EP0814886A1 - Separateur liquide/solides - Google Patents

Separateur liquide/solides

Info

Publication number
EP0814886A1
EP0814886A1 EP96908186A EP96908186A EP0814886A1 EP 0814886 A1 EP0814886 A1 EP 0814886A1 EP 96908186 A EP96908186 A EP 96908186A EP 96908186 A EP96908186 A EP 96908186A EP 0814886 A1 EP0814886 A1 EP 0814886A1
Authority
EP
European Patent Office
Prior art keywords
feed
tank
conduit
section
separator according
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP96908186A
Other languages
German (de)
English (en)
Inventor
Ultrasep, (Proprietary) Limited
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Publication of EP0814886A1 publication Critical patent/EP0814886A1/fr
Withdrawn legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D21/00—Separation of suspended solid particles from liquids by sedimentation
    • B01D21/24—Feed or discharge mechanisms for settling tanks
    • B01D21/2444—Discharge mechanisms for the classified liquid
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D21/00—Separation of suspended solid particles from liquids by sedimentation
    • B01D21/0039—Settling tanks provided with contact surfaces, e.g. baffles, particles
    • B01D21/0042—Baffles or guide plates
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D21/00—Separation of suspended solid particles from liquids by sedimentation
    • B01D21/01—Separation of suspended solid particles from liquids by sedimentation using flocculating agents
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D21/00—Separation of suspended solid particles from liquids by sedimentation
    • B01D21/24—Feed or discharge mechanisms for settling tanks
    • B01D21/2405—Feed mechanisms for settling tanks
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D21/00—Separation of suspended solid particles from liquids by sedimentation
    • B01D21/24—Feed or discharge mechanisms for settling tanks
    • B01D21/2427—The feed or discharge opening located at a distant position from the side walls
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D21/00—Separation of suspended solid particles from liquids by sedimentation
    • B01D21/24—Feed or discharge mechanisms for settling tanks
    • B01D21/2433—Discharge mechanisms for floating particles
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D21/00—Separation of suspended solid particles from liquids by sedimentation
    • B01D21/24—Feed or discharge mechanisms for settling tanks
    • B01D21/245—Discharge mechanisms for the sediments

