GB1604968A

GB1604968A - Separator apparatus and separator plates therefor

Info

Publication number: GB1604968A
Application number: GB2499878A
Authority: GB
Original assignee: FS FLUID SEPARATION Ltd
Current assignee: FS FLUID SEPARATION Ltd
Priority date: 1978-05-31
Filing date: 1978-05-31
Publication date: 1981-12-16
Also published as: BE867838A

Description

(54) IMPROVEMENTS IN SEPARATOR APPARATUS AND SEPARATOR PLATES THEREFOR (71) We, F S FLUID SEPARATION LIM ITED, formerly W T D S (Water Treatment Design Services) Limited, a British Company of 7 Pound Court, The Marld, Ashtead, Surrey, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to separator apparatus suitable, for example, for separating solids from liquids, two immiscible liquids, such as oil and water and, possibly, for separating solid particles or liquid in the form of a mist, droplets or the like from a gas.

The invention also relates to separator plates for use in such apparatus.

In the case of the separation of solid matter from liquid it is well known to cause the liquid to flow over a surface, which may be horizontal or inclined to the horizontal, but the use of such a surface means that large areas are required for the separating apparatus, particularly when large quantities of liquid are to be treated, for example in the treatment of sewage or effluent from industrial plants. The need for such large areas of equipment is costly both in terms of the land required and the material used in the construction of the equipment. To reduce the size and cost of such equipment, separator apparatus has been devised in which a plurality of plates are arranged in parallel, spaced relation to each other and inclined at an angle to the horizontal and liquid to be treated is caused to flow over the surfaces of the plates, the plates substantially increasing the settling area for the solids in the liquid for a given size of apparatus. The plates are generally planar but corrugated plates have been proposed in which the corrugations extend from the top to the bottom of the plate when it is installed in the separator apparatus. In operation ofsuch apparatus, as the liquid to be treated flows upwardly between the plates, particles of solid material entrained therein separate from the fluid stream and move towards the plate surfaces under gravity and then down the plates by virtue of the tendency of the particles to move down the velocity gradient caused by the upward flow of liquid being treated.

According to the invention there is provided a separator plate having parallel side edges and a plurality of transverse ridges formed on at least one surface thereof, each ridge having a triangular cross-section and extending obliquely with respect to said edges.

The ridges may be parallel to each other and may be non-linear having a peak intermediate their ends. Preferably the ridges are substantially V-shaped.

Plates according to the invention may be provided separately or in the form of modules which can be installed in existing or new separator apparatus.

Further according to the invention, there is provided separator apparatus comprising a plurality of separator plates according to the invention arranged in spaced, substantially parallel relationship and inclined to the horizontal. Thus, in use, fluid to be treated can be caused to flow upwardly between the plates and solid particles having a density greater than the fluid in which they are entrained move as a result of gravity and/or by virtue of the tendency of particles to move down the velocity gradient due to the fluid flow, towards the surfaces of the plates where they are caught by the ridges and then directed downwardly towards collectors situated below the plates.

This invention will now be described by way of example with reference to the accompanying drawings, in which: Figure I is a plan view of an embodiment of a separator plate according to the invention, Figure 2 is a thin, sectional view of part of a stack of plates as shown in Figure 1 drawn to a different scale, Figure 3 is a thin, side sectional view of part of a stack of plates according to another embodiment of the invention, Figure 4 is a front, schematic view of part of an embodiment of a separator apparatus according to the invention, Figure 5 is a side sectional view of the separator apparatus of Figure 4, Figure 6 is a perspective view of part of a separator apparatus according to Figure 4, and Figure 7 is a sectional view of another separator apparatus according to the invention, the section being taken parallel to a corresponding separator plate in each of the four banks of separator plates.

In the drawings, like parts are given like references.

