US3399769A - Dense media separator for coal dressing - Google Patents

Description

Sept. 3, 1968 E CHERKOV ET AL 3,399,769

DENSE MEDIA SEPARATOR FOR COAL DRESSING Filed Oct. 15, 1964 4 Sheets-Sheet l Sept. 3, 1968 E CHERKOV ET AL 3,399,769

DENSE MEDIA SEPARATOR FOR COAL DRESSING 4 Sheets-Sheet 2 Filed Oct. 15, 1964 Ill llll Sept. 3, 1968 E CHERKOV ET AL 3,399,769

DENSE MEDIA SEPARATOR FOR COAL DRESSING I Filed Oct. I5, 1964 4 Sheets-Sheet 5 FIG.6

Sept. 3, 1968 E CHERKOV ET AL 3,399,769

DENSE MEDIA SEPARATOR FOR COAL DRESSING Filed Oct. 15, 1964 4 Sheets-Sheet 4 United States Patent 3,399,769 DENSE MEDIA SEPARATOR FOR COAL DRESSING Efim Mikhailovich Cherkov, Veniamin Sergeevich Tikhonov, and Alexei Ignatjevich Ilchenko, Lugansk, U.S.S.R., assignors to Gosudarstvenny Proektno-Konstruktorsky Institute Gipromashugleobogashchenie, Lugansk, U.S.S.R.

Filed Oct. 15, 1964, Ser. No. 404,088 15 Claims. (Cl. 209-1725) ABSTRACT OF THE DISCLOSURE A separator for concentrating coal, ore and other minerals in heavy media, the separator containing a tank in which there is vertically installed a rotating elevator wheel with buckets. The buckets are provided with charge openings facing inside the tank, and with discharge openings facing outside, and are further provided with flaps that automatically close the discharge openings during the loading phase of the separation and the charge openings during the discharging phase of the separation.

This invention relates to heavy media separators for coal preparation and particularly heavy media separators with vertical rotary elevators for coal, ore and other mineral preparations.

The known heavy media separators for coal, ore and other minerals preparation discharge the heavy fraction by means of a vertical rotary elevator. Some separators of that kind have rotary elevators with a solid shell and they are discharged of their heavy fractions by introducing the latter into the elevator, so that removal of this material from the separator requires supplementary taps, troughs or other conveying means.

Other separators have elevators of the blade type without shells and the heavy fraction is discharged and conveyed from over the bottom of the separator tank by the blades of said elevator. This involves increased wear of and damage to the separator-tank bottom and the elevator blades as well as crushing of the heavy fraction. As one particular object the present invention aims to provide for the separator tank a discharge of the feed heavy fractions, sunk in a heavy medium, for instance in a mineral suspension, without using, under ordinary conditions, additional trays, troughs and other means of conveyance, thereby reducing to a minimum the abrasive effect of the lump material, sunk in the given part of the tank, on the structural members of the separator as well as precluding the crushing of the discharged material. In accordance with the present invention the heavy media separator for coal, ore and other minerals preparation, comprises a housing with a tank for separation of the feed into clean coal i.e., a light fraction and refuse (a heavy fraction), and a vertical rotary elevator, arranged in said housing, the bottom part of which forms a tank filled with a heavy medium. Vertically installed within said tank is a rotary elevator wheel comprising two annular discs arranged parallel to each other. Between said annular discs there are located buckets filled with the heavy fraction in the lower part of the tank. According to the invention, the buckets are formed by transverse plates installed between the discs of the elevator wheel at the outer portions of the discs, grates joined to the transverse plates from the side of the inner part of the elevator wheel discs in such a manner as to form charge openings with the adjacent plates in the direction of rotation of the wheel, plates fastened above the grates and between the discs from the sides of the outer portions of the discs so as to form discharging openings with the plates adjacent to them in the direction of rotation of the wheel, and flaps which are pin-connected to the free ends of the transverse plates and which can rotate under the action of their own weight. These flaps alternately close the discharging openings when the buckets are being loaded and the charge openings when the buckets are being discharged.

To limit the rotation of the flaps, it is desirable to install transverse beams between the discs of the elevator wheel, Which beams serve at the same time as supports for one end of each of the grates.

To remove the solid particles that accumulate at the bottom of the tank, it is also desirable to install scrapers on the outer part of the discs.

Other objects and advantages of the invention will have been clearly understood from the following description and the annexed drawings, wherein:

FIG. 1 is a view of the separator from the side of the sink (refuse) discharge;

FIG. 2 is a view of the separator from the side of float discharge;

FIG. 3 is a longitudinal sectional view of the separator;

FIG. 4 is a transverse sectional view of the separator;

FIG. 5 is a view of the rotary elevator with a partial section;

FIG. 6 is a side elevational view of the rotary elevator with a partial section;

FIG. 7 is a side view of the rake mechanism;

FIG. 8 is a view of the rake mechanism from the driving shaft side.

