DE202010016700U1 - hydrocyclone - Google Patents

Abstract

Hydrocyclone for cleaning a pulp suspension (1) having a chamber (2) of circular cross-section, into which at one end an inlet (3) and a light part outlet (4) and at the opposite end a heavy part separator (5) opens, characterized in that the inner surface of the chamber (2) is at least partially formed by a soft plastic layer (6) which is supported on one or more outwardly stabilizing support elements (7, 8) and / or in which one or more shape-stabilizing support elements (9 , 10) are embedded.

Description

The invention relates to a hydrocyclone for the purification of a pulp suspension with a chamber of circular cross-section, in which at one end an inlet and a light part outlet and at the opposite end a heavy-part separator opens.

Hydrocyclones are well suited to concentrate by centrifugal forces heavy parts and light parts in pulp suspensions and to discharge via the outlet or the separator.

As a rule, they are used for the removal of small metal parts, glass splinters and sand or styrofoam and other light plastic parts.

In this case, the material of the chamber is subject to high wear, which is why this is usually made of ceramic, a dimensionally stable plastic or metal. This is all the more because of the high pressure of up to 4 or even 6 bar at the inlet of the chamber in the purification of a pulp suspension.

The object of the invention is therefore to significantly improve the wear resistance of the hydrocyclone even at high inlet pressures.

According to the invention, this object is achieved in that the inner surface of the chamber is at least partially formed by a soft plastic layer, which is supported on one or more outwardly lying, shape-stabilizing support elements and / or in which one or more shape-stabilizing support elements are embedded.

Soft plastics wear much less than hard, dimensionally stable plastics. In order to make the plastic usable, however, the dimensional stability on the support elements must be ensured.

It has been found to be particularly advantageous if the surface of the plastic layer has a hardness between 30 and 95, preferably between 80 and 95 ° Shore A.

For the plastic layer is particularly suitable polyurethane.

In order to ensure the dimensional stability of the chamber even at high pressures at the inlet and in the chamber, it may be advantageous if the support element lying outside the plastic layer is formed by a shaped body which is coated on the inside with the plastic layer or is connected thereto and preferably made of metal or a dimensionally stable plastic. A connection is simply possible by gluing.

Alternatively or additionally, the shape of the hydrocyclone, in particular the chamber can be ensured by at least one outwardly lying support element in the form of a dimensionally stable ring on which the plastic layer or another support element of the plastic layer is supported.

Alternatively or additionally, it may be advantageous if the embedded in the plastic layer support elements of dimensionally stable wires, strips o. Ä., In particular metal wires are formed.

A particularly advantageous embodiment with high dimensional stability results in this case if the embedded support element is a preferably dimensionally stable grid, in particular a metal grid. The grid can be formed by wires or a sheet-like structure, for example a correspondingly punched and bent sheet metal.

In order to simplify the manufacture of the hydrocyclone, in particular of the chamber, it can be advantageous if the chamber consists of a plurality of interconnected hydrocyclone sections. This also allows the hydrocyclone sections to be made of different materials according to the complexity of the shape or the difference in load.

Because of the high pressure in the chamber, it is advantageous for establishing a simple and pressure-proof connection between adjacent elements when the hydrocyclone or a hydrocyclone section has at at least one end a connecting flange formed by the plastic layer.

This connection flange can thus easily be connected to another connection flange of an adjacent hydrocyclone section or to a flange of a connection on the hydrocyclone.

Since the connecting flange is formed by the plastic layer of the chamber, the seal against the chamber is ensured. However, the dimensional stability of the connecting flange must be improved.

This is done by associating with the connecting flange a supporting element in the form of an annular disc, which is preferably embedded in the plastic layer.

The dimensional stability can be significantly improved by the fact that the disc is connected to the grid.

For a secure connection to an adjacent element, however, it may also be advantageous if the hydrocyclone or a hydrocyclone section has at least one end of a thread, preferably an internal thread, which is formed by the plastic layer. Because of the higher stability due to the smaller diameter of the chamber, this can be done especially on the heavy part separator.

The pulp suspension is generally placed on a circular path by tangential blowing through the inlet in the chamber, the pulp suspension being forced against the wall of the chamber by centrifugal force. The fibrous suspension moves in a spiral from the inlet towards the gravity separator.

In this case, the chamber should be at least partially conical, whereby the diameter of the chamber is reduced to the separator. The reduction of the diameter leads to an increase in the rotational speed and thus to an increase in the centrifugal and centrifugal forces. As a result, the heavy parts are pressed against the wall of the chamber and concentrated there. At the end of the chamber, the heavy parts can then be removed via the separator.

Since concentrate in the center axis of the chamber, the light parts, a preferably tubular, running along the center axis light part spout should protrude into the middle of the chamber at the inlet end of the chamber. About this outlet so the light parts of the suspension can be pumped.