Definitions

  • This invention relates to a clarifier/thickener or separator of the type adapted to be used to separate suspended solids from a liquid.
  • Clarifiers/thickeners of the above kind are used in many different applications and have particular relevance in the clarification of water, and thickening of slimes produced in mining and mineral processing operations. However, it is to be understood that the invention is not limited to use in any particular application.
  • liquid and suspended solids are fed into the inlet of the separator at relatively low density.
  • a large portion of the solids is separated out of the liquid and a clear liquid is then discharged, usually at the top of the separator, and the solids which usually settle under the influence of gravity are withdrawn from the separator at the lower end thereof.
  • the clarified liquid is frequently referred to as "overflow”.
  • the high density solids, in the form of a sludge is frequently drawn out of the bottom outlet from the separator. This sludge material is frequently termed "underflow”.
  • the largest of the solid particles generally will separate under gravity to the lower region of the separator.
  • the smaller particles known as colloidal solids, will generally not settle within an acceptable time frame.
  • Clarifiers/thickeners therefore rely on the addition of a coagulant or flocculant which provides an effective bridging mechanism between small particles. This bridging mechanism results in larger particles being formed which will then settle under the influence of gravity.
  • Prior art clarifiers thickeners have often suffered from one or more disadvantages. Generally what is required is that the separator will operate to an acceptable degree of efficiency, be relatively automatic and maintenance ree, and will require acceptable levels of flocculant.
  • a separator for separating solids and liquids from a feed material containing a mix of solids and liquids, the separator comprising:
  • a tank having a top, generally vertical side walls, and a convergently tapered bottom;
  • the feed conduit including a feed section and a discharge section, the feed section being adapted to receive feed material and the discharge section being adapted to discharge feed material into the tank below the top thereof, the discharge section being of wider diameter than the feed section.
  • the discharge section preferably tapers divergently in a downward direction.
  • the feed conduit may be centrally located and vertically aligned within the tank.
  • the feed section is cylindrical, and the discharge section is of inverted cone shape, and the axis of the feed section and the discharge section are coincident with each other and with the vertical axis of the tank.
  • the discharge section may terminate in a lower edge which is substantially equidistantly spaced away from the vertical side walls of the tank around the entire periphery of the tank, thereby defining an annular throat between said lower edge and the vertical side walls.
  • the width of the throat may be between 5% and 15% of the diameter of the tank.
  • the width of the throat is approximately 10% of the diameter of the tank.
  • the upper surface of the cone shaped discharge section may define, together with the vertical side walls of the tank, an upwardly diverging settling bed.
  • the half cone angle of the discharge section may be between 20" and 45°.
  • the half cone angle of the discharge section is approximately 30°.
  • the separator may include a recycle conduit which extends upwardly within the tank from a region below the discharge section to the top or near the top of the tank.
  • the recycle conduit may be located within the feed conduit, preferably coaxially therewith.
  • the recycle conduit may comprise an upper right-circular cylindrical section, and a lower, downwardly diverging, conical section.
  • the discharge section may comprise a downwardly diverging conical section, with the lower conical section of the recycle conduit nesting within the discharge section.
  • the cone angles of the discharge section and the lower conical section are preferably substantially the same.
  • the separator may further include a plurality of downwardly converging truncated cones suspended, one below the other, within the tank, the lowermost truncated cone leading towards the tapered bottom of the tank.
  • the separator has three truncated cones.
  • the truncated cones are preferably suspended from and lie below the feed conduit.
  • the separator may include a launder at or near the top of the tank into which clarified liquid will flow in use.
  • the feed conduit may have an open upper end into which clarified liquid may flow in use.
  • the levels of the launder and the upper end of the feed conduit can be adjusted relative to each other to thereby provide means for selectively varying the relative percentages of clarified liquid which flow into the feed conduit and the launder respectively.
  • the launder may be of annular shape and surround, but be spaced from, the upper end of the feed conduit.
  • the launder preferably incorporates a weir over which the clarified liquid will flow into the launder, the weir comprising a plurality of V-shaped notches.
  • V-shaped notches are preferably evenly spaced around the launder.
  • the launder may be adjustable relative to the open upper end of the feed conduit
  • the level of the open end of the feed conduit may also be adjustable relative to the launder.
  • the open upper end of the feed conduit may include a weir over which clarified liquid will flow into the feed conduit, the weir comprising a plurality of V-shaped notches spaced around the upper end of the feed conduit.
  • the feed material may be fed into the feed conduit through a lateral supply conduit which joins into the feed conduit below the upper end of the feed conduit
