US2145315A

US2145315A - Concave spiral separator

Info

Publication number: US2145315A
Application number: US133776A
Authority: US
Inventors: Pardee Frank
Original assignee: ANTHRACITE SEPARATOR CO
Current assignee: ANTHRACITE SEPARATOR CO
Priority date: 1937-03-30
Filing date: 1937-03-30
Publication date: 1939-01-31
Anticipated expiration: 1956-01-31

Description

J1. 311, 939 F. PARDEE CONCAVE SPIRAL SEPARATOR Filed March 30, 1937 2 Sheets-Sheet l INVENTOR;

BY fir- 4 MACE] RDEE.

ATTORNEYS Emma 33b1, 1m PAR'DEE 5 3 'CONCAVE SPIRAL SEPARATOR Filed March 50, 1957 2 Sheeis-$he ai 2 ATTORAIEYE Patented Jan. 31, 1939 UNITED STATES PATENT OFFICE CONCAVE- SPIRAL SEPARATOR Application March 30, 1937, Serial No. 133,776

8 Claims.

This invention relates to separators of the spiral or helical type, in which materials of varying specific gravities and frictional characteristics are separated into different streams as they flow along the runway.

In separators of this type, previously invented and patented by me, the runways have frequently progressed along a spiral or helical path, such runways being inclined downwardly and inwardly toward the ax s of the separator in a straight transverse line.

While such separators have been successfully used for many years, it is nevertheless a fact that in separating coal and slate, the slate being the heavier material, has a. tendency to first move inwardly toward the central axis and then, because of the steeper drop near the axis, to gain momentum and thus move crosswise or outwardly and into the path on the spiral runway where only coal is supposed to travel. Thus the materials in the old spiral separators do not travel downwardly in a truly constant spiral line. That is to say, the path of travel as viewed in plan, does not correspond to a circle centered on the axis of the separator.

The present invention is based upon my recent discovery that, if the runway surface of the separator instead of being inclined radially inward along a straight line as heretofore, is transversely curved, thus forming a helical valley, a decided improvement in the separation can be effected and for any given lump size of material handled, a predetermined zone or region of separation can be maintained along a substantially constant spiral line. Thus the material to be separated will follow a substantially constant helical path which, in plan View, will correspond substantially to a true circle.

One of the chief features of the present inven- 0 tion is the provision of a helical or spiral separator having such a transversely concaved runway. The location of the valley line or zone of separation, as measured transversely of the runway, will vary for different lump sizes of material, although the helical pitch or drop for a given turn around the helix or spiral may remain constant. For example, the helical line of travel for small size lumps of material on a runway of given longitudinal or helical pitch will be along 50 the line of a circle of a relatively small diameter, as viewed in plan, while the line of separation for larger lmnps will be along the line of a circle of larger diameter viewed in plan. A more detailed feature of the invention contemplates pro- 55 vision of guide means at the delivery end of the separator for guiding material coming from one side of the line of separation toward one discharge point and guiding material coming from the other side of separation to another discharge point.

This guide means will preferably be laterally 5' adjustable so that for a given separator it can be varied to suit slight changes in the zone of separation when handling materials of slightly differing lump sizes. The above and other more detailed features of the invention will be fully 10 apparent from the following detailed disclosure when read in connection with the accompanying drawings.

In the drawings- Fig. l is a somewhat diagrammatic elevation-l5 illustrating the contour lines of one embodiment of the invention; Fig. 2 is a side elevation illustrating one turn of the separator runway; Fig. 3 is a plan view thereof; Fig. 4 is a fragmentary plan view showing one of the plate-like sections 20 of the separator runway and a portion of the central supporting column; Fig. 5 is a section taken approximately on line 5-5 of Fig. 4; Fig. 6 is a similar section illustrating a modified construction; Fig. 7 is a plan view of one of the'run- 25 way plates in flat condition before being warped or formed to produce the concave runway surface; Fig. 8 is a fragmentary plan View of the delivery end of the separator showing adjustable guide means for directing differing materials to 30 separate storage points; Fig. 9 is an end elevation thereof, and Fig. 10 is an enlarged detail of the adjustable guide means.

Referring in detail to the drawings, i0 represents a central supporting post, to which may 35 be secured suitable supporting rods or brackets II, on which will rest a plurality of plate-like sections l2, which are overlapped and riveted as at l3 or otherwise secured to one another, so as to form a substantially continuous helical runway.

