US2093470A - Mechanism for separating intermixed divided materials - Google Patents

Description

Sept. 21, 1937. J. D. MORGAN MECHANISM FOR SEPARATING INTE RMIXEDDIVIDED MATERIALS Original Filed Aug. 5, 1951 INVENTOR.

III/II" I I l m! IIIIIIIIIG VIII,

Patented Sept. .21, 1937 PATENT OFFICE 'MEcnANIsM son. SEPARATING INTER- Mrxsn DIVIDED MATERIALS John D. Morgan, Summit, N, J assignor to Rich-' ard Peale, Clearfield, Pa., W. Sanders Davies,

- New York, N. Y., and William B. Oakes, Ruth eri'ord, N. J., as trustees Original application August 5," 1931, Serial No. 555,160. Divided and this application July 5,

1935, Serial No. 29,868

- 40mins. (01. 209-414) I The invention relates to a novel and useful mechanism for separating intermixed, divided materials, and more particularly to a novel and useful mechanism for purifying raw, run-of-themine coal.

Objects and advantages of the invention will be set forth in part hereinafter and in part will be obvious herefrom, or may be learned by practice with the invention, the same being realized and attained by means of the instrumentalities and combinations pointed out in the appended claims. v

The invention consists in thepovel parts, constructions, arrangements, combinations and improvements herein shown and described.

The accompanying drawing, referred to herein and constituting a part hereof, illustrates one embodiment of the invention, and together with the description, serves to explain the principles of the 20. invention.

of the drawing:-

Fig. 1 is a vertical longitudinal section of a mechanism embodying the invention; and

Fig. 2 is a fragmentary top plan taken substantially on the line 2-2 of Fig. 1.

This application is a division of my copending application Ser. No. 555,160, filed August 5, 1931. The invention relates to a novel and improved mechanism especially capacitated for separating intermixed broken, or other finely .divided, ma-

terials varying widely in range of sizes of thepieces or particles, and some at least of the intermixed mat'erials-varying but little in their specific 'gravities. An lntermixture of this kind to which 3 the invention is particularly applicable, is raw or impure coal as it comes from the mine, with only the very large lumps or pieces crushed orremoved. That is, effective and satisfactory commercial purification of such coal is effected without the costly and cumbersome pre-sizing which is widely practiced, and which has been necessary in the greater part of the prior art processes and mechanisms" Due to the concurrent wide size range of the pieces, and the close approximation in specific gravities of the intermixed materials, successful and efficient commercial separation, such as purification'of run-of-mine coal above-referred to, presents a problem of great practical 'dimculty, especially in view of the commercial requirements for an exceedingly close approximation to the washability curves, or fioat-and-sink tests.

In carrying out my invention I employ as the separating agency or medium a dry, particulate fluid or fluid agency, of variably predeterminable specific gravity. I employ as the present preferred form, a dry, finely-divided or otherwise particulatematerial through which air, or other gas, is infiltrated to render it thoroughly fluid, and in such regulated proportion as to secure a specific gravity 5 which will establish and maintain the desired splitting point for the particular coal being purified;

The most efiicient dry fiuid medium, so far as now known, consists of finely particulate materials, such as sand or very fine coal, into which a regulated quantity of air is infiltrated to impart practically complete fluid properties to the infiltrated material, and at the same time to give a specific gravity to the dry fiuid medium between that of the lightest material of one separated group and that of the heaviest material of the other separated group, or a specific gravity which in cooperation with currents or flowage movement likewise created in the fiuid medium will effect a separation of the intermixed materials at the required or desired splitting point.

By my invention there are brought together predeterminedly proportioned, positively fed quantities or volumes of raw coal and of the fluidic separating medium, with regulated infiltration of air into the fluidic material, to impart fuller fluidic properties, and a predetermined or necessary specific gravity thereto. A selectively variable amount of head is also imposed on the fluidic medium. There is thus created a positively impelled forwardly flowing current of desired depth, velocity and direction ofthe fluidic medium bearing a proportioned stream or bed of coal undergoing separation and purification. These conditions cooperate to create efllcient separation of the materials at the desired specific gravity splitting point, and also to impart an adequate and relatively great propulsive forward efiect to the bed or layer of, coal, or other material, and imposing on the bed of coal a dynamic and agitational separating action of the fluidic medium, while involving in the dynamic or en masse movement only a comparatively small quantity of the fluidic medium. This current action of the proportioned quantity of fiuldic medium greatly increases the separating 'em-' ciency and capacity of the mechanism, and at the same time circulation and other handling of only a minimum quantity of the fluidic medium is necessitated.

