US1990288A - Paper pulp screening machine - Google Patents

Description

Feb.5, 1935. t. l v N'. M. KNIGHT v 1,990,283

` PAPER PULP SGRE'NING MACHINE Filed sept. 17, 1932 2 sheets-sheet 1 Nelson lVLKnghT Feb. 5, 1935. N M. KNIGHT PAPERPULP SCREENING MACHINE 2 Sheets-Sheet 2 Filed Sept. 17, 1932 4 ATys.

lnvenTor. Nelson lVLKnghT MSM-kw Patented FeJrS, 1935 i T712' l I a' UNHEDSTATES PATENT'OFFICE-g1* v v 1,990,2ss "PAPER PULP SCREENING MACHINE Nelsonk M. Knight, Brookline, yMass. v Application september 17,1932, serial Na'eaasec.

* 11 claims. (c1. 'az-34)'v i i This invention relates to a machine for screenis formed, circular end frames'l secured to the ing paper pulpvand particularly to that type of base 6, and end walls or lend members which paper pulp-screening machine which comprises` ormfthe ends of the vat or casing and are a vat or container having van inlet and an outsuitably secured to the endframes 7. Thedis- 'let, a cylindrical screen situated `within the vat charge-ports 3 are formed in these end members A 5 between the inlet' and outlet, a plunger or pulsa.- 8 and the discharge conduits 141 are secured' to tor within the screen, and means to vibrate the 'saidv end members: The end members -8 are samein the direction ofthe axis of the screen, vformed with conical-shape inner'faces as indi'- such operation keeping the pulp agitated and also cated at 9, the apices of the :conical 4faces 9 l0 assisting-to keep the screenclear. y l being directed toward each other. :L 1'0 Oneobject of my present invention is to pro- The enclosing side Walls 10 of the'vatvor casvide an improved pulp-screening machine of this ing `1 are in the form of side plates`50 which are type which has novel means for keepingthe ysecured at their lower edges to the basememscreen plate clean. ber 6 and at their upper edges -toatop frame Another object of ther invention is to provide ymember 111 which extends from-onefend-frame`1`5 a pulp-screening machine which will have an in- 7 to the 4other` and is secured to bothrend'frames. .v creasedpulp screening capacity and at the same This'topl frame member 11 is provided with an ytime a relatively 10W power consumption for op- "opening 12 through which the dirt screened from eration. y 'the-pulp may be ejected. lThe side plates 50 i 50* Another 'object ofthe invention vis to provide a are also secured atftheirends to the endframes'7. 20 vf pulp-screening machine which has relatively few The cylindrical screenmember is "stationarily movingparts and which is constructed to ensure supported onV the end members .8.` For this ypurlong'life; posev said end members are formed'with annular Other objectsy of the invention are to improve seats 13 which areencircled by the ends of the '25j generally Vpulp-screening machines inthe par- `screen 5, the latter-being clamped to said seats 25 tcularshereinafter'set forth. bymeans of two-part clamping vrings 14 which the drawings wherein-I have illustrated a encircle the ends of vsaidscreen and the meet- @selected embodiment of my invention,y Fig. 1 ing ends of which are clamped together asindijis' avertical sectional view through a pulp-screencated at 1 5.

"l30'ingmachine embodying the invention taken. on Situated within the 'stationary cylindrical I 30 "a5-lar section line 3-3, Fig. '1. A l

theline 1 1, Fig. 3; y l screenv is la plunger or pulsating member indi- Fig. 2 is an end viewof the pulp-screening cated generally at 16 l"and which is shownv as machine looking from theright Fig.-1; v mounted upon a shaft 17-that slides back and Fig. 3 is a section onsub'stantially the irreguforth in bearings 18 formedl inl the end mem-.

