US2382409A - Thickener apparatus - Google Patents

Description

.bmg-14,1945.l J. H. v. FINNEY' 2,382,409

THICKENER APPARATUS 'Filed sept..A 28, 194'2 v 4 sheets-sheet 2` Aug. 14, 1945.

JQ H. y. FINN'EY THICK'ENERAPARATUS Y Filed sept. 28.- 1942 4 sheets-sheet s karound the Scrapers.`

vor after shutdowns'has `been feasible.V

Patented ug. 14, 1945 THIoKENEn APPARATS John Il. V. Finney,` Denver, Colo.,` assignorvto i Mining Process and Patent Company, Denver, i r I c0010., a corporation of Delaware,` N Application September 28, 1942, Serial No. `453,909

' 12 claims. i ol. 21u- 55) Ihisinvention relates to Settling apparatus for the treatment of solids in yliquids and more particularly relates to traction-type thickeners.

Such-apparatus `providesa quiescent pool in which solids settle freely through the liquid `and deposit onto a bottom; usually conical, above and in proximity to Which,rotary scrapers move at slow speed to direct the settled solids toa dis- 1 charge outlet centrally of the bottom.

Industrial demands necessitate the production of such `apparatus yin a wide variety of sizes. Wherethe diameter of the tank is forty feet 'or less, it usually is expedient to drive the scraper assembly throughthe intermediary ofia central shaft suitablyvconnected with a prime mover.

However, when larger sized tanks are specified,

such obstructionsand thus avoid damage `to the mechanism.

, While suchanarrangement has been incorpo`` rated into central drive vshaftA Vthickener i mech-` anism',` the design of the traction type mechanism has not been adapted to utilization of theseflifting features. s r u. It is an object ofthe presentinvention to provide". traction-type actuating mechanism for thickenersi having simple. eicie-nt and `economi-` cal means kfor elevating'the associated scraper and particularly those of a diameter of` onehunu dred feet-:or larger,l traction drivemechanism `is employed to avoid subjecting` the `central shaft to undue stresses. In `such a structure, a supporting truss memberis pivotally mounted on a central column in the tank, and has one or more of `its ends mounted onl a wheel-supported carriage traveling on an endless `track on the rim of the tank. i 4 g These carriages1constitute vthe driving members of the assembly and carry motors for` driving' the wheels. The Scrapers` :are suspended from the truss structure `for conjoint rotation therewith and rotate at a fxeddistance above the bottom.V

All of `the device-sy hereinbefore described are subjected to occasional or intermittent shutdowns due to power failure or other causes, and when the stoppageis of i any considerable duration, the settled solids form a very compact and inert mass all In the central drive shaft designs,y the deleterious effects of the `resistance of such a mass are avoided through the provision `of lifting mechanism by which `the rakes can be elevated to approximately the iop of. the ,settled body, `and then after they are rotating they are allowedr to descend gradually to vtheir normaloperating posi-y tions. `Asfaiconsequence.'undue stresses on the driving mechanism are avoided. r i

Unlike the central shaft type, the traction type` mechanism has been so designed heretofore that no meansfor elevating the rakes during operation This Con"- dition has another disadvantage in that obstructions sometimes develop during normal operation, due to the presence of rocksg'tramp iron and'the likev whichfoccas'ionally 1enter the tank. If the fakes were selfelevating, they could` ride .up over Another objectl of` fthe' invention is to providel traction-type actuating` mechanism for thickeners,` inclusive of self-elevating scraper members.

d Ajfuriner bbjectoi trie inventionis tpiprevide tractionltypeactuatingmechanism in which the associated scraper members may be selectively and/or differentiallyspaced fromthe bottom of the tank in whichtheyV are positionedat different distancesfrom the `axis of rotation., 1 J Qther objects" reside in novel combinations and arrangements of, `partsland in novel `details of construction, alllofwhich will be described inthe course. of the u following description.

