US1490420A

US1490420A - Hydraulic classifier

Info

Publication number: US1490420A
Application number: US240997A
Authority: US
Inventors: Elder Robert Baxter
Original assignee: ANDREW DARWIN ELDER
Current assignee: ANDREW DARWIN ELDER
Priority date: 1918-06-20
Filing date: 1918-06-20
Publication date: 1924-04-15
Anticipated expiration: 1941-04-15

Description

April 15 1924. 1,490,420

r R. B. ELDER HYDRAULIC CLASSIFIER F l J ne. 20; 1 1 5 S aw-Sh t 3 3 Sheets-Sheet 2 April 15 1924,

R. B. ELDER HYDRAULIC CLASSIFIER Filed June 20, 1918 ATTORNEYS g, m 4 m m a? W 4 J F 7 I 2 a a o c v n/ 0 IM "m m 9 lxll) 0 0 b u p u 9 T w nd .m z z 5 m w @v Q m 4 u 4 flaw n n 5 m WITNESSES WWW April 15 1924.

R. B. ELDER HYDRAULIC cLAss-IFIER 3 Sheets-Sheet 5 Filed June 20 1918 WITNESSES 94 A TTORNEYS t atented Apr, 3%, 392%,

ataata RQBERT BAXTER ELDER, 0E UNSANKINKO, CHOSEN, JAPAN, ASSIGNOR 1'0 ANDREW DARWIN ELDER, 01 DENVER, COLORADO.

HYDRAULIC CLASSIFIER.

Application filed June 20,

To all whom it may concern Be it known that I, Ronna'r BAXTER ELDER, a citizen of the United States, and a resident of UnsankinkoyChosem, Japan, have invented certain new and useful Improvements in Hydraulic Classifiers, of which the following is a specification.

My invention is an improvement in hydraulic classifiers, and has for its object to provide a device ofthe character specified, wherein a teeter chamber is provided, arranged above hydraulic and discharge chambers, the latter communicating with the teeter chamber by arestricted opening and the former by. a number of openings, and wherein a stand pipe having an overflow is provided-in connection with the discharge chamber.

A further-object is to provide a means for introducing water into a teeter chamber in such a manner as to maintain even distribution of the water to all portions of the teeter chamber and so to prevent the formation of banks of sand in any portion thereofland to maintain a uniform liquid bed of pulp over the entire teeter chamber area.

A further object is to provide a simple means for regulating the flow of water to the teeter chamber so that the regulation may be made and established correctly and thereafter will not be dependent on the judgment or guess of operating attendants.

A further object is to provide a device of the character specified wherein the discharge of the heavy classified pulp from the teeter chamber depends on the thickness and density of the bed of pulp in the teeter chamber.

In the drawings:

Figure 1 is a longitudinal section, showing the improvement applied to a single pocket classifier of the launder type;

Figure '2 is a section on the line 2-2 of Figure 1;

Figure 3 is a vertical section of the improvement applied as a cone classifier;

Figure 4 is a longitudinal section showing the improvement.applied as a .four spigot classifier;

Figure 5 is a front view of another embodiment of the invention;

1918. Serial No. 240,997.

Figure 6 is av plan view;

Figures 7, 8 and 9 are sections on the lines 7-7, 88 and 9-9, respectively, of Fig ure 6;

Figure 10 is a section on the-line 10.10 of Figure 5.

In the embodiment of the invention shown in Figures 1 and 2, acasing is provided having its enclosing walls at the bottom perpendicular, as indicated at 1, and flaring above the perpendicular portion, as indicated at 2, where they connect with the launder 3. A partition 4 is arranged in the bottom of the casing, the said partition inclining downwardly from the inlet toward the outlet end of the casing, andthe said partition is between the perpendicular walls of the casing.

Another partition 5 is arranged between the partition 4 and the bottom of the cas-. ing at the outlet end of the casing, and this partition 5 divides that portion of the casmg below the partition 4 into two chambers, a iydraulic chamber 6 and a discharge chamber 7, and a delivery valve or spigot 8 leads from the discharge chamber. This discharge chamber communicates with the space in the casing above the partition which is the pulp chamber, and a series of openings 9 is provided in the partition 4 for furnishing a means of communication between the hydraulic chamber and the pulp chamber.

Drain valves 10 are provided in the bottom of the casing for draining the hydraulic chamber, and water is furnished to the chamber by a pipe 11 which is controlled by a valve 12. A stand pipe 13 is provided at one side of the casing, the said pipe extending from the bottom of the casing to above the top of the launder, the bottom of this pipe being connected with the discharge chamber, as shown, and this pipe has a discharge opening 14; above the pulp level through. which the water may flow on to the pulp in the launder. A pipe 15 communicates with the bottom of the stand pipe by means of which water may be supplied to the pipe to maintain the water level at the overflow opening 14, and a valve 16 is arranged in the pipe forcontrollin the same.

