US2205432A - Method and apparatus for separating solids of different gravities - Google Patents

Description

June 25, F. PARDEE METHOD AND APPARATUS FOR SEPARATING SOLIDS OF DIFFERENT GRAVITIES Filed June 20, 1939 2 Sheets-Sheet 1 INVENTOR. fiA/WKB DEE 2,205,432 METHOD AND APPARATUS FOR SEPARATING SOLIDS OF DIFFERENT GRAVITIES E E D m P F Filed June 20.' 19:59 2 Shets-Sheet 2 INVENTOR. [EA NKB: PDE'E Patented June 25, 1940 UNITED STATES DHITHOD AND APPARATUS FOR SEPARAT- ING SOLIDS OF DIFFERENT GRAVITIES Frank Pardee, Hazleton, Pa., assignor to Anthracite Separator Company, Hazleton, Pa., a corporation of Pennsylvania Application June 20, 1939, Serial No; 280,025 8 Claims. (01. 209 45e) My invention relates to a method and apparatus for separating solids of different densities or specific gravities such, for example, as a mixture of coal and slate, and more particularly to improvements on an apparatus of the above type disclosed in my co-pending Patent 2,199,091, April 30, 1940.

In the method and apparatus described in my co-pending application, the mixture of slate and coal or other materials of different densities, is supplied to an inclined surface, a conical surface being shown by way of example.

The inclined surface is perforated or otherwise permeable to liquid and a liquid is forced periodically upwardly through the plate buoying up the material thereon to an extentdepending upon the sizes of the particles of material and the density thereof. As a result the lighter materials are buoyed up higher and settle more slowly and, therefore, gradually accumulate on top of a lower layer or stratum of heavier particles. While stratification is advantageous, the method and apparatus operate satisfactorily without stratification.

As the buoying liquid then flows downwardly over the inclined plate it carries with it the lighter particles. The heavier particles are moved upwardly by a scraper, for example, a spiral scraper when a conically inclined surface is used, which is rotated in such a manner as gradually to move the lower heavier stratum upwardly to an upper discharge edge as, for ex-, ample, a central opening in an upwardly inclined conical surface. The lighter material overflows with the buoyant liquid into an annular receiving trough in which it is caught and from which it is removed mechanically while the buoying liquid returns and is again forced upwardly through the inclined plate.

The apparatus of the above application operates efficiently but in larger sizes Where there is a considerable change in altitude from the lowest to the highest part of the inclined plate and consequently a considerable'amount of water over the lower part of the plate, the flow of water may take place considerably above the particles of material on the plate and thus not to be fully effective in sweeping the lighter particles over the scraper and downwardly into the receiving trough.

Also in the larger size of apparatus the pulsating movement of the buoying liquid outwardly through the plate and over the lower edge thereof, and a stopping of this movement, may set up a wave motion inwardly and-outwardly that in certain cases may detract from the effectiveness of the buoying and moving action of the liquid.

In the present invention, I provide means whereby the flow of buoying liquid over the inclined surface is rendered more eifectivein its action on the particles of material to be separated and in which the tendency toward wave motion of the buoying liquid above the separating plate 'is eliminated.

The invention also provides an improved means for receiving the lighter particles and separating them from thebuoying liquid to be returned to the plate.

The various features of my invention are illustrated by way of example in the accompanying drawings in which Fig. l is a plan View of an apparatus embodying a preferred form of the invention, and

Fig. 2 is a vertical section of the apparatus taken on line 2-2 of Fig. l.

In the accompanying drawings the invention is illustrated as applied to a separator having a conical perforated plate Ill with an inner cen' tral discharge opening ll into which the heavier or denser material, such as slate or rock, isdischarged, and a lower outer edge having, an upstanding'wall [2 over which the lighter material, such as coal, is discharged.

The wall l2 extends downwardly to form an annular chamber beneath the plate It) and about the central opening or passage II. The wall of the central opening ll extends to and is supported on an annular base plate 13 on which the wall 12 is supported by an annular ring M. The ring !4 is provided with openings and plates l5 that swing inwardly and act as inwardly opening check valves to permit the flow of liquid, or buoying fluid, inwardly into the annular chamber within the wall l2- The wall I2 is enclosed in an outer wall it extending upwardly from the base plate [3 to form an annular chamber about the wall 12.

In the annular chamber between the central discharge passage II and the outer wall l2 there is provided a horizontal vertically movable plate ll having openings closed by upwardly swinging doors l8 that act as upwardly opening check valves. The plate I! is supported on and moved upwardly and downwardly by a number of vertical rods I!) that extend upwardly through suitable stufiing boxes 29 in the floor or bottom wall It and are in turn supported by a verticallymovable cross head 2! that'may be moved up and down by a walking beam 22 to which it is connected by a clevis 23.

