US2025412A - Classification apparatus - Google Patents

Description

Dec. 24, 1935. R, s, HANDY CLASSIFICATION APPARATUS Filed Sept. l0, 1934 2 She@13S-611891l 1 IVNVENTOR Foy@ )65mg BY we( ATTORNEY Dec. 24, 1935.

`R. s. HANDY 2,025,412

CLASSIFICATION APPARATUS Filed Sept. 10, 1934 2 SheejtS-Sheet 2 INVENTOR Wag/al ,X/zmcy Wd' ZTTORNEY Patented Dec. 24, 1935 UNITED STATES PATENT OFFICE CLASSIFICATION APPARATUS Royal S. Handy, Kellogg, Idaho Application September 10, 1934, Serial No. 743,349

9 Claims.

'Ihis invention relates to an improved means for classifying sand-grains.

It is a feature of this invention to maintain a constant density of the sand bed, and also a constant density of the discharge therefrom, wholly by the novel manner in which the discharge is effected, and irrespective of variation of feed and variation of the specific gravity of the material acted upon.

It is also a feature of the invention to prevent depletion of thebed either suddenly or gradually, and to maintain the bed at a substantially constant depth or volume and of a definite character.

The invention also involves the novel feature of controlling discharge of the bed in a manner to build up a plurality of superimposed strata of sand-grains with the heavier strata lowermost and the succeeding lighter strata uppermost or above the heavier strata, whereby, among several important functions, I am able to sustain thev slimes and colloidal matter above and wholly out of range of the material being discharged, and4 thereby prevent such deleterious matter from ever entering the flotation. and other subsequent treatments.

A novel feature of my improved means of effecting discharge of the bed is that it is not periodic or capable of completely or partly depleting the bed and thereby destroying or impairing the density thereof, but on the contrary, the discharge is substantially rapid but intermittent, thereby permitting the bed to be built up and sustained at a constant density and volume.

My novel manner of discharge involves an automatic control whereby the discharge will be varied in quantity as the bed grows heavier or lighter, and this automatic control is centered and isolated in that zone where it will be immediately responsive to the material itself. In other words, the nature of the material, in that zone where discharge occurs, is the motivating agent in automatically controlling and governing the discharge. s

The invention has many other objects and features which will be more fully described in connection with the accompanying drawings and which will be more particularly pointed out in and by the appended claims.

In the drawings:

Fig. 1 is a vertical sectional view showing my invention embodied in one form of classifying apparatus.

Fig. 2 is a vertical sectional View of another embodiment of my invention. Fig. 3 is an enlarged fragmentary sectional View livers to a classifying chamber B, which may be formed by an extension 6, of the walls I, the `bottom of the chamber B being formed by a constriction plate 1, having suitable openings 8. Below l5 the classifying chamber B, the walls 9, and a bottom wall I0, form a hydraulic chamber C. A pipe I I, connected with a suitable source of water under pressure, delivers to chamber C, and forces -the water therein to iiow upwardly through the 20 openings 8, into the classifying chamber B.

This flow of water into the classifyingchamber sets up teeter in the sand bed which results in hindered Settling' in the classifying chamber. However, it may be informative to State that in 25 some phases of my invention, classification will extend from the restriction plate to lip 3.

A pipe I2, usually termed a spigot, extends from the chamber B, downwardly through chamber C, and throughthe lower wall of the latter, and 30 said pipe I2 is closed to chamber C. The upper intake end I3, of said pipe I2, forms a valve seat closure and is disposed in what I will term the zone of greatest density of the bed, or in other words, in the lower portion of the classifying 35 chamber B. The lower end I4 will discharge the material into any suitable receiver (not shown) for the next stage of treatment. A plumb-bob valve closure indicated at I5, coacts with the valve seat I3, to control discharge through pipe 40 I2, and has a controlling rod I6, which extends upwardly through the receiver A and has an enlarged guiding terminal II.

Reference will next be made to what I will term my hydrostatic control mechanism. 40 A hydrostatic pressure pipe I8, conveniently sleeves said controlling rod IS, and is disposed axially of the receiver A, and extends into the lower zone of the classifying chamber B. The open intake end I9, is in alinement with said 50 spigot I2 and is disposed in longitudinally spaced relation from the closure seat I3, and cage bars 20 may serve to support said pipe. Said bars 20 may be secured to said pipe I8 and to said spigot I2. The upper end of pipe I8 may have a guiding 55 collar 2 I, through which the enlarged upper end I1, of rod I5, is freely slidable.