fro afford-a beiterjunderstanding afi-.he intention reference willbe madeto the accompanying `drawings `illustrating typical embodiments of the inventio`n` ,In the x drawings in the' several` 'views of which like partsl have beendesignated'simiA lain; "l y lV Figure 1 is a verticalcentral section through a thickener tank including mechanism embodying featuresof the present invention;` E y Figure2 isa fragmentary top plan `vievvgof one embodiment of the mechanism of thepresent irl--` ve'ntion, partially broken to showconce'aled partsy and drawnfto an enlarged scale;

Figure 3" is a fragmentary `sideelevation partially in section and corresponding to the Aappa-v ratus of Figure2; f

Figuresis a section taken along the line 4-4,` Figure 3;.af1d

i Figure 5 is another fragmentary side elevation partiallyl in section of another embodimentof the mechanism of the present invention,v also drawn to an enlarged scale.

` Referring iirst to Figure 1, the thickener comprises a tank 1` having an upright peripheral wall 8,'supporting atits top anendless track 9 andlpro-` vided With an Overflow launder l0 extending alon the top of the inner` surface of wall 8. 1

Thebottom Il` of tank 1 1s corneal and -ports a column l2 at its center about which an annular sumpl`3 is provided to collect the solids i descending along the conical bottom. Solids collecting in sump I3 are drawn off through a suitable valve-controlled conduit I4 by the action of a pump (not shown) Preferably, the conduit I4 and its associated valves are located in a tunnel I5 beneath the bottom II of the tank, which permits access for able arrangement of structural members, here shown as consisting of four 'radial members disposed at 90 intervals. Two of these members positioned in lengthwise alinement areV relatively shortas indicated at I'Ia in Figure 2, while the other two coact to form a tank spanning member, one or more of the outer ends of which are suitably connected as shown at I8, to a wheelsupported carriage I9 mounted on track 9. Each carriage has a motor in driving connection with its wheels 2l and it will be understood that suitable speed reduction mechanism may be included in the motor transmission system to rotate the truss at the desired speed.

The center of the rtruss is journaled on a suitable bearing 2'I mounted on the top of the column or Apier I2 and the upper portion of this pier is enclosed by a feed well 22. I'he truss I'Icomprises a rectangular framework` suitably braced in a manner well known in the art.

In order to provide access to the bearing 21 and feed well 22, as well as the main truss sections II, a walkway truss is suspended above the movable truss by attachment to the central column I2 as indicated at 23, anda second support 24 located beyond the peripheryof-the tank.`

Feed to the wellk 22 is supplied by ka conduit 26 supported beneath walkway truss 25 -which discharges into the feed, well. throughga hollow cylinder 29 having openings into the feed well. Adjacent to the feed, a series of slip Vrings 28 are provided which carry electric current stationary power lines (not shown) to rotating lines on thetruss which are connected to the motor 29.

'Scraper members 30 are supported in depend-- ing relation from truss II Vforconjoint rotation therewith and carry a plurality of blades 3l posi-- tioned at an inclination to their paths of movement and in close proximity to thebottom II -to push settled. solids thereon toward rand into sump I3. These Scrapers are made in` separate sections designated 30A, 30B and 30C inFigureB,

but it will be understood that any desired number of such sections may be employed and this number usually will -be varied as the size ofthe terminating above theliquid level in'an eyelet 3'5.

The beams 32 also are held by two parallel braces 36.and 31 pivoted on a side bar of truss I1 as indicated at 38 *and 39 respectively in'Figure v4 and pivotally connected with the beam as-.indicated at M and 4|.

By this arrangement, the position of the beam 32 remains unchanged upright or vertical throughout the range of its angular movement, which is an arcuate path substantially at right angles to the lengthwise axis of the truss, as is 'clearly shown in Fig. 4, and this is true whether Iand the manner of suspending Scrapers 30 through the intermediary of beams 32, such oppo- Vsitionto forward movement induces a self-elevating component into the scraper assembly with vthe results that the blades 3| encountering the obstruction rise above the obstruction whereupon they are free to settle again to normal operating position determined by the location of stops '33.

