GB2110554A

GB2110554A - Removal of solids from liquids

Info

Publication number: GB2110554A
Application number: GB08225483A
Authority: GB
Inventors: Georg Mayer
Original assignee: Taprogge GmbH
Current assignee: Taprogge GmbH
Priority date: 1981-09-16
Filing date: 1982-09-07
Publication date: 1983-06-22
Also published as: IT8223298A0; AU8746882A; DE3136647C2; DE3136647A1; IT1152602B; JPS6017562B2; JPS5855017A; FR2512686A1

Abstract

Equipment for the removal of solids from a liquid stream (such as power station cooling water), has a cylindrical separator housing (1) in which there is a similarly cylindrical separating sieve (5) forming an annular space (6) together with the separator housing, and an adjustable control flap unit (8) is disposed centrally in the entry channel region to divide the entry channel (2) into two half-channels and has two independently controlled control flaps (11, 12) on axes (11a, 12a) parallel to the housing axis 22, to control and even close, as required, on the one hand one of the half-channels (9, 10), and on the other hand the annular space (6) between the separation sieve (5) and the separator housing (1) in the region of the control flap unit (8). An additional semi-annulus control flap (20) is disposed in each semi- annular space (6a, 6b) between the control flap unit (8) and the drainage channel (4) for the discharge stream containing the separated solids, the adjustment axis (21) being parallel to the housing axis (22), and each semi- annulus control flap (20) can close the semi-annulus (6a or 6b) in which it is disposed. <IMAGE>

Description

SPECIFICATION Removal of solids from liquids This invention relates to equipment for the removal of solids from a liquid stream, more particularly a stream of pose; station cooling water contaminated by solids, having a substantially cylindrical separator housing, an entry channel for the liquid stream requiring treatment opening radially into the separator housing, an exit union for the treated liquid stream, connected to the separator housing from below, and a drainage channel or a discharge stream containing the separated solids, connected on the far side from the entry channel, in which the separator housing contains a similarly shaped separation sieve axially parallel to the separator housing, and which together with the separator housing forms an annular space, while an adjustable control flap unit is disposed centrally in a mouth region of the entry channel to divide the entry channel into two half-channels, the control flap unit having two independently controlled control flaps whose adjustment axes are disposed in the separator housing in the region of the mouth of the entry channel and run parallel to the housing axis, and each control flap being adapted tc constrict and even close, as required, on the one hand one of the half-channels, and on the other hand the annular space between the separation sieve and the separator housing in the region of the control flap unit.

Known equipment of this type (DE-PS 29 28 093) has proved intrinsically sound. It performs reliably as intended, even when the operating conditions are highly variable in respect of the flow rate of the liquid stream requiring treatment and its solids content. Under normal operating conditions it can remove large amounts of solids without hurting any fish that pass through. This arises from the fact that, given a wide range of control flap settings, the flow conditions over the separation sieve can be kept symmetrical, thereby avoiding turbulence inside the separation sieve which would increase the pressure losses at high separation rates. A definite streamlining is maintained from the entry to the discharge channel, thereby ensuring the discharge of separated solids with minimum damage to any fish.By suitably adjusting the control flaps, one can readily maintain the discharge of separated solids under unusual operating conditions, provided that such unusual operating conditions are quite exceptional and only recur after long intervals. However, if the liquid stream is particularly heavily laden with solids and/or if the solids are such that they readily form deposits or tenacious growths, additional measures are required to prevent the solids from building up tenacious growths which can only be removed subsequently with difficulty. These special measures consist (in the prior art) of a peripheral spray unit disposed in the sieve space. The introduction of such a spray unit is difficult and its operation is costly.

The object of the invention is to provide equipment of the type described with which even when the liquid stream is particularly heavily laden with solids and/or when the solids are such that they readily form deposits or tenacious growths, the formation of tenacious solid growths is kept within safe limits and in any case they can be removed without difficulties during the cleaning cycles.

According to the present invention, an additional control flap is disposed in each semiannular space between the control flap unit and the drainage channel for the discharge stream containing the separated solids, each adjustment axis for the semi-annulus control flaps being parallel to the housing axis, and each semiannulus control flap being capable of closing the semi-annulus in which it is disposed.

In a preferred embodiment of the invention, the semi-annulus control flaps are curved in conformity with the curvature of the semi-annuli, so that the flow resistances and pressure losses are low when they are set parallel to the surface of the separator housing.

