GB2252737A - Separation devices - Google Patents

Abstract

An oil water mixture is applied to a first set of discs 5 spaced along a rotary shaft 6, the oil adheres to the discs and the water passes between them. The oil is transferred from discs 5 to successive sets of intercalated discs 9, 10 and finally removed by scrapers 15 and/or heater 16, which could be located within shaft 12. The mixture may be directed on to discs 5 by floor 3 or by spraying, or discs 5 are largely submerged (Fig. 2). A magnetic separator (Fig. 5) comprises first and second sets of discs, also intercalated, and each disc is divided into sectors which are alternately magnetised and demagnetised as they rotate, to pick up magnetisable material at one location on their peripheries and discharge it, to an outlet or on to the next set of discs, at another location. The separator includes a third set of non-magnetic discs, and the combined magnetic separation and screening enable large and small, magnetisable and non-magnetisable particles in machine coolant to be discharged at four separate outlets. <IMAGE>

Description

"separation Devices and methods" It is an object of this invention to provide a device an a method for the separation of liquid mixtures, such as oil and water. Generally, the separation will be in respect of different characteristics of the materials, such as specific gravity/density, adhesion and viscosity of two mixed but separate liquids, or even of solid particles dispersed in a liquid.

From one aspect of the invention there is provided a device for the separation of liquid mixtures wherein a liquid input reservoir leads to a set of discs carried by a rotatable shaft whereby one of the liquids adhering to the discs will be carried out to a region where a barrier member is provided to remove that liquid from the discs to direct it to a first outlet section, whilst another liquid or particles in the mixture fall through the gaps between the discs into a second outlet section.

Desirably there will be a number of sets of interleaved discs carried on separate shafts leading to the barrier member. The barrier member can be comb-like in form and can consist of either rigid or flexible material which will be capable of wiping the liquid from the discs.

The input reservoir reduces gravitational forces on the input mixture and also absorbs any oscillation of the incoming flow. A horizontal exit from the reservoir into the discs provides an even flow over all the discs thus providing good efficiency. If the input flow is as even as possible the chance of contamination of the output is kept down.

In an alternative arrangement a set of discs (or the first set of discs in an array) will dip into a reservoir so that one of the liquids can adhere to the rotating discs and be carried off towards the barrier member.

In another possible arrangement there are two sets of interleaved discs adjacent, portions of which are magnetically charged so that magnetic products can be carried over from the first set of discs to the second set of discs whilst other sections of the two sets of discs are selectively discharged to allow the magnetic particles to be released at predetermined positions.

The invention further extends to a method of separating liquid mixtures by passing the mixture over a separation device of this invention as hereinbefore defined.

The invention may be performed in various ways and preferred embodiments will now be described, by way of example, and with reference to the accompanying drawings, in which: Figure 1 is a diagrammatic section through one form of liquid mixture separation device of the invention, with one input and two outputs; Figure 2 is a diagrammatic section through another example of a separation device of this invention; Figures 3 and 4 are views of discs and heating elements for use in the devices of Figures 1 and 2; Figure 5 is a diagrammatic section through a third embodiment of the invention for separating particles from a liquid; Figure 6 illustrates an array of discs for use in the embodiments shown in the previous Figures; Figures 7 to 9 show alternative arrangements of spikes formed on the shafts of the arrangement of Figure 6; and Figures 10 to 12 are illustrations of still further embodiments of the invention.

In the device shown in Figure 1 a liquid mixture of oil and water enters the device 1 via inlet 2 and thus falls into a reservoir 3. The walls of the reservoir are at their lowest point at 4 which delivers the mixture on to a first set of discs 5 separably spaced on a shaft 6. The maximum level of fluid is important and is indicated at 7. The flow into inlet 2 should be controllable to maintain the correct level, to ensure optimum efficiency of the device.

When the mixture comes into contact with the discs 5, oil adheres to the edge of the discs whilst water passes through the gaps between the discs and is collected in the catchment area 8. The rotary action of the discs conveys the oil from the first set of discs 5 onto subsequent sets 9 and 10 carried on shafts 11 and 12, with the disc sets interleaved with one another and rotating in the direction of the arrows 13. By this means the oil is moved towards the catchment area 14 where devices 15 are placed to remove the oil from the discs. These devices comprise barrier members, which can be made of flexible or solid material.

Heating elements 16 can also be included to assist in this removal of the oil from the discs 10. Figure 3 shows the inclusion of heating elements 16 into the shaft 12. For the separation of oil and water, it would be expected that only the shaft above catchment area 14 would have the inclusion of heating elements 16. Figure 4 shows the inclusion of a heating element 16 into a barrier member 15.

Figure 2 shows a device where the first row of discs 5 are mostly below the level of the liquid. This device could be built into a floating platform 18. The operation is similar to the device shown in Figure 1, the main difference being the slope of the lines of the discs 5, 9A, 9B, 9C and 10. (This may restrict the device to separating heavy oil only).

