NO138645B - DEVICE FOR SEPARATION OF PRECIPITATION AND / OR FLOTATION COMPONENTS FROM A LIQUID - Google Patents

Description

The present invention relates to a device for separation

of light, i.e. floating and heavy, i.e. sinking components from a liquid with an arrangement of substantially superimposed partitions such as plates or trays from separation passages sloping upwards or downwards in the direction of flow to if at least one end of these passages is provided with means for conveying the separated components from the liquid to a collection chamber.

With such devices, it is achieved that the components that flow along the tops of the thus separated passages, and/or components that settle to the bottom in the valleys of these passages, can be largely kept separate from the liquid that is supplied to the upper end of the structure as well as from the waste liquid at the lower end. This prevents the separated components from mixing again due to turbulence.

A shortcoming of such known devices is that at the end of the passages the total flow passage is reduced to about half of the total cross-section, which can be particularly disadvantageous at the supply end for the liquid to be treated, because the separation effect can only be fully achieved at a certain distance from the inlet, i.e. when the beam has diverged sufficiently to fill the construction's effective cross-section completely, which means that the effective length is significantly reduced.

The invention aims to remedy this deficiency and this is achieved by the partition walls being located in a tank or a pool between a supply chamber and the collection chamber and that the devices consist of guide plates (9, 10) which are essentially arranged parallel to each other and across the dividing walls of the separation passages in at least one of these chambers.

Particularly preferred embodiments of the invention will now be explained in more detail with reference to the drawings, where: Fig. 1 and 2 are schematic elevations of separator sets consisting of corrugated plates with different arrangements of the guide plates. Fig. 3 is a simplified cross-section through a separator device with such guide plates. Fig. 4 shows a broken piece of a guide plate on a larger scale in the plane.

Fig. 5 shows a special design of a plate set.

Fig. 6 shows in perspective a broken piece of guide plates with a special design. Fig. 7 shows a further modification of such a guide plate. Fig. 8 is a cross-section through part of one end of a modified design of the device in fig. 3. Figs. 9A and 9B show schematic cross-sections through two different slotted walls for the device in fig. 8.

The one in fig. 1 and 2 shown plate set comprises a number of corrugated plates 1 with peaks 2 and valleys 3. When, as shown in fig. 3, such a batch of corrugated plates is placed at an angle in a vessel 4 which is divided by a transverse wall 5 into two chambers 6 and 7, an upward flow can be produced in the plate batch 1 when the chamber 6 acts as a supply channel, while a downward directed current when the chamber 7 serves as a supply chamber.

When the liquid flowing through the set of plates contains light (i.e. liquid) components, these will collect near the peaks 2 of the plates 1 corrugations, while heavy (i.e. settling) components will collect in the valleys 3. As a result of the inclined position of the set, the floating components will move upwards to the chamber 7, and the settling components will move downwards to a deposition chamber 8 which communicates with the chamber 6. The former components will float on the surface of the liquid in the chamber 7, while the latter can be emptied from the bottom of the chamber 8. The direction of flow in batch 1 thereby depends on the predominant component according to which this should preferably be separated in countercurrent.

In fig. 1 shows guide plates 9 connected with tops of the plates 1 arranged above each other. These guide plates are e.g. placed, as shown in fig. 3, in the chamber 7 and can extend over its full length. It has been shown that many liquid components, e.g. oil separated from water, is inclined to move upwards along such guide plates in the flotation chamber 7 after they have left the tops of the passages between the plates 1.

Such guide plates then control the liquid components, but do not occupy any significant space and thus do not limit the flow of the carrier liquid or, when the chamber 7 is also a supply chamber, of the liquid to be treated. At the other end of the plate set, in the chamber 6, similar guide plates can be arranged, or as shown, these 10 can be set so that they engage in the plates 1 valleys 3.

In some cases, the adhesion to such guide plates may be less strong. It may then be advisable to arrange them as shown in fig. 2, whereby the guide plates come into contact with the corrugated plates 1 in the transition between their peaks 2 and adjacent valleys 3. The guide plates then suppress turbulence and lines

the separated component more or less calmly longitudinally

its surface.