In present preferred practice, the raw coal and the fluidic separating medium are positively fed in regulated predetermined proportions into a bed, the coal being supported on, and the s paration and purification taking place, in connection with and by reason of, the flowage or current of the air infiltrated fluidic medium of definite, regulated depth and velocity. All these factors will be fixed or maintained at the highest practicable efficiency for a particular raw coal being cleaned; that is, to effect purification as closely as possible to the washability curve, and also with the minimum amount of fiowage, handling and recirculation of the fluidic separating medium. By this positive proportional feed of the raw coal and fluidic separating medium, all the conditions can be correlated nicely and accurately for efficient separation despite the wide variations of various raw coals as to such items or factors as proportion of coarse and fines, percentage of free ash, physical nature of impurities, relative proportions of impurities in coarse and fines, and other factors which may be present, in various conditions and proportions, in any particular case. The depth and velocity of the fluidic medium current can be varied with respect to each other, and these and the total flowage volume of the fluidic separating medium can be varied or regulated with respect to the volume or bed of raw coal, and the speed of the latter may also be controlled to meet the conditions or requirements of maximum separating efficiency.

It will be clear, therefore, that the wide and minute regulation of the feed of the fluidic medium independently of the inclination of the bed, or other head imposed, which is provided by my invention, createsan entirely different and novel purifying action and agency not otherwise obtainable. A wide range of variation and regulation in the velocity and depth of fiow of the fluidic medium is made possible apart from the structural features of the mechanism. This regulation of the fluidic medium is made or maintained proportional to the likewise regulated volume of raw coal which is fed to the table, as well as being correlated to the physical nature and condition of the particular coal. Thus the purifying action of the fluidic medium, both dynamic, agitational and otherwise is nicely determined and regulated; and in addition the capacity of the table can be regulated and raised greatly. above the normal capacity of the mechanism, and to the highe t point consistent with efficient commercial puri cation. Furthermore, these enhanced results are obtained with a minimum amount of the fluidic medium.

It is found eflicient or advisable in separating certain kinds of coal to establish in the fluidic.

separating medium a surface current oi. desired depth and velocity traveling forwardly over a relatively quiescent body of the fluidic medium to the place of discharge of the forwardly moving layer or bed of coal, or the like, undergoing separation or purification, and the present invention is well adapted to such process. In practicing such process, there is provided or maintained above a. relatively quiescent body or mass of the fluidic medium, by the positive, proportional feed of raw coal and fluidic material, a surface current of accurately predeterminable depth, velocity and direction, the currentsupplying a rela-,

tively great en masse or mass movement effect while the e e body of the fluidic medium participates inthe separating and purifying process or action. It will be understood that a very strong en masse movement or effect is obtained from the ciroulationof a relatively small part of the body of fluidic medium while the entire body thereof participates in the sink-and-float separating action. In this case, the air infiltration may be effected entirely in the relatively quiescent body of the fluidic medium, or both in the body and in the positively fed-in stream of fluidic material.

The surface current of the desired velocity and thickness which is created by the positive and regulable feed of the dry fluid medium and the impartation of the desired head, at the desired specific gravity, exert a strong and effective en masse eifect uponthe supported bed or layer of raw coal, both as to the stratifying and separating action and the propulsive action, while at the same time an exceedingly small amount of the dry fluid medium is handled and circulated in proportion'to the effect realized therefrom. When sand or the like is used, most of the trouble and labor of separating the sand from the coal and of recirculating the sand is avoided. At the same time the action of a fuller and deeper bed, with less action in the deeper parts thereof, is realized in the separating action.

