US2665809A

US2665809A - Vortex concentrator

Info

Publication number: US2665809A
Application number: US143223A
Authority: US
Inventors: Gilbert G Chisholm
Original assignee: Ferros Metals Res Co Ltd
Current assignee: Ferros Metals Res Co Ltd
Priority date: 1950-02-09
Filing date: 1950-02-09
Publication date: 1954-01-12
Anticipated expiration: 1971-01-12

Description

Jan. 12, 1954 G, G, CHlsHOLM 2,665,809

VORTEX CONCENTRATOR Filed Feb, 9, 1950 2 Sheets-Sheetl l Jan. l2, 1954 G. G. cHlsHoLM 2,665,809 VORTEX coNcENTRAToR Filed Feb. 9, 1950 2 Sheets-Sheet 2 ffnenor Patented Jan. 12, 1954 VORTEX CONCENTRATOR Gilbert `Gr. Chisholm, Lucan, signor to Ferros Metals Ontario, Canada, as-

Research Company Limited, Toronto, Ontario, Canada Application February 9, 1950, Serial No. 143,223

1 Claim.

' This invention relates to a vortex concentrator ofthe class which may be employed for mineral separations. p

Previous cyclone devices have been employed for dust catching and in the cleaning of fine coal, particularly in a heavy medium. In previous constructions the pulp is pumped into the cyclone structure which is usually in the form of a simple cone-shaped cavity having an outlet at the bottom and an outlet at the top, the latter being in the region of the base of the cone. The pulp is introduced usually near the base of the cone and tangentially under pressure and the heavy or thickened mineral sprays out the bottom end of the cyclone, the light overfiow forcing its way out of the opening in the upper regions of the base. y

A disadvantage in prior cyclone arrangements for these purposes is that the control in separation is not sufficiently definite by reason of the uncontrolled vortex action within the cyclone concentrator structure.

It is a principal object of the present invention to provide means for controlling the vortex action to more effectively control the separating action.

Another object of the invention is to provide a cyclone separator of a vortex concentrator type embodying an inner cone that spreads the vortex of the pulp ow over a much greater surface than would be the case with a natural vortex thus giving a larger area of action and a more selective operation against the pulp passing through the device.

A still further object of the invention is to provide an inner cone in a cyclone concentrator wherein the sides of the cone are formed to converge to a point substantially coincident with the theoretical convergent point of the inner surfaces of the cone of the cyclone device.

i A still further object of the invention is to provide means for feeding a plurality of pulps into a concentrator or a plurality of media of different densities to more effectively control the separating action.

Other objects of the invention will be appreciated by a study of the following specification taken in conjunction with the accompanying drawings.

In the drawings:

Figure l is a sectional view of an improved cyclone concentrator according to the invention.

Figure 2 is a sectional view of the concentrator of Figure l on the line 2-2 thereof.

Figure 3 is a sectional View of a modified form of concentrator according to the invention includng a heavy media input.

Figure 4 is a sectional view of the device of Figure 3 on the line 4 4 thereof.

Figure 5 is a diagram of a method of concentrating ore pulps employing cyclone concentrators according to the invention.

Referring to the drawings, and particularly to Figure l, the improved concentrator of :my invention comprises a relatively conventional cyclone casing I0 having an input nozzle II arranged tangentially with respect to the inner cavity I2 thereof, but having disposed therein the inner cone member I3 according to this invention, which serves to spread the vortex of the material moving within the casing over a much greater surface to give a greater area of action and increase the selectivity of the device.

In detail, one practical form of structure may comprise an upper cylinder I4 having an outlet pipe I5 extending therefrom, The cylinder I4 has upper and lower flanges I6 and I 1. The upper fiange is fastened to the closure plate I8 which forms part of the inner cone I3 and serves to locate the latter centrally within the casing I0. An intermediate cylinder I9 has mounted thereon the injector nozzle II which extends therefrom tangentially as indicated in Figure 2. Suitable fianges 20 and 2I are provided on the intermediate cylinder which match the flanges I1 and 22 on the upper cylinder and truncated cone component 23 respectively. The component 23 converges to terminate in a fitting 24 carrying suitable threads 25 designed to mate with the threads 26 of the control nozzle or concentrate regulator 21 having a port 28. I

It is particularly important to note that the inner surfaces 29 of the cone component 23 converge theoretically to the same point as the ex terior surfaces 30 of the vortex regulating cone I 3.

In operation, the pulp is injected through the injector nozzle II under considerable pressure between the walls of the intermediate cylinder I9 and the converging walls 3| of the pulp' divider 32 which is mounted by a flange 33 extending between the flanges I1 and 20 of the upper and intermediate cylinders. The tangential introduc- `j tion of the pulp under pressure causes the pulpto circulate rapidly, thus setting up great cen-` As a result, the heavier frac-` trifugal forces. tions tend to move toward the walls of the intermediate cylinder I9 and at the same time the; increased force of gravity caused by the cen-l trifugal force draws the pulp downwardly to" The', heavier fractions remain on the outside whereas` wards the concentrate outlet port `28.

the lighter material remains about the vortex which is in the form of a small air space extending about the converging surface 30 of the vortex regulating cone I3. The lighter fra-ctions tend to rise rapidly against gravity through the annular space 34 between the pulp divider 32 and the surfaces 30 of the vortex regulating cone I3, whereby the lighter fractions arise to` the annular chamber 35 in the upper cylinder and pass out of the device through the pipe I5' to tailings discharge.