  • the lateral supply conduit may have an auxiliary conduit feeding into it, the auxiliary conduit being used to introduce flocculent into the feed material in use.
  • a feed conduit for a liquids/solids separator comprising a cylindrical feed section, and a downwardly diverging discharge section which is fixed to and coaxially aligned with the feed section, the feed conduit being adapted to be mounted with its axis generally vertical within a liquids/solids separator.
  • the feed section may be right circular cylindrical, and the discharge section conical.
  • the feed conduit may further include a recycle conduit which extends through and is coaxially aligned with the feed section and the discharge section.
  • the recycle conduit may have an upper, right circular cylindrical section, and a lower, downwardly diverging, conical section.
  • a solids concentration apparatus for use within a liquids/solids separator, said solids concentration apparatus comprising a plurality of aligned, truncated, right angled cones, adapted to be mounted one below the other within a liquids/solids separator, each cone being oriented so as to be downwardly convergent.
  • the cone-angles of all of the truncated cones are preferably substantially the same.
  • a separation tank which has generally vertical side walls and a feed conduit including a downwardly diverging discharge section centrally located within the tank and spaced away from the walls of the tank thereby defining an annular throat between the tank and the discbarge section, the method including the steps of:
  • the method may include the step of diverting a percentage of the clarified liquid into the feed conduit to mix with the feed material.
  • the method may include the step of varying the percentage of clarified liquid introduced into the feed conduit so as to vary the specific gravity of material passing into the feed conduit and thereby optimise the separation characteristics of the separator.
  • Figure 1 shows a cross-sectional side view through a typical clarifier thickener according to the invention.
  • Figure 2 shows a plan view of the clarifier/thickener shown in Figure
  • a separator 10 for separating solids from liquids in a feed material includes a generally vertically extending tank 12 having vertical side walls 14, a substantially open top 16 and a downwardly tapering or cone shaped bottom 18.
  • the tank 12 shown in the drawings is circular in cross-section, but the tank may be square or rectangular in cross-section and would operate in substantially the same manner as is described below.
  • the tank 12 has a clarified liquid outlet 20 located near the top 16, and a sludge outlet 22 through which sludge which has collected in the tapered bottom will be discharged.
  • a feed conduit 24 is located widiin the tank 12 near the upper end thereof.
  • the feed conduit is generally vertically aligned and includes a feed section 26 and a discharge section 28 which is located below the feed section 26.
  • the feed section 26 is preferably of cylindrical form.
  • the discharge section 28 is of larger diameter from the feed section 26 and is preferably of downwardly diverging form as shown.
  • the cross-sectional shape of the discharge section should match that of the tank so that the lower edge 30 of the discharge section is equally spaced from the walls 14 of the tank around the entire lower periphery of the discharge section 28.
  • Feed material is supplied to the feed conduit 24 through a feed pipe 32 which passes through the side wall 14 of the tank and extends into the feed conduit 24.
  • the discharge end 34 of the feed pipe 32 may be downwardly directed as shown in the drawings to direct incoming feed material downwardly.
  • the feed pipe has a flocculant supply pipe 36 connected thereto by means of which flocculant is added to the feed material as it travels in the feed pipe 32.
  • the discharge section 28 is, as mentioned above, preferably conically shaped.
  • the half-cone angle of the discharge section may be between about 20° and 45° and is preferably about 30°.
  • the axes of the feed section and the discharge section are preferably coincident with the axis 38 of the tank.
  • a throat 40 is defined between the lower edge 30 of the discharge section 28 and the side walls 14.
  • the throat 40 is preferably of constant width around the entire periphery of the discharge section.
  • the width of the throat may be between 5% and 15% of the total width of the tank 12. In the preferred arrangement the width of the throat 40 is about 10% of the diameter of the tank 12.
  • a recycle conduit 42 is located within the tank, co-axially with the feed conduit 24.
  • the recycle conduit includes an upper cylindrical section 44, and a lower truncated conical section 46.
  • the conical section 46 is downwardly diverging as shown and is nested within the discharge section 28.
  • An annular gap 48 is thus defined between the discharge section 28 and the conical section 46.
  • the solids concentration apparatus comprises a plurality of downwardly converging truncated codes 52.
  • the cones 52 lead one into the other and serve to direct solids settling within the tank 12 towards the sludge outlet 22.
  • the cones 52 are suspended from the recycle conduit 42 by a plurality of suspense rods 54.
  • the clarified liquid outlet 20 is supplied with clarified liquid from the separator via a launder 56.
  • the launder is of annular shape and is supported in position from a gantry 58 located at the top of the tank 12.
  • the launder receives liquid which has been clarified in the tank 12.
  • the liquid flows into the launder over a weir which is defined by both the radially inner edge 60 and the radially outer edge 62 of the launder 56.