Referring to the embodiment of the invention illustrated by way of example in the accompanying drawing, the embodied means for creating a positive current of .the dry fluidic medium of the depth, velocity and specific gravity desired to most effectively purify a particular kind of raw coal comprises devices for feeding positively to a table I a definite regulated amount of dry fluidic medium and infiltrating same to the desired degree with air to render it completely fluid and to secure the particular specific gravity-desired. Said embodied means for feeding the dry particulate material comprises a screw feed mechanism or mechanisms l0, shown as a plurality of screw feed devices, side-by-side along the rear end of the table I. A suitable supply of sand or other fluidic medium is provided, such as a hopper H, which may be common to a plurality of the screw feeds. The plurality of screw feeds I2 are mounted in the bottom of the hopper, and may work in feed pipes I6 in the usual manher. The screw feeds are driven, respectively, by a variable speed drive l3, which may be of any standard or other suitable construction. While the various screw feeds are shown with individual drives, it might be found convenient or expedient in particular cases to drive them by gear connections from a common variable speed drive.

By regulating the speed of the feeds for the sand or other fluidic medium, a positive current flow having the characteristics already described may be established. These feed pipes may be variably positioned both 'laterally and vertically, and

Fig. 1. The primary objective is to positively sup- I ply an accurately regulated, proportional amount of the fine coal, or sand to create a current flow of the desired or required depth, velocity and direction, and having the specific gravity requisite for most efiicient separation of the particular coal being purified. Y

The air infiltrating means\ as shown and described in these figures comprises an air chamber- 21 extending beneath the table I, the table 24, arear wall 25 and a front wall 23, the side and front walls extending downwardly and forming corresponding parts of the air chamber 2|. Air is conveyed to the chamber 2| by suitable means such as a duct 21, and the air may be supplied into the air duct by any suitable device,

- such as a fan (not shown). To regulate the air supply, the fan may have a variable speed drive, and also, if desired, a shutter 29 on the fan intake. In the air chamber are shown variably positionable vanes 30, which can be'used if desired, to variously direct the air upwardly to-' ward the air-pervious bottom 22 of the table in various parts of the air chamber.

Means are provided for'regulably and variably ,supplying the raw coal in desired proportional volume to the current flow of the fluidic medium for efficient purification of a particular coal, and as embodied (Fig. 1) a hopper 31 is provided having a variable speed feeding device 38 in the bottom thereof feeding the coal onto and across therear end of the table and onto the current of fluidic medium. As embodied, the feed device comprises a horizontally-disposed shaft 4|, journaled in the open, p'arti-cylindrical bottom of the hopper, the shaft having discs 42 fixed thereon, and a plurality of tangentially disposed blades 43 extending along the shaft and between the discs, and rotating within the cylindrical part of the hopper bottom. By varying the speed of rotation of this device the volume of feed may be very accurately determined, and the volume of raw coal and fluidic medium, as well as the depth and velocity and direction of the currents be coordinated so as to effect the most efficient separation of the particular coal. Means are provided further by the invention for varying the head imparted to the current of fluidic medium, that is, the forward and downward inclination or fall from the feeding-on locus for the raw coal at the rear of the bed to the discharge locus for the purified coal at the forward end of the bed, and for this purpose the upper part of the front wall of the table comprises a verticallydisposed plate 24|, which projects upwardly from the top edge of the wall 26, and is connected thereto by bolt and slot connection 242. A suitable lip or chute 243 extends forwardly from the table I, above. the air-pervious bottom 22,

the-plate being longitudinally reciprocable in a short path to propel forward and eject the settled heavy impurities at the lower front end of the table. The air from chamber 2| is forced upwardly through the air -pervious bottom 22, through perforated plate 49 and. upwardly through the raw coal in the bed. The perforate. plate maintains or promotes the activity and fluidity of the bed by adding its forwardly directed mechanical. propulsion effect to the natural forward flowage of the bed. The refusepropelling plate is shown inclined downwardly and forwardly from the rear of the bed toward the refuse discharge orifice 53 at the front lower end.-