The arrangement whereby the surfaces of the vortex regulating cone and the lower cone component 23 converge to substantially a common point is important in that all forces are brought to a common point whereby they may be easily regulated by the concentrate regulator 21. As the'regulator is screwed up the apex 36 or" the vortex regulating cone pierces the outlet port 28 reducing the sectional area of the opening and thus causing the vortex created by the circulation of the pulp within the concentrator tovcarry a larger proportion of the pulp to tailings discharge. The components just described, that is to say, the upper cylinder il), pulp divider 32, intermediate cylinder i9, and cone component 23 may be fastened together by passing bolts through the holes shown in the anges thereof and, further, the vortex Vcontrolling cone may be mounted in similar manner in conjunction with the upper flange I6 of the upper cylinder i4.

A modification of the concentrator according to the invention is illustrated in Figure 3, the modification particularly embodying the provision of a pulp divider skirt 3l of apparent greater depth than the skirt of the pulp divider 32 illus-y trated in Figure 1. The greater depth is necessary by reason of the inclusion of a heavy media ore pulp injector 38 which is placed below the oreV pulp injector 39. In all other respects this structure is similar to that previously disclosed in Figure 1 but the modication embodying the heavy media ore pulp injector is important in the control of separation.

The greater control will allow a cleaner conf centrate to be obtained in one operation. Thus, a heavy media pulp is injected at the same pressure as the pulp to be concentrated, the heavy media being injected through the injector nozzle 38 andthe pulp being injected through the nozzle 39. In using the device of Figure 3 in the separation of two minerals of diierent specific gravities, the latter as a pulp may be introduced into the injector nozzle 39 and a separate medium of a specific gravity adjusted to a value between the speciiic gravity of the two minerals is introduced by way of the heavy media nozzle 38. As a result, the lighter mineral, in eiect, does not sink but is washed up and out of the cyclone. The heavier mineral is quickly drawn down by the amplified gravitational pull and passes out the Youtlet port 28 of the concentrate regulator The chief operating variables encountered involve the speciiic gravities of the pulp constit- Although the device oi Figures 3 and 4 is presented as a modification which will allow a satisfactory concentrate to be obtained in one pass, it is preferred that devices of the type disclosed in Figure 1 be employed in series. ''husy in Figure 5,`

a pump 40 draws pulp from a reservoir 4i Yand delivers it through the injector nozzleinto a vortex concentrator 42 of the invention. The lighter fractions pass out the pipe 43 to tailings discharge but the concentrate is again pumped by a pump 44 and delivered under pressure into a second' concentrator 45 similar in construction to the concentrator 42. The lighter fractions discharged by this second concentrator are re-circulated by the line l5 to the ore pulp reservoir 4|. The clean concentrate is delivered by the concentrator 45 as indicated.

A capacity of fifteen .tons per hour can be accomplished by constructing a device according to Figure 1 of a height of about 171/2 inches with quired for comparatively large capacities.

,g an overall diameter of about '7l/2 inches thus indicating the relatively small size of the unit re- The grading of the pulp may be from minus 1/8 to less than 120 mesh and, in fact, the concentrator of this invention finds its greatest application in the separation of pulps of a high degree of fineness greater than minus 120 mesh. It is Well known that gravity methods heretofore have not been particularly successful in the separating of media of a iineness greater than minus 120 mesh except by the use of cyclone concentrators, the latter being on a small scale. In mineral separation it is important that a maximum degree of control be afforded in the separating action, this being provided in the construction of my invention by the inclusion of a vortex control coneas disclosed herein, and further by incorporation of a heavy media injector nozzle as disclosed herein.

There will be many modifications obvious to skilled persons in respect to specific details of: design of the concentrator unit disclosed' herein.

. It is thus intended that this invention should not be construed in any limiting sense other than that indicated by the scope of the following claim.

What I claim as my invention is:

The combination in avconcentrator of the cyclone type having separate tailings and'concerb trate discharge openings, of: a vertically disposed vortex controlling cone converging downwardly to a point; a truncated cone component, the side walls of which are disposed in spaced apart' rela tion to said vortex controlling cone, being cocone component having a tailings discharge opening located at the upper end thereof; an inlet to direct the pulp into said casing tangentially and disposed in said casing between theiconcentrate discharge opening and the truncated cone component; and a plup dividing skirt surrounding a portion of said vortex controlling cone being in spaced relation thereto and including`A a flange of annular form extending to the walls of said cylindric casing between the inlet port and the tailings discharge opening of the latter whereby heavier fractions of pulp injected into said concentrator through theinlet port thereof rise through the space between said skirt ari'd said vortex controlling cone in a manner controllable by adjustment of said nozzle of said tailings discharge opening with respect to said vortexA controlling cone.

GILBERT G. CHISHOLM.

References Cited in the ille of this patent UNITED STATES PATENTS Number Name Date 2,504,944 Atkinson Apr. 18, 1950 FOREIGN PATENTS Number Y Country Date 809,570 France Mar. 6, 1937: M9985 Austria June 25, 1937 886,187 France Oct. 7, 1943 608.026 Great Britain Sept. 8; 1948