AU648432B2 - Submersible solid material lifting and classification device - Google Patents

Description

AUSTRALIA

Patents Act 432 COMPLETE SPECIFICATION

(ORIGINAL)

Class Int. Class Application Number: Lodged: Complete Specification Lodged: Accepted: Published: Priority Related Art: Name of Applicant: De Beers Marine (Proprietary) Limited Actual Inventor(s): Johannes Duijzers Address for Service: PHILLIPS ORMONDE FITZPATRICK Patent and Trade Mark Attorneys 367 Collins Street Melbourne 3000 AUSTRALIA Invention Title: SUBMERSIBLE SOLID MATERIAL LIFTING AND CLASSIFICATION DEVICE Our Ref 304176 POF Code: 1503/184484 The following statement is a full description of this invention, including the best method of performing it known to applicant(s): -1- 6006 -2 *AKRt TOTE.N O THI ineto reae*oasbesbesldmtra itn n *~--ifcto deiead*ehd la unere miea eoeyoeain i sncsayt eoe patclt soi.aeilfo.h ebd.Atpcle pl si h THIS~ in o eaelatei to arsubmerim olnds. trllfin n 3- &1llMMAEX.9F MH INVENTION A firs aspect of the invention provides a submersible solid material lifting and classification device compising a centrifugal, rotatable impeller, a suction conduit through which slurry is drawn in use into the impeller, and a screen surrounding the imqpeller against which slumy that is drawn, into the impeller is directed outwardly by the impeller, the screen serving to classifyr the particulate content of the slurry Into relatively fine, and relatively coarse particles.

Typically, the screen defines a coarse par-ticle chamber and the device farther comprises: a passage leading from the coarse particle chamber through which coarse particles are discharged in use to a submerged location, and a housing surrounding the screen, the housing and screen defining.

between them a fine particle chamber from which fine particles can be removed to su~rface.

Conveniently, the passage leading from the coarse particle chamber is arranged to discharge coarse particles to a submerged location under gravity. Conveniently also, the flne particle chamber includes a fine particia collection zone accommodating the end of a fine particle removal conduit, such as an airlift conduit, through which flne particles can be removed to surface.

4- The housing may be of perforated construction to prevent rxcessive pressure bild-up. lIn a preferred version of the invention, the housing is made of saueen material having screen apertures smaller than the screen apertues of the screen suirrounding the impeller so that fine -particles, smaller than a predetermined size, cannot escape through the housing- A second aspect of the Invention provides an operatively submerged solid material lifting and classification appairatus for lifting and classfying solid seabed material, the apparatus comprising a submersible device as summarised above, a submersible motor for driving the impeller of tha device and means fbr supporting the. device and maor The suction. corCilt may include flexible joints and means are provided :to articulate the ,anduit about the flexible joints. The means for supporting the apparatus on the seabed may comprise a sItid-type basr., A third aspect of the invention provides a method of lifting and classfying- solid submerged tuterlal, the method comprising the steps of *49drawing a slurry containing particulate solid material from a submerged location to the eye of a rotating, centrifugal ixnpelleri arg~ng the slurry outwardly from the impeller against a screen which surrounds the impeller so that relatively fine particles pass through the screen while relative coarse particles are ret~ned within the screen dIischarging the relatively coarse particles back to a submerged location and lifting the relatively fne particles to surface The invention exends to the device, apparatus and method summarised abafe when used to recover diamonds or diamondiferous material from.

the seabed.

BRIEE DESCRIMTON OF M~l DRAWINGS The invention will now be described i mare deta by way of example o*l, with reference to the accompanying drawings in which: ****Figure 1L is a digrammatic; cross-secton. illustratinga submeisible solid material lilting and classification device of the invention; Figure 2 ilustrates the impeller of the device seen in Figure Figure 3 shows a submerged apparatus that includes a t.device of the invention.

Fig=r 1 diagrammatically ilustrates a submersible solid material lifting and classification device 10,which includes a suction. pipe 12 having a free end 14 and leading to the ,eye 16 of an impeller 18 rotated at a suitable speed via a shaft 21, by a motor Indicated in Figure 1 by the mneral -6- The impeller 18 has a central boss 22 to which the motor shaft 21 is connected. A series of cur-ed vanes 24 are located between upper and lower circular plates 28 and radiate outwardly from the eye 16 of the impeller.

There ar openings 26 between the roots of the vanes, The upper end of the suction pipe 12 leads into the eye 16 of the impeller 18 with minimal clearance as indicated by the numeml 23.

o*o.

The invention is of counse not limited to an impel~er 18 as illustrated. In fact any centrifugal impeller capable of pumping a fluent slurry can be used in the device Situated radially outwardly of the impeller 18 is an annular, Inner screen 30 which has a tapering lower portion 3. The screen aperture size is S: chosen for the screen to pass particulatz material having a size smaller than a predetermined size.

Surrounding the screen is a housing 36 which has a top 38 and which is, in this case, formed of screen material having an aperture size less than that of the inner screen 30. An anumlar fine particle chamber 40 is defined between the housing 36 and the screen 30, with the screen itelf defining an inner coarse particle chamber 42. A fine particle zone is defined at the lower end of the fine particle chamber 40 and accommodates the lower end of an airlift pipe 47. An outlet passage 44 leads from the base of the chamber 42 to discharge oversize materiaL -7- Although an arlift device is used in the Illustrated embodiment to raise maerial from the zone 45 to surface, it should be appreciated that other embcgliments of the invention may employ different forms of suction devicm for this purpose.

Figure 3 shows a submerged installation which is used, in this case, for recovering diamonds from the seabed 50. The installation includes the device 10 mounted on a skid-type support 52 standing on the seabed. A prime mover 20 that drives the Impeller 18 of the device 10, in this case an electric motor, is supplied with electrical power from the surface by electrical cables 54.

