US2466491A - Process and apparatus for classifying materials - Google Patents

Description

April 5, 1949. A. D. SINDEN 2,466,491

PROCESS AND APPARATUS FOR CLASSIFYING MATERIALS Filed Sept. 10, 1943 4 Sheets-Sheet l FIE].

INVENTOR.

April 5, 1949. A. D. SINDEN 2,466,491

PROCESS AND APPARATUS FOR CLASSIFYING' MATERIALS Filed Sept. 10, 1943 4 Sheets-Sheet 2 I INVENTOR.

l aLfr'd I]n fiz'ndan April 5, 1949.

PROCESS AND Filed Sept. 10, 1943 Dz'scharzgns m INVENTOR. dlfr'ed D. 61 nden.

' Filed Sept. 10, 1945 4 Sheets-Sheet 4 April 5, 1949. A. D. SINDEN 2,466,491

PROCESS AND APPARATUS FOR CLASSIFYING MATERIALS INVENTOR.

dlfr'ed D. Sjndan. BY

Patented Apr. 5, 1949 UNITED STATES PATENT OFFICE PROCESS AND APPARATUS FOR CLASSIFYING MATERIALS 11 Claims.

The principal object of this invention is to provide a commercially practical process and apparatus for accurately and rapidly classifying materials between 10 mesh and 100 mesh. So far as I know, no process or apparatus having the emciency of that provided by the present invention is now available.

Generally speaking, this principal object is accomplished by forming the material to be separated into a flat stream of suitable speed and intersecting that stream with a flat jet or current of air. The most satisfactory results with ground limestone have been had with apparatus in which the stream of material to be separated is directed downwardly at approximately 45 degrees, and the intersecting stream of air is directed downwardly at right angles to the first stream, and therefore at 45 degrees also.

In this most satisfactory apparatus yet developed, the stream of material is formed by an endless belt travelling about idlers, one of which is driven, and within the group of which the belt is looped about a drum formed of spaced rings and enclosing a screw conveyor, the casing of which is slotted to provide feed openings to direct the material onto the belt in such a posi--- tion that it will gather sufficient speed to pass around the loop and be delivered from the upper side thereof in a stream directed downwardly at 45 degrees.

The thickness of the stream, its speed, the relative speed of the stream of material and the stream of air or other fluid will, of course. be varied to correspond with the conditions imposed by the particular material to be separated.

In the accompanying drawings illustrating the best known form of the apparatus- Fig. 1 is a side elevation with practically all of the mechanism enclosed within a casing;

Fig. 2 is a vertical section taken on the line 2 -'2 of Fig. 1;

Fig. 3 is a vertical section taken on the line 3-3 of Fig. 2;

Fig. 4 is a section taken on the broken line 4-4 of Fig. 1; and

Fig. 5 is a detail of the conveyor casing and the means for varying the size of the feed openings and the height of the feeding edge above the bottom of the conveyor casing.

But these drawings and the corresponding description are used for the purpose of disclosure only and are not intended to impose any limitations on the claims beyond what is made necessary by the prior art.

In these drawings and with particular reference now to Figs. 1 and 3, the means for project ing a mixture of different sizes of material in a stream is shown generally at A, the blower at B, the dust separator at C, and the discharge chutes for the classified material at D, all of these being within a casing generally indicated atE and supported upon a suitable framework generally indicated at F.

The projecting means A includes an endless belt 18 running on four idlers ll, l2, l3, and I4 grouped around a drum l5, and about which the belt is looped substantially as shown in Fig.

As best shown in Fig. 2, the drum is made up of a series of spaced rings Hi secured in proper relation by rods IT, to which they are welded or otherwise made fast. The right end ring [8 in Fig. 2 has a reduced hub portion l9 fitted with a hardened ring 9 to run against idlers 20 journalled on anti-friction bearings generally indicated at El. With the arrangement of the belt shown and the location of the idlers 20 shown in Fig. 1, two are necessary, though three or more may be used if preferred.