  • the weir is defined by a series of V-shaped notches.
  • the elevation of the launder 56, relative to the tank, is variable.
  • the upper end 64 of the feed conduit also serves as a weir for clarified liquid.
  • the upper end 64 of the feed conduit is also provided with a series of V-shaped notches.
  • feed material which contains a mix of solids and liquids will be introduced through the feed pipe 32.
  • a controlled volume of flocculant will be added to the feed material via the flocculant supply pipe 36.
  • the feed material as it enters the feed conduit 24, will move downwardly towards the discharge section 28.
  • the flocculant will assist particles to join together.
  • the floe bed 66 will form naturally as a consequence of the upwardly diverging configuration of the flow path above the discharge section 28.
  • the cone-shaped form of the discharge section serves firstly to slow the velocity of flow to allow larger particles to settle, and then secondly, as after flow has passed through the throat, to again slow the flow velocity above the throat to allow the floe bed 66 to form.
  • the density of the feed material is optimised for proper efficiency of the settler. For this reason it is preferred that at least some of the clarified liquid which is available for discharge from the settler is fed back into the feed conduit 24 for mixing with fresh feed material.
  • the relative elevations of the launder 56 and the upper end of the feed conduit should be adjustable. This can be achieved by either raising or lowering the launder, or by raising or lowering the feed conduit In the embodiment shown the elevation of the launder 56 is adjustable and for this reason a flexible connecting pipe 67 is fitted between the launder 56 and the clarified liquid outlet 20.
  • the V-shaped notches which define the respective weirs ensure relatively precise control of flow into the feed conduit and launder. Dilution of the fed material results in less flocculant consumption and higher settling rates.
  • the lower part of the tank is referred to as the consolidation zone.
  • the cones 52 serve to de-water solid material passing downwardly into the consolidation zone so that material drawn out of the sludge outlet 22 is sludge-like in nature.
  • cones 52 serve to guide solid particles moving down in this consolidation zone towards the centre of the cone shaped bottom 18. It will be noted that a solid particle build up as indicated at numeral 70 occurs below the lower most cone 52.
  • the advantage of this is that discharge which takes place through the outlet 22 will tend to draw sludge from this central region and thus the problem of open sludge free passages (known as "rat holes") being formed in the sludge will, to a large extent, be eliminated. Instead, discharge which does take place through the outlet 22 will tend to consolidate the solid sludge material and this sludge material will generally be guided towards the centre of the bottom 18 thereby plugging any such "rat holes” that may tend to occur.
  • a separator of the type described will have a number of advantages.
  • the separator will, it is envisaged, remove suspended solids over a wide range of flow rates and solids levels. It will also remove particles of varying densities and provide a relatively clear overflow. Controllable underflow densities over a wide range of densities is also possible.
  • the separator can also be used to achieve classification of solid particles by monitoring the feed flow rate, flocculant addition levels and optimising or adjusting the annular opening to suit the required classification.
  • dilution of the feed may be automatically controlled over a full range of operational conditions and could be changed to cope with changes in feed flow rates and feed material liquid/solids ratios.
  • the change in area of the annular passage leads to a very high rate of mixing due to the change in feed velocities. This is particularly advantageous when multiple units are employed in counter current decantation (washing) when high mixing efficiencies are required.
  • the change in cross-section of the clarifier/thickener upward of the annular throat 40 quickly stabilises the depth of the floe bed and also increases the efficiency of the floe bed since the upward velocity imparted on the floe particles rapidly decreases. This will lead to more collisions between particles and larger floes will quickly occur thus allowing the larger floe particles to fall under gravity through the throat 40 thereby constantly depleting the floe bed of solids.
  • the discharge from the consolidation cone is essentially above the underflow discharge.
  • the bulk of the high density sludge is thus allowed to build from the centre outwards thereby ensuring minimising the effect of "rat holes” and blockages or compaction which often results from “rat holes” forming.
  • corrosion erosion rates will be low due to the slow movement of solids in a downward direction.
  • the apparatus will be self- cleaning and it is envisaged that it wil] have a low flocculant consumption due to the larger particles tending to settle under gravity so they will not be carried up into the floe bed.
  • the floe bed above the annular throat 40 is self-balancing.
  • the form of the throat 40 can be varied.
  • a downwardly depending skirt could be attached to the lower edge of the discharge section 28.
  • Such a skirt will than define an annular cylindrically shaped throat which will have the effect of lowering the top of the floe bed but would possibly improve the efficiency of the floe bed.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Separation Of Suspended Particles By Flocculating Agents (AREA)
  • Cyclones (AREA)
  • Treatment Of Liquids With Adsorbents In General (AREA)
  • Treatment Of Sludge (AREA)

