GB2036606A

GB2036606A - Vortex separators

Info

Publication number: GB2036606A
Application number: GB7845954A
Authority: GB
Original assignee: PLENTY GROUP Ltd
Current assignee: PLENTY GROUP Ltd
Priority date: 1978-11-24
Filing date: 1978-11-24
Publication date: 1980-07-02

Abstract

In a separator for separating particles of matter from gas, a vortex tube (18) is positioned axially within a separator vessel (2) so that gas having particles of matter entrained therein flows spirally up the vortex tube causing the matter to be centrifugally forced against the inner wall of the vortex tube. A baffle (12) is provided below the vortex tube within the vessel and a baffle or, as shown, a conical duct (38) is positioned above the vortex tube. A conical skirt (32) of a lip member (22) is positioned adjacent the upper mouth of the vortex tube to effect separation of the entrained matter from the gas, the separated matter being removed by gravity down a duct (36) connected to an external reservoir or, as shown, to the lower portion (14) of the vessel. <IMAGE>

Description

SPECIFICATION Improvements in and relating to separators This invention relates to separators and in particular to separators for separating particles of matter from gas, e.g. dust or liquid from air or other gas.

Separators have been proposed in which the incoming contaminated gas is caused to circulate around the inside of the main separator vessel which is, at least in part, in the form of a cyclone tube. At a point adjacent the bottom portion of the, or each, tube, the gas forms a vortex and then flows up through a vortex tube positioned centrally within the main cyclone tube and exits at the top of the vessel.

The matter to be separated is acted on by centrifugal force during the passage of the gas down the tube and impinges on the inside wall of the tube and then falls down to be discharged through an outlet at the base of the main tube or vessel. Such a separator will hereinafter be referred to as a separator of the type described.

Such separators have a high separation efficiency but it has been found that some of the matter to be separated may be drawn up the vortex tube by the upward gas flow and lost from the separator. The general object of this invention is therefore to try to reduce this loss.

In accordance with this invention, the top, or top portion, of the vortex tube of a separator of the type described communicates with a duct or the like for discharge, preferably by gravity, of matter to be separated which matter is caused by centrifugal force to impinge against the inner wall of the vortex tube as the gas flows spirally up the said vortex tube.

The communication beween the vortex tube and the duct is preferably through a gap between the top edge of the vortex tube and spaced annular lip member which extends inwardly over the top of the tube edge. The lip member preferably has a conical skirt which extends downwardly around the top part of the vortex tube. It may also extend over a part of, and be spaced from, a downwardly extending conical wall connecting the top of the vortex tube and the inner surface of the main tubular cyclone vessel. Alternatively the conical wall may be re placed by a horizontal wall extending across the vessel below the skirt.

The matter to be separated flows over the top of the tube through the gap between the top of the tube and the lip member and then flows either down the conical wall to collect in a pool adjacent the main vertical wall of the cyclone vessel or falls onto the horizontal wall.

The discharge duct may then communicate with the space in the corner between the conical wall and the main wall of the vessel or with the space immediately above the horizontal wall, through the wall of the vessel.

The lip member is preferably smoothly curved over the top of the tube and the angle between the conical wall and the vortex tube is preferably acute.

Such an arrangement provides a very effective "secondary" separation of matter from the gas which is flowing up through the vortex tube and can then be fed by gravity, either back to a deposit of separated matter in the bottom of the main separ atorvessel orto any other desired point.

The gas flowing up the vortex tube may be caused to impinge against a flat horizontal baffle located centrally in the vessel above the open top of the vortex tube, there being a substantial gap between the edge of the circular plate and the edge of the tubular vessel so that the gas can flow around the edge of the plate to exit from the vessel outlet. This baffle plate which directs the spinning gas towards the walls of the vessel is valuable in cases where serious temporary overload of matter in the gas may occur, as the action of urging the gas towards the wall of the vessel would achieve a yet further separation of matter.

An alternative and in many ways preferable, arrangement is to have an upwardly tapering open ended cone positioned above and separated from, the open upper end of the vortex tube to receive the main gas flow. This creates a lower pressure in the chamber above the conical wall to help to produce an increased suction at the gap between the top of the tube and the lip, to help to draw the separated matter from the tube.

Aflat horizontal circular baffle plate may be present in the lower portion of the separator below the vortex tube and slightly spaced from the walls of the tubular vessel. This helps to prevent separated matter in the lower portion of the separator from being sucked up into the low pressure gas vortex whilst allowing the matter to flow down the sides of the main separator vessel to reach the reservoir in the bottom of the vessel.