l ybers 8. The plunger v16 is in the shape 'vof fa `The machine herein shown comprisesA a cas- -doublecone,that is, the opposite faces 19fthereof 7ving' vor housing indicated generally at 1 and are cone-shapedgwith the. apices of the conesy which is provided -in .its bottom with an inlet directed in opposite directions'.y This pulsating port 2 throughwhich the pulp to bescreened is member 16 has a diametricaldimen'sion suflicie'nt 4"F40 delivered to the vat, vand with "an outlet port 3 to nearly fill theA cylindrical `screen A5. Means 40' at each end through which the screened pulp are provided for vibrating Vthe shaft 17 "and the is discharged from the 'vat or casing 1. EachI plunger 16 in an axial directions Such pulsatinlet port 3 communicates with a delivery coning-movement operates to` forcethe pulp back rduit 4 through which the Vscreened pulp-is'deand forth through the screen-:thereby to keep 545 liverd. 'l the latter from'cloggingup. v f 45 Situated within the vat or casing -1` and be-l LWhile any suitable means may befemployed tween theinlet 2 and'discharge ports 3 isacylinfor thuspulsating ory vibrating ythe plunger 16 drical screenjmember so that in passing from Ihave herein illustrated for this purpose a drive ``the inlet to4 the discharge ports the pulp is; shaft 20`which is vjournalled in a crankcase "m0 'compelled topass through't'he screen member, housing 21; Said housing isfshown as secured 50 thisbeing a common construction in pulp-screento a draining drum 22 whichin `turn is secured ing machinesof this type. to one of the heads 8 A v yWhilethe vat or casmg 1 may have anyfsuit- The shaftl 20 which may be driven by a pulley yable construction that herein shown comprises' 23 or by'any suitable means, is'provided with y 55 abase member in which Vthe inlet opening 2 aneccentric 24 whichis'encircled'by'an'eccentric 55 y 'fthe right hand discharge port 3 into the dis- Ycharge conduit 4 while another portion of said d 1 s l 8 may be drainedaway, vand -will thusbezpre-ego f1.0wi11 cause Vthe vhm-water4 mixture tenues strap 25 carried on the end of a link or connectin'g rod 26. This connecting rod is pivoted at 27 to one end of the shaft 17 which projects through the draining drum 22 and into the crank case housing 23. Said housing maybe'supplied with oil as indicatedy at 28 to provide lubricathrough which the dirt, foreign matter and other,

materialto, be ejected, is discharged and the pu1p win be delivered to theeinletz, which 'itY will be noted is. situated centrallyfat thebottom of the Vat or casing under a sufticient'sheadutc maintain the tank filledffatrlcastuptoand preferably slightly into the opening inI thefframe lmember 11.

e When the plungerglmoves tothe rightFig.' 1

the chamber .V39 .between the ,right hand Vface 19 of the plunger 16 andthe right hand head memberk 8 .will be reduced in size with, the result that, aportion of the paper pulp oriibre-water.

v-mixture Whichvis within the screenand which, therefore, has been screenedfis forced vthrough screened pulp will be forced outwardly through the screen 5 During this same stroke of the ,plunger 16 by which the chamber 39 is decreased ,v

, in sizevthercharnber 40 on the opposite sidev of the plunger willbe increased insize and the lincrease will.. produce a reduction. .in pressure i withinthe chamber ,4;0.vv yThe forcingof the pulp outwardly through the screen fromthe chamber 39 as above kdescribed tends to create an increased pressure of the pulp ontheoutside of the screen.

esetherx-Wthrthe'redueed; pressure in the chamber v,iulufurdly through the Screenvinto the y ehanber 40. Hencevwh'en the plungerlfmoves to the ,Y

right there will be a flow -ofliibre-water mixture outwardly-through the `screen y from the; chamber -31 endtethe right between the screenandthe easing and 'inwardly through the eereeniinto the chamber`40. f A 's When the kplunge'relt'` is -mvedin theppposite -direction or to the left ,inrv Fig,Y 1 thechamber 40 .will 'be decreased :size and the ,chamber 39T wulbe increasedinfsize- 'me'reductionin l size of thechamber 40, will cause.; part .o1-'the fibre-Water mixture. therein@ be. forcedL out- 4vyardlythrough the rleft hand discharge port 3 and will also cause part of 'saidiibre-water mix ture to be Vforced'.outwardly through` the .screen` y f'lint'o `the space between the screen and thebwalls of the casing, :therebyftending tdincrease the pressure ofthe fibre-Water mixtureoutside kof "31Vtends`to reduce the pressure of, said,r chamber and this together with the pressure of the flbre- "water mixture outside of the chamber causes a lThis pulsating of the. spreeWeter`V mixture' 'through the screen servesk 'to preventltlieA screen l from 4becoming clogged 'and fduringfthis loperation the dirt orforeig'n matter. which Aisfscreened 1 from the pulpor'fibre-water mixtureiwill remain on the outside of the screen'and VV.willi be "dis-w v charged throughthefopenng 1,2 of the tcpfframe fable fwater, Seals 33W Prevent leakage -0f 'Water `alongthe shaft..'4'I'he drainingA Adrum 22 V-h;as an This increased pressure outside` vthescreen toy vibrati1 1g therewith.

11 into a suitable receptacle as usuall in pulpscreening machines of this general type.