As the walking beam or lever 22 tilts in oppo- Site directions on a fulcrum 24 it alternately lifts the head 2| and lowers it and. with it rods I9 and plate IT. The upward and downward movement of the plate I! acts as a piston to lift the liquid above the plate I! through perforations in the plate II) from the upper side of which it flows into the annular chamber between the walls l2 and I6 while water from this chamber flows past the gates I5 into the space below the plate I'I. As the plate I? descends the water below this plate is trapped by the valves or gates I5 and lifts the gates I8 to flow upwardly into the space above the plate i'I. 'With each upward movement of the plate I I water is forced upwardly through the plate I0 and thence into the annular chamber about the plate, then remains stationary while the plate descends so that there is a periodic upward movement of the water, or

buoying liquid, through the plate.

Material of different or differing specific gravity-is supplied from a hopper 25 above the plate I0 onto an annular distributing ring or mechanism 26 from which it is distributed by a rotating spiral scraper 21 in an annular path of distribution between the central and outer edges of. the plate-II], or the spiral scraper 21 may be stationary and the ring or mechanism 26 may rotate. I i

The material thus supplied is buoyed up by the water forced upwardly through the plate I0 by the plate II, the lighter material being buoyed more than the heavier or denser and settling more slowly, The material is gradually forced inwardly and upwardly to the center passage or opening I I by means of a spiral scraper 28 closely. fitting the upper surface of the plate ID and rotated in such a direction as to cause the material to be pushed upwardly on the slope of the plate I 0 toward the discharge opening II. The lighter material, however, is not only buoyed up by the buoying liquid, but is .washed downwardly of the slope as the liquid flows outwardly into the annular space between the walls I2 and I6.

Owing to the slope of the. plate I0, it will be apparent that as shown in Fig. 2, there will be a considerable depth of water at the outer or lower edge of the plate, if the plate be one of large diameter. As the plate I I rises it will cause a rapid circulation of water outwardly from the center part of the plate Illinto the annular channel between the plates I2 and I6 meanwhile giving considerable momentum to the mass of water thus moved. When the plate stops or moves downwardly the momentum of the water will carry it outwardly causing it to raise the level toward the outer wall It and then surge back and cause waves and pulsations in the water. The increasing depth of the water toward the outer edge of the plate I0 and the back surge of the water both decrease the tendency of the flowing water to carry the lighter products downwardly and over the outer edge of the plate In and thus impair the effectiveness of the apparatus.

To-overcome the surging of the water and to cause it to flow downwardly in immediate contact with the plate II] or the material resting thereon, -I provide a number of spiral baflle plates 29, 38, SI and 32 extending in spaced relation from the outer edge of the plate Ill to the inner edge or'opening thereof. The spiral plate 29 is arranged with its lower edge above or spaced from the upperedge of the scraper 28 so as to provide a passage therebetween for the downward.

flow of liquid and the particles carried with the liquid. The remaining baffles 30, 3| and 32, four baffles being shown by way of example, have their lower edges spaced from the upper surface of the plate Ill sufficiently to permit the passage of solid particles upwardly of the plate and downwardly and to confine the flow of liquid to the space between theplate I 0 and the lower edge of the baffles.

Accordingly, the up-flow of water through the plate It carries the particles .upwardly and brings the lighter particles toward the top and above the heavier particles and the out-flow of the water being confined between the plate I0 and the lower edges of the baffles 2932 flows in a more rapid current carrying the lighter particles with it downwardly over the overflow edge I2. Thus these baflies not only confine the flow of liquid to the upper surface of the plate Ii] but also prevent an inward and outward surge thereof. I

The bafiles 2932 are supported and carried on a number of radial arms 33 from which the baffles are suspended. The scraper plates 28 are in turn supported from the baflie 29 by any suitable means, such as the connecting bars 34. The arms 33 are suspended from a central shaft 35 which may be rotated to move the scrapers 28 over the surface I0. Any other suitable arrangement may be made whereby the baflles 2932 may be supported above the plate I0. 1

The lighter particles discharged over the up-' per edge of the wall I2 fall into an annular trough formed by a bottom 36 and a side wall 31. The arms 33 have depending projections 33 extending downwardly into the trough so as to carry the particles in the trough around toa discharge chute 39 which delivers them to a conveyor 40 which removes them from the annular chamber formed between the walls I2 and I6. The above arrangement provides ample space for the circulation of the water and enables the discharged particles to be separated from the water and be delivered in clean washed condition. 1