A hydrostatic oat chamber is indicated at 23, and is connected with pipe I8 by a pipe 24. A hydrostatic governor float 25, is disposed in said float chamber, which latter is open at the top. A float stem 26 is connected with said float 25, by adjustable means generally indicated at 21, for lengthening or shortening said stem.

Reference will next be made to'an improved actuator mechanism for operating the closure I5, and to the novel means whereby the action of the actuator is controlled by the hydrostatic governor float.

As shown, a cam lever is indicated at 28 and its end 29 is pivoted at 30 to a hanger 3I, fixedly mounted. The remaining end 32, rides on the periphery of a cam 33, mounted on a driven shaft 34. Depending from lever 28 is an actuating rod 35, which is pivoted to said lever 28 at 36. The free lower end of said rod is provided with a stop 31, which may be inthe form of a nut having threaded engagement with rod 35, to permit of adjustment of the stop.

The actuator mechanism and the governor oat are operatively associated by means which, in the present construction, is in the form of a floating lever 38, which is pivotally connected with closure rod I6 at 39, nearer one end of said lever than the other. The longer end cf said lever 38 is pivoted at 49 to the oat stem 26, and the shorter end is provided with a'slot or enlarged opening 4I, through which the rod 35 is freely slidable, the stop 31 being disposed below said lever 38. The arrangement is such that the closure I5 will close by gravity to shut off discharge of the bed.

In the form shown in Fig. 2, the receiver for the pulp is in the form of la tank D, having a flat bottom 42, and a vertical wall 43, which latter is usually cylindrical. The tank D is equipped with a launder 44, and the pulp may be delivered to lthe tank through a pipe 45. The pulp level is shown at E and the sand-grains F are fed -or advanced toward the classifying chamber, to be later described, by a spirally arranged flight, the convolutions 46 thereof` being mounted on an inverted truncated frame 41, converging to a suitable supporting head 48.- A driving shaft 49, fixed to said frame, may be slowly rotated by any suitable means such as a worm drive generally indicated at 58. This construction, which is not novel as thus far described, serves to receive the pulp and regulate discharge of the sand-grains into the classifying chamber.

A classifying chamber G, formed by wall 5I, is connected with the bottom wall 42, in registry with a discharge opening 52 therein, to receive the sand-grains therefrom, as will now be clear. Below the chamber G is a hydraulic chamber H formed by wall 5I, and a bottom wall 53, and separated from the classifying chamber G, bya constriction plate 54,'having suitable openings 55 therein. ,A pipe 56, connected with a suitable supply of water under pressure, delivers to chamber H to maintain the sand bed in teeter, as in the v preferred construction. A discharge pipe or spigot 51 extends from the classifying chamber G, through the constriction plate 54 and hydraulic chamber H, to deliver the sand-grains to any suitable point of deposition, not shown. This discharge pipe 51 is closed to the hydraulic chamber H and has a valve seat intake end 58 opening to said classifying chamber G, through the constriction plate 454, in which the valve seat opening is actually formed so. that pipe 51 can be completely detached, as will later appear.

Reference will next be made to the form of hydrostatic control mechanism which I have applied to this embodiment of the invention.

A plumb-bob type of valve closure 59, having an actuating rod 60, extends upwardly through pipe 51, and is adapted to coact with valve seat 58 to close the same from the lower side thereof. A suitable guide 6I, having an open spider connection with the interior of pipe 51, so as not to prevent discharge therethrough, holds the closure 59 in alinement with said valve seat 58. A bell-crank lever pivoted at 62, to a suitable stationary part 63, has one arm 64 thereof connected with rod 60, and the remaining arm 65 is connected with a transmission rod 66. A spring 61, connected with arm 64 and with the hydraulic chamber H, normally acts to seat said closure 59. bell-crank lever pivoted at 69 to a suitable stationary part 10, the remaining arm 1I being con-- nected with rod 12 whose vertical movement is suitably guided at 13.v

A hydrostatic pipe 14 extends into the classi- 2 fying chamber G and may open downwardly therein as shown at 15, the upper end forming a guide for a valve stem to be later described. T'he remaining end of this hydrostatic pressure pipe 14 opens to a float chamber 16, in which I dis- 3 pose a hydrostatic governor float 11, having a stem 18. In this form of the invention the floating lever 19 is pivotallyconnected with said float stem 18 at 80, and with rod 12 at 8|. l The actuator rod 82 may be reciprocated by the same means shown in Fig. 1,' and its lower endI extends slidably through end 19' of lever 19, and is provided With a stop 83, which may be adjustable on rod 82.

