US2321207A - Screen for centrifugal machines - Google Patents

Description

June 8, F. HOWEV SCREEN FOR CENTRIFUGL MACHINES Filed Aug. 25, 1941 2 Sheets-Sheet 1 `lune 8, 1943. A. F. HowE Y SCREEN FOR CENTRIFUGAL MACHINES 2 Sheets-Sheet?l Filed Aug. 25, 1941 Patented June 8, 1943 SCREEN FOR CENTRIFUGAL lVIAGHINES Andrew F. Howe, University City, Mo., assigner to B. H. & M. Company, St. Louis, Mo., a corporation of Missouri applicati@ August 25, 194.1, serial No. 408,145

12 Claims.

This invention relates to Screens to centrifugal machines; and has special- Vreference to screens of the general type disclosed in my copending application Serial No. 357,348, filed September 19,

1940, and in my prior Patent No. 2,022,114,Vv No` vember 26, 1935.

An object of the invention is to provide an improved screen of long durability for use in centrifugal machines comprising a rotary conical screen basket made of. durable metal or the like and having numerous large discharge openings therethrough, in combination with a screen of novel construction and of long durability attached to the inner side of said basket and having numerous outwardly diverging passages therethrough communicating With said openings through the basket and relatively of much smaller area than said openings.

Another object of the invention is to provide an improved long lasting screen for use in centriugal machines comprising an inclined series of rings arranged one above the other, and means for supporting said rings in superimposed relationship and providing numerous outwardly diverging passagesr therethrough or between s aid rings for the discharge of liquid and smaller particles of waste material from within` the screen 'duringVv rotation thereof.

Another object',` ofV the invention is to provide an improved long lasting screen of the character mentioned4 in combination with a conical basket enclosing the screen and having numerousrelatively large discharge openings therethrough, and means for supporting the screen and in rigid relationship with the basket and providing` passages wherebyV the substances dischargedY through the screen may pass into and` through said openings Ain the basket.

Another object of the invention is to provide an improved screen composed of a plurality of ringsA of graduated diameters and means for supporting said rings inf spaced relationship to provide passages for the discharge of liquid and entrained substances from within the screen during centrifugal operation of the machine for which the screen is provided.

Another object of the invention is to provide an improved screen composed of a coiled band or strip forming a screen device tapering upwardly, and means for attaching together the adjacent coils of said` band or strip in rigid relationship and providing outwardly enlarging passages for thedischarge of liquids and entrained substances during operationV of the screen.

Other objects will appear from the following description, reference being made to the annexed drawings, in which- Fig. 1 is a viewpartly in elevation and* partly .in section showing my improved screen and basket attached together in cooperative relationship for operation in a centrifugal machine,`

Fig. 2 is an enlargedA sectional view` showing. more clearly the arrangement` and4 construction of the screen and' its association with the basket.

Fig. 3 is an enlarged sectional View similar to Fig. z showing a screen of modified construction in which the screen rings are supported in spaced relationship by devices also providing the passages through the screen.

Fig. 4 is a perspective view'sllowing` a coiled band or strip which may be usedin forming, the

screen.

Fig. 5` is a detail sectional view showingamodication of the construction shownin Fig. 2.56parate spacers being attachedtov thei rings..

Fig. 6 is a perspective viewofa portion or. fragment of the spacer shown iny Fig. 3.

Fig. 'l is an enlargedplan view. of. a. ring. hav.- ing the spacers integrally united with the upper side of the lower ring. i

Fig. ,8. is a side elevation or. edge. view of the Fig. 9 is an inverted. plan view of the ring: shown inFigs. ll and2.

Fig. 1l),A is a side elevation or edge View of the same ring inverted.

The present inventionl isv designed and adapted for use in centrifugal separators or clarifiers-of tegral with the upper end'- of the-basket.` 'line-v lower end' ofthe basket I- is formed with an outwardly extended flange or frame portion. 4 jar'- ranged tobe attached to-*a sub-structurewhich', in turn, isv connected.`l with the rotating or ydriv'-I ing mechanism in the mannergdisclosecl in my.

said copending application, or otherwise, as dea sired. The metallic basket I is rotative about a vertical axis and is formed with a considerable number of relatively large outlet openings 5. As shown, these openings may be arranged in annular series and spaced apart circumferentially and vertically.

