US1689490A - Centrifugal extractor - Google Patents

Description

Oct. 30, 1928.

Inventor ClfmarlesA. Keley. by

His Attorn ey.

Patented Oct. 30, 1928.

UNITED STATES PATENT OFFICE.

CHARLES A. KELSEY, 0F SCHENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELC- TRIC COMPANY, A CORPORATION OF NEW YORK.

CENTRIFUGAL EXTRACTOR.

Application filed December 10, 1927.

My invention relates generally to centrifugal extractors and more particularly to an improved construction for continuously feeding material therethrough.

In centrifugal extractors as heretofore constructed it has been the practice to provide a rotatable perforated receptacle into which liquor containing solid material in suspension was delivered, the liquid being thrown outwardly through the perforations in the receptacle by centrifugal force and the solid material being retained on the inner wall of the receptacle. It was necessary to stop the rotation of these extractors periodically and remove the solid material from the walls of the receptacles which was inconvenient and which decreased the capacity of the extract-ors over any given period of use.

It has been proposed t0 continuously feed material through extractors of this type by various means so that it would be unnecessary to interrupt their operation to remove solid material therefrom, but such arrangements as heretofore proposed have been objectionable because of the excessive amount of power required to operate theextractors when the feeding devices were used; The increase of power required in using these feeding devices has been due largely to the fact that solid material became packed between the feeding elements and the wall of t-he receptacle. Moreover, in many forms of these devices the power applied to them has been such as to produce a torque directly opposing` the means employed for rotating the eX- tractor which further increased the power required.

The object of my invention is to provide an arrangement for `feeding material through the perforated receptacle of a centrifugal. extractor of this type such that the power required to operate the feeding mechanism will he minimized, and such that the feeding means will not increase the load on the means for driving the extractor. I accomplish this by providing means for feeding the material through the perforated receptacle, which moves in one direction along a wall of the receptacle and which then moves in another direction along and away from the wall of the receptacle. Such `an arrangement feeds the material along the wall of the receptacle during movement of the feeding means in one direction without caus- Serial No. 239,100.

ing thematerial to become packed between the feeding means and the receptacle, and 'permits the feeding means, during its movement in the other direction, to slide freely over the solid material. In this way force is applied for feeding the material only in the direction of feed without producing any substantial torque resisting the means foi' driving the extractor and without accumulating packed solid material between the receptacle and the feeding element.

My invention will be more fully set forth in the following description referring-to the accompanying drawing, and the features of novelty which characterize my invention will be pointed out with particularity in the claims annexed to and forming a part of this specication.

ln the drawing Fig. l is a vertical, sectional view of a centrifugal. extractor embodying my invention; Fig. 2 is a transverse sectional view on the line Q-Q of Fig. l, and Fig. 3 in a fragmentary section of the extractor, in which the position of the feeding element during its downward movement is indicated in full lines, and in which its posit-ion during its upward movement is indicated in dotted lines.

Referring to the drawing, I have shown my invention, for convenience in illustration, in connection with a centrifugal eX- tractor'comprising a rotatable cylindrical receptacle l0 having a perforated side wall l0a within which the solid material is retained and through which the liquid is discharged, the openings in the perforated side wall being made small. enough to retain the solid material therein. The perforated wall l0, which is reenforced bya plurality of bands l0b so as to withstand centrifugal stresses, is mounted on a base member 10C of the receptacle provided with outlets l0d through which solid material separated from the liquor fed into the receptacle is discharged. The receptacle is driven by an electric motor ll or other suitable means mounted on an overhanging framework l2, and the receptacle is suspended from this framework by a shaft 18 which is driven by the motor. The shaft 13 entends through an opening 100 inthe upper wall of the receptacle and is secured to the base l()C of the receptacle so as to form a driving` connection between the motor ll and the receptacle. Liquid discharged from the receptacle 10 impinges against the wall of a cylindrical chamber 1d arranged about the receptacle and flows into an annular liquid receiving trough 15 formed in the bottom thereof from which it flows through a ipe 16. A wall 15a of the trough extends a out the base 10c of the receptacle in spaced relation thereto so as to permit the base member to turn freely in the chamber lll. The wall 15a extends above the openings 10 in the base 10c and is inclined toward the openings 101 so that the solid material discharged from the receptacle is directed by the wall into the hopper 17 arranged below the liquid receiving trough.