The invention will now be further described by way of example with reference to the accompanying sketch drawings in which: Figure 1 is a section through one embodiment of a separator in accordance with the invention, Figure 2 is a view similar to Figure 1, but having a modified gas flow path adjacent to the outlet, and Figure 3 is a further view similar to Figures 1 and 2 but illustrating a modified collection area for the separated liquid.

The separator shown in Figure 1 is intended to separate liquid from a gas and comprises a main tubular separator vessel generally indicated at 2 having domed upper and lower ends 4 and 6. The gas and liquid mixture is caused to flow tangentially into the vessel through an inlet 8 and then flows spirally down the vessel, the spiral downward movement of the gas and liquid causing the liquid particles to be thrown out by centrifugal force to impinge against the inner wall of the main tubular vessel. The liquid then runs down the wall through the space 10 between the wall and a central baffle place 12 to the lower portion of the separator vessel where it accumulates in a reservoir pool generally indicated at 14 and from which the liquid can be discharged through an outlet 16.

The spinning gas effect creates a vortex so that the gas above the baffle plate 12 is caused to flow spirally upwardly along the centre line of the separator through a vortex tube 18 as generally indicated by the arrowed line 20.

The baffle 12 prevents liquid which has flowed down through the gap 10 from being caught up by the vortex which might otherwise cause it to flow up through the vortex tube.

It has been found that in practice some liquid in the main separator vessel is not acted on by centrifugal force or at any rate does not impinge the walls of the vessel to flow through the gap 10, and this liquid albeit a relatively small proportion of the whole, tends to be drawn up through the tube 18. It is desirable for this residue of liquid also to be separated from the gas.

In order to effect this further separation, an annular conical lip member 22 is positioned over the top edge 24 of the vortex tube 18 with the inner edge 26 of the annulus of the lip member being curved so as to lie over, but spaced from, the top edge 24 of the tube. A conical wall 28 connects the top of the vortex tube with the inner wall of the main vessel 2, the angle between the wall 28 and side of the vortex tube being acute.

A gap 30 is created between the top edge 24 of the tube and the inner lip 26 of the lip member 22 and this gap is subjected to a pressure differential due to the low pressure in the chamber above the wall 28.

The gap is connected to a narrow passage between the conical wall 28 and a skirt 32 of the conical lip member so that liquid which is thrown out by centrifugal force as the gas travels spirally up the vortex tube is sucked through the gap 30 over the top 26 of the vortex tube and down the upper surface of the conical wall 28 to lie in a pool, illustrated at 34, in the corner between the conical wall 28 and the inner wall of the separator vessel.

A duct 36 communicates with this space through the wall of the vessel, enabling liquid in the space 34 to flow from the top of the separator by gravity down the duct 36 which can either be connected to any desired reservoir or be connected back into the separator vessel at the lowest portion thereof below the normal level of liquid in the reservoir 14. In this latter case, a liquid seal is formed to prevent any gas flow from the top to the bottom of the separator.

An upwardly tapering cone 38 is positioned above the open top of the vortex tube 18 to receive the main flow of gas passing through the vortex tube.

The top of the cone is connected to the main gas outlet 40. Any gas flowing through the gap 30 and down the passage between the wall 28 and the skirt 32 is sucked up from the bottom of the space between the bottom of the wall and skirt as illustrated by the arrow 42 back into the bottom end of the conical member 38. The gas flowing through the cone 38 induces a somewhat lower pressure in the upper portion of the separator above the wall 28 which helps to produce a greater suction at the gap 30.

The separator illustrated in Figure 2 is substantially the same as that shown in Figure 1 and operates in the same manner except that the conical member 38 connected to the outlet 40, is not present, but rather a horizontal circular baffle plate 44 is positioned in the upper portion of the separator above the open top of the vortex tube. This baffle directs the spinning gas which impinges against its undersurface outwardly towards the inner wall of the separatorwhich helps to provide further separation of liquid from the gas in cases where serious temporary "overload" of liquid in the gas may arise. The "further" liquid is then thrown against the inner tubular wall of the main separator vessel and would flow down this wall into the pool 34 for subsequent discharge through the duct 36. The gas flows up around the edge of the baffle plate through the space between the plate and the walls of the main separator vessel to exit out through the main outlet 40.

The separation shown in Figure 3 is also substantally the same as that shown in Figure 1 and operates in the same manner except that the conical wall 28 of the Figure 1 embodiment is replaced by a horizontal wall 46 extending across the vessel above the inlet 8 but below the bottom of the skirt 28.

Liquid flows down the skirt of the drips onto the wall 46 from whence it exits through duct 36 to the liquid reservoir 14.