The screen shown in Figs. l and 2 is composed of a series of rings 6 of graduated diameter and circumference complementary tothe inside diameter and inside circumference of the basket I. One of these rings is shown in lower plan View in Fig. 9 and in edge or side elevation in Fig. 10. An-

annular series of spacers 7 is attached to the underside of each ring 6. These spacers extend from the inner edges of said rings to the outer edges thereof in approximately radial directions. The adjacent walls of the respective spacers flare or diverge outwardly to provide outwardly flaring or enlarging passages 8 when said spacers are superimposed upon and attached to the subjacent ring. The inner surfaces or walls 9 of the rings 6 and the spacers 'I are smooth, and the walls of all of the rings are in the same conical plane in order not to interfere with the movement Yin any direction of the liquid and entrained substances toward the discharge passages 8. Thus, the inner surface ofthe screen, considered in its entirety, is a smooth perforated wall parallel with the inner surface of the basket I. Also, the rings 6 taper outwardly in cross-section, as clearly shown in Fig. 2, so that the passages 8 are of considerably llarger area at their outer or exit ends than at their inner or inlet ends. Due to the cross-sectional tapered formation of the rings 6, the vertical width of the outer ends of the passages 8 is greatly in excess of the vertical width of the inner or inlet ends of said openings. A large proportion of the passages 8 communicates directly with the openings 5. This arrangement functions to expedite rthe discharge of substances through'the openings 5 and to prevent the machine from becoming clogged. The screen rings B'are madeA of hard metal not easily-abraded or worn, so that they will indefinitely or for a long time resist and endure the abrasive of the liquid and'entrained substances and other solids passing through the machine.

An annular series of upwardly extended ribs I0 is formed integral or rigid with the inner Aside of the basket I, and spaced peripheral portions of the rings 6 are rigidly attached theretol by welding or otherwise. The ribs I0 provide attachments for spaced peripheral portions of the ringsl, and also hold said rings out of contact withthe innersurface of the basket I, and additionallyprovidevinclined passages between said rings-6 and the basket I to permit unobstructed owfofthe contents discharged from within the Y screen to the discharge openings 5 in the basket. i

As shown, a large proportion of the rings 6 extends across the openings 5 so that a large numberl of the passages are in direct communication with said openings 5 to expedite discharge through said openings 5.

Instead of forming the spacers I on the undersides ofthe ringsV 6, they may be formed integral or rigid with the upper sides of said rings. As shownin Figs. 7 and 8, `the spacers l', which are the analogs of the spacers 1, are formed integral with or rigidly attached to the upper sides of the rings 6. These spacers 'I' are attached to the undersides of the superimposed rings 6 just as the spacers'l are attached to the upper sides of the subjacent rings. Weldings may be utilized as the medium' of attachment in both instances.

A variation of the invention is shown in Fig. 3, the variation consisting in the means for holding the rings 6 spaced apart. Each spacer shown in Fig. 3 comprises an annular strip of sheet metal distorted to form arches II integrally united at their lower ends by connections I2 which may also be said to consitute inverted arches. When the annular strip of metal is thus distorted, it provides an annular series of outwardly flaring or enlarging passages I3 for the discharge of the liquid and entrained lighter solids from within the screen. The upper surfaces of the arches I I are attached to the undersides of the respective superimposed rings 6 and the lower surfaces of the connections I2 are attached to the upper sides of the respective subjacent rings. Spaced peripheral portions of the rings B and of the annular strips forming the spacers and passages between said rings are attached to the ribs I0, just as spaced portions of the rings 6 in Figs. 1 and 2 are attached to the ribs IG. Thus, in this instance, the rings 6 and the spacers therefor are held out of direct contact with the inner surface of the basket I so that the liquid and entrained lighter substances discharged from within the screen may flow freely to and through` the openings 5.

