the tie rods 3 in a particularly surprising - but practical - way from the opposite end of the drum 3 - ie from the cylindrical end ago - in this led. In Fig. 3, it is reversed.

Fig. 2 differs from Fig. 1 by the manner of actuation of the adjusting disk 25th

The ring 31 does not run on a bearing as shown in FIG. 2 but serves as a fluid-actuated, piston-like slide element 39, wherein the rod 35 is replaced by a tube 37, which for the supply and discharge of the fluid (eg a hydraulic fluid such as water) in the and from the pressure chamber 48 is used.

The emptying can also be done via one or more holes in the screw body 29 (not shown).

The axial position of the slide element 39 and thus the position of the adjusting disk 25 is dependent on the feed quantity of the actuating fluid and on the adjusting disk 25 acting, counteracting solids conveying force, which also acts as a restoring force. The slide member 39 is sealed to the inner wall of the cylindrical portion 3 a of the screw body and on the tube 37 with O-rings 43 and axially displaceable.

Fig. 5 shows a variant with pivotable adjusting disc 25, which also realizes the required axial mobility or displacement relative to the screw end. The adjusting disk 25 is articulated by means of a shaft 45 or a joint pivotally mounted on the axial screw end, whereas in turn remote from the shaft 45 peripheral region of the adjusting disk one or more of the tie rods 27 are hinged. As a result, the cross section of the solids discharge opening 17 available for discharging solids can likewise be changed in a simple manner. Advantageously, the joint lies opposite the screw opening at the end of the screw.

LIST OF REFERENCE NUMBERS

Solid bowl centrifuge

1

drum

3

slug

5

cylindrical sections

3a, 3c, 5a

tapered sections

3b, 5b

inlet pipe

7

distributor

9

centrifugal chamber

11

camp

13

discharge chamber

15

solids discharge

17

Overflow openings

19

weir

21

screw nuts

23

adjusting disk

25

pull bar

27

chamber

28

check body

29

ring

31

camp

33

pole

35

pipe

37

slide element

39

Worm drive shaft

41

screw blade

42

O-rings

43

wave

45

pressure chamber

48

Claims (23)

1. Solid-bowl screw centrifuge, which includes the following:

   - a rotatable drum (3) with an in particular horizontally oriented axis of rotation,

   - a rotatable screw (5) arranged in the drum (3),

   - at least one discharge opening (17), oriented at an angle to the axis of rotation of the solid-bowl screw centrifuge, for discharging solids from the drum (3), in the lateral surface of the drum (3),

   - the at least one discharge opening (17) being assigned a regulating device which can be used to change the outlet cross section for the solids,

   - the regulating device furthermore having a movable regulating disc (25) which is arranged in the drum (3) as an extension of the screw (5) and is rotationally fixedly connected to the drum (3), the screw (5) or the screw body (29),

   characterized in that

   - at least one or more connecting rod(s) (27) is/are secured to the regulating disc (25).
2. Solid-bowl screw centrifuge according to Claim 1, characterized in that the outlet openings (17) in the drum lateral surface extend radially outwards.
3. Solid-bowl screw centrifuge according to one of the preceding claims, characterized in that that end of the connecting rod (27) which is remote from the regulating disc (25) is directly or indirectly connected to a rod (35) or a tube which passes centrally through an inlet tube (7) in the axis of rotation of the solid-bowl screw centrifuge.
4. Solid-bowl screw centrifuge according to one of the preceding claims, characterized in that the at least one or more connecting rods (27) are guided through the screw (5) from the opposite end of the drum (3) from a drive for the screw centrifuge.
5. Solid-bowl screw centrifuge according to one of the preceding claims, characterized in that that end of the connecting rod (27) which is remote from the regulating disc (25) is secured to a ring (31) which, by means of a bearing (33), is mounted on a rod (35) which passes centrally through an inlet tube (7) in the axis of rotation of the solid-bowl screw centrifuge.
6. Solid-bowl screw centrifuge according to one of the preceding claims, characterized in that the regulating disc (25) is oriented radially with respect to the axis of rotation.
7. Solid-bowl screw centrifuge according to one of the preceding claims, characterized in that the regulating disc (25) is arranged as an axial extension of the drum end in a discharge chamber (15) which axially adjoins the screw.
8. Solid-bowl screw centrifuge according to one of the preceding claims, characterized in that the regulating disc (25) is axially displaceable in the drum (3).
9. Solid-bowl screw centrifuge according to one of the preceding claims, characterized in that the regulating disc (25) is of pivotable design.
10. Solid-bowl screw centrifuge according to one of the preceding claims, characterized in that the regulating disc (25) is pivotably mounted at the axial screw end.
11. Solid-bowl screw centrifuge according to one of the preceding claims, characterized in that three connecting rods (27) are secured to the regulating disc (25).
12. Solid-bowl screw centrifuge according to one of the preceding claims, characterized in that the connecting rods (27) pass through the axial end of the screw body (29) or a screw drive shaft (41) of the screw (5) into a chamber (28) in the screw body (29).
13. Solid-bowl screw centrifuge according to one of the preceding claims, characterized in that the at least one or more connecting rods (27) are guided through the screw (5) from the cylindrical end of the drum (3).
14. Solid-bowl screw centrifuge according to one of the preceding claims, characterized in that the chamber (28) adjoins the distributor.
15. Solid-bowl screw centrifuge according to one of the preceding claims, characterized in that the regulating disc (25) can be adjusted by means of a regulating unit that can be actuated by electric motor means.
16. Solid-bowl screw centrifuge according to one of the preceding claims, characterized in that the regulating disc (25) can be adjusted by means of a hydraulic or pneumatic device.
17. Solid-bowl screw centrifuge according to one of the preceding claims, characterized in that the connecting rod can be actuated by means of the hydraulic device or the regulating unit that can be actuated by electric motor means.
18. Solid-bowl screw centrifuge according to one of the preceding claims, characterized in that the ring (31) is designed as a fluid-actuable slide element (39).
19. Solid-bowl screw centrifuge according to one of the preceding claims, characterized in that a tube (37), through which the inlet tube (7) for the material to be centrifuged passes, opens out into a chamber (28) which serves as feed and discharge for the actuating fluid.
20. Solid-bowl screw centrifuge according to one of the preceding claims, characterized in that the regulating disc has recesses.
21. Solid-bowl screw centrifuge according to one of the preceding claims, characterized in that the inlet tube (7) does not rotate with the screw (5).
22. Solid-bowl screw centrifuge according to one of the preceding claims, characterized in that the inlet tube (7) rotates with the screw (5).
23. Solid-bowl screw centrifuge according to one of the preceding claims, characterized by a computer-controlled control device for controlling the regulating disc, in particular as a function of the dry matter content of the solids.

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