I-he opening 53 can be regulated as desired, and

v may'be closed sufliciently so that the refuse will bank against it and no sand will be .passed except the slig ht quantity that is intermingled with the refuse, and there will be a minimum loss of fine coal or sand with the refuse. To effect the reciprocatory movement, the plate at its rear end mounted upon the table rear wall. The lever 56 is reciprocated by suitable means, such as an eccentric device 59. The plate 49 is preferably stepped transversely at various points, so that on its forward movement it will propel forwardly the heavy impurities resting thereon, and on its backward movement it will tend to retract the fluidic medium and thereby to discharge a minimum thereof with the refuse. The plate thus acts to maintain or enhance the activity and fluidity of the bed. The refuse discharge aperture 53 may be varied in height or area so as to discharge all the refuse and to prevent unnecessary discharge of.the fluidic medium. As embodied, a vertically-di sposed gate 6| is mounted against the inner face of the front wall 26, over the refuse discharge opening 53 by bolt-and slot connections 62, gate 6| being slidable up and down to vary the size of the opening 53. The refuse is discharged on to a vibrating screen 63. The sand from both the screens 44 and 63 may be recirculated and used repeatedly.

In the operation of the mechanism previously described, as already indicated, the volume of .ment also facilitating and expediting the separating action, partly by loosening the particles and effecting a continual interaction and change of position among the particles and pieces. The pure coal will float or will sink at an exceedingly slow rate and will be carried forward with the stream of the fluidic medium and be discharged at the front of the bed, while the heavy refuse will sink rapidly to the bottom and be discharged from the bottom of the table. By proper regulation of the flowage of the fluidic medium, a buoyant coefflcient may be created which will coact with the specific gravity in determining the efiective or practical splitting point. The system may be regulated to substantially bring the top of the current flow just above the front spillage edge of the table. Thus, a relatively small quantity of-flne coal or sand or other fluidic medium is required for the separating action, with a consequent minimum of separation of sand from the pure coal and refuse, and reconveyance and handling of sand. At the same time, due to the positive impartation or creation of a current flow of considerable velocity and depth, the capacity of the table is very greatly increased over that secured by a purely gravitational flow. The speciflc gravity and velocity will be such that all of the refuse will sink downwardly through the carry it to the place of discharge for the pure coal.

The invention in its broader aspects is not limited to the specific mechanisms shown and described but departures may be made therefrom within the scope of the accompanying claims without departing from the principles of the invention and without sacrificing its chief advantages.

What I claim is:

1. Mechanism for purifying raw coal including in combination a stationary table, means for maintaining on said table a forwardly moving bed comprising particulate material capable of being rendered fiuidic by the passage of air therethrough, a stationary air pervious bottom for the table, means for forcing air upwardly through said bottom and bed, means for feeding raw coal to the bed at the rear end of said table, a forwardly and downwardly inclinedperforated feeding and supporting plate within said table and above and spaced from said air-pervious bottom and extending substantially throughout the width and length of said table, means for longitudinally reciprocating said feedingand supporting plate, means at the forward end of the table for discharging clean coal, and means at the forward end of the table for discharging the refuse.

2. Mechanism for purifying raw coal including in combination a stationary table, means for maintaining on said table a forwardly moving bed comprising particulate material capable of being rendered fluidic by the passage of air therethrough, a stationary air pervious bottom for the table, means for forcing air upwardly through said bottom and bed, means for feeding raw coal to the bed, a forwardly and downwardly inclined perforated feeding and supporting plate within said table, above said bottom, means for longitudinally reciprocating said feeding and supporting plate, means for discharging the clean coal,

air-pervious bottom and extending substantially throughout the width and length of said table, means for longitudinally reciprocating said feeding and supporting plate, means for discharging the clean coal, and means for discharging the separated refuse.

4. Mechanism for purifying raw coal including in combination a stationary table supporting a forwardly moving bed, means for maintaining a bed of fluidic particulate material on said table, means for feeding raw coal to the table at the rear of the bed, means for discharging the clean Stratified coal at the forward end of the table, said coal-discharging means being at a lower level than that of said coal feeding means to impart a head to the moving bed, a stationary air-pervious bottom for the table, means for forcing air upwardly through said bottom and bed, a forwardly and downwardly inclined perforated feeding and supporting plate within said table and above and spaced from said air-pervious bot tom and extending substantially throughout the width and length of said table, means for longitudinally reciprocating said feeding and supporting plate, and means at the forward end of the table for discharging the refuse.

JOHN D. MORGAN.

Images