Figure 5 illustrates a four outlet device, consisting of three sets of discs. The first two sets of discs 26, 28 are of a magnetic type, enabling the device to separate magnetic particles from non-magnetic particles and also to separate two particle sizes. The arrangement incorporates electro-magnets which are built into the discs in sections.

with the discs in the positions shown, only sections F, A, G, H, I, and J would be magnetised (via bushes on the support spindles for the discs). As the discs are rotated in the directions shown the magnets entering sections B and K will be switched off, while the magnets entering sections E and L will be switched on. only the upper portions of the discs will therefore be magnetised and will carry over magnetic particles. This enables magnetic particles to be separated from non-magnetic particles. The main use of this device would be as as filter on a central machine coolant system. Where the coolant enters the separator at an inlet 21 and flows onto a region 22 of the discs between shafts 23 and 24, non-magnetic particles of a small size or just the coolant pass through to an outlet 25.Larger non-magnetic particles will tumble off a first set of discs 26 to be collected in an outlet 27.

Magnetic particles being introduced onto the first set of discs 26 will be transferred to the second set 28, and are then carried over to come into contact with a third set 29. Small magnetic particles will be able to pass between the second and third sets 28, 29 and be collected in an outlet 30. The larger particles will be carried over the third set 29 and will collect in an outlet 31.

The diameter and position of the sets of discs in relation to each other is dependent upon the expected use of the device. In the arrangement shown in Figure 5 the shaft 24 is mounted higher than shaft 23. Discs 28 have a larger diameter than discs 26. These two factors result in a rotating barrier for particulate material which is too large to pass between the gaps in the inter-meshed discs of 26 and 28 which causes such large particles to tumble within the region 22. The result of this tumbling would be the division of large particles into magnetic and non-magnetic.

This is achieved by the attraction of magnetic particles to the edge of the discs 28 and their subsequent transportation to region 32 in which these large magnetic particles then come into contact with the set of discs 29.

The position of the set of discs 29 is optional, dependant on the required separation of magnetic particles between outputs 30 and 31. In Figure 5 the sets of discs 28 and 29 are shown inter-meshed, but this need not be necessary. A gap here would define the maximum size of magnetic particles in outlet 30 and the minimum size of particles in outlet 25. In fact there could even be a gap between discs 26 and 28. A barrier member 33 is shown inter-meshed with discs 28 to provide a barrier between outlets 30 and 31. A heater is shown at 34.

Figure 6 illustrates several sets of interleaved discs 5 etc. on their respective shafts with variable spacing between the discs from one set to the next. Spikes 35 protruding from the shaft help with the cleaning of the device. The increased spacing of the discs to produce different grades of output would remove some of the ability of the machine to clean the space between inter-meshed discs. The spikes 35 are to be spread out over the length of a shaft in such a way as not to allow contact with a spike or discs, on an adjacent shaft. The spacing of the spikes should also take into consideration the angle of the spikes in relation to other spikes on the same shaft.

Whilst the spikes are shown in Figure 6 only at 1800 to each other, in practice the best arrangement to avoid excessive loading being placed suddenly on a shaft, would be to space out equally the number of spikes throughout 3600, so a shaft requiring 4 spikes would have them spaced at 900 to each other. These spikes could protrude straight out at 900 to the shaft as shown in Figure 7, or curve out from the shaft as shown in Figures 8 and 9.

Whilst the arrangement shown in the previous Figures incorporates a series of sets of discs, for the purpose of separating liquids, it would be feasible to employ just one set of discs as shown in Figure 10. Here liquid entering the inlet passes through a reservoir 36 onto a set of discs 37 carried on a single shaft 38. Oil sticks to the discs and is carried round to a series of barrier members 39 which separate off the oil and direct it into an outlet section 40. Water will cascade down between the discs from the reservoir and fall into a separate outlet section 41.

As shown in Figure 11, the liquid could be delivered by means of a sprinkler device 42 to the set of discs 43. As Figure 12 shows the sprinkler 42 can direct the spray of liquid only into an inlet reservoir 44.

Claims (8)

1 A device for the separation of liquid mixtures wherein a liquid input reservoir leads to a set of discs carried by a rotatable shaft whereby one of the liquids adhering to the discs will be carried away to a region where a barrier member is provided to remove that liquid from the discs to direct it to a first outlet section, whilst another liquid or particles in the mixture fall through the gaps between the discs into a second outlet section.

2 A device according to Claim 1, wherein there is a number of sets of interleaved discs carried on separate shafts leading to the barrier member.

3 A device according to Claim 1 or Claim 2, wherein the barrier member is comb-like in form and consists of either rigid or flexible material which will be capable of wiping the liquid from the discs.

4 A device as claimed in any one of Claims 1 to 3, wherein a horizontal exit from the reservoir leads to the discs.

5 A device according to any one of Claims 1 to 4, wherein a set of discs, or the first set of discs in an array, dips into the reservoir so that liquid can adhere to the rotating discs and be carried off towards the barrier member.

6 A device for separating magnetic particles out of - liquid mixture and comprising two sets of interleaved discs, adjacent portions of which are arranged to be magnetically charged so that magnetic particles can be carried over from the first set of discs to the second set of discs whilst other portions of the two sets of discs are selectively discharged to allow the magnetic particles to be released at predetermined positions.

7 A device for separation of constituents of liquid mixtures substantially as herein described with reference to the accompanying drawings.

8 A method of separating liquid mixtures by passing the mixture over a separation device of this invention as defined in any one of Claims 1 to 7.