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Patent Searching and Data


Title:
CLARIFIER
Document Type and Number:
WIPO Patent Application WO/2019/016755
Kind Code:
A1
Abstract:
A clarifier for removing entrained fines from a solution from a plant, the clarifier consisting of a fines settling system comprising:- a chamber (12); a filter compartment (34) comprised by a pair of spaced wire screens (32) which are located midway along the height of the chamber (12) and which retain filter media therebetween; a settling compartment (36) in the chamber below the filter compartment, having a base (14) which is sloped downwardly to lead to a discharge outlet (16) whereby in use fines which settle on the base can be discharged through the discharge outlet to waste; a feed line (42) for solution from the plant leading to the chamber (12) below the filter compartment; and an overflow compartment (40) that in use receives the solution that has passed through the filter compartment and from which solution is passed for further use.

Inventors:
KUKARD RUAN (ZA)
SMIT ABRAHAM BAREND (ZA)
BEYLEFELD BAREND JACOBUS (ZA)
DU PREEZ CHARL JAN (ZA)
Application Number:
PCT/IB2018/055388
Publication Date:
January 24, 2019
Filing Date:
July 19, 2018
Export Citation:
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Assignee:
KUKARD RUAN (ZA)
SMIT ABRAHAM BAREND (ZA)
BEYLEFELD BAREND JACOBUS (ZA)
DU PREEZ CHARL JAN (ZA)
International Classes:
B01D21/02; B01D36/04
Foreign References:
AU2006222735A12007-04-26
US3482694A1969-12-09
US5958240A1999-09-28
US4396506A1983-08-02
US4192746A1980-03-11
AT395410B1992-12-28
Attorney, Agent or Firm:
GALGUT, John (ZA)
Download PDF:
Claims:
Claims

1 A clarifier for removing entrained fines from a solution from a plant, the clarifier consisting of

a fines settling system comprising:- a chamber;

a filter compartment located midway along the height of the chamber, the filter compartment being comprised by a pair of spaced wire screens which are adapted in use to retain filter media therebetween;

a settling compartment in the chamber below the filter compartment, the base of the chamber, which forms the bottom of the settling compartment, being sloped downwardly to lead to a discharge outlet whereby in use fines settle on the base and can then be discharged through the discharge outlet to waste or product capture;

a feed line for solution from the plant leading to the chamber below the filter compartment; and

an overflow compartment that in use receives the solution that has passed through the filter compartment and from which solution is passed for further use.

2 A clarifier as claimed in claim 1 wherein the discharge outlet is connected to a fines receiver.

3 A clarifier as claimed in claim 2 wherein the discharge outlet is connected to a fines discharge pump for drawing the settled fines from the settling compartment and delivering the settled fines into a fines receiver. 4 A clarifier as claimed in claim 2 or claim 3 wherein the fines receiver is a fines bag.

5 A clarifier as claimed in any one of the preceding claims wherein in use filter compartment contains low-density polyethylene (LDPE) beads to form a suspended filter bed through which the solution may pass and be filtered.

6 A clarifier as claimed in claim 5 wherein the beads comprise between 40% and 60% by volume of the filter compartment.

7 A clarifier as claimed in claim 6 wherein the beads comprise 50% by volume of the filter compartment.

8 A clarifier as claimed in claim 6 or claim 7 wherein the beads are in the shape of cylinders.

9 A clarifier as claimed in claim 8 wherein the beads are in the shape of 3 x 4mm cylinders.

10 A clarifier as claimed in any one the preceding claims further comprising a backwash bar entering filter compartment.

11 A clarifier having parts arranged and operating substantially as hereinbefore described and as illustrated in the drawing.

Description:
CLARIFIER

[0001] This invention relates to a clarifier for removing entrained fines from solution.

[0002] According to one aspect of this invention, there is provided a clarifier for removing entrained fines from a solution from a plant, the clarifier consisting of a fines settling system comprising:- a chamber;

a filter compartment located midway along the height of the chamber, the filter compartment being comprised by a pair of spaced wire screens which are adapted in use to retain filter media therebetween;

a settling compartment in the chamber below the filter

the base of the chamber which forms the bottom of the settling compartment, the base being sloped downwardly to lead to a discharge outlet whereby in use fines settle on the base and can then be discharged through the discharge outlet to waste or product capture;

a feed line for solution from the plant leading to the chamber below the filter compartment; and

an overflow compartment that in use receives the solution that has passed through the filter compartment and from which solution is passed for further use for example back to the plant or to the feed line.

[0003] The discharge outlet is preferably connected to a fines discharge pump for drawing the settled fines from the settling compartment and delivering the settled fines into a fines receiver which is conveniently a fines bag. [0004] The system when used preferably contains low-density polyethylene (LDPE) beads contained in the filter compartment to form a suspended filter bed through which the solution may pass and be filtered. The beads preferably comprise between 0% and 60% and preferably 50% by volume of the filter compartment.