Abstract

Cette invention concerne un séparateur permettant de séparer des solides et des liquides d'une substance de base contenant un mélange de solides et de liquides. Ce séparateur comporte un réservoir ayant une partie supérieure, des parois latérales sensiblement verticales et un fond conique convergent. On dispose d'un orifice de sortie pour liquide clarifié au niveau de la partie supérieure du réservoir, ou à proximité de celle-ci, et l'on dispose d'un orifice d'évacuation de la boue au niveau du fond conique du réservoir. Une conduite d'alimentation, à alignement sensiblement vertical, se trouve à l'intérieur du réservoir, près de la partie supérieure de celui-ci, et cette conduite comporte une partie alimentation et une partie évacuation. La partie alimentation est conçue pour recevoir la substance de base et la partie évacuation est conçue pour évacuer ladite substance vers l'intérieur du réservoir, en dessous de sa partie supérieure. De préférence, la partie évacuation forme un cône s'élargissant vers le bas.
EP96908186A 1995-03-22 1996-03-22 Separateur liquide/solides Withdrawn EP0814886A1 (fr)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
ZA952331 1995-03-22
ZA9502331 1995-03-22
PCT/GB1996/000688 WO1996029135A1 (fr) 1995-03-22 1996-03-22 Separateur liquide/solides

Publications (1)

Publication Number Publication Date
EP0814886A1 true EP0814886A1 (fr) 1998-01-07

Family

ID=25584940

Family Applications (1)

Application Number Title Priority Date Filing Date
EP96908186A Withdrawn EP0814886A1 (fr) 1995-03-22 1996-03-22 Separateur liquide/solides

Country Status (6)

Country Link
EP (1) EP0814886A1 (fr)
AU (1) AU704644B2 (fr)
BR (1) BR9607887A (fr)
CA (1) CA2214538A1 (fr)
NZ (1) NZ304348A (fr)
WO (1) WO1996029135A1 (fr)

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2001022059A2 (fr) * 1999-09-18 2001-03-29 Path Tech Limited Procede de separation
DE202006003816U1 (de) * 2006-03-10 2007-07-12 Hugo Vogelsang Maschinenbau Gmbh Vorrichtung zum Zerkleinern und Fördern von Suspensionen
US8919575B2 (en) 2012-03-26 2014-12-30 Syncrude Canada Ltd. In Trust For The Owners Of The Syncrude Project As Such Owners Exist Now And In The Future Bitumen froth storage and separation using an improved froth tank
CN102824764B (zh) * 2012-09-12 2014-11-12 广西梧州双钱实业有限公司 一种分体式龟苓膏料液除砂器
CN112717482A (zh) * 2020-11-27 2021-04-30 中国恩菲工程技术有限公司 用于锌电积阳极泥处理的沉降装置和处理系统

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1066997B (de) * 1959-10-15 Gutehoffnungshütte Sterkrade Aktiengesellschaft, Oberhausen (RhId.) Vorrichtung zum Klären verunreinigter Flüssigkeiten durch Absetzen, insbesondere saturierten Zukkersaftes
GB463213A (en) * 1935-12-19 1937-03-24 Charles Davis Improvements relating to sedimentation tanks or reservoirs
US4303517A (en) * 1979-01-15 1981-12-01 Sydlo Inc. Liquid treatment apparatus

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO9629135A1 *

Also Published As

Publication number Publication date
AU704644B2 (en) 1999-04-29
MX9707129A (es) 1998-06-28
CA2214538A1 (fr) 1996-09-26
AU5151796A (en) 1996-10-08
BR9607887A (pt) 1999-11-30
NZ304348A (en) 1999-10-28
WO1996029135A1 (fr) 1996-09-26

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