The left ring 22 of the drum has an extended hub 23 journalled on anti-friction bearings 24 carried at the outside of the casing E as best shown in Fig. 2. This is the driven end of the drum, and the arrangement of bearings gives it a satisfactory support, although, of course, some will prefer to use the same sort of mounting as is shown for the right end of the drum.

The end rings l8 and 22 have peripheral flanges 26 which, together with the circumferences of the intermediate rings, form the drum surface on which the belt [0 runs.

In this particular apparatus, the material to be classified is charged at 21 (Fig. 2) into a cylindrical casing 28 for a screw conveyor 29. For convenience in drive, the screw 29 is made coaxial with the drum l5, and its shaft 30 projects through a tubular extension 3i on the casing to connect with the drive generally indicated at G (Fig. 2).

The conveyor casing is provided with a series of openings or slots 32, here shown as rectangular and located in alignment with the spaces between adjacent rings of the drum. The size of those slots and the position of the lower edge will be varied to suit the material and other operating conditions. The pitch of the screw will determine how high the material tends to ride up on the conveyor casing, and the lower edge of the slots probably will have to be adjusted to suit the difierent materials; but, generally speaking, that edge should be somewhere around 20 to 30 degrees from the bottom meridian of the conveyor casing. In the apparatus here shown, the casing is provided with a strip or bar 33 (Fig. having its ends adjustably mounted in guides 34 and made fast by pins 35, so that the operator can by cut and try get the most suitable adjustment for the material. The conveyor will probably keep the material above the slots and the adjustment of the strip will determine the speed with which the material is fed from the conveyor casing onto the belt.

It will be observed from Fig. 3 that the material will be fed onto the belt in the general area indicated by the arrow H as it is proceeding downwardly and to the left. This will afford suflicient opportunity for the material to get the necessary speed and travel by centrifugal force on the belt around to the approximate position of the idler II, from which position it will be projected in a stream indicated by the arrow 36 passing through a tube or passageway 31 by which it is conducted beyond the idler l2 at the lower right corner of the group of idlers ll, [2, l3, and [4.

As before indicated, the thickness of the stream and its speed will be varied to suit the particular materials and other operating conditions.

In this particular apparatus, which has been found satisfactory for ground limestone, the fluid for the intersecting stream is air and is supplied by a centrifugal blower B, delivering through an air passage 38 in the general direction indicated by the arrow 39 intersecting the stream of material at right angles and within a sizable separating chamber generally indicated by 40. The thickness and the speed of the air stream will be a matter of choice and design to meet particular conditions and personal preference. Its effect is to take hold of the particles or lumps of material in the stream 36 and deflect them from the indicated course to an extent that is determined by their mass, volume, and shape, all of which affect the resistance they offer to the air stream, but the net result is that the material is separated approximately according to size, the heavier particles being deflected the least, the next heavier the next least, and so on until the impalpable powder is reached, which is entrained by the air stream and passes into the dust separator C.

In this particular apparatus, the separating chamber 40 is provided with adjustable vanes 4| and 42 (Fig. 3), which may be set from the outside of the casing by the levers 43 and 44 and locked in position by the wing nuts 45 and 46. These vanes effect a separation of the classified material between three passages 41, 48, and 49,

ending in chutes 50, 5|, and 52. These, of course, are merely illustrative. Any number of chutes and passages may be used.

The impalpable powder or dust entering the separator through the curved passage 53 will, in the main, be discharged at slot 54 and settled down into the discharge 12. Any remainder that is not so removed by the first passage in the separator will be fed in through the slit 55 to the main stream from the oncoming current of air.

The ends of the separator C are connected with return conduits 56 leading back to the end inlets 51 of the blower B. This arrangement of streams at 45 degrees with respect to the vertical and right angles to each other provides surfaces generally too steep for the angles of repose of any of the materials to be handled, and particularly the very fine material. In order to prevent dust from gathering just above the intersection of the two streams in the area indicated by 58, a slot 59 is provided to effect a continual feed into the swiftly moving stream, which will result as, of course, from Bernoullis theory.

