GB2308987A

GB2308987A - self cleaning liquid filter

Info

Publication number: GB2308987A
Application number: GB9606113A
Authority: GB
Inventors: Kenneth Albert Stagg
Original assignee: Individual
Current assignee: Individual
Priority date: 1996-01-11
Filing date: 1996-03-22
Publication date: 1997-07-16
Also published as: GB9600592D0; GB9606113D0

Abstract

A filter uses a bed of floating beads 5 in a chamber 1. Liquid to be filtered enters at the bottom via pipe 6 and flows upwardly through the chamber, forcing the beads together beneath a filter screen 12, thus forming a filter bed. Solids 11 fall to the bottom of the apparatus and into a sump 4. Sump 4 is normally closed by a ball valve 2 but when flow starts this is drawn up, opening the sump. Ball valve is prevented from rising too far by screen 10. When the through flow of liquid is stopped, siphon 14 allow liquid to drain out of chamber 1. The floating bodies 5 are thus allowed to spread out and any trapped material falls to the bottom. Freeing of trapped material can be enhanced by passing air through the liquid or by back flushing in known manner.

Description

SELF CLEANING LIQUID FILTER This invention relates to a Self Cleaning Water or Liquid Filter The Sand Filter is the oldest known method of cleaning water or liquid.

See Fig. 1. Dirty water enters at valve "A" and is simply passed through a bed of sand by gravity or by pressure and descends through the sand.

Clean water leaves from a position lower down or at the bottom of the sand bed at valve "B", leaving a build up of sludge on the surface necessitating expensive cleaning by mechanical means or backflushing.with clean liquid.

The present invention uses tightly packed floating beads as the filter medium., which are automatically cleaned when liquid flow ceases, and the beads become unpacked A specific embodiment of the invention will now be described by way of example with reference to the accompanying cross-sectional drawings in which:- Figure 2 shows a cross-sectional drawing of the self-cleaning liquid filter component parts new and as yet unused.

Figure 3 illustrates the filter in use with fluid flowing through it as shown by A 1 and A2.

Figure 4 shows the cessation of the fluid flow causing the inlet fluid level to drop to point A in the inlet pipework, followed by a further level drop to B as fluid is slowly syphoned off by 14, allowing the freed sludge to accumulate in sludge bucket 4.

Key to to the drawings: see Figure.S. The filter comprises filter body 1 a slightly weighted sealer ball 2, which will float, the lower conical chamber 3 the sludge bucket 4 a large quantity of filter beads, which will float 5, the inlet pipework for the liquid Al to be filtered 6, dirty liquid to be filtered 7, (as shown on Figure 3), the outlet pipework for liquid A2 after filtering 8, the sludge line 9 for directing of solids A3, the sealer ball entrapment grid 10, falling solids 11 (as shown on Figures 3 & 4), trapped solids 11A, filtered solids 11B, gauze filter 12, upper chamber 13, small bore syphon pipework 14, chemical treatment access 15, liquid sampling access 16.

Referring to the drawings, Fig.2 shows the filter dry.

Figure 3 illustrates the filter beads 5 forming a filter bed as they float upwards to their highest position when liquid enters through 6.

Simultaneously, the slightly weighted sealer ball 2 floats off its bottom position, allowing sludge 11A to enter the sludge bucket 4, and the syphon line 14 to be filled with clean newly filtered liquid. As long as liquid continues to flow, solids 11B are trapped on the underside of the filter bed.

Figure 4. When the flow of liquid ceases, the slow syphon 14 allows the liquid level in the filter body 1 to drop, resulting in the filter bed 5 unpacking, releasing the filter bed, so allowing the sludge 11 to fall by gravity into the sludge bucket 4.

Claims

1. A liquid filter which automatically self cleans when forward flow of liquid is cut off.

2. A liquid filter as claimed in Claim 1 wherein more rapid cleaning is achieved by backflushing the filter bed with clean liquid to drain 9.

3. A liquid filter as claimed in Claim 1 wherein the slow syphon 14 allows the liquid level in the filter body to drop thereby unpacking the filter bed beads.

4. A liquid filter as claimed in Claim 1 wherein injection of a gas into the filter bed would result in unpacking of said beads.

5. A liquid filter as claimed in Claim 1 wherein should the shape of the filter body be changed as in Figure 6a unpacking of filter beads would occur more rapidly.

6. A liquid filter as claimed in Claim 1 wherein should the shape of the filter body be changed as in Figure 6b unpacking of filter beads would occur more rapidly.

7. A liquid filter as claimed in Claim 1 wherein the shape of the lower conical chamber could be changed as in Figure 7 thereby easing discharge or sludge.

8. A liquid filter as claimed in Claim I wherein the shape of the upper chamber could be challgex3 as in Figure 8a or 8b thereby allowing speedier uiscllargv of clean liquid.

9. A liquid filter as claimed in Claim 1 wherein the liquid treatment access 15 could be inserted directly into the filter body thereby allowing more thorough chemical treatment to be applied.

l 0. A liquid filter as claimed in Claim I wherein the sludge bucket could be valved off from the lower conical chamber thereby becoming removable allowing easier access to sludge for monitoring/ disposal/ reuse as applicable.

11. A liquid filter as claimed in Claim 1 wherein the sealer ball is retained in the lower clamber by either an ann or sliding rod attachment.

12. A liquid filter as claimed in Claim 1 whereby the gauze filter is replaced by a sintered plate.

13. A liquid filter as claimed in Claim l whereby the spherical beads are replaced by objects, which can be uniformly shaped or mixed, the sizes of which may also be uniform or various.

14. A liquid filter as claimed in Claim l whereby the dosing point for treatment may be located either in the upper chamber or in a position on the filter body as shown on Figure 5.

15. A liquid filter as claimed in Claim 1 whereby a sampling point is located in the outlet pipework 16 A liquid filter as claimed in Claim l whereby the sample obtained from the sampling point will be used to automatically control the dosing required.

17 A liquid filter as claimed in Ciaim l whereby the syphoning process may be speeded up by pump action 18. A liquid filter as claimed in Claim 1 whereby the fixing of the upper chamber on the filter body may be rapidly unclamped for maintenance, addition of extra beads etc.