When liquor containing solid material, such as crystals or pulp, is fed into the rotat ing receptacle 10, it is desirable that the liquid should pass through the perforated side wall of thereceptacle 10 and that the solid material should gradually move toward the bottom of the receptacle and be discharged through the openings 10d into the hopper 17. However, it is apparent that unless some arrangement is provided for feeding the pulp or crystals toward the bottom oft-he receptacle that it will be retained on the side Walls of the receptacle by centrifugal force. In accordance with my invention the flow of the material along the wall of the receptacle 10 is controlled by providing a feeding element arranged adjacent the inner wall of the receptacle and moving this element in one direction along the axis of rotation of the receptacle so as to feed the material toward the bottom of the receptacle, and then moving the feeding element toward the top of the receptacle and away from tho side wall thereof, so that the material. moved downwardly during the first mentioned movement will not be disturbed by the element in returningto its initial position. In the construction illustrated in the drawing, a plurality of suoli feeding elements 19 are arranged between a hollow reciprocating cylindrical member 2O of somewhat smaller diameter than the inside of the receptacle 10 and the perforated side wall of the receptacle. The feeding elements are arcuate in form and pivotally connected at 19a to the reciprocating cylindrical member 2O so that upon rotation of the member the feeding elements are thrown outwardly to a substantially horizontal position by centrifugal force. The feeding elements are formed so that when they are in this horizontal. position they overlap, as indicated at 19", and extend closely adjacent the wallsA over the inner surface of the solid material against which they are urged by centrifugal force. ln this way the feeding elements are moved upwardly to their initial position without disturbing the solid material which has been fed along the inner wall of the receptacle during downward movement of the feeding elements in a horizontal position against the stops 20u. Although I have shown the feeding element-s arranged in series of annular groups in which the feeding elements overlap they may be arranged in any other convenient manner. The cylindrical member 2O is supported during its reciprocatory movement, which actuates the feed` ing elements as above described, by a lower bearing 2Ob and an upper bearing 20c which is carried by a transverse imperforate partition wall 20d formed in the cylindrical member in spaced relation to the upper wall thereof, the lower bearing 2()d being slidably keyed at 13a to the shaft 13 so that the receptacle and the cylindrical member are rotated together by the motor 11. lt is not essential, however, to rotate the cylindrical member 2O with the receptacle 10 and in some instances it may be desired to dispense with the lrey 13a and rotate or oscillate the cylindrical member relative to the receptacle by other suitable mechanism. The cylindrical member 20 may be reciprocated in any suitable manner, but in the construction shown it is reciprocated by a gear and crank mechanism including a lever 21, which is pivotallysupported at -22 on a bracket 23 carried by the framework 12, and which is driven by a worm 24 secured to the shaft 13 connecting the motor 11 with the receptacle 10. rllhe movement of the lever 21 is transmitted to the cylindrical member 2O so as to reciprocate the same by a roller 25 secured to the lever 21, which is arranged between flanges 26 formed on the hollow shaft 27 extending through the open ing 2Oe in the upper wall of the member 2O and secured to the imperforate partition wall 2()d formed in the cylindrical member adjacent the upper wall thereof. A supply pipe 18, which is supported in any convenient manner, is arranged to discharge liquor having solid material in suspension through the opening 2Oe in the upper wall of the cylindrical member 20 into the space between the upper wall of the cylindrical member and the imperforate partition 20d, from which it flows through openings 2()f into the space between the two uppermost of the feeding members 19, the cylindrical member 20 and the perforated wall 10a of the receptacle. As the openings 20f are formed in the side wall of the cylindrical member' 2O at the upper surface of the imperforate partition 20d and between the two uppermost feeding elements 19, the solid material and liquor will not be trapped within the cylindrical member 20 and the solid material will not accumulate in the top of the receptacle 10.