Likewise, after shutdowns, this feature permits an operator tostand on walkway truss 25 and hook onto an eyelet 35 with suitable lifting mechanism such as a block and tackle assembly for example, and thus manually raise the Scrapersl over obstructions or for positioning the Scrapers albove or on top of a bed of vsettled solids, when required.

The form of the invention illustrated in Figure 5 attains the same objects of the invention, but diiers somewhat in certain particulars, described hereinafter. The principal difference resides in the construction of the m'ain truss and the suspension system for Scrapers 3l).v k

In this form` the section of the main truss tapers from its outer end toward its center support,

` and as a consequencavthe `under surface of the truss is spaced` a substantial distance'from bottom I I, particuarly adjacent central pier I2 `and thereby provide la relatively wide range of movement for beams 32 and associated Scrapers 3I.

Inthe various forms4 illustrated, it vusually will be unnecessary Ito provide more than one driving carriage I9 for the main truss memberI'I, but it will be understood that 4when desired a plurality of such driving carriages may be mounted at the ends of the truss sections.

The sectional scraper assembly is common to the various forms illustrated, butis will be understood that the number of such sections may. be two or more as required to meet manufacturing, assemblingv and operational requirements.

What I claim and desire to secure Iby Letters Patent is: l

1. In la thickener of the traction-drive type, inclusive of a tank having an overflow determining a liquidl level in the tank, and a truss mounted for rotary movement in the tank, the improvement which comprises a plurality of submerged scraper members carried in a depending position on said truss between its center and outer extremity, each said scraper member being piv- 1 otally mounted on saidv truss for angular up and down movement in an ancuate course transverse to the lengthwise axis of the truss and being positioned normally in proximity to the bottom of the tanzk to urge solids settling thereon centrally a'esafeoe j of the tangens lifting means connected with'` to'andla fee'aiiet, saidpverflow determininga each said scraper member and extending'above the Vliquid levelf-in the-tank for selective yelevationof said scraper members.

a `thicken-'eriofl'thetraction-drive type,

inclusive of atank 'having arifoverflowdetermining a liquid level in the? tank; and a'ft'russ' mounted for l' rotaryY movement' inl-the tank," the improvementwhich comprises -aplurality of sub-l merged' scraper members lcarried in a idepending position onfsaid'trussfbetween its center and outer extremityj `each saidscraper member beingpiv-` otally mounted lonv sai-d truss for angular selielevating movement in an arcuate course transverse `tothe lengthwise axis of the truss whenever an obstruction to its'circumferential move-` ment is encountered, each said scraperbeing posi-1 tioned normally in proximity tothe'bottom of the tank ftolurgeA solids; settling thereon centrally of the tank, and lifting means connected with each said scraper member and extending above the liquid level in the tank for selective elevation of said `scraper members independently of said selfelevating action.

3. In a thickener of thev traction-drive type,

inclusive of a tank having an overflow determining a liquid level in the tank, anda truss mount-ed for rotary movement in the tank, the improvel ment which comprises a plurality, of submerged scraper members carried in a depending posiselective manual elevation of said scraper members.

4. In a thickener of the traction-drive type, inclusive of a tank anda truss mounted for rotary movement in the tank, the `improvement which comprises a plurality of scraper members carried in a depending position on said truss between its center and `outer extremity, and means for holding each said scraper in said depending position. including a pair of parallel supports pivoted` on the truss and movable through. an elevating `arc in a path transverse to the lengthwise axis of the truss, whenever an obstruction to the circumferential movement of the Scrapers is encountered.

5. In a thickener of the traction-drive type, inclusive of a tank and a truss mounted for .rotary movement in the tank, the improvement which comprises a plurality of scraper members carried liquidlevel-inithe tank,a central pier in thetank enteriding`` [above the liquid level, l a tank-spanning truss journaled for {rotationlfat the upper end oi the piervfandl supported onjat least one of `its and-sectional scraper" members'depending from the truss in proximity to thetanklbottom to lurge settledv solids toward said discharge; each" saidA scraper member being mounted forlimited upi and down movement relative to thetruss in `an arcuate path transverse to thelengthwise axis of-the truss, and means connected with `each said scraper member and extending abovethe liquid level determined bysaid` overflow for selective `up and down `movement offsaid scraper members.