In conjunction with the control flaps in the control flap unit, the semi-annulus control flaps create specific flow conditions in the individual semi-annuli. For this purpose, the semi-annulus control flaps can be disposed midway between the control flap unit and the drainage channel.

According to another proposal of the invention, they are to be disposed near the drainage channel.

Another alternative, of independent significance, has two connecting unions to the drainage channel, one communicating with one of the semi-annuli and the other with the other semiannulus control flaps or valves being disposed in the connecting unions and a setting flap being provided between the connecting unions.

The accruing advantages are to be seen in that the flow conditions in equipment in accordance with the invention can be adjusted by the combined adjustment of the control flaps in the control flap unit on the one hand and the semiannulus control flaps on the other hand, and that if the liquid stream is particularly heavily laden with solids and/or if the solids are such that they readily form deposits or tenacious growths there is no danger that the solids might build up to a deleterious extent and/or resist removal in special cleaning cycles.

A number of embodiments of the invention will now be described, by way of example only, with reference to the accompanying diagrammatic drawings in which:~ Figure 1 is an axial section through one form of equipment in accordance with the invention; Figure 2 is a horizontal section through the equipment of Figure 1; Figures 3 to 5 correspond to Figure 2 to a smaller scale and depict the equipment in other operating settings; and Figures 6 and 7 are similar views to Figure 2 of two other embodiments of equipment in accordance with the invention.

The equipment shown in Figures 1 to 5 or Figure 6 or Figure 7 is intended for the removal of solids from a liquid stream. More particularly, it can be used to remove solids from a stream of power station cooling water contaminated therewith. In basic construction, the equipment has: a substantially cylindrical separator housing 1, an entry channel 2 for the liquid stream requiring treatment opening radially into the separator housing 1, an exit union 3 for the treated liquid stream, connected to the separator housing 1 from below, and a drainage channel 4 for a discharge stream containing the separated solids, connected on the far side from the entry channel 2.

The separator housing 1 contains a cylindrical separation sieve 5, which together with the separator housing 1 forms an annular space 6, but the axis 7 of the separation sieve 5 runs parallel to that of the separator housing 1. The annular space 6 extends back to a mouth region of the entry channel wherein is disposed an adjustable control flap unit 8, which divides the entry channel 2 into two half-channels 9, 10. The control flap unit 8 has or itself consists of two control flaps 11, 12, whose adjustment axes 11 a, 1 2a are disposed in the separator housing 1 in the region of the mouth of the entry channel 2 and run parallel to the housing axis 22. They intersect a circular arc which is an extension of the circular outline in plan of the separator housing 1 in this region.These two control flaps 11, 12 are to be actuated independently of each other, specifically so that each control flap 11. 12 can constrict and even close, as required, on the one hand one of the halfchannels 9, 10 and on the other hand the annular space 6 between the separation sieve 5 and the separator housing 1 in the region of the control flap unit 8. The control flaps 11, 12, are simply indicated as having turbulence-producing trailing edges 13.

In the embodiment shown in Figures 1 to 5, the two control flaps 1 1, 12 are attached to a streamlining member 14 extending in wedge form in the direction of flow. This member sits diametrically across the entry channel 2 and defines the two half-channels 9, 10 already referred to. The streamlining member 14 has a streamlining face 15 of arcuate radial section facing the separation sieve. The radius R of curvature of this streamlining face 1 5 corresponds to that of the separator housing 1. The separation sieve 5 is fitted with a streamlining wall 16, similarly arcuate in horizontal section, in the lee of the control flaps 1 1, 12, and thus in the lee of the streamlining member 14. Its radius of curvature corresponds to that of the separation sieve 5.The annular space 6 is broader between the separator housing 1 and the separation sieve 5 in the region of the control flaps 11, 12 than in the region of the drainage channel 4. This is brought about by mounting the separation sieve 5 eccentrically in the separator housing 1 towards the drainage channel 4. The separator housing 1 has a stagnant-water sump 1 7 over the full height of the drainage channel 4, which comprises discharge pipe unions 18 disposed radially and each having a portion 19 protruding into the stagnant-water sump 17. The stagnant-water sump 17 also extends over the full height of the separator housing 1 and over the full height of the separation sieve 5.An additiana! control flap 20 is disposed in each of the semi-annular spaces 6a, 6b midway between the control flap unit 8 and the drainage channel 4 for the discharge stream containing the separated solids, each adjustment axis 21 being parallel to the housing axis 22. The control flaps 20 are curved in conformity with the curvature of the semi-annuli 6a, 6b. It will be seen from Figures 3 and 4 that each of the semiannular spaces 6a and 6b can be closed by the respective control flaps 20. in Figure 5 the control flaps 2G are both disposed as in Figure 2 (i.e., in open position) while the control flaps 11, 12 have been adjusted to modify entry into the semi-annuli Sa, 6b.

