WO2017029022A1

WO2017029022A1 - Centrifuge having attachments for deflecting the suspension

Info

Publication number: WO2017029022A1
Application number: PCT/EP2016/065997
Authority: WO
Inventors: Markus Kuhn; Michael Reichenbach; Stefan Weis
Original assignee: Andritz Technology And Asset Management Gmbh
Priority date: 2015-08-14
Filing date: 2016-07-06
Publication date: 2017-02-23
Also published as: AT517210B1; AT517210A4

Abstract

The invention relates to a centrifuge, in particular a solid bowl centrifuge, comprising an axial suspension feed tube (9), which leads into a feed chamber (4) of the centrifuge provided with outlet openings (5). The centrifuge is principally characterized in that the outlet openings (5) are designed having curved attachments (8) for deflecting the suspension. The invention further relates to an attachment for use in centrifuges. By means of the invention, gentle introduction of the suspension into the pond can be achieved, whereby the risk of grain fractures in the case of granular suspensions is greatly reduced.

Description

CENTRIFUGE WITH EXTRACTS FOR SUSPENSION SLEWING

The invention relates to a centrifuge, in particular solid bowl screw centrifuge with axial Suspensionszuführrohr, which opens into a provided with outlet feed chamber of the centrifuge. A decanter or a decanter centrifuge uses the centrifugal force to separate solid and liquid phases. The task of the suspension is usually carried out axially by means of an axially arranged tube in a task chamber. In this chamber, the suspension is set in rotation and enters the decanters drum through outlet openings with feed sockets. In the transition from the feed chamber to the drum, the suspension is exposed to high loads resulting in the grain breakage of the solid phase. Such a centrifuge is e.g. described in DE 40 41 868 A1. Here a replaceable wear-resistant feed socket is inserted into the outlet openings. The suspension has after exiting the feed socket a large radial velocity perpendicular to the rotating pond surface. The pond surface is here by the

Outflow edge set at the outlet weir. Especially along the

Feed bushes, the suspension is greatly accelerated and there are high

Energy transfers take place. Part of this energy is dissipatively converted into heat but also into grain breakage. The aim of the invention is to reduce or avoid the breakdown in particular kömigen suspensions.

According to the invention, this takes place in that the outlet openings are designed with curved attachments for deflecting the suspension, wherein the curvature can take place in the direction of rotation. This results in a more uniform and thus gentler acceleration of the suspension, whereby the suspension also hits the pond surface with less force, which substantially reduces the collapse.

An advantageous development of the invention is characterized in that the curvature is approximated by juxtaposed straight parts. This allows a favorable production, which can be carried out independently of the material. l A favorable embodiment of the invention is characterized in that the angle α between the trailing edge of the attachment and the tangent to the pond surface is greater than 0 ° to 60 °, in particular 10 ° to 30 °. Thus, a favorable introduction of the suspension is achieved in the pond without strong shocks and thus greatly reduces a possible grain breakage.

An advantageous embodiment of the invention is characterized in that the ratio of the length 12, which measures the distance of the flow outlet edge to the circular tangent of the worm shaft at the flow inlet edge after mounting on a worm shaft, to the length 11, which the distance

Flow inlet edge along the circular tangent of the worm shaft to

Vertical measured on the flow outlet edge is greater than 1: 3, preferably greater than 1: 1. This geometry achieves a good flow deflection without subsequent tearing off in a more radial direction and thus supports a gentle introduction of the suspension into the pond. An advantageous embodiment of the invention is characterized in that the attachments have lateral openings for the supply / supply of air. This allows the airflow to be optimized.

A favorable development of the invention is characterized in that the attachments are made of steel, ceramic or tungsten carbide, the attachments alternatively being provided with wear protection, e.g. Ceramic or tungsten carbide, can be lined.

An advantageous development of the invention is characterized in that the outlet openings are provided with outlet sockets, wherein the attachments can be integrated into the outlet sockets.

A favorable embodiment of the invention is characterized in that the outlet openings are substantially covered by the attachments, wherein the outlet openings are preferably completely covered by the attachments.

The invention also relates to an attachment for a centrifuge, characterized

is characterized in that a curved surface is provided for diverting the suspension. Through this separate essay, the function of existing Machinery greatly improved and also occurring grain breakage in solids-containing and granular suspensions are greatly reduced.

A favorable development of the invention is characterized in that the curvature is approximated by juxtaposed straight parts. This allows a favorable production, which can be carried out independently of the material.

