US3405866A

US3405866A - Centrifuge

Info

Publication number: US3405866A
Application number: US593163A
Authority: US
Inventors: Amero Clifford Leonard
Original assignee: Bird Machine Co Inc
Current assignee: Bird Machine Co Inc
Priority date: 1966-11-09
Filing date: 1966-11-09
Publication date: 1968-10-15
Anticipated expiration: 1985-10-15
Also published as: SE332601B; DE1632270B1; GB1135720A

Description

c. 1 AMER@ Oct. 15, 1968 CENTR IFUGE Filed Nov. 9, 1966 United States Patent O 3,405,866 CENTRIFUGE Clifford Leonard Amero, East Walpole, Mass., assignor to Bird Machine Company, South Walpole, Mass., a corporation of Massachusetts Filed Nov. 9, 1966, Ser. No. 593,163 8 Claims. (Cl. 233-14) ABSTRACT OF THE DISCLOSURE The disclosure concerns a centrifuge of the rotary bowl type wherein the slurry and another fluid such as a ilocculant are separately fed into one end of the bowl by feed means which discharge'the respective fluids into separate compartments from which they are fed into the bowl. The compartments are rotatable about the feed means and are separated longitudinally of the bowl axis by a splash baille which has a clearance from the feed means through which slurry fed to one compartment may splash into the other. To eliminate fouling of the other iluid and its outlet to the bowl by such splashing slurry there is disclosed a chamber located within the compartment for the other iluid which receives such fluid and discharges it to the bowl' through one or more conduits removably attached to the chamber and extending through the compartment wall. The chamber is spaced axially of the bowl from the splash baille and radially of the bowl from its compartment outer wall to provide space to receive splashing slurry which is discharged therefrom to the bowl. The chamber is removably mounted on an end wall of its compartment and has a frusto-conical end facing the bafile with its base closest to the baille, with a central sleeve surrounding the feed means.

This invention relates to centrifugal separators in which the slurry and a secondary fluid y(e.g. washwater or ilocculant) are separately fed into separate feed compartments located inside of a rotating bowl, and then pass radially outwardly into the bowl.

In such centrifuges, the feed compartments are usually located in a rotary member, such as the hub of a conveyor rotating at a differential speed to that of the bowl, which rotates relative to the feed pipes to the compartments, these being normally stationary and extending into the bowl from one end. VTo completely isolate the separate compartments wouldV therefore require a rotary seal in a wall between them surrounding the stationary feed pipes. Such seals are not only expensive but when exposed to splashing slurry feed are likely to become contaminated and to foul. The practice has therefore been to provide only a splash baille or shield between the compartments with clearance around the feed pipes. Slurry splashing through this clearance not only contaminates the secondary iluid but also in time plugs the feed outlets, normally small diameter pipes, from the secondary feed compartment. This necessitates stopping and dismantling the machine to clean the plugged outlets.

A primary object of the invention is to provide such a centrifugal separator in which, without rotary seals, the feed of secondary fluid through its compartment to the bowl is so effectively shielded from the slurry that contamination of the secondary iluid with slurry and plugging of its feed outlets are prevented. Other objects are to provide such secondary iluid feed apparatus that is reliable, easily installed and serviced, and low in cost.

In general, the invention features a main feed compartment into which the slurry is initially fed; a secondary feed compartment spaced axially along the bowl from the main compartment; a splash baille, located between the feed compartments and having a feed conduit openice ing; a secondary fluid chamber located inside the secondary feed compartment, having a secondary iluid feed conduit opening, and spaced at least in part from the wall of the secondary feed compartment and from the baille to provide ilow space radially outwardly of the chamber opening for slurry that splashes through the splash baille; and at least one conduit communicating between the bowl and the secondary iluid chamber and passing through the wall of the secondary feed compartment. The wall of the secondary feed compartment is provided with one or more outlets to drain slurry that splashes from the main compartment through the splash baille into the flow space. In preferred embodiments the conduit between the chamber and the bowl passes through an enlarged opening in the secondary feed compartment wall, to provide the drainage for splashed slurry, the secondary iluid chamber is removably mounted in the secondary feed compartment, preferably on a radial baille adjacent one end of the secondary compartment, and the conduit or conduits are removably secured to the chamber wall.

Other objects, features, and advantages will appear from the following description of a preferred embodiment of the invention, taken together with the attached drawings thereof, in which:

FIG. l is a side view partly broken away and partly in section, of a separator embodying the present invention; and

FIG. 2 is a section taken along 2-2 of FIG. l.

In the illustrated embodiment, separator bowl 10 is supported at its ends by hollow shafts 11, 12 respectively journaled in bearing supports 14, 1-6, shaft 11 being removably connected to bowl 10 by disc 10b fastened thereto by bolts 15. Conveyer 17, including helical blade 18 mounted on generally cylindrical hub 19, is rotatably supported inside bowl 10 on shafts 20, 22 respectively journaled within shafts 11, 12. Shafts 11 and 20 are coupled through gear unit 26 so that when shaft 12 is driven by a belt (not shown) through sheave 28, the bowl and conveyer will rotate at slightly different speeds.

Slurry feed pipe 34 extends axially inside conveyer hub 19. A feed pipe 40 for a secondary fluid, in this case flocculant, surrounds pipe 34. Liquid eilluent pipe 42 surrounds and is eccentrically mounted for rotation at its forward end on pipe 40. Liquid skimmer assembly 44 is mounted at the forward end of pipe 42 and includes skimmer 46 which extends radially outwardly from the bowl axis into annular enlargement 48 of hub 19. The other end of eilluent pipe 42 extends into a worm gear arrangement (not shown) in bearing assembly 36, which allows pipe 42 to be rotated while the machine is in operation, thereby, by virtue of the eccentric mounting, to change the radial position with respect to the bowl axis of skimmer 46. Liquid enters hub enlargement 48 through openings 50 to be scooped up by skimmer 46. Further details of a skimmer assembly and eccentric mounting of this type are disclosed in U.S. Patent 3,279,687.

