US1931496A - Centrifugal machine - Google Patents

Description

1 D. JONES CENTRIUGAL MACHINE oct. 24, 1933.

Filed Oct. 2, 1929 3 Sheets-Sheet l l? ENTOR BY @(m. d

ATTQRNE s Oct. 24, 1933. D. JONES 1,931,495

CENTRIFUGAL MACHINE Filed Oct. 2, 1929 5 Sheets-Sheet 2 4Z 70 INVENTOR l 3 @aww e LQ/55- Oct. 24,1933. L D, JONES CENTRIFUGAL MACHINE Filed Oct. 2, 1929 3 Sheets-Sheet 5 IN ENTOR @25M ATT ORNEY Patented Oct. 24, 1933 CENTRIFUGAL MACHINE Leo D. Jones, Philadelphia, Pa., assignor to The Sharples Specialty Company, Philadelphia, Pa., a corporation of Delaware Application October 2,

5 Claims.

This invention relatesv to centrifugal machines and particularly that type of centrifugal separation in which a stratum of solids is formed in the rotor as a result of the centrifugal separating operation. Certain features of my invention relate more particularly to a process andapparatus whereby liquid-free solids may be continuously discharged from the centrifugal rotor.

In the centrifugal separation of liquids from solids continuous removal of the liquid-freed solids from the rotor during rotation thereof presents a diicult problem. To accomplish the discharge of the collected solids, rotors of special shape have been employed and various devices have been proposed for pushing the solids toward a point of discharge but while such devices may be iinally rendered effective with respe'ct to certain materials by special refinements and alterations, such devices are f ound unsatisfactory with other materials. It has been proposed to employ a cylindrical rotor and to use a scraper in the form of a helix that is rotated at a slightly different speed from the speed of the rotor for the purpose of causing the helix to push the collected solids toward one end of the rotor in a manner similar to that in which the solids are advanced in;a screw conveyer. In such a construction the helix is sometimes continuous and sometimes consists of disconnected parts, but in either case the solids are being forced against the wall of the rotor by centrifugal force and the scraper must overcome the tendency of that force to prevent movement ofthe solids. As a result the solids that are under the influence of centrifugal force must be slid along the wall of the rotor or over a layer of solids lying on that walland there is also a sliding of the solids with respect to the scraper. Moreover such scrapers tend to move the liquid along with the solids vand to cause the discharge of liquid with the solids; and such Scrapers tend to maintain the inner surface of the annular layer of solids in a relatively smooth state that is conducive to the flow of liquid toward that point of the rotor from which the solids are discharged.

A feature of this invention is that the solids' in an operation that involves turning over of the layer of solids in a movement comparable to the 1929. Serial No. 396,654 (Cl. 21o-69) turning over of the surface of the earth by a plow. Another feature of this invention is that the inner surface of the cylindrical layer of solids is caused to consist of a series of annular furrows that prevent escape of liquid toward the point of the rotor from which solids are discharged and ensure that the centrifugal force will cause'the liquid to pass through the body of solids and through the wall of a perforated rotor. A feature of this invention is that the solids are advanced along the rotor toward the proper point of discharge therefrom by plows that turn over the material upon which they'act, the material being turned in a direction ,toward the proper Y point for discharge of the solids from the rotor. The plows are arranged to act one after another upon the material in order that it may be ad- I vanced to the discharge point from the most remote point of the rotor. The plows may be of the disk type and the disks may be allowed toA rotate or they may be held stationary or the plows may be of any other shape so long as they effect the purpose in the manner described. 'I'he rotor and the support for the plows will have a differential rotation and effect relative movement of the stratum of solids and the plows and the differential rate or rotation may be so chosen as to ensure that the solids will be in the rotor long enough to be freed of liquid to a desired degree. In some embodiments of my invention the' plow elements will be so positioned that they lie at an angle to a radius from the axis of rotation to the point at which the plow engages the annular bed of solids in the rotor and at an angle to the tangent to the path of the solids engaged by the plow.

Apparatus embodying my invention will preferably provide for distributing the mixture to be separated over the interior surface of the rotor at a point thereof remote from the point at which solids are discharged therefrom; and washing liq uid may also be supplied to the solids in the rotor, as by distributing it over the inner surface of the layer of solids in the rotor.

Other and further objects and advantages of my invention appear from the following detailed description of apparatus merely constituting i1'- lustrative embodiments of my invention and whereby my process may be practiced.

In the drawings, in which such illustrative embodiments of my invention are shown, similar reference characters indicate like parts, and

Fig. l is a top plan view with parts broken away of centrifugal machine embodying my invention and whereby my process may be practiced;

Fig. 2 is a sectional view generally on line 2--2 loi Fig. 1;

Fig. 5 is a sectional view generally on the line 5 5 of Fig. 4: i

Fig. 6 is a diagrammatic development of a part o1 the construction shown in Figs. 4 and 5; and

Figs. 7, 8, 9 and 10 are detail views.