As the streams intersect, there is a farming out of the material stream and, of course, some deflection of the air stream, but, in the main, there i a considerable part of the air stream continu ing generally in the line of the arrow 39. The circular portion of the dust separator is cut off from the separating chamber 40 by the angular plates 62, at the corner of which is the adjustable blade 63 which serves to shear the currents as the air and impalpable powder form the stream passing into the separator.

The entire apparatus is driven from a single electric motor 64 through the drive designated G in Fig. 2, comprising V belts $5 running over grooved pulleys 66 on the blower shaft and 61 on the shaft for the idler I l, as shown in Fig. 3. The motor is mounted on the top 68 of the casing E by hinges 69 at the left in Fig. 3 and adjustable bolts 10 at the right, whereby the belt tension can be regulated to suit conditions.

In this apparatus especially designed for classifying ground limestone at 10 mesh, 20 mesh, 40 mesh, and mesh, the belt is 24 inches wide with a lineal speed of 1600 F. P..M., While the air velocity in the jet or stream indicated by the arrow 39 is 5,000 F. P. M. The apparatus will satisfactorily handle a speed of 15 tons per hour. It is contemplated that apparatus will be designed with belts as wide as 48 inches, if not wider, and, as before indicated, the characteristics of different materials will require corresponding variations in the size and speed of the apparatus forming the two streams.

Enclosing the entire apparatus within the tight casing E and the arrangements for collecting all the dust and delivering it to an appropriate discharge is of great advantage in this apparatus.

I claim:

1. The process of classifying which includes forcibly projecting at a constant speed all the particles of a mixture of different sizes of material in a relatively thin stream of uniform thickness that is inclined downwardly so as to have a substantial vertical component and intersecting the stream of material substantially right angularly with a downwardly inclined fluid stream to deflect particles of the material according to their resistance to the fluid stream, whereby gravity and the projecting force are additive in opposition to the deflecting tendency of the fluid stream and the difference in deflection of light and heavy particles is enhanced.

2. The process of classifying which includes conveying a mixture of different sizes of material substantially horizontally, forming the conveyed material into a whirl about a substantially horizontal axis, discharging the material tangentially from the whirl in a downwardly inclined fast stream, of considerable width and of uniform thickness along its length and intersecting the fast stream of material with a fluid stream directed downwardly and inclined oppositely to the stream of material to deflect the material according to the resistance to the fluid stream.

3. In apparatus of the class described, means for projecting a mixture of different sizes of material in a downwardly inclined stream including a hollow, radially open drum mounted for rotation on a substantially horizontal axis, a belt running in a loop about said drumand a conveyor for conveying material into the drum and distributing evenly across the belt, and means for intersecting the stream of material projected by the belt with a downwardly directed and oppositely inclined stream of fluid to deflect the material according to the resistance to the fluid stream.

4. In apparatus of the class described, means for projecting a mixture of different sizes of material in a stream including an open, hollow drum comprising axially spaced rings journalled on a substantially horizontal axis and unconnected to each other at their peripheries, a conveyor running lengthwise to and inside of the drum feeding material through openings in the drum to its periphery, a belt looped about said periphery for receiving said material in a substantially even layer across the belt, and means for intersecting the stream of material projected by the belt with a stream of fluid to deflect particles of the material according to their resistance to the fluid stream.

5. In apparatus of the class described, means for projecting a mixture of different sizes of material in a flat, wide stream of uniform thickness, said means including a hollow, radially open drum, a belt runnin on idlers grouped around said drum, said drum Comprising axially spaced rings unconnected to each other at their peripheries, and means for intersecting the stream of material projected by the belt with a stream of fluid to deflect particles of the material according to their resistance to the fluid stream.