Radial bailles 52 and 54 deilne main feed compartment 56 and secondary feed compartment 5S inside hub 19. Batlle 52 acts as a splash baille and has opening 60 through which feed pipe 34 passes. Slurry fed through pipe 34 enters the bowl through holes 62 in the conveyor hub. Secondary iluid chamber 64 is removably bolted by Wall 66 to baille 54 and includes cylindrical wall 68 of diameter less than that of the conveyer hub, frusto-conical wall at its end nearest splash baille 52, and a sleeve 72 passing axially through wall 70 to define opening 74 through which pipe 34 passes, the sleeve and wall together eilectively preventing slurry from entering chamber 64. Flocculant feed pipe 40 enters through wall 66 and terminates inside chamber 64 and has a discharge opening 65 into said chamber. Four radial pipes S0 extend from chamber 3 64 through enlarged holes 82 in hub 19 into the bowl, these pipesbeing removably mounted on the chamber by screw threaded ends 81 received in threaded apertures 83 in wall 68 of the chamber. By this arrangement chamber 64 may, after removal of pipes 80 therefrom, be readily separated bodily from the conveyer for cleaning or repair.

Bowl 10 has a frusto-conical portion 10a, leading to solids discharge chamber 84 and outlet pipe 86.

In operation, slurry is fed through pipe 34 into compartment 56'and through openings 62 into the bowl. Centrifugal action produces a radially outermost layer of solids that moves along the bowl wall under the action of conveyer 17 toward and out openings 85. The radially inward layervof retained liquid is scooped up by skimmer 46 and passes out through pipes 42, 42a. Flocculant is fed through pipe 40 into chamber 64 and hence into the slurry in the bowl through pipes 80. Any slurry that splashes from compartment 56 through opening 60 in splash baffle 52 tends to be thrown radially outwardly, to enter the ow space between wall 68 of chamber 64 and hub 19, and to pass into the bowl through enlarged openings 82. Wall 70 and sleeve 72 effectively prevent the slurry from entering chamber 64.

Other embodiments will occur to those skilled in the art and are within the following claims:

1. In a centrifugal separator comprising a rotatable bowl, means for feeding slurry and another fluid separately into said bowl from one end thereof, main and secondary feed compartments for initially receiving and thereafter discharging into the bowl said slurry and other fluid respectively, said compartments being mounted Within the bowl for rotation about said feed means, and a splash baille between said feed compartments and spaced radially of the bowl from said feed means, the combination of a secondary fluid chamber located inside said secondary feed compartment communicating with said feed means for receiving said other fluid from said feed means, said chamber spaced axially of the bowl from said bathe and spaced radially of the bowl from the outer wall of said secondary feed compartment to provide space in said secondary compartment external to said chamber for receiving slurry splashing from said main compartment through the space between said baffle and said feed means;

at least one conduit extending from said chamber and through said secondary compartment outer wall for discharging said other lluid from said chamber into said bowl; and

at least one outlet in said secondary compartment outer wall for draining slurry received in said compartment into the bowl.

2. The separator according to claim 1 wherein said outlet comprsesan aperture in saidcompartment Outer wall through which passes a said conduit, said aperture being substantially larger than thel outer diameter of said conduit.

3. The separator according to claim 1 further including a conveyer rotatably mountedwithin the bowl for rotation 'relativeethereto aboutvthe bowl axis, said conveyer having `a generally cylindricalfhub comprising said compartments and forming saidfouterwalliof said `secondary feed compartment.'4 Y j 4. The separator'accordig to'claim 3l wherein the end of said chamber nearer said V`splash'baflle is provided with a wall closely surrounding a portion ofvsaidfeed means. 5. The separatoraccording to`clain'1 4 wherein said chamber end wall is frusto-conical with its base nearer said baie and is provided centrally toward the apex with a sleeve surrounding said portion of said feed means.

6. The separator according to-claim 1 wherein'said secondary compartment is provided with an end wall spaced longitudinally of the bowl axis from said baffle', said chamber is removably mounted on said end wall and each said conduit is removably secured to said chamber. Y

7. A centrifugal separator comprising a rotatable bowl;

Ymeans for feeding slurry and another fluid separately into said bowl;

a member mounted in saidv bowl and having a wallrotatably surrounding said feed means to provide a zone to initially receive and thereafter discharge into the bowl said slurry; f v l a chamber located inside said member and surrounded by said wall for receiving said other fluid from said feed means, said chamber being spaced radially from said wall to provide space in 'said member external to said chamber, said space being in at least partial communication with said zone for receiving slurry splashings; and l f at least one conduit yc extending from said chamber and through said wall for discharging said other uid from said chamber into -said bowl.

8. The separator of claim 7 wherein said chamber is removably mounted in said member and said conduit iS removably secured to saidchamber. f 1

-References Cited UNITED STATES PATENTS 2,578,456 12/1951 Smith 233-14 XR `2,670,131 27/ 1954 Ried 233-14 2,685,369 8/1954 Crossley 233-14 XR 2,711,854 6/1955- Kjellgren 233-7 3,228,594 l/1966 Amero 233-7 HENRY T. KLINKSIEK, Primary Examiner.