Claims

1. A separator for separating particles of matter of the type described having a vortex tube wherein the top or top portion of the vortex tube communicates with a duct for discharge of matter to be separated, which matter is caused by centrifugal force to impinge against the inner wall of the vortex tube as the gas flows spirally up the said vortex tube.

2. A separator as claimed in claim 1 wherein the communication between the vortex tube and the duct is through a gap between the top edge of the vortex tube and spaced annular lip member which extends inwardly over the top of the tube edge.

3. A separator as claimed in claim 2 wherein the lip member has a conical skirt which extends downwardly around the top or top portion of the vortex tube.

4. A separator as claimed in any one of claims 1 to 3 wherein the vortex tube has a downwardly extending conical wall connecting the top or top portion of the vortex tube and the inner surface of the main separator vessel.

5. A separator as claimed in claim 4 when dependent on claim 2 wherein the lip member extends over a part of and is spaced from the conical wall.

6. A separator as claimed in claim 2 or 3 wherein the lip member has a conical skirt which extends downwardly over a horizontal wall extending across the vessel below the skirt.

7. A separator as claimed in any of claims 2 to 6 wherein the lip member is smoothly curved over the top of the vortex tube and the angle between the conical skirt and vortex tube is an acute angle.

8. A separator as claimed in any one of claims 1 to 7 wherein a flat horizontal baffle is located centrally in the vessel above the open top of the vortex tube, there being a substantial gap between the edge of the baffle and the inner wall of the separator vessel so that gas can flow around the edge of the baffle to exit from a vessel outlet.

9. A separator as claimed in any one of claims 1 to 7 wherein an upwardly tapering open-ended conical duct is positioned above and separated from the open upper end of the vortex tube to receive the gas flow from the vortex tube.

10. A separator as claimed in any one of claims 1 to 9 wherein a flat horizontal baffle plate is positioned in the lower portion of the separator vessel below the vortex tube and is slightly spaced from the walls of the separator vessel.

11. A separator for separating particles of matter of the type described substantially as described with reference to Figure 3 of the accompanying drawings.

11. A separator for separating particles of matter of the type described substantially as described with reference to Figure 1 of the accompanying drawings.

12. A separator for separating particles of matter of the type described substantially as described with reference to Figure 2 of the accompanying drawings.

13. A separator for separating particles of matter of the type described substantially as described with reference to Figure 3 of the accompanying drawings.

New claims or amendments to claims filed on 28.2.80.

Superseded claims 1 to 13.

New or amended claims:

1. A separator for separating particles of matter of the type described having a vortex tube wherein the top or top portion of the vortex tube communicates with a duct for discharge of matter to be separated, which matter is caused by centrifugal force to impinge against the inner wall of the vortex tube as the gas flows spirally up the said vortex tube wherein the communication between the vortex tube and the duct is through a gap between the top edge of the vortex tube and a spaced annular lip member which extends inwardly over the top of the tube edge and wherein a baffle plate is positioned in the lower portion of the separator vessel below the vortex tube and is slightly spaced from the walls of the separator vessel.

2. A separator as claimed in Claim 1 wherein the lip member has a conical skirt which extends downwardly around the top or top portion of the vortex tube.

3. A separator as claimed in Claim 1 or 2 wherein the vortex tube has a downwardly extending conical wall connecting the top or top portion of the vortex tube and the inner surface of the main separator vessel.

4. A separator as claimed in any one of Claims 1 to 3 when dependent on Claim 2 wherein the lip member extends over a part of and is spaced from the conical wall.

5. A separator as claimed in any one of Claims 1 to 4 wherein the lip member has a conical skirt which extends downwardly over a horizontal wall extending across the vessel below the skirt.

6. A separator as claimed in any one of Claims 1 to 5 wherein the lip member is smoothly curved over the top of the vortex tube and the angle between the conical skirt and vortex tube is an acute angle.

7. A separator as claimed in any one of Claims 1 to 6 wherein a flat horizontal baffle is located centrally in the vessel above the open top of the vortex tube, there being a substantial gap between the edge of the baffle and the inner wall of the separator vessel so that gas can flow around the edge of the baffle to exit from a vessel outlet.

8. A separator as claimed in any one of Claims 1 to 6 wherein an upwardly tapering open-ended conical duct is positioned above and separated from the open upper end of the vortex tube to receive the gas flow from the vortex tube.

9. A separator for separating particles of matter of the type described substantially as described with reference to Figure 1 of the accompanying drawings.

10. A separator for separating particles of matter of the type described substantially as described with reference to Figure 2 of the accompanying drawings.