AU599935B2 - Wool scouring apparatus - Google Patents

Description

Form PATENTS ACT 1952-1973 COMPLETE SPECIFICATION (ORI G INAL) FOR OFFICE USE Class: Int. CI: Application Number: 0000t1 0 I Lodged: *008 Complete Specification-Lodged: ott Accepted: Published: *0 o a i 8 Priority: Vt 00 0 00 8 oe, Related Art: 04 80 9 lOt IThis documcwnt contains the a a'Ile[d Pellts made linder Section 49 and is correct for printin 0.4 TO BE COMPLETED BY APPLICANT N1 1ame of Appl'icant: HER MAJESTY THE QUEEN IN RIGHT OF NEW ZEALAND ,,:-Address of Applicant:. Parliament Buildingis, Wellington, New Zealand Actual Inventor: Address for Service: GRAHAM GORDON NICHOLLS WOLFGANG ROBERT JANATA DONALD JOHN BELL SANDERCOCK, SMITH BEADLE, 203 Riversdale Road, Box 410) HAWTHORN V IC 3122.

Complete Specification for the invention entitled: WOOL SCOURING APPARATUS The following statement is a full description of this invention, Including the best method of performing it known to me:- 'Note, The description Is to be typed In double spacing, pica tW-,e lace. In an aria not exceeding 250 mm in depth and 160 mm In width, on tough white paper of good quality and It Is to be Inserted inside this form.

1010/76-L 1171076.LF. D. Atklnson. Governmewnt PrInter, Canberro Aulian (Signature) attorney trADERCOCK, SMITH BEADLE THE COMMISSIONER OF PATENTS This form must be'accompanied by either a provisional specification (Form 9 and true copy) or by a complete specification (Form 10 and true copy).

-2- This invention relates to apparatus for the treatment of woolscour liquor within the w6olscour industry, and in particular, but not solely, to apparatus for removing suspended solids and/or emulsified grease from the discharge liquor.

The preliminary processing of raw or slipe wool requires the wool to be scoured or washed with a cleansing liquor which is normally an aqueous soap or synthetic detergent solution. Grease, water soluble material and dirt are removed in the scouring process which typically consists of a train of 3 or 4 scouring bowls containing the cleansing 10 liquor, followed by a maximum of two water rinsing bowls.

So~o The effluent from scouring operations consists of a combination of onta aO grease, suint (the water soluble salts of the wool), dirt, vegetative Oo matter, fine wool fibre and detergent. Untreated it is a highly Q0 0 o 0 0 I o polluting stream with biological oxygen demand (BOD 5 values prior to dilution ranging from 15 to 60 kg/m 3 It is desirable to reduce the volume of the liquor to be discharged and to lessen the suspended "o solids and grease content of this liquor.

o"o° Conventional wool scouring bowls typically consist of large tanks with sloping bottom sections. The wool is raked along a plate located in the top of the tank and is squeezed out through rollers before o passing to the next bowl. The liquor is recirculated through the bowl via an adjacent sidebowl. A sidebowl is a bowl positioned alongside the main scour bowl enabling recirculation of the liquor through the main bowl. Modern bowls have hopper bottom sections for the discharge of sedimented solids. Grit and sand scoured from the wool settle A readily to the bottoms of the bowls and are removed by time sequenced discharge through valves. However, the suspended solids concentration builds up during the operation of the scour system, due to an inability to sediment the fine particles. These particles are too small to be removed efficiently by a conventional settling tank. Improved scouring

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I~f will result if the levels of suspended solids are minimised. This allows one both to reduce the required volumes of scour bowls and to increase the time intervals between dumps of liquor from the scour bowls, thereby reducing the overall rate of discharge of effluent liquor.

The scour operator will additionally be able to increase the specific throughput of wool per unit volume of scour liquor in the scour train, as improved scouring results due to tile continuous removal of the suspended solids and other impurities, washed out of the wool, from the liquor.

It is therefore an object of the present invention to provide apparatus and/or a method to go some way toward achieving the abovementioned desiderata or at least to provide the public with a useful choice over the known art.

Accordingly the present invention may be said broadly to consist in a wool scouring apparatus including therein, in a portion of said apparatus through which wool scour liquor containing suspended solids is passed or in which wool scour liquor containing suspended solids is contained, a l4minra plate settler and means associated with said settler for the removal of solids settled by said settler.

In one embodiment said settler is provided in a tank within a recycle loop in said apparatus.

In a second embodiment said settler is provided in the main scour bowl of said apparatus.

In a third embodiment said settler is provided in a sidebowl alongside the scour bowl of said apparatus.

In a fourth embodiment said settler is provided in a separate tank to treat the flocculated heavy solids discharged from each bowl.