The present invention is broader than the specific example of the embodiment contained in the specification and illustrating the invention, and the scope of the invention is not to be limited thereto, but is to be limited by the appended claims. Referring now to the drawings, the separator comprises a housing 1 erected on supports 2. The lower part of the housing is designed as a tank 3 where the raw feed is separated into a light fraction and a heavy fraction. The separator housing has a rotary elevator 4 intended for the extraction and discharge of the refuse or heavy fraction from the tank. The rotary elevator includes two annular discs 5 between which elements 6, 7, 8 and 12 form buckets spaced at a considerable distance from each other. The working and structural relationship of these elements will now be described in greater detail. These buckets consist of transverse sheet metal plates 6 secured on said discs. The length of these transverse plates corresponds to the width of an elevator wheel ku:ket, the plates are installed peripherally on said discs and form one wall of each bucket. Joined to these transverse plates are grates 7 directed toward the inner part of said discs, forming additional walls of the buckets. The grates are arranged along the entire width of the wheel, while at the joints of the grates to transverse plates 6 an end of the latter is left free for securing the hinge of guide flap 9. Plates 8, which may be made perforated, are installed along the entire bucket width at the outer part of the discs and the opposite sides of transverse plate; 6. To reduce frict on against the bottom of the tank, plates 8 are installed with a certain displacement from the outer generatrix of the annular discs. Scrapers 12 comprising roled strips are' installed along the entire width of the wheel at the edges of plate 8. Between the buckets and the discs and inside the elevator wheel there are formed at the outer portions of these discs discharging openin s, and at the inner portions of the discs charge openings. For alternating opening and closing of the above-described discharging-and charge-openings, flaps 9 are installed, said flaps being pin-connected to the free ends of plates 6. These flaps have a length corresponding to the width of the wheel and a width somewhat greater than the corresponding dimension of the discharging and charging openings. The ends of the flaps opposite the pin-connected ends rest on plates 8 when the discharging openings are closed, and on transverse beams 11 secured to grates 7 and discs when the charge openings are closed. A soft pin connection of flaps 9 may be used, for instance, one made of a rubber-fabric material. The rotary elevator is equipped with rims 13 fastened to the discs 5; the internal surfaces of said rims rest upon roller supports 14 Whi.h are mounted upon the separator-housing cross beams 15 located over the tank which is filled with a heavy medium e.g. a mineral suspension.

The elevator is rotated by means of a chain drive 16 arranged in the upper part of the housing and meshing toothed rims 17 fixed on the external sides of the discs 5. The light fraction coming to the surface of the suspenpension, is carried from the tank to a discharge trough 18 by a rake mechanism 19 mounted in the tank above the level of the suspension. Rake mechanism 19 is a double-chain conveyor with strips 22 freely hung from the links ofits opposite branches 20 by means of rods 21, said strips 22 by turns sinking into a heavy medium.

For a partial drainage of the light fraction, the discharge trough 18 is provided with a drainage bar-screen or other screen 23.

The feed is delivered into the separator tank through a feeding chute 24.

The process of coal preparation in the separator is carried out in the following manner: an upward suspension current 25, is delivered into the separator housing through perforations in its bottom part; simultaneous therewith a conveying suspension-current 26 is supplied to the same tank by means of feeding chute 24. After having been brim filled with a suspension of the necessary density the separator tank is charged with a screened feed 27 through feeding chute 24.

The heavy fraction, the density of which exceeds that of the suspension, sinks down directly into the buckets through the charge openings and settles on the rotary guide flaps 9, which flaps under the action of their own weight close the discharging openings in the lower part of the elevator wheel.

As the elevator slowly rotates upwardly and downwardly, as shown by the discharge arrows, the heavy fraction under the action of its own weight moves along the inclined flaps 9 into the buckets. When the elevator wheel continues to move in the direction indicated by the rotary guide flap, approaching the horizontal center line of the wheel, it retains a vertical position under the action of gravity, and only the hinge by means of which the fiap is connected to the free part of transverse plate 6 turns. This rotation of the hinge continues until the free end of flap 9 rests on transverse beam 11. In this position, the flap 9 respectively opens the discharging opening and closes the charge opening of the elevator wheel. Under further motion of the elevator Wheel in the direction indicated by the discharge arrow, when the bucket occupies the top position in respect to its vertical center line, the buckets will begin to move downwardly along a circular path, while grate 7 and flap 9 begin to occupy an inclined position, making it possible for the heavy fractions to be unloaded through the discharging openings under the action of gravity.

Thus, a heavy fraction is extracted by the elevator wheel from a tank or bath filled with a liquid heavy medium when the elevator wheel moves upward along a circle, the heavy fraction of the material being concentrated is dehydrated when it rises above the level of the liquid, the water flowing off through slots of the grates and perforations in plate 8. The dimensions of the grate bars, their number, the size of the slots, the degree of perforation of plate 8 and the rotary speed of the elevator wheel depend on the grain size of the heavy fraction and the desired moisture content of the material being discharged.

The circular elevator wheel with a rotary flap is capable of insuring internal loading (without scooping up) under the action of the weight of the material itself, and external discharging. In comparison with existing designs, it solves more successfully the problem of exracting a large-size heavy fraction and insuring a compact design of a heavy-medium separator. The light fraction 28, the density of which is lower than that of the suspension, comes to the surface of the latter and is carried by the rake mechanism 19 to the drainage screen 23 through the discharge trough 18.