To assist in keeping the screen clean I have' provided a plurality of cleaner rings 29 which are -situated within the rcylindrical screen 5 and are of a size` so that their peripheries are closely adjacent the inner face of said screen. These cleaner rings are connected to the plunger 16 and thus `have pulsating or vibrating movements therewith. These cleaner .ringsare #shown as annular rings. which are. "mounted Ion Ifrods 30 that are supported in the peripheral' portion of fthe plunger 16. The adjacent rings are separated kby suitable spacersv 31 carried by the rods. The

peripheries oft-he cleaner rings 29 are preferably 15 `beyelled as shown at 32 and the bevel faces 32 of the cleaner -rings on the right hand side of -theplunger' are bevelled in an opposite direc.- tion from those on the left hand side of said plunger. The vibrating movement of these 2o e1eanerrinss assiste the; action 0f the plunger in keeping .the screenifrom clogging y.up during the screeningioperation. .Y I s' s A'Ihe head Lmembers `8 ,are provided Withsuit- `AOpening `34u11 vits:betihnfl and it provde-ins whereby any waterfwhich Vmayleak v.past the watergseal in the, right hand vhead {member vented from being carried into .'thefcranlgcasing-21.., lr lIclaim:`

1. Apulp-screeningmachinehcomprisingalcasy 1;, ing `havinggan inlet andanputletfa cylindrical e.2.@A.pulp-screeuinamaehine@Qmiiesesing having an inlet and an outlet, a cylindrical screen within saidcasing situated -betweenthe inlet and.the1out1et,a plunger v element'within .the545 cylindrical screen,A means .to vibratesaid element an axiale-direction, end .a Series vOfiffwfitn- 1 cleaning rings extending fromv fone 4end of yfthe screen tothe other?, means for securing saidngs .;,.t0 the v4plumzer te 'vibrate -therewith, saidlrinssiuo having their peripheri'es k.closely adjacent 'A1/.the

A, inner facej of the screen. i

3. A pulpfscreeuinamachinecemprisinaeasv,ing havinganinletfand an .outleaa cylindrical screen within said casing, situated between Vftheli izuetandthe Qutlet eiplunserfelemeutthe y cylindricalscreen, means to vibratesaid Aelement 1in an i axial .directicm rods carriedby said plunger .andextending -paral1elto-the-axis of ythe cylin. der andpcleaner rings mounted in-s'paced ire1ation0 n s Y Y y on saidrods, the peripheriesoffthe.cleanenrings `:the-screen. The increase in size ofy the chamber n being situated Iclcsely adjacent the inner l face lof 4. A1 pulp-Screening mach-ine Comrrifng 65S- ing having an inlet and an outlet, a cylindricalfl screen within'said casingsituated betweenrther inlet and the outlet,`jap1unger:element-:Within-Jihe and projecting fromfeach `facetlierec.andcleanifl yerrringscarl'xjied by the rods each Sideff'the plunger. ,y 5. t.A pulp-screening" achine ving having a centralinlet and an outletateach neI1y;1,eacli end wall of the shaped, a cylindrical screen within the casing situated between the inlet and the outlet, a shaft mounted in bearings in said end walls, a plunger carried by said shaft and having cone-shaped ends, means to reciprocate the shaft in the direction of its length, and cleaner rings secured to and reciprocating with said plunger, the peripheries of the cleaning rings being situated closely adjacent the inner face of the screen.

6. A pulp-screening machine lcomprising a casing having a central inlet in its bottom and a discharge port in each end, a cylindrical screen stationarily mounted within the casing and situated between the inlet and lthe discharge ports, a plunger element Within the cylindrical screen, and means to vibrate said plunger element in an axial direction.

7. A pulp-screening machine comprising 'a casing having an inlet and an outlet, a stationary cylindrical screen within the casing situated between the inlet and the outlet, a plunger element within the cylindrical screen,.means to vibrate said element in an axial direction, and a series of .screen cleaning rings extending from one end of the screen to the other and carried by and moving with said plunger.

8. A pulp-screening machine comprising a casing having a cylindrical sidewall and two end members to which the side wall is secured, said side wall having a central inlet in the bottom of the casing and each end member having a discharge port therethrough, a stationary cylindrical screen situated between the inlet and the discharge ports and having its ends supported by and stationarily mounted on the end members, a plunger element within the cylindrical screen, and means to vibrate said plunger element in an axial direction.

' 9. A pulp-screening machine comprising a cas,- ing having a cylindrical side wall and two end members to which the yside wall is secured, said side wall having a central inlet in the bottom of the casing and each end member having a discharge port therethrough, a cylindrical screen situated between the inlet and the discharge ports and having its ends supported by and mounted on the end members, a plunger element within the cylindrical screen, means to vibrate said plunger element in an axial direction, and means separate from the plunger but mounted thereon and vi.- brating therewith for cleaning the screen throughout its entire length.

10. A pulp-screening machine comprising a casingfhaving a side Wall and two end members, said side wall having an inlet in the bottom of the casing and each end member having a discharge port therethrough, a stationary screen situatedbetween the inlet and the discharge ports,

said screen having a tubular shape and having its ends secured to and supportedby the end members, and means within the screen to cause the pulp to flow back and forth through the screen during its movement from the inlet to the dischargey ports.

l1. A pulp-screening machine comprising a casing having a sidewall and two end'members,v

said side Wall having an inlet in the bottom of the

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