In order to clean pulp suspensions of high consistency, it is advantageous if, for example, as in the EP 1 069 234 described in the chamber opens at least one supply line for dilution liquid.

Particular advantages arise when the hydrocyclone is used to clean the pulp suspension of heavy parts while the purified pulp suspension is discharged through the light part outlet.

However, it is also possible to remove light parts via the outlet from the pulp suspension and to remove the purified pulp suspension via the separator.

Because of the high wear resistance, the hydrocyclone is advantageously suitable for the purification of pulp suspensions, which serve for the production of a paper, board, tissue or another fibrous web and preferably a consistency of between 0.5 and 6%, in particular between 1.5 and 3.5% have. This applies in particular when dilution liquid is supplied via a supply line.

The invention will be explained in more detail below with reference to several exemplary embodiments.

In the attached drawing shows:

1 a schematic cross section through a hydrocyclone;

2 : a support element 7 . 8th a plastic layer 6 and

3 + 4 : other hydrocyclones.

The hydrocyclones described here serve to purify a pulp suspension 1 with a material density between 1.5 and 3.5% of heavy parts.

The fixed housing of the hydrocyclone encloses an elongated chamber 2 with circular cross-section.

At one end of the chamber 2 there is an enema 3 over which the pulp suspension to be cleaned 1 according to 1 tangentially in a cylindrical inlet section 11 the chamber 2 is injected. As a result, the pulp suspension 1 placed on a circular path, wherein the pulp suspension 1 against the wall of the chamber 2 is pressed.

Due to the centrifugal and centrifugal forces acting on it, the heavy parts accumulate 17 on the wall of the chamber 2 and the light parts 18 in the middle of the chamber 2 at. In this way get the heavy parts 17 on the wall of the chamber 2 spiraling to the opposite end of the chamber 2 with the heavy part separator 5 over which the heavy parts 17 be removed from the hydrocyclone.

To clogging of the heavy part separator 5 counteract, is in the range of Schwerteil separator 5 via a supply line 16 Dilution liquid in the chamber 2 directed.

This allows the trouble-free use of the hydrocyclone even at high material densities, as sought here.

The one in the middle of the chamber 2 existing, from the heavy parts 17 purified pulp suspension 1 is here as a lightweight component 18 over the light part drain 4 pumped out.

For this purpose, a tubular light part drain is sufficient 4 at the inlet end along the center axis 19 in the middle of the chamber 2 ,

At the inlet section 11 closes in the direction of the separator 5 a conical hydrocyclone section 12 in which is the diameter of the chamber 2 to the separator 5 continuously reduced.

By this taper, the rotational speed of the suspension increases in such a way that the heavy parts 17 on the wall of the chamber 2 concentrate. The light part spout 4 extends into the inlet section 11 into it.

Shall light parts 18 from the pulp suspension 1 are removed, then purified by this pulp suspension 1 as a heavy component 17 over the heavy section cutter 5 transported from the hydrocyclone, while the light parts 18 over the light part drain 4 be dissipated.

At the inlet 3 the chamber 2 becomes the pulp suspension 1 injected with a pressure of up to 4 or even 6 bar, resulting in a high load in terms of wear on the inner surface of the chamber 2 leads.

Therefore, the inner surface of the chamber becomes 2 essentially of a plastic layer 6 made of soft polyurethane. In this case, the inner surface of the plastic layer 6 a hardness between 80 and 95 ° Shore A.

This plastic layer 6 also has a much higher wear resistance than previously used dimensionally stable materials, such as steel and rigid plastics because of their softness.

To the dimensional stability of the plastic layer 6 To be able to come in the embodiments different support elements 7 . 8th . 9 . 10 for use. at 1 there is the cylindrical inlet section 11 Made of a dimensionally stable material (steel, dimensionally stable plastic, ceramic). At this closes in the direction of separator 5 the conical hydrocyclone section 12 from the plastic layer 6 at. The connection of both sections 11 . 12 via a flange of the inlet section 11 and a connecting flange 14 conical hydrocyclone section 12 as well as one of these flanges 14 enclosing V-band clamp 13 , The cylindrical separator 5 is here in an internal thread 15 the chamber 2 screwed, also because of the smaller diameter or hydrocyclone section 12 is sufficiently stable.

To the plastic layer 6 conical hydrocyclone section 12 to give sufficient dimensional stability are in these support elements 7 . 8th cast.

These support elements 7 . 8th exist, as in 2 represented, from one in the connecting flange 14 cast in annular metal disc 7 and an associated cone-shaped metal grid 8th for the cone-shaped plastic layer 6 ,

The metal grid 8th is formed by a network of wires welded together. The wire thickness is about 0.2 to 2 mm, preferably 0.4 to 0.8 mm. The mesh size of the grid 8th is between 2 and 10 mm.