In the embodiment shown in Figure 6, the semi-annuius control flaps 2C are disposed near the drainage channel 4. Figure 7 depicts another sliernative in which the drainage channel 4 has two connecting unions 23, 24, one communicating at 23 with one of the semi--annuli 6a and the other at 24 with rh~J other semiannulus 6b. in tha connecting unions 23, 24 there are disposed valves 25, cr control flaps and furthermore a setting flap 26 is provided between the connecting unions 23, 24. It is possible by these means to attain the same effect as when using the semi-annulus control flaps 20.The pearshaped cross-sec ion of the sieve 5 and corresponding cross-ssetion of the housing 1 in the embodiments shown in Figures 6 and 7 is another feature of special significance, and it will be seen that the axes 7 and 22 of the part cylindrical portions of the sieve and housing are again parallel with that of the sieve nearer the drainage channel 4. It should also be noted that the control flap unit 8 consists solely of control flaps 11, 12 adjustable on axes 1 a, 1 2a.

By variously setting the various control flaps 1 1, 19, 20 or 11, 1-, 2G and valves 25, one can create both local turbulence on the separation sieve 5 and increased flow rates round one side of the separation sieve 5. The settings cater for all operating conditions, even when handling a liquid stream which is heavily laden with solids and/or is laden with solids which tend to fern deposits readily, so that either no deleterious deposits build up or deposited solids can be easily dislodged in a cleaning cycle. As before, fish can pass through the device without being hurt.

The semi-annulus control flaps 20 can be mounted on the housing 1 as shown in Figure 1, or on the separation sieve 5 (not shown).

Claims

1. Equipment for the removal of solids from a liquid stream. having a substantially cylindrical separator housing, an entry channel for the liquid stream requiring treatment opening radially into the separator housing, an exit union for the treated liquid stream, connected to the separator housing from below, and a drainage channel for a discharge stream containing the separated solids, connected on the far side from the entry channel, in which the separator housing contains a similarly shaped separation sieve axially parallel to the separator housing, and which together with the separator housing forms an annular space, while an adjustable control flap unit is disposed centrally in a mouth region of the entry channel to divide the entry channel into two half-channels, the control flap unit having two independently controlled control flaps whose adjustment axes are disposed in the separator housing in the region of the mouth of the entry channel and run parallel to the housing axis, and each control flap being adapted to constrict and even close, as required, on the one hand one of the half-channels, and on the other hand the annular space between the separation sieve and the separator housing in the region of the control flap unit, an additional control flap being disposed in each semi-annular space between the control flap unit and the drainage channel for the discharge stream containing the separated solids, each adjustment axis for the semi-annulus control flaps being parallel to the axis of the housing and each semi-annulus control flap being capable of closing the semi-annulus in which it is disposed.

2. Equipment as in Claim 1, wherein the semiannulus control flaps are curved in conformity with the curvature of the semi-annuli.

3. Equipment as in either of Claims 1 and 2, wherein the semi-annulus control flaps are disposed midway between the control flap unit and the drainage channel.

4. Equipment as in either of Claims 1 and 2, wherein the semi-annulus control flaps are disposed near the drainage channel.

5. Equipment as in Claim 1, wherein the drainage channel has two connecting unions, the one communicating with one of the semi-annuli and the other with the other semi-annulus, control flaps or valves being disposed in the connecting unions and a setting flap being provided between the connecting unions.

6. Equipment for the removal of solids from a liquid stream substantially as hereinbefore described with reference to Figures 1 to 5 of the accompanying drawings.

7. Equipment for the removal of solids from a liquid stream substantially as hereinbefore described with reference to Figure 6 of the accompanying drawings.

8. Equipment for the removal of solids from a iiquid stream substantially as hereinbefore described with reference to Figure 7 of the accompanying drawings.