Reference will next be made to an improved valve device for closing egress of the sand-grains from the classifying chamber G, when the appa'- ratus is shut down for changing spigots or other repairs, so as not to disturb the sand bed during such repair period.

The valve seat 58 is capable of coaction with valve closures above and below the same and I have shown what may be termed a repair closure at 84, provided with a stem4 85, that is i loosely guided at 81. A valve operating lever 88 is slidably fulcrumed in a holder 89, secured by its flange 98, to the wall 5I, of the classifying chamber G. The lever 88 is pivoted at 9|, to valve stem 85. A flexible sleeve 92, of rubber or other suitable material, is sleeved over a portion of the lever 88 which is Idisposed inside chamber G, and one end 93 is secured to holder 89, and the other end 64 is secured to a collar 95, throughI which lever 88 passes.

By this novel means, I can gain operative access to the interior of the classifying chamber G, and close discharging egress therefrom at any time, without permitting discharge of the contents of chamber G, through the holder 89.

'I'he operation will next be described, as regards Fig. 1.

The pulp will discharge from pipe 5, when the latter is opened, and ll the receiver A and the chamber B, and the pipe II will be opened to cause Water to fill chamber C and ascend through the constriction plate into the classifying chamber B, to-start teeter of the sand-grain and sustain hindered settling classification. Water will rise in pipe I8 to the level which it, or rather the Said rod 66 is connected with arm 68 of a 2 pulp acquires in receiver A, but as the float chamber 23 is above any such level,` the iioat 25 will descend by gravity to its lowest position thereby raising the short end of lever 38 above stop 31. The closure I5, will remain seated by gravity, and as the cam 33 is rotated, the actuator rod 435 will be reciprocated vertically and idly because the short end of lever 38, which I will designate at D, will be elevated out of the range of action of stop 31, as shown in dotted lines. At this point it may be stated that in the particular structure herein shown, the cam 33 is intended to rotate continuously and of course it will impart a range of action or reciprocating stroke to rod 35, that will be regular and of a definite length, and at a definite rate of speed.

Due to both the action of gravity, when initially starting the mechanism, and primarily to hindered settling after starting, the particles of greatest specific gravity will seek the lowermost zone nearest the constriction plate 1, and as the bed builds up, hydrostatic pressure in pipe I8 will cause the water to ascend therein, due to building up of the sand bed, and this will be reected in the oat chamber 23, and consequently,

the float 25 will rise.

Assuming that the sand bed has generated sufficient hydrostatic pressure to raise the float 25 to the full line position shown, then, and in that event, the short end D of lever 38 will be disposed within the range. of, action of the lost motion connection to such an extent that on rotation of the cam 33, the hill portion thereof will elevate leverl 28, causing stop 31 to engage and elevate lever 38 about pivot 48, as an axis. This will elevate rod I6, and unseat closure I5, and permit discharge of a small quantity of the sand bed through spigot I2. As the hill portion of cam 33 again reaches the full line position shown, the closure will be seated by gravity and cut off further discharge. g In the full line position shown, the stop 31 is not in engagement with end D of lever 38, and hence there will be some slight lost motion or slack to take up. Further, the cam 33 gradually opens'and gradually permits seating of the valve closure, so that there is no sudden or abrupt action. In practice, I have successfully operated the closure so that a complete cycle, or one complete rotationof cam 33 will take place about every three or four seconds. Thus, while the action of closure I5 is intermittent, its movement is continuous in successively opening and closing pipe I2, and the action is fairly rapid, and consequently, the volume of discharge is commensurately large, and yet with this rapid opening and closing of the valvefno sudden or even pa.rtiaLdep1e tion of the sand bed can take place. Thus, the sand bed can build up between discharges and I can maintain a constant density and a constant volume and depth, in the lower zone. or stratum.

With the governor float 25, in the full line position shown, it will be assumed that the density of the lower stratum has almost reached a maximum, as each upward reciprocation of rod 35 will lift closure I5 to a nearly maximum extent within the capacity of the apparatus shown, the slight space between stop 31 and the end D, reducing the stroke to slightly4 less than the maximum. If the density increases from the adjustment shown, then the float governor 25 would rise until end D would never be released from stop 31, hence the maximum stroke would be imparted.