[0005] An embodiment of the invention will now be described by way of example with reference to the accompanying drawing.

[0006] In the drawing there is shown a diagrammatic view of a fines settling system of the invention.

[0007] The fines settling system 10 comprises a main parallelipipedal chamber 12 having a pyramid sloped bottom wall 14 with its lower point 16 at one sidewall 18 of the chamber 12. At this lower point 16 there is an out-let 20 controlled by a valve 22 leading through a conduit 24 to a fines discharge pump 26 which when operated pumps the settled fines into a discharge fines bag 28. When the bag 28 is filled, it is replaced by a new bag and it is taken away.

[0008] Spanning the upper portion of the chamber are a pair of vertically spaced horizontal wedge wire screens 32 mounted on opposite sides of the chamber 12 and defining between them a filter compartment 34. The filter compartment 34 is filled with 50% by volume of LDPE beads. These beads are in the shape of 3 x 4 mm cylinders. [0009] The space 36 within the chamber 12 below the filter compartment 34 will form a settling compartment 36 as will be described more fully below.

[0010] Above the filter compartment 34 there is an overflow space 38 which leads to an overflow compartment 40 which is located beside the chamber 12.

[0011] The screens 32 are of such a size that they prevent filter media from escaping out into the overflow space 38 or settling into the settling

compartment 36.

[0012] A feed line 42 from a feed (not shown) enters into the chamber 12 through an inlet port 44 below the filter chamber 34.

[0013] At the bottom of the overflow compartment 40 is an outlet 46 which leads via a control valve 48 to a pump 50. The pump 50 is a connected to a line 52 which pumps the filtered liquid back to the plant. Also at the bottom of the compartment 38 is a drain outlet controlled by a valve 54 to drain the overflow compartment 40 for maintenance and otherwise when necessary. The valve 54 leads to a spillage sump.

[0014] A make up feed line 56 connected to a water source (not shown) is connected through a control valve 58 to the overflow compartment 40 near the upper portion thereof. In the compartment 40 is a float controlled valve 60 which is opened should the level of solution in the compartment 40 fall below a predetermined level.

[0015] An overflow line 66 leads from the upper end of the compartment 40 when this is overfilled and conveys overflow solution to a sump or on to the ground.

[0016] A head replacement line 62 connected to a source (not shown) leads to an inlet 64 to the chamber 10 into the filter chamber 34.

[0017] The system is fitted with a long backwash bar (not shown) entering and running along the filter chamber 34.

[0018] A flush nozzle 64 is connected to the chamber 12 close to outlet 20.

[0019] In use, the filter compartment 34 is filled with beads to an extent of 50% by volume of the filter compartment 34. These beads will form a suspended filter bed in the filter compartment 34. The valves 22 and 54 will be closed. Solution from the plant is now fed into the chamber 12 through the feed line 42 filling the settling compartment 36 and then passing through the filter compartment 34. The bulk of the fines in the solution in the settling compartment 36 will now settle on to the bottom wall 14 and then move to the lowest point 16 of the wall 14. Some of the fines will be entrained in the solution and will drift upwardly into the filter compartment 34 where they will be captured by the suspended filter bed. The overflow solution which escapes from the filter compartment 34 will now be clean. It passes into the overflow space 36 and then into the overflow compartment 38. When the overflow compartment 40 is substantially full, the valve 48 is opened and the pump 50 is operated delivering the clear solution for re-use.

[0020] From time to time the valve 22 is opened so that the settled fines on the bottom wall 14 can be fed to the discharge pump 26 which delivers the fines to the fines bag 28. When the fines bag 28 is filled it is replaced by a new bag.

[0021] In due course the filter media will become saturated with fines which will reduce the filter efficiency and will result in a reduced overflow rate. Therefore periodically, say weekly, there will be a backwash cycle with cleaning water driven into the filter compartment 34 by the backwash bar. The valves 22 and 54 are opened draining the content of the chamber 12 and the overflow compartment 40. The valve 48 is closed. Cleaning water solution will be feed from the backwash bar for a suitable period which is preferably about five minutes. This will loosen the entrained fines from the filter media. The loosened fines escape both through the overflow compartment 40 and down into the settling compartment 36. The solution in the overflow compartment 40 escapes though valve 54 to the spillage sump (not shown) for recycling. The solution in the chamber 12 escapes through the valve 22 to the spillage sump.

[0022] If necessary after backwashing solution is introduced under pressure through the flush nozzle to assist in loosening the fines in the settling compartment 36.

[0023] The filter media could wear during use. Fresh media is fed into the filter chamber via the valve 64 which is disconnected from the line 62 for this purpose.

[0024] The invention is not limited to the precise constructional details hereinbefore described and illustrated.