Fig. 4 shows a broken piece of a preferred form of the end edge of such a guide plate 9 or 10. In this case, the edge which is to be in contact with the plates 1 is provided with V-shaped and preferably symmetrical incisions 11. When these are symmetrical, the guide plates do not have a preferred current direction, which can simplify the rate.

As mentioned, separation of heavy (i.e. settling) components to the valleys 3 and/or light (i.e. liquid) components to the peaks 2 takes place during the flow of the treated liquid through the passages in the plate set 1. This separation effect can be improved by designing steep connection parts between the peaks and valleys of the passages, which also prevents re-mixing. For conventional plate sets, supported in the transitions between peaks and valleys, as shown in fig. 2, the steepness of the slope is limited when it is only to be supported with slotted guide plates or the like, as otherwise transverse forces on the guide plates and the corrugated plates may be too great. It should then be taken into account that the separation plates 1 and also the guide plates 9, 10 are preferably made of flexible plastic material. When, however, the deposit is as shown in fig. 1, no such difficulties arise. Slopes above 45° may be allowed for the transitions between peaks and valleys.

Fig. 5 shows a design of corrugated plates with a steep slope, in which the peaks 2 are narrower than the valleys 3. When

the peaks are narrow, the contact surfaces with the adjacent plate 1 will be smaller, with the same amount of liquid component, than with a wide peak, so that the friction will also be smaller, which causes a quiet discharge of this component. For settling components, however, a wide valley can be beneficial to prevent blockage at the outlet end. By designing the plates as shown in fig. 5, both requirements can be satisfied, while at the same time a steeper slope can be achieved. and further, the space between the transitions can be significantly narrower than between peaks and valleys, so that the contact surface where recombination takes place is reduced.

It may sometimes be necessary by means of such guide plates to suppress turbulence in the developing liquid stream at the point where the separated component leaves batch 1. Arrangements for this purpose are shown in fig. 6 and 7. These comprise a comb-shaped plate 12, shown dashed in fig. 3, for a settling component, in which case the plate is connected to the underside of the set 1 with the end of the comb teeth, while the guide plates 10 are then made shorter and are inserted symmetrically into the spaces 13. The teeth on the comb plate increase the flow resistance for the liquid between the guide plates 10 in such a way that the liquid is forced towards the tops of the passages in batch 1. If it is a light (i.e. liquid) component, a similar plate can be placed in the chamber 7 near the top of batch 1. In this case, the guide plates can continue towards the outer edge of the spaces 13, or may be placed at some distance from there.

To prevent as much as possible inflow into the passages in rate 1

in the vicinity of the guide plates 10 of the liquid to be treated, it can, as shown in fig. 6, additional transverse plates 14 are inserted largely parallel to the guide plates 10. As shown in fig. 3, such guide plates can have an inclination in relation to the end surface of the set 1. These transverse plates 14 can be connected to the guide plates 10. As

shown in fig. 3 and 6, the transverse plates 14 do not extend further than the cam plate 12. However, the transverse plates 14 can optionally be extended past the cam plates 12.

As shown in fig. 3, the comb plate 12 does not extend to the wall of the vessel 4. This is to provide a passage to the collecting chamber 8 for a component that has already been bottomed out in the chamber 6. Furthermore, the edges of the teeth of the comb plate 12 can be provided with inclined edge flanges 15, which shown in fig. 7, by means of which the sediment moving downwards along the plates is forced against the guide plates 10 in order to prevent the spread of this stream of sediment and thus reduce the tendency for re-mixing due to turbulence. In addition, the flanges 15 suppress upward liquid flow, which could have a disruptive effect on the separation. If you are dealing with upwardly floating components, similar devices can be used, which are then of course directed in the opposite direction. If a light component is supplied to the chamber 7, difficulties may arise when the liquid to be treated is supplied across the plates 9, e.g. by means of a cross wire. It is usual to supply the liquid by means of an overlap which delimits the chamber 7 on one side, but then the layer of the separated component floating on the liquid surface is disturbed, and re-mixing with the liquid is likely. If, on the other hand, the weir is closed, the liquid component will spread to the supply line, and the guide plates 9 which would then extend into the supply stream, will cause turbulence, as the flow direction will be changed quite abruptly by the guide plates.