Referring to Figures I and 2 of the drawings, there is shown a separator plate 10 having a plurality of spaced, parallel, transverse ridges 12 formed on one surface thereof. Each ridge 12 is substantially Vshaped and has limbs 12a, 12b extending obliquely towards a peak or apex 12c. The apexes 1 2c thus define a substantially straight line which bisects the plate 10 from the top edge l0a (in Figure 1) to the bottom edge lob. The distal ends of the limbs 12a and 12b terminate at positions spaced from side edges lOc, lOd respectively of the plate 10 to provide two substantially planar marginal areas 14 and 16 respectively along each side of the plate 10. The distal ends of the limbs 12a, 12b are provided with slight curvatures 12d, 12e respectively as shown, so that the said ends extend in a direction generally parallel with a line drawn through the apexes 12c of the ridges. However, although preferable, the provision of the marginal areas 14, 16 and the curvatures 12d, 1 2e is not essential and, indeed, the ridges could extend to the side edges I Oc, 1 Od of the plate 10. As shown in Figure 1, the ridges 12 do not extend along the full length of the plate so that a planar area 18 devoid of ridges 12 is left at one end.

In another embodiment, such as that shown at Figure 4, the ridges 12 could extend along the full length of the plate 10 and this would generally be the case if the plates were cut from preformed lengths of material. In the former case, the ridges 12 would probably, but not necessarily, be formed on pre-cut plate blanks although it would be seen that a length of material could be preformed with the ridges 12 and the areas 18 interspersed at appropriate intervals. As will be described hereinafter, the plates 12 shown in Figure 1 have the advantage that particles of material migrating along the ridges all each reach the areas 14 or 16 and then move downwardly for collection in trough-like collectors situated below the plates. With the plates shown in Figure 4, solid particles migrating along the ridges which intersect the lower edge lOb of the plate may not reach the marginal areas 14, 16 and thus will re-enter the main stream of inlet liquid where they may assist in flocculation of other particles contained in the main stream. The ridges 12 may take various forms in cross-section such as shown in Figure 2 and a generally saw-toothed section is found convenient to form and efficient in operation. The upper faces l2fof the ridges 12 (Figure 2) are shown to be at an angle of 90' to the main surface of the plate 10 but they may include an acute angle with that surface to form channels or troughs. The plates 12 are made of metal, such as aluminium or stainless steel, or of plastics or any other suitable material and may typically be 39in (99cm) in length by 20in (51cam) in width. In use, the plates 10 are arranged parallel to each other in one or more stacks and inclined to the horizontal. The spacing between the plates, the angle of inclination of the plates, and the angle of the limbs 12a, 12b, that is the apex angle of the ridges, should be arranged according to the application. Typically, the plates may be spaced 2 to 4 in (5cm to 10cm) apart and inclined at an angle between about 30 to 80' to the horizontal, a preferred angle being of the order of 60' to the horizontal. The plates may be supplied separately for installation in new or existing separator apparatus or may be provided in pre-assembled stacks or modules in a suitable supporting frame (not shown).

Figure 2 shows a thin, side sectional view of part of three separator plates according to the invention as they may be stacked in use.

Figure 3 shows a thin, side sectional view of part of five separator plates 22 according to the invention provided with ridges 24, 26 on the two surfaces respectively of the plate 22; the ridges may be V-shaped as described with reference to Figure 1 and in one embodiment, the ridges 24 are orientated in a direction similar to that shown in Figure 1 and the ridges 26 are orientated in a direction turned through 180'. With such an arrangement, it would be possible to separate from a liquid to be treated particles having a greater density than the liquid by means of the ridges 24 and an immiscible liquid of lower density than that of the carrier liquid, such as oil from water by means of the ridges 26.

Referring now to Figures 4 to 6, there is shown a separator apparatus 30 for separating solids from liquids, the solids having a greater density than that of the liquid to be treated. As shown in Figure 4, the separator apparatus 30 includes a single module 32 comprising a plurality of plates 10 mounted in a frame including wall members 34 and 35, the plates being arranged in spaced, parallel relationship and inclined to the horizontal at an angle of about 60 . The plates are so orientated that the limbs 12a and 12b of the ridges 12 slope downwardly from their associated apices 12c.

Liquid to be treated containing entrained solid particles is introduced into the apparatus 30 through inlets shown diagrammatically at 36 below the plates 12 and flows upwardly in the direction of the arrows 37 between the plates 10 and towards an outlet 38 formed by vertical walls 40, 42. As the fluid with entrained solid particles passes over the plates 10, the particles are caught by the ridges 12, migrate along the ridges towards the marginal areas 14, 16 and then travel down the areas 14, 16 and drop into collector troughs 44, 46 which extend longitudinally of the apparatus below the plates 12. Particles migrating down the two lowermost ridges 12 in Figure 4 do not fall into the collector troughs 44, 46 but re-enter the main stream of inlet liquid where it is believed they assist in the flocculation of particles in the main stream. The sludge in the collector troughs 44, 46 can be removed, by gravity for example, continuously or intermittently by operation of valves (not shown) in outlet pipes from the troughs and the sludge removal may be further assisted by the use of pumps (not shown).