Heretofore, the runways of spiral separators have been so disposed that the runway surface, as viewed from any substantially radial vertical plane, will be inclined in a straight line downwardly and inwardly at an angle, for example, as indicated by the broken lines (1-!) in Figs. 1 and 5. This straight line radial inclination of the runway toward the axis of the helix is now generally known in the art as the flare.

Such a straight flare on the runway surface results in a very rapid drop of the material particularly in the zone nearest the axis thereof. According to the present invention, instead of having a straight inward flare, I provide what may be termed a transversely concaved flare, such as shown on an enlarged scale in Fig. 5. Such concavity of the runway at various points throughout the length of the runway is indicated graphically in the diagrammatic view of Fig. 1. In this figure, the straight broken lines a-b correspond to the old form of straight flare runway surface. The line a.b at the top of Fig. 1 may be considered as lying along a horizontal center line of Fig. 3 passing through the axis of the post l0.

' In the novel separator of the present invention I provide a runway having a concave supporting surface, such as illustrated, forming a valley between the inner and outer edges of the runway. For a given lump size of material handled, there will be a substantially constant helical zone or line of separation, such as indicated by the dotted line -0 in Figs. 4 and 5, or by the dotted circle 0 in Fig. 3. These lines c represent the lowest point in the valley of the runway. The location of this valley or zone of separation will vary for different sizes of material. For example, for separating materials of the relatively large lump size known as egg, the zone of separation may be considered as taking place along the line cc--c. Assuming that a larger lump size is to be handled, the low point in the valley or zone of. separation will lie at a greater distance from the vertical axis of the separator, for example, along the helical line indicated at 11-11. In the improved separator, therefore, the runway surface is depressed between its inner and outer edges, thus forming the concave surface acd/b of Fig. 5. This cross-sectional configuration provides what I term a valley which corresponds to the zone or line of separation.

, This valley or helical zone of separation will be located at different predetermined radial distances, depending upon the lump size of material being handled. That is to say, that for a separator adapted to handle small size lump mavterial, the valley will be located nearer the center or axis of the separator than will be the case for i a separator adapted to handle large size lump material.

In operation when the separator is used for ridding coal of slate initially mixed therewith, the slate or heavier material traveling along the runway will slide or move inwardly toward the axis, and the coal or lighter material will work its way outwardly and eventually travel in a path along the outer side of. the line or zone of separation. This uniformity of helical travel is a novel functional characteristic which could not be attained by my old types of separators which had a straight line inward flare.

The difference between the action of my old separators and the novel one of the present invention will be apparent from reference to Fig. 5, when taken with the following explanation.

The inner part of the concave surface of the improved runway provides an upward inclination on one side of the line cc, while in the old form of straight flare the runway surface from the inside of the said line cc was inclined downwardly toward the axis of the separator. The inclination of the surface of the runway outwardly from the line of separation 0-0 in the case of the novel concaved runway is relatively steeper than the old straight flare runway, as will be apparent by comparison of the curved portion c-db of Fig. 5 with the straight line portion a'b corresponding to the old straight inward flare.

fact that the runway was inclined toward the axis caused the larger particles of slate to gain momentum and cut crosswise and enter the outer coal stream instead of continuing downward in a true helical path. This difficulty is overcome by the present invention by the relatively simple yet heretofore unobvious expedient of forming the runway with a concaved flare above de scribed.

Tests, which I have made show that with such a concave flare the objectional cross-flow of slate is overcome and thus the separation on my new separator takes place along a substantially constant helical path for any given lump size.

With the improved runway having the concaved flare, the upwardly curved or inclined surface on the inner part of the separator runway will result in a slowing up of the slate travel. At the same time, it will slightly retard the coal travel. The net result of this, combined with the action of gravity, friction and centrifugal forcewill, for a given helical pitch, give the materials a greater time interval to bring about the desired separation into different streams, as they travel helically downward along the runway surface. Thus, it is clear that, as compared with the old type of straight line flare, the novel concave flare of the present invention results in an important functional improvement.

The concave runway is produced by taking relatively flat plates, such as shown in Fig. '7, and bending or warping them to the desired concave curvature. However, in some cases, instead of having a curved concave configuration the concavity may be in the nature of oppositely inclined straight surfaces. 7 Such a modification is shown in detail in Fig. 6.