Instead of forming the rings 6 separately, the screen may be formed of a continuous strip I4 coiled; in conical form to provide a conical screen generally of the shape shown in Fig. 1, or a series of coiled strips may be used to form the conical screen. Spacers I5 are located between adjacent convolutions. These spacers may be similar to the spacers I and attached to the adjacent con? volutions of the coiled strip to provide outwardly flaring or enlarging passages I6. When thel spacers I5 are attached to the adjacent convolutions throughout the length of the strip or strips forming the screen; a conical screen is pro-l and having separate spacer blocks I'I Welded orotherwise attached thereto and being of the gene eral shape of the spacers 'I and functioning in the `same manner and for the same purpose. The' showing of the invention-embodied in a structure comprising a truncated cone is for illustrative purposes only. It is plain` that the invention may be used in forms other than truncated cone form. `Other variations may be made Within the scope ofthe invention without departure from the na-Y ture and principle thereof.

I claim:

outward flow of liquid'and` suspended particles;

a metallic frusto-conical screen within said cone l comprising a series of rings of graduated diameter and circumference complementary to the inside diameter and inside circumference of said cone, and certain of which rings cross said openings,

within said screen, and ribs integral with the pev,ripheries of said rings and with the inner sur.- -face of s aid cone holding said screen in rigid.

spaced relationship with respect to said cone.

2. In a device of the character described in -A cluding a metallic truncatedV cone having numer- 75 ous relatively large openings therethrough for the -1. In a device of the character described in` cluding'a-metallic truncated cone having numer. ous relatively large openings therethrough for the outward flow ofliquid and suspended particles; a metallic frusto-conical screen within 4said cone comprising a series of rings of graduateddiameter and circumference complementary to the inside diameter and inside circumference of said icone and certain of which rings cross said openings, means rigidly attaching spaced peripheral portions of said rings to said conebetween said open-V outward flow of liquid and suspended particles; aA

metallic frusto-conical screen vvithin said cone comprising vertically spaced annular elements .of graduated diameter and circumference complementary to the inside diameter and inside circumference of said cone and certain of which ringscross saidv openings, spacers between and.

holding said elements in vertically spaced relationshipand providing numerous outwardly opening passages between said rings and communicating dir ectly with said openings for the, ilow of liquid and suspended particles from within said screen, and means integrally attaching spaced portions of the peripheries of said, rings to the inner side of said cone and providing passages for the flow-of saidliquidrand suspended particles to said openings.

4. In a device of the character described including a metallic truncated cone having numerous relatively large openings therethrough for the outward flow of liquid and suspended particles; a metallic frusto-conical screen within said cone comprising a series of rings of graduated diameter and circumference complementary to the inside diameter and inside circumference of said cone and certain of which rings cross said openings, spacer blocks between and holding said rings in vertically spaced relationship and providing numerious outwardly opening passages between said rings and communicating directly with said openings for the flow of liquid and suspended particles from within said screen, said spacer blocks being rigid with the respective rings, and means holding said screen integral with and spaced from said cone and providing passages for the flow of said liquid and suspended particles to said openings.

5. In a device of the character described including a metallic truncated cone having numerous relatively large openings therethrough for the outward flow of liquid and suspended particles; a metallic frusto-conical screen Within said cone comprising a series of rings of graduated diameter and circumference complementary to the inside diameter and inside circumference of said cone, an annular strip of sheet metal located between each pair of adjacent rings and having bent portions attached to said rings between which it is located and providing outwardly opening passages between said rings for the now of liquid and suspended particles from within said screen, and means holding said screen in rigid connection with said cone and providing passages for the iiow of said liquid and suspended particles to said openings.

6. In a device of the character described including a metallic truncated cone having nuthe outward flow-of liquidi and suspended particles; a frusto-conical screen within vsaidcon'e comprising a coiled strip'in conicalmform comple'- mentary to the inside diameter` and inside cir-.-

cumference of -said cone, spacers between and attaching together the convolutions of said strip and holding them in vertically spaced relationship and providing outwardly opening .passagesbetween said convolutions for the flow of liquid andsuspended-particlesfrom within said screen,

and means attaching spaced peripheral portions of said screen to the inner side of said cone and providing passages for the flow of said liquid andsuspended particles to said openings. l