The plastic layer 6 here has a thickness between 8 and 40 mm, preferably between 12 and 25 mm.

In contrast, the housing is in 3 from a stable molded body 9 made of metal or a dimensionally stable plastic such as polyamide, whose inner surface consists essentially of a plastic layer 6 that is consistent with the molding 9 is glued. The thickness of the plastic layer 6 is here about between 2 and 20 mm.

At the in 4 The embodiment shown is the cylindrical inlet section 11 as in 1 educated. However, the stabilization of the plastic layer takes place 6 formed, conical hydrocyclone section 12 on the one hand by an annular disc 7 in the connecting flange 14 which at least something in the conical section 12 has in-reaching elements and on the other hand on external support elements 10 ,

The outer support elements 10 are formed by rings that make up the plastic layer 6 and thus stabilize their shape even at high pressure.

For this purpose, the rings are uniform over the length of the conical section 12 arranged distributed.

The invention is not limited to these embodiments. For example, more than two hydrocyclone sections 11 . 12 to be available. Also, the inlet sections may be conical and other sections 12 be cylindrical.

Likewise, the hydrocyclone sections 12 at both ends or the hydrocyclone at the separator 5 one, especially one annular disc 7 reinforced connecting flange 14 have.

As a result, the wear resistance of the chamber increases 2 and thus the hydrocyclone considerably, without this should significantly affect the function, safety or the production cost.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 1069234 [0024]

Claims (18)

Hydrocyclone for cleaning a pulp suspension ( 1 ) with a chamber ( 2 ) of circular cross-section, into which at one end an inlet ( 3 ) and a lightweight outlet ( 4 ) and at the opposite end a heavy particle separator ( 5 ), characterized in that the inner surface of the chamber ( 2 ) at least partially from a soft plastic layer ( 6 ) formed on one or more outboard, shape-stabilizing support elements ( 7 . 8th ) and / or in which one or more shape-stabilizing support elements ( 9 . 10 ) are embedded. Hydrocyclone according to claim 1, characterized in that the surface of the plastic layer ( 6 ) has a hardness between 30 and 95, preferably between 80 and 95 ° Shore A. Hydrocyclone according to claim 1 or 2, characterized in that the plastic layer ( 6 ) consists of polyurethane. Hydrocyclone according to one of the preceding claims, characterized in that the external support element ( 9 ) is formed by a shaped body which is internally with the plastic layer ( 6 ) is coated or connected to it and preferably consists of metal or a dimensionally stable plastic. Hydrocyclone according to one of the preceding claims, characterized in that the external support element ( 10 ) is formed by dimensionally stable rings. Hydrocyclone according to one of the preceding claims, characterized in that the embedded support elements ( 8th ) of wires, in particular metal wires are formed. Hydrocyclone according to one of the preceding claims, characterized in that the embedded support element ( 8th ) is formed by a preferably dimensionally stable grid, in particular a metal grid. Hydrocyclone according to one of the preceding claims, characterized in that the chamber ( 2 ) of several, interconnected hydrocyclone sections ( 11 . 12 ) is formed. Hydrocyclone according to one of the preceding claims, characterized in that the hydrocyclone or a hydrocyclone section ( 11 . 12 ) at at least one end a connecting flange ( 14 ) possessed by the plastic layer ( 6 ) is formed. Hydrocyclone according to claim 9, characterized in that the connecting flange ( 14 ) a support element ( 7 ) is assigned in the form of an annular disc, which is preferably in the plastic layer ( 6 ) is embedded. Hydrocyclone according to claim 10, characterized in that the disc is connected to the grid. Hydrocyclone according to one of the preceding claims, characterized in that the hydrocyclone or a hydrocyclone section ( 11 . 12 ) at at least one end a thread ( 15 ), preferably has an internal thread, which of the plastic layer ( 6 ) is formed. Hydrocyclone according to one of the preceding claims, characterized in that the chamber ( 2 ) is conically formed at least in sections. Hydrocyclone according to one of the preceding claims, characterized in that the inlet ( 3 ) tangentially into the chamber ( 2 ) leads. Hydrocyclone according to one of the preceding claims, characterized in that at the inlet end of the chamber ( 2 ) a preferably tubular light part spout ( 4 ) in the middle of the chamber ( 2 protrudes. Hydrocyclone according to one of the preceding claims, characterized in that in the chamber ( 2 ) at least one supply line ( 16 ) for dilution liquid. Hydrocyclone according to one of the preceding claims, characterized in that the purified pulp suspension via the light part outlet ( 4 ) is discharged. Hydrocyclone according to one of the preceding claims, characterized in that the pulp suspension serving for producing a paper, board, tissue or another fibrous web ( 1 ) preferably has a consistency between 0.5 and 6%, in particular between 1.5 and 3.5%.

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