Now assume that the density in the lower zone decreased, then, and in that event, hydrostatic pressure in pipe I8 would be reduced correspondingly and the float 25 would accordingly descend, thereby elevating end D of lever 38, and increasing the lost motion between stop 31 and end D, on each downward stroke of rod 35, and there- 5 fore end D would not be' lifted as high as in the present full line adjustment and the closure Would open to a lesser extent and close more quickly. 'Ihis would permit the sand bed to build up to a greater density. l

It will thus be -seen that` when the float 25 changes the position of pivot 40, about which the lever 38 is rocked, it changes the extent of opening and closing movement of the closure I as regards the distance which this closure moves. Thus, While the actuating mechanism operates at a. xed and definite speed, the governor means, which is the float, shortens or lengthens the stroke of rod I6 to either reduce or increase the quantity of discharge in accordance with the 20 density of the bed. Thus the device of my invention is intensively responsive to density changes,- and this not only enables me to maintain bed density and volume, but it also affords a discharge of sand-grains' of a uniform density, the 25 importance of which will be obvious to those skilled in the art.

In actual operation, the closure I5 is practically constantly in motion, opening and closing without interruption, when the feed is normal, and the adjustments made by the float to vary the action of the closure, are almost imperceptible to the eye, and throughout many periods of time, rthe float may actually remain stationary. However, if the feed varies, the float, due to the hydrostatic change, will quickly alter the action of closure I5, as hereinbefore described.

At this point, I desire to emphasize the distinction between the necessarily prolonged periodic action of a diaphragm, on the one hand, and the 40 device of my invention, on the other. In the first place there is nothing gradual in the movement of a diaphragm as its resistance to movement must be overcome by an accumulation of pressure, andthen it moves suddenly and not gradually. If such movement opened the closure, the sand bed would be depleted, or at least the density woud be so reduced as to result in actual impairment, before a counter-acting pressure such as a weight, for instance, could cause the diaphragm to be restored to an initial position and seat the closure. Therefore, there is a. fundamental diierence between a constantly actuated closure, governed by a hydrostatic float, and a periodically actuated diaphragm. 55

I next desire to point out another important feature of the invention which is rendered possible by the novel manner in which the closure I5 is intermittently operated and controlled.

In order that this feature may be understood, reference is hereby made to my pending application filed July 18, 1934, Serial No. 735,862, for an improvement in Concentration of ores, issued vOctober 29, 1935, No. 2,019,306. In this applica- Thus the lowest stratum adjacent plate 1 is of the greatest specific gravity, and the next upper succeeding strata are of corresponding lighter specific gravity. This disposition of the material is directly traceable to the fact that I intermittently discharge and control such discharge in a manner to maintain constant density in the lowest stratum.

It will now be clear why such deleterious materialas colloidal matter. and slimes can never descend within discharging range of the spigot I2, because they are both of very light specific gravity. Hence these materials can never enter subsequent flotation or other-treatments.'

It is desired to point out that the floating 1ever 38, rocks about pivot 40, as an axis, when the float 25 is functioning to change the length of stroke of the closure l5. However, when the float 25 is not functioning, as shown in dotted lines, the lever 38 moves about pivot 39, when it assumes the dotted line position.

The operation of the form shown in Fig. 2, is in all respects essentially the same as that in Fig. 1,k except that in the flat bottom tank D, the sandgrains of different specific gravity are not disposed or formed into superimposed strata, as in the cone shaped tank of Fig. 1. Actual classification in the Fig. 2 form, is restricted to the classifying chamber G, the liquid level in the tank being approximately shown at line E. Instead of the plumb-bob valve acting by gravity, as in the Fig. 1 form, it is closed by spring 61, when the connections are not under stress to open said valve.

The terminal 15, of pressure pipe 14, is in the lower zone of chamber G, and when the density of the sand bed increases, the float 11 will rise, due to hydrostatic pressure increase in pipe 14, and hence the end 19', of floating lever 19, will `be shifted into closer relation to stop 83. This will lengthen the intermittent stroke applied to valve rod 60, and increase the rate of discharge from chamber G.- As density in chamber G is reduced, pressure in pipe 14 will decrease and the float 11 will descend and thereby shift end 19 upwardly and shorten the movement of rod 60, to decrease the rate of discharge and-build up the sand bed, entirely automatically.