7. In a device of thechar'acter described-including a substantiallyy inflexible metallic vbasket arranged to rotate about a vertical axis and hav-- ing numerous relatively largeopenings therethrough for the outflovvl of liquid and suspended particles; a rigid screen within said basket having an outside diameter complementary to the inside diameter of said basket and comprising parts of outwardly decreasing tapered thickness in Vertical cross-section arranged in verticallyspaced relationship and providing passages from the inner periphery to the outer periphery of said screen, the upper and lower walls of said 'pas--v sages diver-ging outwardly and forming the outerl vportions of said passages of much greater-ven ticalwidth than their inner portions, certain of said passages communicating directly with saidA openings in said basket for the ilow'of `liquid andy suspended particles from within said screen, and means located between said openings in`V said basket attaching and holding said screen rigidly within said basket.

8. In a device of the character described including a substantially inflexible metallic basket arranged to rotate about a vertical axis and having numerous relatively large openings therethrough for the outflow of liquid and suspendedv particles; a rigid screen Within said basket and comprising vertically spaced parts having an outside diameter complementary to the inside diameter of said basket and of outwardly decreasing tapered thickness in vertical crosssection, spacers between and holding said parts in vertically spaced relationship and forming circumferentially spaced passages through said screen and having their outer portions of much greater vertical width than their inner portions, certain of said passages communicating directly with said openings in said basket for the flow of liquid and suspended particles from within said screen, and means located between said openings in said basket attaching and holding said screen in rigid connection with said basket.

9. In a device of the character described including a metallic truncated cone having numerous relatively large openings for the outward flow of liquid and suspended particles; a metallic frusto-conical screen within said cone comprising v a series of rings of graduated diameter and circumference complementary to the inside diameter and inside circumference of said cone, said rings tapering outwardly in cross-section and having their outer peripheries of relatively much less cross-sectional thickness than their inner peripheries, spacers between and holding said rings in vertically spaced relationship and providing numerous outwardly opening passages between said rings having their outer portions of much greater vertical width than their inner portions and communicating directly with said openmerous relativelyla'rge openings therethrough-for:-

ings for the ow of liquid and suspended particles,

from within said screen, and ribs integral with the peripheries of said rings and with the inner surface of said cone holding said screen in rigid spaced relationship in said cone.

10. In a device of the character described including a metallic truncated cone having numerous relatively large openings for the outward ilow of liquid and suspended particles; a metallic frusto-conical screen within said cone comprising a series of rings of graduated diameter and circumference complementary to the inside diameter and inside circumference of said cone and tapering outwardly in cross-section and having their outer peripheries of relatively much less cross-sectional thickness than their inner peripheries, means integrally attaching spaced peripheral portions of said rings directly to said cone between said openings, and spacers located between and holding said rings in vertically spaced relationship and providing numerous outwardly opening passages between said rings having their upper and lower walls diverging outwardly from each other and forming the outer portions of said passages of much greater vertical width than their inner portions.

l1. In a device of the character described including a substantially inflexible metallic basket arranged to rotate about a vertical axis and having numerous relatively large openings therethrough for the outow of liquid and suspended particles; a screen mounted within said basket and having an outside diameter complementary to the inside diameter of said basket and having numerous passages opening outwardly from the inner periphery to the outer periphery of said screen, said passages having upper and lower:

walls divergingV outwardly from each other 4and `forming the outer portions of said passagesV of.

for the flow of liquid and suspended particles from.

within said screen, and means for holding said screen in rigid connection withvsaid basket.

12. In a device of the character described including a substantially inexible metallic basket arranged to rotate about a vertical axis and having numerous relatively large openings therethrough for the outow of liquid and suspended particles; a screen mounted within said basket and having an outside diameter complementary to the inside diameter of said basket and having numerous passages opening outwardly from the inner periphery to the outer periphery of said screen, said passages having upper and lower walls diverging outwardly from each other and forming the outer portions of said passages of much greater vertical width than their inner portions, certain of said screen passages communicating directly with said openings in said basket for the ow of liquid and suspended particles from within said screen, and means located between said openings in said-basket attaching spaced peripheral portions of said screen rigidly to said basket and providing passages for the flow of substances from said screen passages to said openings through said basket.

ANDREW F. HOWE.

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