While the concave runway referred to will usually be formed of a plurality of bent plate-like sections, with the lower edges of one plate overlapping the upper edge of the next lower plate, the plates may be arranged with their adjacent edges abutting and united by flush seam welds. Or, the sections may be formed of cast metal of the concave form described.

At the lower discharge end of the separator, I preferably provide adjustable guide means adapted to direct the inner flowing stream of. slate to one storage point and the outer flowing stream of coal to another point. This guide means is preferably mounted in such a manner as to permit of lateral adjustment to suit slightly different lump sizes to be handled on a given concaved runway.

By way of illustration, I have shown such an adjustable mounting in Figs. 8 to 10, wherein there is a block 14 having slots l5 therein through which pass fastening bolts [6, which extend through the plate to the lowermost section of the runway. It will be understood that, by loosening the nuts I! on the bolts, the block M can be adjusted laterally so as to position this guide device as a whole to suit different lump sizes of material handled. The guide element of this device in the embodiment illustrated is in the form of a rod I8 extending substantially tangent to the line of separation, for example, the line c--c. To permit of still finer adjustment, the rod It may be mounted eccentrically on an elongated bolt l9. Thus, a rough lateral adjustand a finer or more precise adjustment may be secured by turning the rod l8 about its eccentric bolt mounting l9. Below the guide rod I8, I provide a partition 20 serving as a separating barrier to prevent intermixture of, the coal and slate, as it drops into the chute 2! to be led to suitable storage receptacles, not shown. The chute 2i may be conveniently secured at its end to the block M, as shown.

While I have described quite precisely certain specific embodiments of theinvention illustrated it is to be understood that various modifications and substitution of equivalents may be made by those skilled in the art without departure from the invention as defined in the appended claims.

What I claim is:

1. A separator of the character described comprising a stationary helical runway of fixed vertical pitch suflicient to cause material to slide thereon by gravity and having a supporting surface depressed downwardly from its inner edge for a substantial distance therefrom and thence upwardly to an outer edge above the level of the inner edge to form a helical valley of concave upward flare effective to separate materials of a given lump size but of different specific gravities and frictional characteristics along a helical zone or line of predetermined pitch and diameter.

2. A separator of the character described comprising a stationary helical runway of fixed vertical pitch sufficient to cause material to slide thereon by gravity and having a supporting surface depressed downwardly from its inner edge for a substantial distance therefrom and thence upwardly to an outer edge above the level of the inner edge to form a helical valley of concave upward flare effective to separate materials of a given lump size but of different specific gravities and frictional characteristics along a helical zone or line of predetermined pitch and diameter and laterally adjustable guide means for directing the separated materials to different discharge points.

3. A separator of the character described comprising a stationary helical runway of fixed vertical pitch sufficient to cause material to slide thereon by gravity and having a supporting surface depressed downwardly from its inner edge for a substantial distance therefrom and thence upwardly to an outer edge above the level of the inner edge to form a helical valley of concave upward flare effective to separate materials of a given lump size but of different specific gravities and frictional pitch and diameter, laterally adjustable guide means for directing the separated materials to different discharge points and means adjustably secured at the lower end of the separator runway for directing the separated materials to different discharge points.

4. A separator of the character described comprising a stationary vertical post, a' stationary helical runway of fixed vertical pitch sufficient to cause material to slide thereonby gravity, secured at its inner edge to said post and having a separating surface depressed downwardly from its inner edge for a substantial distance therefrom and thence upwardly to an outer edge above the level of the inner edge to form a helical valley of concave upward flare effective to separate materials of a given lump size but of different specific gravities and frictional characteristics along a helical zone or line of predetermined pitch and diameter.

5. A separator of the character described comprising a stationary helical runway of fixed vertical pitch suflicient to cause material to slide thereon by gravity and having a supporting surface depressed downwardly from its inner edge for a substantial distance therefrom and thence upwardly to an outer edge above the level of the inner edge to form a helical valley of concave ties and frictional characteristics along a helical zone or line of predetermined pitch and diameter, the lowermost point in said valley being nearer the inner edge than the outer edge.

6. The separator of claim 1 in which said separating surface is concaved in a radial direction on a smooth unbroken curve.

7. The separator of claim 1 in which said separating surface is depressed to an angle extending helically at a distance from the inner edge of said surface and then extends upwardly to the outward edge edge thereof.

8. The separator of claim 1 in which said separating surface is made of a succession of plates having the lower edge of one plate overlapping the upper edge of a successive plate.

FRANK PARDEE.