In the practice of this invention the rotor may be perforate or imperforate, and in the centrifugal machine shown in Fig. 2, rotor 10 comprises a perforate cylindrical side wall llhaving rim 12 that is connected by arms 13 with hub 14 that is keyed to hollow driving shaft 15. Side wall 11 is provided with suitable perforations 16, and in the construction shown the rotor is provided with 'an inner lining 17 that is` provided with perforations of a size suitable to the material to be treated, and that lining is spaced from the side wall of the rotor by a pervious spacing member 18 that may consist of coarse wire screening. In the construction shown the rotor is provided with an inwardly extending ange or rib 19 that prevents escape in a downward direction of material treated in the rtor.

The solid-discharging apparatus and mixturedistributing means may be supported in any way with respect to the rotor, and in the construction shown, shaft 20 is supported in bearing 41 within hollow shaft 15. Keyed to shaft 20 is hub 21 that is provided with an upwardly-opening chamber 22 into which is fed the mixture to be separated. Hollow fan-like distributing members 23 are carried by hub 21 and communicate with radial passages 24 that lead through the side wall of hub 21. Within the interior of distributing members 23 there are located, vanes 25 that bring the material up to the speed of the outer ends of the distributing members by the time that material is discharged onto the inner wall of the rotor.

Plows 26 are carried by hub 21, being supported therefrom by brackets 27. Each bracket and its attachment to hub 21 provides for adjustment of the clearance between the plow and the inner wall of the rotor, and of the angle that the plow makes with a radius of the rotor, and of the -angle that the plow makes with a tangent to the path of the solids at the point where the plow engages the solids. In the construction shown each bracket 27 comprises a part 28 'that is threaded into hub 21 and locked in position, as by lock nut 29, and a part 30 pivoted to part 28. The pivot 31 is so constructed that the parts 28 and 30 may be locked in any chosen annular relation lto one another. Plows 26 are mounted on bracket-parts 30 in such manner that plow disks 26 may rotate or be held against rotation. To this end plow disks 26 are held to bracket parts 30 by screw 32 which may be surrounded by a bushing 33 located in the central opening of disk 26.

The position of the plow disks may be so adjusted, depending upon their shape, that the advancing edge of the plows cuts into the stratum of solids and the lface of the plow rolls the solids `over and toward the point at which solids rare In using disk plows In operation the mixture is introduced into chamber 22 and distributed over the inner wall of the rotor by members 23 and liquid passing through the Wall of the rotor is collected in chamber and withdrawn therefrom by pipe 36. Diierential rotation between shafts 15 and 20, accomplished in any known manner, will cause the plows to advance with respect to the collected solids and the resulting plowing operations, which advance an annular strip of solids by turning it over, will carry the solids over the upper edge` of the rotor and they will discharge therefrom and may be collected in any suitable receiver. The plows are so arranged in the construction shown that the lowermost plow of one group will turn over a strip of solids and that strip of solids is then engaged by the lowermost plow of the opposite group of plows. In this manner the solids are engaged alternately by a plow of one group and then by a plow of another group. Thus the plows of one group are in staggered relation with respect to the plows of another group and the solids are advanced throughout the full length of the inner wall of the rotor until they discharge therefrom. In the construction shown in Figs. 1 and 2 hub 2l is rotated clockwise with respect to the ,rotor in order that the plows will move the solids upward therein by plowing.

In the construction shown in Figs. 4 to 10 inclusive the mounting of the rotor is similar to the mounting of the rotor in the construction shown in Figs. 1 and 2 and the rotor is generally similar. lBetween ring 40 and rirn 12 of the rotor there is clamped an upwardly diverging frustoconical plate 42 that deflects `upward liquid discharged through the side wall of the casing in order that such liquid will pass over the inner wall 43 of the trough formed in the bottom of the liquid-collecting compartment 44. -The side wall of the rotor is cylindrical and the solids are discharged from the bottom of it into any suitable collecting compartment. To this end the bearing for shaft 15 is provided with a felt seal 45 (see Fig. 2) that acts upon a downward extension 46 of `hub 14 to prevent solids from enteringthe bearing. As shown in Fig. 5, a hub 47 is mounted upon the inner shaft 20 by means of a key 48 and a screw 49. Hub 47 is provided with an upwardly opening central chamber 50 for the reception of mixture that is to be4 separated and fan-shaped distributing members 23 lead outwardly therefrom and distribute mixture upon screen 17 of the side wall of the rotor, at a point near the upper tralizi/ng the pipe that supplies mixtureto the rotor and having orices 57 which discharge into vthe axial opening of chamber 53 liquid that is supplied through pipe 58. Leading downwardly from liquid chamber 53 are liquid passages 59 of which any number may be employedl and leading from passages 59 are pipes 60'which are provided with caps 61 having liquid discharge slots 62 as shown in Fig. 10; Thus, wash-liquid supplied through pipe 58 will be distributed through slots 62 upon the inner surface of the cake of solids in the rotor.