An advantageous embodiment of the invention is characterized in that the ratio of the length 12, which measures the distance of the flow outlet edge to the circular tangent of the screw tube at the flow inlet, to the length 11, which measures the distance of the flow inlet edge along the circular tangent of the screw tube to the vertical to the flow outlet edge greater than 1: 3, preferably greater than 1: 1. This geometry achieves a good flow deflection without subsequent tearing off in a more radial direction and thus supports a gentle introduction of the suspension into the pond. A favorable development of the invention is characterized in that the attachment has lateral openings for the removal / supply of air. This allows the airflow to be optimized.

An advantageous development of the invention is characterized in that the attachment made of steel, ceramic or tungsten carbide, wherein it is alternatively with

Wear protection, e.g. Ceramic or tungsten carbide, can be lined.

A favorable development of the invention is characterized in that the attachment is integrated in the outlet bushing of a centrifuge. This can be used a common wearing part and thus cheaply replaced.

A favorable embodiment of the invention is characterized in that the outlet bushing has an outlet opening, wherein the outlet opening in the

Is substantially covered by the essay and wherein the outlet opening is preferably completely covered by the essay. This achieves a particularly favorable deflection of the suspension.

The invention will now be described by way of example with reference to the drawings, in which FIG. 1 is an overview of a prior art decanter centrifuge; 2 shows a detail of a decanter centrifuge with essays according to the invention,

3 shows a cross section through an inventive task chamber with attached essays,

4 shows a cross section through an inventive task chamber with attached essays and air channels,

5 shows a cross section through an inventive task chamber with attached essays to cover the entire outlet opening,

6 shows a cross section through a feed chamber according to the invention with additional outlet bushings, FIG. 7 shows a cross section through a feed chamber according to the invention with integrated attachments in the outlet bushes,

8 shows a cross section through a feed chamber according to the invention with an alternative embodiment of the nozzles integrated in the outlet bushes,

9 shows a section of a feed chamber according to the invention

Length indications and

Fig. 10 shows a section of an alternative task chamber according to the invention with angle data.

Fig. 1 shows a decanter centrifuge according to the prior art with a cylindrical drum 1, in which a worm shaft 2 is arranged. By a fixed axial feed pipe 3, the suspension to be separated is a

Feed chamber 4 supplied. Through outlet openings 5, the suspension, for example, solid-liquid suspension, then introduced into the outer part, in which the so-called pond, i. the centrifugal force to the outside pressed liquid is located. In Fig. 1 can also be seen that a separation of the suspension takes place, the clear liquid flows in the picture to the left to the outlet 6 for clear liquid and the solid through the

The worm wing is transported to the right. The pond surface is adjusted by the trailing edge of the weir at the outlet 6. In the end area (here on the right shown), the drum runs conically, so that a better separation of the liquid takes place and a highly concentrated solid at the solids outlet 7 is discharged.

Fig. 2 shows a section of a decanter centrifuge in the task of suspension in the pond. One recognizes here the worm shaft 2 with the

Schneckenflügeln and the outlet openings 5 for the suspension in the pond 12. The attachments 8 according to the invention can also be seen here. The

Suspension flow is deflected here in the direction of rotation, so that the

Impact with small force hits the surface of the pond 12 with almost no radial velocity component. It is also obvious that the

Suspension, which is often a granular suspension, is abandoned outside the pond. The direction of rotation is shown here by the arrow 13.

The section essentially shows the feed chamber 4, which is separated from the remaining part of the interior of the centrifuge shaft 2 by the end wall 10 and the bulkhead 11. The suspension is introduced through a supply pipe 9 in the feed chamber 4 and then passes through the outlet openings 5 and is fed by means of the essays 8 in the pond 12. In Fig. 3 is a section through the

Centrifugal shaft 2 shown in the region of the feed chamber 4, wherein one looks at the feed tube 9. The outlet openings 5 from the centrifuge shaft 2 can be seen well. The attachments 8 adjoin the outlet openings 5, which here cause a deflection of the flow by 90 ° in the approximate direction of the tangent to the pond surface. The attachments 8 are mounted here on the centrifuge shaft 2 in the region of the outlet openings 5.

FIG. 4 shows an analogous section to FIG. 3. Here, the air openings 15 in the attachments 8 are clearly visible. This allows the air currents to be well controlled.

FIG. 5 shows an analogous section to FIG. 3. In contrast, the attachments 8 cover the outlet openings 5 almost completely, whereby a particularly good deflection of the suspension in the approximate direction of the tangent to the pond surface can be achieved. All other parts correspond to FIG. 3. FIG. 6 shows a variant of the invention in which outlet bushes 14 made of a wear-resistant material are inserted into the outlet openings 5 in order to protect the wall of the worm shaft 2 against wear. In this embodiment of the invention, the attachments 8 according to the invention are welded to the worm gear (not shown) and arranged at a distance from the worm shaft 2.