Next the partially drained light fraction enters a drainscreen and the suspension from under the screen is returned back into the circulation.

What we claim is:

1. A separator for concentrating coal, ores and other minerals in heavy media, said separator comprising a housing having a bottom part, a tank in said bottom part adapted for being filled with a heavy medium which separates feed particles into light and heavy fractions, a rotatable elevator wheel comprising two parallel annular discs vertically arranged within the tank, means defining with said discs a plurality of buckets positioned at regular intervals between the discs for extracting the heavy fraction from the bottom of the tank as the wheel rotates, the latter said means comprising a transverse plate for each bucket having opposite ends connected to the discs, a grate having opposite ends, one of which is connected to each transverse plate and a guide flap for each bucket having one end pivotally connected to the transverse plate of the next successive bucket and an opposite end which is free, the other of the ends of the grate being secured to the discs, a second plate connected to the discs near the connection of the transverse plate to the discs, each guide flap being free to swing as the wheel rotates such that the free end of the guide flap alternates between the grate and the second plate such that charge and discharge openings are alternately formed in succession on the rotating wheel.

2. A separator as claimed in claim 1 comprising trans verse beams secured to the discs under the said other of the ends of the grate to limit the distance through which the guide flaps swing.

3. A separator as claimed in claim 1 comprising scrapers peripherally secured to the discs for loosening the heavy fraction within the bottom of the tank.

4. A separator as claimed in claim 1 comprising means for removing the light fraction from the separator.

5. A separator as claimed in claim 4, wherein said means for removing the light fraction comprises a discharge trough and a continuously driven rake, said rake continuously urging the light fraction into the discharge trough.

6. A separator comprising a tank adapted for containing a heavy medium which separates feed particles into light and heavy fractions, a rotatable elevator wheel including two vertical parallel annular discs which are partly immersed in the tank, means for rotating the elevator wheel about a substantially horizontal axis, means defining with said discs a plurality of buckets positioned at regular intervals between the discs for extracting the heavy fraction from the tank as the wheel rotates, the latter said means comprising for each bucket a first plate extending between the discs, a grate secured to said first plate and a second plate secured to said first plate, said plates and grate forming a three-sided enclosure with one open side, and a guide flap pivotally connected to one of the plates of the next successive bucket and movable under the action of gravity as the wheel rotates, between positions in alternate contact with the second plate and the grate whereby to define charge and discharge openings at said open side which respectively face inwardly and outwardly of said discs.

7. A separator as claimed in claim 6, wherein each second plate is perforated and constitutes an outer wall for the respective said bucket.

8. A separator as claimed in claim 6, wherein each first plate constitutes an inner wall for the respective said bucket.

9. A separator as claimed in claim 6 comprising for each said bucket a transverse beam secured to the discs under the said position in which the guide flap contacts the grate to limit the distance through which the guide fiap moves.

10. A separator as claimed in claim 6 comprising scrapers peripherally secured to the discs for loosening the heavy fraction within the bottom of the tank.

11. A separator comprising a tank adapted for containing a heavy medium which separates feed particles into light and heavy fractions, a rotatable elevator wheel including two vertical parallel annular discs which are partly immersed in the tank, means for rotating the elevator wheel about a substantially horizontal axis, means defining with said discs a plurality of buckets arranged in an annular array between the discs for extracting the heavy fraction from the tank as the wheel rotates, said discs and buckets defining in said wheel, a ring of spaced internal apertures and a ring of spaced external apertures, each of said buckets having an opening facing an adjacent bucket on one side thereof and a guide flap 00- operating with the opening of the bucket adjacent thereto on the other side thereof, each guide flap being pivotably supported from its respective bucket to undergo pivotal movement under the action of gravity as the wheel rotates to :provide alternate communication between the opening of the adjacent bucket and the internal and external apertures.

12. A separator as claim in claim 11 wherein the means defining with the said discs the said plurality of buckets comprises members having perforations for drainage of liquid therethrough.

13. A separator as claimed in claim 12 comprising for each of said buckets a transverse beam secured to the discs for limiting the distance through which the guide flaps pivotably move.

14. A separator as claimed in claim 11 wherein each guide flap undergoes pivotal movement between two positions, a first position providing communication between the said opening of the adjacent bucket and an internal aperture and a second position providing communication between the said opening of the adjacent bucket and an external aperture, said guide flaps blocking communication between the said opening of the adjacent bucket and the external aperture when in the first position and blocking comunication between the said opening of the adjacent bucket and the internal aperture when in the second position.

15. A separator as claimed in claim 11 comprising scrapers peripherally secured to the discs for loosening the heavy fraction within the bottom of the tank.

References Cited UNITED STATES PATENTS 2,482,747 9/1949 Davis 209172.5 2,675,128 4/1954 Saxe 209173 FOREIGN PATENTS 603,071 9/1934 Germany.

FRANK W. LUTTER, Primary Examiner.

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