Fig. 8 shows a slotted partition wall 16 according to the invention, which prevents the transverse flow from turning inwards by the edges of the guide plates 9. Although such a slotted wall reduces the effective flow cross-section, this reduction is acceptable if only the slotted wall from the adjacent end of batch 1 is sufficiently large that a uniform flow completely fills the cross-section at the inlet to batch 1.

If the supply takes place by means of a transverse channel 17 (fig.

8), the upper side of the slotted wall .16 can extend over

the normal liquid level in the channel 17 and the chamber 7, while the upper ends of the slits 18 in the wall 16, which are usually directed generally vertically, do not extend as far as the layer 19 of the separated component floating on the liquid.

Fig. 9A shows a section through the partition wall 16, fig. 8, with the vertical slits 18. Horizontal or inclined slits 18 can also be used. Fig. 9B shows a modified design comprising two slotted walls 16 and 16'; whose slits 18 are substantially parallel but arranged staggered as shown,

and thus form labyrinth passages that contribute to achievement

of uniform current distribution at the entrance to the separator set 1.

Many modifications are possible within the scope of the invention. The guide plates 9 and 10 can e.g. set obliquely when the peaks and valleys are not set directly above each other. The corrugated plates can be replaced by corresponding gutters and in certain cases to nn more* ri of nine athp nlaters.

Claims (12)

1. Device for separating light, i.e. floating and heavy, i.e. sinking components from a liquid with a device of substantially one above the other arranged partition walls as plates or trays from separation passages sloping upwards or downwards in the direction of flow to if at least one at the end of these passages, organs are arranged to lead the separated components from the liquid to a collection chamber, characterized in that the partitions (1) are located in a tank or a basin between a supply chamber and the collection chamber and that the guide devices consist of guide plates (9, 10) which are essentially arranged parallel to each other and across the separating walls of the separation passages in at least one of these chambers. 2. Device according to claim 1 where the partition walls of the separation passages are shaped so that these passages alternately have peaks and valleys, characterized in that at least part of the guide plates (9, 10) are in contact with the partition walls (1) in the chrome either of the peaks (2 ) or the valleys (3) of these passages (Figure 1). 3. Device according to claim 1, in which the partition walls of the separation passages are shaped so that the passages alternately have peaks and valleys, characterized in that at least part of the guide plates (9, 10) are in contact with these partitions (1) at the transition between adjacent peaks ( 2) and valleys (3) (figure 2). 4. Device according to one of claims 1 to 3 in which the guide plates also serve as supports and spacers for the partitions, characterized in that the guide plates (9, 10) are equipped with essentially symmetrical V-shaped notches (11) (figure 4). 5. Device according to claim 2 or 4, characterized in that the slope of the dividing walls (1) in the points exceed 45°. 6. Device according to claim 5, characterized in that the peaks (2) and the valleys (3) have different widths (figure 5). 7. Device according to one of claims 1 to 6, characterized by a comb-shaped plate (12) whose teeth are arranged at the outlet end of one of the separated components and symmetrically between the guide plates (10), and which is in contact with the separating device's intermediate peaks and valleys (figures 6, 7). 8. Device according to claim 7, characterized by transverse plates (14) parallel to the front edges of the guide plates (10) and in connection with the ends of the opening (13) between the teeth of the comb-shaped plate (12). 9. Device according to claim 8, characterized in that these transverse plates (14) are placed on the free edges of the guide plates (10), almost perpendicular to these (figure 6). 10. Device according to one of claims 7 to 9, characterized by guide strips (15) on the side edges of the teeth of the comb-shaped plate (12) oblique to its plane. 11. Device according to any one of claims 1 to 7 for separating suspended matter from a*liquid which is led to the upper end of the dividing wall (1), characterized in that substantially perpendicular to the guide plates (9) near their free edges in the supply chamber ( 7) is placed at least one transversely slotted plate (16) whose slots (18) are parallel to the open passages between the guide plates (9) (figure 8). 12. Device according to claim 11, characterized in that the slotted plate (16) separates a liquid supply channel (17) from the supply chamber (7), the upper ends of the slots (18) being below the normal liquid level in the supply chamber (7).