FIG. 7 shows a variant of the invention in which the attachments 8 according to the invention are integrated into the outlet bushes 14 and are thus designed as one part. As a result, the wearing parts can be exchanged in a simple manner.

FIG. 8 shows a different type of assembly of the attachments 8 integrated with the outlet bushings, in which case this part is inserted from inside and glued into the recess provided for this purpose.

FIG. 9 shows the geometric lengths on the example of an attachment 8 according to FIG. 3. The length 11 sets the distance of the flow inlet edge 16 along the circular tangent 20 of the worm shaft 2 to the vertical to the

The length 12 is analogous to the distance of the flow outlet edge 17 to the circular tangent 20 of the worm shaft 2 at the flow inlet edge 16. The ratio of the lengths 11:12 is greater than 1: 3, preferably greater than 1: 1.

Fig. 10 then shows the geometric configuration of an angle a, wherein the angle a between the tangent 18 to the attachment to the flow outlet edge 17 and the tangent 19 to the surface of the pond 12 is. The angle α is greater than 0 ° and is up to 60 °, wherein it is advantageously between 10 ° and 30 °.

The invention is not limited by the examples in the drawings. The

Attachments can for example be attached in any way to the worm shaft or integrated in any form with the outlet sockets. Such attachments can also be used in other types of centrifuges.

Claims

claims

1. Centrifuge, in particular solid bowl centrifuge with axial

Suspension feed tube (9) which opens into a feed chamber (4) of the centrifuge provided with outlet openings (5), characterized in that the outlet openings (5) are designed with curved attachments (8) for deflecting the suspension.

2. Centrifuge according to claim 1, characterized in that the curvature takes place in the direction of rotation.

3. Centrifuge according to claim 1 or 2, characterized in that the

Curvature is approximated by juxtaposed straight parts.

4. Centrifuge according to one of claims 1 to 3, characterized in that the angle α between the trailing edge of the attachment (8) and the tangent to the pond surface (12) is greater than 0 ° to 60 °, in particular 10 ° to 30 ° ,

5. Centrifuge according to one of claims 1 to 4, characterized in that the ratio of the length 12, which is the distance of the flow outlet edge (17) to the circular tangent (20) of the worm shaft (2) on the

Flow inlet edge (16) measures, to the length 11, which the distance of the flow inlet edge (16) along the circular tangent (20) of the

Worm shaft (2) measured perpendicular to the flow outlet edge (17) is greater than 1: 3, preferably greater than 1: 1.

6. Centrifuge according to one of claims 1 to 5, characterized in that the attachments (8) have lateral openings (15) for the supply / supply of air.

7. Centrifuge according to one of claims 1 to 6, characterized in that the attachments (8) made of steel, ceramic or tungsten carbide are.

Centrifuge according to one of Claims 1 to 6, characterized in that the attachments (8) are provided with wear protection, e.g. Ceramic or tungsten carbide, lined.

9. Centrifuge according to one of claims 1 to 8, characterized in that the outlet openings (5) with outlet bushes (14) are provided.

10. Centrifuge according to claim 9, characterized in that the attachments (8) in the outlet bushes (14) are integrated.

11. A centrifuge according to claim 10, characterized in that the attachments extend at least substantially over the outlet openings, wherein they may extend for example 40% to 100% of the length of the outlet opening beyond this.

12. attachment for a centrifuge, characterized in that a curved surface is provided for diverting the suspension.

13. Attachment according to claim 12, characterized in that the curvature is approximated by juxtaposed straight parts.

14. Attachment according to claim 12 or 13, characterized in that the ratio of the length 12, which after mounting on a worm shaft (2) the

Distance between the flow outlet edge (17) and the circular tangent (20) of the

Worm shaft (2) at the Strömungseintrittskannte (16) measures to

Length 11, which is the distance of the flow inlet edge (16) along the

Circle tangent (20) of the worm shaft (2) to the vertical on the

Flow outlet edge (17) measures greater than 1: 3, preferably greater than 1: 1.

15. Attachment according to one of claims 12 to 14, characterized in that the attachment (8) has lateral openings (15) for the supply / supply of air. 6. Attachment according to one of claims 12 to 15, characterized in that the attachment (8) made of steel, ceramic or tungsten carbide.

Attachment according to one of Claims 12 to 15, characterized in that the attachment (8) is provided with wear protection, e.g. Ceramic or tungsten carbide, lined.

18. Attachment according to one of claims 12 to 17, characterized in that the attachment (8) is integrated in the outlet bushing (14) of a centrifuge.

19. An attachment according to claim 18, characterized in that the outlet bush (14) has an outlet opening (5), wherein the attachment (8) extends at least substantially over the outlet opening (5), wherein the attachment (8), for example, 40th % to 100% of the length of the outlet opening (5) can extend beyond this.