Preferably in the second embodiment the scouring bowl is modified by sealing the wool-way plate from the bottom hopper section of the i i .3 i: i a

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i L -4main bowl thereby to reduce the bowl volume of an existing wool scouring apparatus." Preferably there is provided a baffle positioned at the top section of said apparatus adjacent the collector of the settler.

Preferably said settler has a conically shaped bottom section and an outlet positioned at the centre of said section to aid the removal of the solids therefrom.

Preferably the plates of the settler are stacked in a cradle and are of an even length and width.

Preferably the plates of the settler are constructed from a "o i galvanised and corrugated material.

Preferably said apparatus has a distributor pipe constructed of a 0 So,0 single length of material of the desired shape (as herein described).

o o° The invention may also be said broadly to consist in a wool scouring apparatus substantially as herein described with reference to the drawings accompanying the prvisie a- specification.

In a further aspect the present invention may be said broadly to o 4 consist in a method of reducing the solids content of a woolscour 0o°* liquor during a woolscouring prccess comprising passing a woolscour liquor with a high solids .nt.Anthrough a laminar flo plate settler, which separates and partially removes both the solids fraction and the emulsified grease content therefrom.

Preferably said liquor is passed through said settler under pump suction conditions, with the settler uncovered or covered.

Alternatively said liquor is passed through said settler under pump pressure.

The invention consists in the foregoing and also envisages constructions of which the following gives examples.

The preferred form of the invention will now be described with o 30 reference to the drawings accompanying the provisional specification in 1-- LT.0 which: Figure 1 is a schematic oblique pictorial view of a scour bowl and plate settler arrangement wherein the plate settler unit is installed in a recycle loop.

Figure 2 shows a perspective plan view of a laminar fl: plate settler unit, schematically incorporated into a recycle liquor treatment process.

Figures 3a-d show the desired shapes and profiles of the distributor and collector.

More specifically Figure 3a is a vertical cross-sectional view of s the distributor 32 in Figure 2.

Figure 3b is an oblique view of the distributor.

o Figure 3c is a vertical cross-sectional view of the collector.

Figure 3d is an oblique view of the collector.

Figure 4 is a partially broken away oblique view showing the stack configuration in main elevation and the preferred shape of the plate settler unit.

A woolscouring process typically involves a train of three or four oi" wash bowls followed by two rinse bowls. The wash liquor is fed typically from the last through to the first wash bowl, progressively increasing in solids, grease and other impurities content as it is fed from one bowl to the next. The wool is.passed along the train s4 t countercurrently to the wash liquor. Most of the solids, dirt, grease and other impurities are removed from the wool in the first wash bowl.

Figure 1 shows squeeze roller 12 positioned above wool way plate Underneath the roller arid plate is the main scour bowl 17. A sidebowl 16 is shown positioned alongside main bowl 17. Separate to the bowls 16, 17, is plate settler tank 25. i Greasy wool is raked above a plate 10 located inside each scour t!/s 30 bowl and squeezed out through squeeze roller 12 before passing (in the

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direction shown by arrow 11) to the next bowl. The liquor squeezed from the wool (indicated by arrow 14) and the makeup and flowback liquor (indicated by arrow 13) from the succeeding scour bowl (the total flow back is indicated by arrow 15) is normally recirculated via a recycle loop comprising sidebowl 16, pump 18 and heat exchanger Heavy solids from the main bowl settle at the bottom and are discharged 22.

to a heavy solids tank via line 48-- In operation with the plate settler separate from the main and side bowls and the existing recycle loop, the scour liquor is removed from the conical bottom section 24 of the side bowl 16. The liquor is oo then fed into the plate settler tank 25. In the plate settler tank part of the suspended solids are separated and the liquor is recycled 0 od into the main bowl 17 via pump 48. The separated suspended solids are o 0 0 collected from the conically shaped bottom section 36 of the plate settler tank 25 and discharged to the heavy solids tank through line 38.

091 Figure 2 shows a plan perspective/schematic view of the apparatus 6 00 a oof one embodiment of the present invention with the plate settler run under pump suction conditions. The conical bottom section 24 of the sidebowl 16 is shown. Plate settler tank 25 is located downstream of 0/ sidebowl 16 with pump 48 located in turn further downstream.

0001 The scour liquor flows through line 28 into distributor 32 of the plate settler 25. Valves 33 and 51 are used for taking samples of the liquor before and after treatment.

Figure 3a shows a preferred profile of the distributor. The i liquor flows through inlet holes 37 and out through the exit gap 41 between the bottom 43 and side 45 of the distributor, thereby achieving the desired distribution of the liquor along the length of the distributor.

Passage of the liquor through the free cross-sectional area of the

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dr/2~7 W u i -7plate stack 34 alters the turbulent flow condition of the scour liquor to a laminar flow c6ndition. This enables the heavy solids to settle and grease droplets to rise to the surface.