6. In apparatus of the class described, means for projecting a mixture of difierent sizes of material in a flat, wide stream including a hollow, radially open drum mounted for rotation on a substantially horizontal axis, a belt running in a loop about said drum, a screw conveyor running into the drum including a casing open at one side to feed material in an even layer on the belt, means for intersecting the stream of material projected by the belt with a stream of fluid to deflect particles of the material according to their resistance to the fluid stream, and means for varyin the effective opening in the side of the conveyor casing.

7. In apparatus of the class described, means for projecting a mixture of different sizes of material in a flat, wide stream of uniform thickness, said means including a radially open hollow drum of spaced rings unconnected at their peripheries, a wide belt loop about the drum and a conveyor runnin into'the drum for feeding material between the rings to the belt, and means for intersecting the stream of material projected by the belt with a stream of fluid to deflect particles of the material according to their resistance to the fluid stream.

8. In apparatus of the class described, an enclosure providing a passageway, means for projecting through the passageway all the particles of a mass of mixed sizes in a wide, thin stream of substantially uniform thickness lengthwise of the stream at high and uniform velocity with all the particles moving in substantially the same direction, said means comprising a plurality of axially spaced rings forming an open drum, a belt driven around the drum in contact with the rings and means feeding mixed particles through the drum to the belt, in combination with means for directing a stream of fluid into intersecting relation with the particle stream to deflect particles according to their resistance to the fluid stream.

9. In apparatus of the class described, an enclosure providing a passageway, means for projecting through the passageway all the particles of a mass of mixed sizes in a wide, thin stream of substantially uniform thickness lengthwise of the stream at high and uniform velocity with all the particles moving in substantially the same direction said means comprising a plurality of axially spaced rings forming an open drum, a belt driven around the drum in contact with the rings and a conveyor extending lengthwise in the drum for supplying mixed particles through the drum to the belt, in combination with means for directing a stream of fluid into intersecting relation with the particle stream to deflect particles according to their resistance to the fluid stream.

10. In apparatus of the class described, an enclosure providing a, passageway, means for projecting through the passageway all the particles of a mass of mixed sizes in a wide, thin stream of substantially uniform thickness lengthwise of the stream at high and uniform velocity with all the particles moving in the same direction, said means comprising a radially open hollow drum, a belt looped around the drum in contact with it, means extending into the drum for depositing particles on the belt in a layer of uniform thickness lengthwise of the belt, means for driving the belt to project said stream, and means for directing a stream of fluid into intersecting relation with the particle stream to deflect particles according to their resistance to the fluid stream.

11. The process of classifying which includes projecting all the particles of a mass of mixed sizes through a passageway in the form of a wide, thin stream of substantially uniform thickness lengthwise of the stream at high and uniform velocity with all the particles moving in substantially the same direction and spaced from the walls of the passageway by a layer of air moving with the stream, and intersecting the stream with a stream of fluid to deflect particles according to their resistance to the fluid stream.

ALFRED D. SINDEN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,080 Phillips et al May 4, 1841 530,445 Newby Dec. 4, 1894 974,395 Kidder Nov. 1, 1910 1,066,918 Kidder July 8, 1913 1,346,015 Gibson July 6, 1920 1,348,043 Parkinson July 27, 1920 1,420,593 Titchmarsh June 20, 1922 1,491,429 Stebbins Apr. 22, 1924 1,903,046 Hunter Mar. 28, 1933 2,081,182 Malke May 25, 1937 2,135,716 Johnson Nov. 8, 1938 2,210,505 Sinden Aug. 6., 1940 2,247,385 Huyett July 1, 1941 FOREIGN PATENTS Number Country Date 589,236 France Feb. 18, 1935 828,125 France Feb. 7, 1938 Certificate of Correction Patent No. 2,466,491. April 5, 1949.

ALFRED D. SIN DEN It is hereby certified that errors appear in the printed specification of the above numbered patent requiring correction as follows:

Column 4, line 43, claim 1, before the word constant strike out a; column 5, line 52, claim 7, for loop read looped;

and that the said Letters Patent should beread with these corrections therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 6th day of September, A. D. 1949.

THOMAS F. MURPHY,

Am'atant Uommksioner of Patents.

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