7. Traction-type thickener apparatus, comprising a cylindrical tank having an endless track on its rim, a peripheral overflow adjacent thereto and a feed inlet, said overflow determining a liquid level in the tank, a central pier in the tank extending above the liquid level, a tankspanning truss journaled for rotation at the upper end of the pier and supported on at least one of its ends by a carriage having wheels travelling on said track, means on said carriage for driving said Wheels to rotate the truss, there being a central bottom dischargefrom the tank adjacent the pier, sectional scraper members depending from the truss in proximity to the tank bottom to urge settled solids toward said discharge, the respective sections of said scraper members being mounted for limited up and down movement relative to ,the truss in an arcuate path moving said sections up and down.

in a depending position onY said truss between its center and outer extremity, and means for holding each said scraper in said depending position. including a pair of parallel supports pivoted on the truss and movable through an elevating arc in a path transverse to the lengthwise axis of the truss, whenever an obstruction to the-circumferential movement of the Scrapers is encountered, the supports adjacent the center of the tank being mounted for movement through a longer arc than the supports nearer the periphery of the `tank whereby a greater degree of elevation is imparted to the associated scraper member.

6. Traction-type thickener apparatus, comprising'a cylindrical tank having an endless track` on its rim, a peripheral overflow adjacent `there- 8. In a thickener, inclusive of a tank and a truss mounted for rotary movement in the tank, the improvement which comprises a plurality of scraper memberscarried in a depending position on said truss between its center and outer exl tremity for4 conjoint rotation therewith, said` Scrapers being mounted for differential spacing from the bottom of the tank and in 'proximity thereto to urge solids settling thereon centrally of the tank, the scraper member nearest the center of the tank being positioned at a greater distancev from the bottom of the tank than the scraper members distant from the center of the tank, and having blades of greater width than the other said Scrapers providing a greater impelling surface in said movement of the solids.`

9. In a thickener, a tank, a truss mounted for rotation therein, a plurality of Scrapers suspendied from the truss for conjoint rotation therewith, and means for supporting each such scraper for individual up and down movement comprising a beam extending through the truss in supporting relation to a depending scraper, means on the truss including at least two arms pivotally mounted to elevate the` scraper angularly in an arcuate path transverse to the lengthwise axis of` the truss, and means on the beam coacting with the truss for limiting the extent of downward movement of the beam.

10. In a thickener, a tank, a truss mounted for rotation therein, a plurality of Scrapers suspended from the truss for conjoint rotation therewith, and means for supporting each such scraper for individual up and down movement comprising a beam extending through the truss in supporting relation to a depending scraper, means on the truss including two arms pivotally mounted to elevate the scraper angularly through an arc transverse to the lengthwise axis of the truss, and coasting means on the beam and the truss for limiting the extent of up and down movement of the beam.

11. In a thickener, a tank, a truss mounted for rotation therein, a plurality of Scrapers suspended -from the truss for conjoint rotation therewith, and means for supporting each such scraper for individual up and down movement comprising a beam extending through the truss in supporting relation to a depending scraper, means on the truss including two arms pivotally mounted to elevate the scraper angularly through an arc transverse to the lengthwise axis of the truss, and a stop member on the beam coacting with the truss for limiting the extent of downward movement of the beam.

12. In a thickener, a tank, a truss mounted for rotation therein, a plurality of Scrapers suspended from the truss for conjoint rotation there- With, and means for supporting each such scraper for individual up and down movement comprising a beam extending through the truss in supporting relation to a depending scraper, means on the truss including tWo arms pivotally mounted to elevate the scraper angularly in an arcuate path transverse to the lengthwise axis of the truss, means on the beam coacting with the truss for limiting the extent of downward movement of the beam, and means attached to the beamextending upwardy out of the tank and adapted for connecting with mechanism to raise the scraper in the tank.

. JOHN H. V. FINNEY.

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