Thus as the liquid/solid mixture passes up between the plates 12, the solids are separated out and the clarified liquid flows into the outlet channel 38 and can then be led away in any convenient manner for re-use or discharged to waste.

Thus, the use of the separator plates according to the invention provides the advantage that the separated solid matter is directed into the two troughs 44, 46 at each side of the stack of plates 10 in a module with the added advantage that the liquid inlet to the plates covers a relatively large area defined by the lower edges of the plates 10 intermediate the troughs 44, 46. Furthermore, as shown best at Figures 4 and 6, the troughs 44, 46 can be provided with inwardly sloping walls 44a, 46a respectively which assists in directing the upward flow of liquid to be treated. Thus the provision of plates 10, water inlet 36 and sludge collectors 44, 46, leads to a separator apparatus according to the invention which is both efficient and compact.

As shown the plates 10 are provided with V-shaped ridges 12 but such ridges could be obtained by the provision of two sets of plates side by side, one left-hand set (in Figure 4) having a plurality of ridges extending obliquely upwardly from left to right and another right-hand set having a plurality of ridges extending obliquely downwardly to the right. It will also be realised that other shapes can be selected for the ridges such as a continuous curve provided that solid particles caught by the ridges are caused to travel therealong towards an edge of the plate 10 to thus concentrate them for collection in a trough such as the troughs 44 and 46.

If two immiscible liquids, such as oil and water and/or a liquid containing solid particles of lower density, are to be separated, it is convenient to arrange the ridges 12 on the underside of the plates and to invert their orientation, that is to arrange the ridges so that their apexes are directed downwardly.

With such an arrangement, the lighter oil and/or the particles of lower density will be caught by the ridges and then migrate upwardly therealong on the undersurfaces of the plates and thence along the marginal areas 14 and 16 into collector channels 48 and 50 from which it can be run-off to be recovered or to be discharged in a safe and environmentally acceptable manner.

If the liquid contains both solid particles of higher density and another immiscible liquid of lower density, then the separator apparatus 30 could be provided with plates having ridges on both surfaces such as the plates 22 shown at Figure 3 with their ridges orientated as described with reference to Figures 4 to 6 and to the next preceding paragraph so that solid particles would be collected in troughs 44 and 46 and the lighter liquid in the channels 48 and 50, care being taken to ensure that the clarified liquid flowing into the reservoir 38 does not overflow into the channels 48, 50.

Referring now to Figures 7, there is shown a front, sectional view of part of a separator apparatus 52 according to the invention including four modules 54a to d, each comprising a plurality of separator plates 10 according to the invention, sludge collectors 56a to 56e, each provided with an outlet pipe 58a to 58e and an associated valve, or pump 60a to 60e for removing solid matter deposited in the collectors. As described with reference to Figures 4 to 6, a liquid to be treated is supplied to the apparatus at inlets depicted by arrows 62 and flows upwardly between the plates 10 the solid particles being caught by the ridges 12 and caused, as described, to migrate along the ridges, down the areas 14, 16 and into the troughs 56 while clarified liquid enters the outlet above the plates 10. The outlet could be as described with reference to Figures 4 to 6, that is an outlet defined by walls 40 and 42. It has been found that the walls 40, 42 serve to direct the clarified water inwardly as it nears the top of a plate and thus prevent any solid matter reaching the marginal areas 14, 16 from the upper ridges from being carried up and into the outlet.

The angles which the plates make with the horizontal, the angles which the ribs make with the direction of slope of the plates and thus with the direction of fluid flow and the spacing between the plates are interdependent with each other and depend on the properties of the materials being separated, the rates of flow and other factors. The results obtained are also affected by the dimensions and cross-sectional shapes of the ribs, as well as by other factors which may affect the smoothness of flow and the way in which the deposited material is collected.

The shapes and dimensions of the various parts could be determined by calculation or empirically.

WHAT WE CLAIM IS: 1. A separator plate having parallel side edges and a plurality of transverse ridges formed on at least one surface thereof, each ridge having a triangular cross-section and extending obliquely with respect to said edges.