In the operation of the centrifugal extractor which I have described, liquid having solid material in suspension is fed into the cylindrical member 20 and is discharged through the openings 20f into the space between the cylindrical member and the per forated wall of the receptacle 10. The re ceptacleand the cylindrical member are rotated at high speed by the electric motor 11 so t-hat the liquid is discharged through the perforations 1()a into the chamber 14 from which it is removed through the pipe 16, and the solid material is retained against the inner wall of the receptacle 10 by centrifugal force. The cylindrical member 2O is rotated with the receptacle 10 by the key 13a and is reciprocated longitudinally of the receptacle at the same time by the roller 25, which is actuated by the Worm 24 driving the link 21 through the gear and crank mechanism supported on the bracket 23. As the cylindrical member 20 is moved downwardly the feeding elements 19 are retained in their horizontal positionagainst the stops 2Oa so that the feeding elements move along the inner wall of the receptacle 10 and feed the solid material, which accumulates therein, downwardly, Upon upward movement of the cylindrical member 20 the feeding elements 19 are swung about their pivotal supports 19a away from the perforated side wall 10a of the receptacle 10, as indicated in dotted lines in Fig. 3, by the solid material indicated at M which is retained against the perforated wall 10a of the receptacle by centrifugal force. Although centrifugal force retains the feeding elements against the material on the perforated side wall of the receptacle 10, it does not exert sufficient force to disturb the material during the upward movement of the feeding elements. As the feeding elements are retained against the solid material on the inner wall of the receptacle by centrifugal force-during this upward move-L ment of the member 20, upon its downward movement which follows the friction of the feeding elements against the material turns them about their pivotal supports 19a to a horizontal position into engagement with the stops 20a and feeds the solid material downwardly, as previously described.

The centrifugal extractor which I have disclosed is merely illustrative of one embodiment of my invention, and I intend, therefore, in the appended-claims to cover all modifications which do not depart from the spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States is 1. A centrifugal extractor comprising a receptacle having a perforated side wall, means for rotating said receptacle, a feeding element adjacent the side wall of said receptacle, means for supporting said element, and means for moving said support so that said element moves back and forth along the side wall of said receptacle, said supporting means being arranged so that said element moves away from said side wall when said supporting means is moved in one direction.

2. A centrifugal extractor comprising a receptacle having a perforated side wall, a member in said receptacle, means for rotatingl said receptacle, means for reciprocating said member along the axis of rotation of said receptacle, and means pivotally supported on said member responsive to reciprocatory movement of said member for feeding material through said receptacle.

3. A centrifugal extractor comprising a receptacle having a perforated side wall, means for rotating said receptacle, a member in said receptacle, a feeding element pivotally connected to said member and adapted to be brought closely adjacent the side wall of said receptacle upon rotation of said member, means for reciprocating said member, and means for retaining said element closely adjacent the side wall of said receptacle during its movement in one directionv only so as to feed material through said receptacle and to permit said element to swing away from the side wall of said receptacle during movement of said member in the other direction.

4. A centrifugal extractor comprising a receptacle having a perforated side wall, means for rotating said receptacle, and means for feeding material through said receptacle comprising a member in said receptacle having a plurality of elementspivotally connected thereto which are adapted to be moved closely adjacent and away from the side wall of said receptacle during rotation of said member, said elements being shaped so as to form a continuous annular wall when they are "adjacent the side wall of said receptacle.

5. A centrifugal extractor comprising a receptacle having a perforated side wall, a memberin said receptacle, means for rotating said receptacle and said member, means for reciprocating said member longitudinally of the axis of rotation of .said receptacle,

and a plurality of feeding elements pivetally connected to said member` which are adapted to be moved closely adjacent the side well of said receptacle in response to rotation of the latter, said elements being shaped so as to overlap and form e continuous annuler Wall when they are closely adjacent seid side Wall, and means for retaining said elements closely adjacent the side Wall of said receptacle during movement of said member in one direction only so es to feed material through said receptacle and to permit said elements to swing' away Yfrom the side Wall of said receptacle during movement of said member in the other direction. Y

In Witness whereof, I have hereunto set my band this 8th day of December, 192?.

CHARLES A. KELSEY.

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