S:i* The suction pipe 12 has flexible joints 56 and 58 about which it can be flexed by hydraulic rams 60 and 62 respectively. A jet water pipe 64, supplied with water under pressure from the surface through a hose 66, is arranged alongside the pipe 12 as illustrated.

V

In use, with the motor 20 ruming, the jet water pipe 64 shoots a jet of, vrater at the seabed adjacent the free end 14 of the pipe 12. This eaffitaWs the seabed material and loosens it for easier uplift by the I suction pipe M The low pressure which is created at the eye 16 of the impeller 18 as a result of its rotation draws the resultant slurry, containingparticulate seabed material in seawater, from the seabed and through the pipe 12 to the impeller.

The slurry enters the eye 16 of the impeller from which it is thrown outwardly, through the openings 26, by the impeller vanes. The outwardly thrown slurry strikes the inner screen 30 and finer particles 8 pass through into the fine particle chamber 40. Coarser particles that arc unable to pass through the screen 30 sink towards the bottom of the coarse particle chamber 42 and are discharged under gravity, back to the seabed, through the discharge passage 44.

The finer particles tt pass through the screen 30 are 'unable to pass through the housing 36 and settle in the chamber 40 to the zone From this zone, the particles are 'withdrawn to the surface through the airlift pipe 47 which Is supplied with compressed air through a line la practice., it is known that the finer particles contain the majority of the diamonds sought to be recovered. The fine particulate material broght to suface from the zone 45 of the fine particle chamber 40 Is then processed further to separate any diamonds from the associated wagte material It Is believed that the screening of the material at the submerged site is a major advantage of the invention, since only a pottion of the material actually sucked up from the seabed is brought to surface for subsequent processing. is means that the capacity of the surface equipment and mirch of the submerged equipment, needs to be only a proportion of what it would havo to be if all the material initilfly raised from the seabed were to be brought to surface for processing there.

Many modifications to the illustrated appas are possible. Por Instance, the device 10 and associated apparatus could be mounted on a mobile tracked or other vehicle thatiIs capable of moving aboat freely on the seabed.

9- Alm, 1 intead of jet water being supplied from surface, a submersible pump could pi ovide the necessary pressuised water. The electric motor cwuld be replaced by an hydraulc or'other submersible motor. The end 14 of the suction pipe 12 could include. a suction head, possibly fted with cuitters or suitable rock breaking or other equipment to facilitate the loosening and capture of solid seabed material.

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Claims (7)

1. 3. A submersible solid material lifting and classification device according to claim 2 wherein the passagA leading from the comre particle chamber Is arranged to discharge coarse particles to a submerged location under grvity.
2. 4. A submersible solid material lifing and classification device according to claim 2 or claim 3 wherein the fine particle chamber includes a fine particle collection zone accommodating the end of a fine particle removal conduit through which fine particles can be remove~d to surface. A9 9tbesbesldmtra fn n lsiiaindvc codn to cli.4hri h iepril emvlcnuti naritcnut Asbesible solid material lifing and classification device according to ayoeo claim 24o wherein the hieprileoa oduig is n a rf orated con.44ton 12
3. 7. A submersible solid material lifting and classification device according to claim 6 wherein the housing is made of screen material having screen apertures smaller than the screen apertures of the screen surrounding the impeller. A stibmersibe solid material lifting and dlassification device according to ay one of the preceding claims and comprising means at end of the suction conduit remote from the impeller for agitating solid material which is to be drawn to the irsipcier through the suction conduit. A submersible, solid material lifting and classiffcation device according ''to clim 8 wherein th agitating means cbomprises a wr jet got* S064* 9 A submersible solid material lifing andi classification device according to claim 8 wherein the agitating means comprises mechanical rock brealtin or cutting meas 13 lif. An Operatively rubmerged solid material lifting and. classification apparatus for lifting and classifing solid seabed material the apparatus wrmprising a submersible device according to any one of the precedii clais, a submersible motor far driving the impeller of the device and means for supporting the device and motor on the seabed. V z ft An operatively submerged solid material Mutig and classification apparatus according to claim 11 wherein tht suction conduit of the device Includes 6lndble joints and means are provided to articulate the conduit abaut the flexible joints.
4. 13. operatively submerged solid material lifting and classification apparatus accrding to clm 11 or claim 12 wherein the means for supporting the apparatus on the seabed comprises a skd-type base..
5. 14. A method of lifting and classifying solid submerged matetial, the method comprising tbe steps of drawing a shiny7 containing particulate solid material from a submerged location material into the eye of a rotating, centiiugal impeller, discharging the slurny outwardly from the impeller' 14 against a scrxeen which surrounds the impeller so that relatively fine particles pass through the screen while relative coarse particles are retained within the screen, discharging the relatively coarse particles back to a submerged location and lifing the relatively fine particles to 4.16. Asumil solid material lifting and classification dppviceu according n n tof anym one o lto 10 when used to recover diamonds or daodfru dimonieonsmateial from the seabed. 417 GooA sothd oaera lifting and cassifiin ldadrateria according to' ofclaim 1 1 when used to recover diamonds or diamondiferous tra ~mateialfrom the seabed.
6. 18. A solid material lifting and classification apparatus substantially as herein described with reference to the accompanying drawings.
7. 19. A method of lifting and classiing solid seabed material substantially as herein described with reference to the accompanying drawings. 0 S 0e0 9009 *e O 0 6 0 0 96 Dated: 8 September 1992 PHILLIPS ORMONDE FITZPATRICK Attorneys for: DE BEERS MARINE (PROPRIETARY) LIMITED 60 0 0S 0* 069~ 0S *9 0 0690 96 6* 6 0000 0 0 0006 0000 *9 S 0096 0