Through the above apparatus separators of the above type may be made of any desired size and an effective well-directed circulation of the water may be provided so as to separate the lighter wardly toward an upper discharge opening, it will I be understood that this arrangement might be plate and rotatable to move material upwardly of said surface, means to supply material to be separated to said plate, means to circulate a buoying fluid through said plate to buoy lighter material over said scraper and downwardly .over said surface and spiral members above said sur-. face and spaced therefrom suificiently to permit downwardly over said surface to the lower outeredge and into said channel, spiral members above said surface and spaced therefrom sufficiently to permit the passage of buoyant fluid and buoyed particles thereunder and a fluid receiving chamber enclosing said annular channel. 1

3. Apparatus of the type described which comprises a conical perforate plate having a central discharge opening and a peripheral discharge edge, a scraper extending spirally on said conical plate and rotatable to move material upwardly over the surface thereof, means to supply ma terial to be separatedrto said plate, means to circulate a buoying fluid through said plate to buoy lighter material over said scraper and downwardly over said surface and bafile members spaced above said surface to permit the passage of buoyant fluid and buoyed particles thereunder and to speed the flow of fluid over the surface thereof.

4. Apparatus of the type described which comprises a conical perforate plate having a central discharge opening and a peripheral discharge edge and sloping downwardly from said opening to said edge, a scraper extending spirally on said conical plate and rotatable about the axis thereof to move material upwardly on the surface of said plate, means to supply material to be separated to said plate in an annular zone between said peripheral edge and said central opening, means to circulate a buoying fluid upwardly through said plate and downwardly over the peripheral edge thereof to buoy lighter material over said scraper to said peripheral edge and means above said scraper to regulate the flow of fluid except along the surface of said plate.

5. Apparatus of the type described which comprises a conical perforate plate having an upper central discharge opening and a lower peripheral discharge edge, a scraper extending spirally on I said conical plate and rotatable to move material upwardly on the surface of said plate, means to supply material to said plate in a zone intermediate its peripheral edge and the central opening, means to circulate a buoying fluid through said plate to buoy lighter material over said scraper and downwardly over said surface and baille members above said surface and spaced therefrom to impede the flow of fluid except over the immediate surface of said plate, an annular fromv said opening and from said edge to form an annular chamber below said plate, a receiving chamber about the outer of said walls, a piston in said chamber, said piston having upwardly opening valves, inwardly opening valves below said piston in the wall extending from said periphery, means to move said piston upwardly and downwardly to circulate fluid intermittently upwardly through said plate to overflow into said outer annular chamber, a scraper arranged spirally on said plate, means to rotate said scraper to move material'upwardly toward said central discharge opening and baflle members in the fluid above said plate to impede radial movement of the fluid, said baiiic members being spaced above said plate to permit the passage of fluid downwardly thereover vin close contact with said plate.

'7. Apparatus of the type described which comprises a conical perforate plate having a centraldischarge opening and .a peripheral discharge edge and cylindrical walls extending downwardly from said opening and from said edge to form an annular chamber below said plate, a receiving chamber about the outer of said walls, a piston in said chamber, said piston having upwardly opening valves, inwardly opening valves below said piston in the wall extending downwardly from said periphery, means to move said piston upwardly and downwardly to circulate fluid intermittently upwardly through said plate to overflow into said outer annular chamber, a scraper arranged spirally on said plate, means to rotate said scraper to move material upwardly toward said central discharge opening and bafiie members in the liquid above said plate to impede radial movement of the liquid, said baiiie members being spaced above said plate to permit the passage of fluid downwardly thereover in close contact with said plate and means to supply material to be separated to said plate in an annular path between said peripheral edge and said central opening.

8. Apparatus of the type described which comprises a conical perforate plate having a central discharge opening and a peripheral discharge edge and cylindrical walls extending downwardly from said opening and from said edge to form an annular chamber below said plate, a receiv ing chamber about the outer of said walls, a piston in said chamber, said piston having upwardly opening valves, inwardly opening valves below said piston in the wall extending downwardly from said periphery, means to move said piston upwardly and downwardly to circulate fluid intermittently upwardly through said plate to overflow into said outer annular chamber, a scraper arranged spirally on said plate, means to rotate said scraper to move material upwardly toward said central discharge opening and bafllemembers in the fluid above said plate to impede radial movement of the fluid, said baffle mempath between said peripheral edge and said central opening, an annular channel in said outer annular chamber toreceive material discharged over said peripheral edge, a conveyor to receive material from said channel and means to sweep material in said channel to said conveyor.

FRANK PARDEE.

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