It is believed that the apparatus of my invention will be fully understood by the foregoing description and drawings, and while I have herein shown specific forms of the apparatus, I do not wish to be limited thereto except for such limitations as I claim:

1. As a means of automatically controlling the rate of discharge of a sand-grain bed to prevent depletion thereof, a classifying chamber, means supplying water to produce sustained hindered settling classification in said chamber to dispose the sand-grains therein in the order of their specific gravity with the heavier particles in the bottom zone of said chamber, a discharge spigot the claims may impart.

leading from said chamber with its intake end in said bottom zone, a gravity acting closure coacting with said intake end of said spigot, an upright hydrostatic pressure pipe having a lower open end disposed near said spigot whereby the heavier sand-grains will increase liquid pressure in said pipe and the upper end of said pipe extending above said chamber, a controlling rod for said closure extending through said pipe and projecting from the upper end thereof, a float chamber connected with said pipe below the upper end thereof, a hydrostatic governor float in said chamber actuated by the varying levels therein responsive to different hydrostatic pressures in said pipe, a floating lever pivoted tov said rod and having an adjusting end and an actuating end, and a constantly driven reciprocating actuator having a lost`motion connection with said actuating end of lsaid lever for causing rapid opening and closing movement of -said closure to' intermittently release and uniformly discharge but not deplete the bed, and the adjusting end of said lever being connected with said governor float to vary the action of said actuator on said lever as said y bed grows heavier or lighter, whereby such uniform discharge will maintain a constant bed density.

2. YAs a means of automatically controlling the rate of discharge of a sand-grain bed to prevent depletion thereof, a classifying chamber for the bed, means hydraulically sustaining hindered settling classification in said chamber to dispose the sand-grains therein in the order of their specific gravity with the heavier particles in the lower zone of said chamber, va discharge spigot leading from said chamber with its intake-end in said lower zone, a gravity closure coacting with said intake end and having a'controlling rodextending upwardly, a hydrostatic pressure pipe sleeved on said rod and having a lower open end disposed near said lower zone whereby the A sand-grains will cause variable pressures in said pipe, a float chamber connected with said pipe, a hydrostatic governor float in said chamber actuatedA by varying levels in said chamber responsive to different pressures in saidpipe, an actuator driven at a regular raterof speed, and means connected with said rod and operatively associated with said actuator for intermittently opening and seating said closure and said means being connected with said fioat to modify the operation of said closure and uniformly control discharge from said bed irrespective of variation of feedto said chamber, whereby the density of said bed will remain constant.

3. In a classifier, a classifying chamber, means producing hindered settling classification there.- in, a discharge spigot for said chamber, a closure for said spigot, closure actuating means having a given range of action and operatively connected with said closure to open and close the same, and hydrostatic governor means actuated by variable hydrostatic pressure as the feed bed grows heavier or lighter to correspondingly dispose said closure into varying range of action of said actuator means to alter the extent of movement of said closure.

4. In a classifier, a classifying chamber, means producing hindered settling classification therein, a discharge spigot for said chamber, a closure for said spigot, closure actuating means having a given range of action and operatively connected with said closure to open and close the same intermittently, and `governor mechanism responsively actuated by changes in the specific gravity of said bed as the latter'grows heavier or lighter v gravity changes in said bed for adjusting said iioating lever to shorten or lengthen the movement of said valve commensurate with density changes in said bed, whereby said bed will remain constant in volume and density.

6. In a classier, a classifying chamber forthe sand bed having discharge means, means producing hindered settling classification in said chamber, mechanical means for operating said discharge means, and hydrostatic apparatus operated responsive to density changes of the bed for modifying the operation of said discharge means by said mechanical means to alter the quantity of discharge as the bed density changes and thereby maintain a constant bed density irrespective of feed and specic gravity changes.

'7. A classifying chamber of the class described having a valve seat, a spigot leading from said valve seat for conveying discharge matter from said chamber, a normally acting Valve for coaction with said seat to control discharge of the sand bed, and a repair closure coacting with said seat to prevent discharge of the sand-bed during periods of repair, and sealed mechanism accessible from the exterior of said chamber for manually operating said repair closure.

8. In a classier, a classifying chamber for the sand bed having discharge means, means producing hindered settling classification in said chamber, mechanical means for gradually opening and closing said discharge means, and hydrostatic apparatus operated responsive to density changes of the bed for varying the operation of said discharge means by said mechanical means to alter the quantity of -discharge as the bed density changes l and thereby maintain a constant bed density irrespective -of feed or specific gravity changes.

9. In a classifier of the class described, a classifying chamber for the sand bed having discharge means, means producing hindered settling classication in said chamber, mechanical means operated at a fixed speed for gradually opening and closing said discharge means intermittently, and hydrostatic apparatus operated responsive to density changes of said bed for increasing or decreasing the operation of said discharge means by said mechanical means to alter the quantity of discharge as the bed density changes and thereby maintain a constant bed density.

ROYAL S. HANDY.

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