The sludge stream is collected from the bottom 36 of the settler tank 25 and pumped from the settler through line 38 to the heavy solids tank. The recycle liquor reduced in solids is removed from the settler through collector Figures 3c and 3d show respectively the preferred profile and an oblique view of the collector 40. The liquor enters the collector a~o through the entry gap between weir 46 and edge 47 and exits through ooo outlet pipes 42. The recycle scour liquor is then passed via line through pump 48 before being fed into main scour bowl 17. A o Cbaffle 44 is placed across the top of the settler, in front of the O) C,a collector 40, to reduce the top surface flow across the plates when the o0 settler is run under pump suction conditions.

A preferred shape of the plate settler is shown in Figure 4. The Co plates 34 are of an even length and width and are stacked in a cradle o held by brackets 53 and thre-ded rods 55. Spacers 57 assist in po a positioning plates 34 of the stack. The plates 34 are preferably constructed from galvanised material, are corrugated, hang in a vertical plane and lie equally spaced at all points from each other.

The preferred material of construction of the plate settler tank and connections is stainless steel.

The bottom section 36 of the plate settler 25 is conical in shape and the solids outlet 52 is provided at its centre.

The form of the invention described incorporates the plate settler unit in a separate recycle loop wherein the plates are supported within a cradle and tank of the described shape. However, the plate stack can be located directly inside the main wash bowl or side bowl thereby reducing the required constructional space.

-8- Incorporation of a laminar flow plate settler of the above design into a commercial w6olscouring train and in parallel with the first wash bowl enabled a 30% increase in suspended solids deposition from scour liquor when compared to a scour train without such a plate settler installed.

The claims form part of the disclosure of this specification.

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Claims (12)

1. A wool scouring apparatus including therein, in a portion of said apparatus through which wool scour liquor containing suspended solids is passed or in which wool scour liquor containing suspended solids is contained, a plate settler and means associated with said settler for the o.0,0 removal of solids settled by said settler. j 2. An apparatus as claimed in claim 1 wherein said settler is provided in a tank within a recycle loop in said 0 00 oo"I apparatus. 0 0 00 0 "'r v

3. An apparatus as claimed in claim 1 wherein said settler is provided in the main scour bowl of said apparatus. o 0

4. An apparatus as claimed in claim 1 wherein said *o°0 settler is provided in a sidebowl alongside the scour bowl 0 4 iof said apparatus. An apparatus as claimed in claim 1 wherein said settler is provided in a separate tank to treat the fflocculated heavy solids discharged from each bowl.

6. An apparatus as claimed in claim 3 wherein said scouring bowl is modified by sealing the wool-way plate from the bottom hopper section of the main bowl thereby to reduce the bowl volume of an existing wool scouring apparatus.

7. An apparatus according to any one of the preceding claims including a baffle positioned at the top section thereof adjacent the settler. r i amspe.003/hermaj 90 5 10

8. An apparatus according to any one of the preceding claims wherein said settler has a conically shaped bottom section and an outlet positioned at the centre of said section to aid the removal of the solids therefrom.

9. An apparatus according to any one of the preceding claims wherein the plates of said settler are stacked in a cradle and are of an even length and width.

10. An apparatus according to any one of the preceding o 0 claims wherein the plates of said settler are constructed o, St.o from a galvanised and corrugated material. o o o

11. An apparatus as claimed in any one of the preceding 0 03 o o 0 claims including a distributor pipe constructed of a single length of material of the desired shape (as herein described). 0 0 015 12. A wool scouring apparatus substantially as herein o 0 described with reference to the accopanying drawings. 0. 13. A method of reducing the solids content of a wool scour liquor during a woolscouring process comprising 00 passing a woolscour liquor containing suspended solids °2C through a plate settler, to thereby separate and partially remove both the solids fraction and the emulsified grease content therefrom.

14. A method according to claim 13 wherein said liquor is passed through said settler under pump suction conditions, with the settler uncovered or covered. A method according to claim 13 wherein said liquor is passed through said settler under pump pressure. amspe03/hermaj 90 5 M- amspe.003/hermaj 90 5 15 I IJ~ O"- 4 4. 11

16. A method of reducirg the solids content oz- a wool scour liquor during a wool scouring process substantially as herein described witLh reference to the accompanying drawings. DATED this 15 May 1990 SMITH SHELSTON BEADLE Fellows Institute of Patent Attorneys of Australia Patent Attorneys for the Applicant: HER MAJESTY THE QUEEN IN RIGHT OF NEW ZEALAND ~0q 44 444 4.o 44. 04 0 44.4 0 04 0 4 4.04. 4. 44 04 4 0441 444~ 44;,

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