2. A separator plate according to claim 1, in which said ridges are substantially parallel.

3. A separator plate according to claim I or 2, in which each transverse ridge is nonlinear and has a peak intermediate its ends.

4. A separator plate according to claim 3, in which each ridge is substantially Vshaped.

5. A separator plate according to claim 1, 2, 3 or 4, in which said ridges extend across the width of the plate to the side edges thereof.

6. A separator plate according to claim 1, 2, 3 or 4, in which the free ends of the ridges terminate at positions spaced from the side edges of the plate to provide a substantially planar marginal area along each side of the plate.

7. A separator plate according to claim 3 or claim 4, 5 or 6, as dependent upon claim 3, in which the ridges are arranged substantially parallel to each other with their apexes along a generally straight line which is substantially parallel to the side edges of the plate.

8. A separator plate according to claim 7 as dependent upon claim 6, in which each end of said ridges is provided with a curvature which extends in a direction closer to a line drawn parallel with a line drawn through said apexes than do main portions of each said ridges intermediate its apex and associated ends.

9. A separator plate according to any one of the preceding claims, having a plurality of transverse, obliquely extending ridges on both surfaces thereof.

10. A separator plate according to claim 9, as dependent upon claim 3, in which the ridges on both surfaces of the plate are so orientated that their peaks extend in opposite directions.

11. A separator plate according to any preceding claim, in which the ridges are of right triangular cross-section and so arranged that, in use, the right-angled side of the triangle is uppermost.

12. A separator plate according to any one of the preceding claims which is generally rectangular.

13. A separator plate according to any one of the preceding claims of metal.

14. A separator plate according to any one of claims I to 12 of a plastics or other non-metallic material.

15. A separator plate substantially as hereinbefore described with reference to and as illustrated in Figures 1 and 2 or Figure 3 of the accompanying drawings.

16. A plurality of plates according to any one of the preceding claims assembled in a framework in spaced, substantially parallel relationship to form a module for incorporation in a separator apparatus, the plates being so orientated in the module that, in use in separator apparatus, they are inclined to the horizontal.

17. Separator apparatus comprising a plurality of plates according to any one of the preceding claims arranged in spaced, substantially parallel relationship and inclined to the horizontal, and inlet means for a fluid to be treated situated below said plates such that the fluid can flow upwardly between said plates to an outlet above said plates.

18. Separator apparatus according to claim 17, in which said separator plates are inclined at an angle between 30 and 80 .

19. Separator apparatus according to claim 18 in which said angle is about 60".

20. Separator appratus according to claim 17, 18 or 19 as dependent upon claim 3, for separating solid particles from a liquid, in which the density of the particles is greater than that of the liquid, and wherein the plates are arranged with the ridges on their upper surfaces such that the peak of each ridge is higher than its associated free ends.

21. Separator apparatus according to claim 20 further comprising collector receptacles below the plates for receiving solid particles separated from the fluid.

22. Separator apparatus according to claim 21, in which the collector receptacles are in the form of troughs positioned below the free ends of said ridges to receive solid particles separated from said liquid.

23. Separator apparatus according to claim 22, in which said troughs are arranged longitudinally of the apparatus in spaced, parallel relationship and facing walls of a pair of troughs below the side edges of the said plurality of plaits are inclined inwardly and upwardly.

24. Separator apparatus according to any one of claims 17 to 23 as dependent upon claim 3 for separating solid particles from a liquid in which the density of the particles is less than that of the liquid and/or for separating two immiscible liquids, and wherein the plates are provided with ridges on their lower surfaces such that the peak of each ridge is lower than its associated free ends.

25. Separator apparatus according to claim 24, comprising channels arranged along the top edges of said plates over the free ends of said ridges to receive said particles and/or the liquid of lower density.

26. Separator apparatus substantially as

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. empirically. WHAT WE CLAIM IS:

1. A separator plate having parallel side edges and a plurality of transverse ridges formed on at least one surface thereof, each ridge having a triangular cross-section and extending obliquely with respect to said edges.

13. A separator plate according to any one of the preceding claims of metal.

19. Separator apparatus according to claim 18 in which said angle is about 60".

26. Separator apparatus substantially as

hereinbefore described with reference to and as illustrated in the accompanying drawings.