Upon hub 47 are mounted plows which advance thesolids lying on screen 17 toward the bottom of the rotor by turning over strips or bands of solids, the ridge of solids turned over by each plow being engaged by another plow and advanced further toward the lower edge of the rotor. For the support of the plows, hub 47 has a. series of hollow bosses 63, the arrangement of which is shown in Fig. 6 which illustrates diagrammatically the development of the outer surface of hub 47. In each of the openings 64 there is positioned a plow-bracket 65 carrying aplow 66, of the general construction shown in Fig. 8. In the openings 69 there is positioned a plow-bracket 70 carrying a plow '71 of the general construction shown in Fig. 9.

The plow members 66 and 71 are generally of the same conguration as disks 26 except that they each constitute only a sector of a disk and they are provided with integral studs 72 positioned in opening 73 in brackets and held against rotation therein in any suitable manner as by pins '74. Each bracket is supported in an opening 64 or 69, as the case may be, and is held against rotation therein, and in proper angular adjustment to effect suitable advance of solids by plowing. in any suitable manner as by pins 75.

In the construction shown there are two sets of plows consisting of nine plowseach, the plows of one set being set in staggered relation with respect to the plows of the other set, to the end that solid material acted upon by a plow of one set is again acted upon by a plow of the other set at a .point directly across the rotor.

The specific shape and arrangement and number of plows in any form of rotor is subject to considerable modification, and although the drawings show concave disk plows that are set at an angle that may be employed, different angles of adjustment may be used. Obviously variations may be made in the shape of the plows so long as the plows advance the solids as described. And various types of rotors, whichl are not necessarily perforated, may be employed.

With a construction similar to that shown in Fig. 2, and embodying a rotor eight inches in diameter, successful drying of salt hasbeen accomplished. The mixture of salt and water was supplied at such rate that 500 lbs. of dry salt were discharged per hour. The differential speed between hub 21 and rotor 11 was '12 R. P. M., i. e. the hub and its plows rotated 'I2 R. P. M. faster than the rotor. Thus, since it required three turns of the plows with respect to the rotor to advance the salt the entire length of the rotor, the contents of the rotor was changed twentyfour times a minute and the salt was retained in the bowl for two and a half seconds. The following results were obtained at various speeds of rotation of the rotor.

Percent.

R'PM' moisture trailing edge throws the solids upward and outward from the plow and turns or rolls the solids o ver in a direction substantially parallel to the axis of. rotation and toward the point at which solids are discharged from the rotor.

While I have described certain embodiments of my invention in great detail in order to assist in a full understanding thereof, I do not intend that my invention shall be limited to such details but that it shall include such modifications and variations as fall within the appended claims.

I claim:

1. In a centrifugal machine of the type wherein a layer of solids is formed on the inner wall of the rotor, a rotor having an inlet and means for the discharge of liquid, a hub mounted coaxially with said rotor for differential rotation with respect to said rotor, plows mounted on said hub for rotation with respect thereto about an axis radial to the rotor axis and adaped to form annular furrows in the stratum of solids by turning over the solids thereof, and means for locking said plows against rotation with respect to said hub.

2. In a centrifugal machine of the type wherein a layer of solids is formed on the inner wall of the rotor, a rotor having an inlet and means for the discharge of liquid, a hub mounted for differential rotation with respect to said rotor, hub brackets mounted on said hub for rotation with respect thereto about an axis radial to the axes of said hub, means for securiig said brackets in diiferent rotational positions with respect to said hub, and plows-carried by said brackets and engaging the layer of solids in said rotor and adapted to form furrows therein k. y turning over the solids of said layer.

3. In a centrifugal machine of the type wherein a layer of solids is formed on the inner wall of the rotor, a rotor having an inlet and means for the discharge of liquid, a hub mounted for rotation with respect to said rotor, plow brackets comprising parts pivoted together and having means for locking said parts in different relative positions, one of said parts being mounted 12u in said hub for rotation with 1 spect thereto, means for locking said parts in different positions of rotation with respect to said hub, and plows carried by the other said parts of said brackets and engaging the solids in said rotor.

4. In a centrifugal machine of the type wherein a layer`of solids is formed on the inner wall of the rotor, a rotor having an inlet and means for the discharge of liquid, a hub mounted coaxially with said rotor for relative rotation with 13u respect to said rotor, plow-brackets carried by said hub and adapted for radial adjustment with respect thereto, and plows carried by said brackets and engaging the solids in said rotor.

5. In a centrifugal machine of the type wherein a layer of solids is formed on the irmer wall of the rotor, a rotor having means for the discharge of liquid, a hub mounted for relative rotation with respect to said rotor and having an internal chamber for the supply of mixture to be iseparated, a distributing member extending from said chamber and adapted to distribute mixture over the irmer surface of said rotor within an annular zone at one end thereof, and means carried by said hub for advancing the solids along the inner wall of the rotor from said zone toward their point of discharge at the other end of the rotor.

LEO D. JONES.

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