In the embodiment of the invention shown in Figure 3 the casing has the portion 17 with perpendicular walls and the portion 18 with flaring walls, and the overflow 5 launder 19 is arranged near the top of the casing in a manner to receive the overflow from the casing. A feed cone 20 is arranged centrally of the casing at the top, and the stand pipe 21 extends upwardly from near the bottom of the casing to above the top of the feed cone. Here the stand pipe is provided with a discharge spout 22 discharging into the cone, and with a supply ipe 23 for maintaining the level of water 1n the stand pipe. This pipe 23 is controlled by a valve 24 and the pulp is fed to the feed cone by a feed launder 25. A partition 26 is arranged near the bottom of the casing the said partition dividing the casing into an upper teeter chamber and a lower portion which is sub-divided by partition 27 into a hydraulic chamber and a dischage chamber, the lower end of the stand pipe communicating with the discharge chamber. The partition 26 inclines downwardly toward the center of the casing, and it is provided with openings 28 forming a communicationbetween the teeter chamber and the hydraulic chamber. The discharge chamber communicates with the teeter chamber and a discharge valve 29 leads from the discharge chamber. Drain valves 30 are pro" vided in the'hyd'raulic chamber, and water is supplied by means of a pipe 31. ,Intheenibo'dimentof the invention. shown Figure githe casing has the portion 31 lwithfverticali wallsa nd the portion 32' with fl ing-walls which connect with the launder 33.,;

jflhelowerportion ofthe casing is difvid ed'fby verticalp a'rtitions 34 into four fpocketaandan inclined partition 35 sepal rates each pocketinto a lower portion and Fan upper portion. These partitions 35 incline downwardly toward the discharge end off the casing-fend a .partition 36 separates each lower portion into a hydraulic chamber and-a discharge chamber. The partitions 35 have openings 37 correspcinding to the open-' ings 9 and 28, and a discharge valve 38 leads from each discharge chamber. Each hy-- draulic chamber has-Ldrain valves 39, and a standpipe 40 leads upwardly from each (lischarge chamber to abovethe level of the top of the launder. These stand pipes 405have overflow outlets 41' corres onding to the outlets 14 and22, and it will be noticed from an inspection of Figure 4 that the said openings are of lessheight above the bottom of the casing at the discharge end of the launder than at the inlet end, that is, the stand pipe 40 at the inletv end has its overflow opening at alhigher level than the remainmg openings, and they are gradually stepped downwardlyirom the inlet to the Outlet end of the casing.

Water is supplied by a water pip: 42 to the hydraulic chambers, each cham I having its supplyinpedendent of the other chamber.

The operation of all. of the embodiments is the same, each being a hindered settlin hydraulic classifier, for classifying crushed ore, preparatory to treating it on Wilfley tables or other concentrators designed to separate the valuble minerals from the gangue. The device consists essentially of the following parts, namely, a teeter chams ber wherein the ore pulp is thickened to a condition of hindered settling, and this condition maintained; second, means for bringingthe unclassified pulp over the teeter chamber in order that the ore particles may have a chance to sink into the teetering mass or be crowded out by heavier articles, as the case may be, with means fidr carryin away the lighter portions of the pulp whicl i could not sink into the teeter chamber; third, means for introducing hydraulic water into the teeter chamber through small holes in the bottom thereof and in such a way as to maintain uniform hindered settling conditions over the entire area of the teeter chamber, and as not to allow parti- 0185 of ore to settle out of the teeter chamber against the incoming hydraulic water; fourth, means for discharging the heavy classified pulp from the teeter chamber, at

or near the bottom, and into a discharge chamber wherein the hydrostatic pressure is regulated independently of the hydraulic water which does the classifying; fifth, means for. maintaining constant or nearly so the hydraulic pressure in the discharge chamber; and, sixth, means for introducing water into the discharge chamber and independently of the water introduced into the teeter chamber.

The problem of making a successful hindered settling classifier may be resolved into two parts; first, to produce and maintain uniform hindered settling conditions over the entire teeter chamber area; second, to discharge the products of classification separate from each other and as fast as they are formed.

In order that there may be uniform hindered settling conditions over the entire area of the teeter chamber it is necessary that there be a slowly upward moving current of water uniform or nearly so over the entire area. The hydraulic water enters the teeter chamber from the hydraulic chamber through the

constriction openings

9, 28 and 37 in the partition which separates these chambers, and a it enters the teeter chamber it is in the form of jets.

spread out as the water' moves upward and mingles with the'pulp, and the result is that a short distance above the bottom of the teeter chamber the hydraulic water is These jets diflused uniformly into the pulp and forms the desired slowly upward moving current of water practically uniform over the enthe water in the jets. The nearer the holes are placed and the smaller the velocity of the incoming water the less depth is re-' quired for thedifi'usion to take place.

The essential function of the constriction plate or partition which separates the teeter and hydraulic chambers is to maintain the even distribution of the hydraulic water over the teeter chamber area. This it does by ofi'ering tothe flow of hydraulic water such a reslstance that the inequalities tending to form in the weight of thepulp bed at difierent points have no appreciable effeet on the flow of water. The bed just over and adjacent to the point where the heavy classified material is discharged from the teeter chamber tends to become lighter since here it is continuously removed, and the bed just under the point where'theunclassified pulp is fed to the teeter chamber tends to become heavier, as heavy ore particles are continuously added at this point. In passing from the hydraulic water chamher to the topof the pulp bed the hydraulic water meets with resistancefirst from the constriction plate and then from the pulp bed. The resistance offered by the constric tion plate must be great enough so that slight variations in the resistance oiiered at different points in the pulp bed do not materially efiect the distribution of water over the teeter chamber area, and at ,the sametime it must not be so great that the velocity of the incoming jets is so great as to require "an undue depth in the pulp bed before they become difiused into the pulp. When the resistance offered by the constriction plate is great enough to maintain the proper distribution of i the hydraulic water, as described, the velocity of the incoming jets of water will be great enough so that no ore particle can settle through the constriction openingsagainst the entering current of water.

The discharge of the heavy classified pulp is regulated by controlling the hydraulic pressure in the discharge chamber. In practice, ifsuflicient water is permitted to flow;

into the discharge chamber, so that a little overflows the top of the standing column or stand pipe the hydraulic pressure will be maintained-practically constant at the opening between the teeter chamber and-tthe discharge chamber and will be fixed by the height of the column of water. The cross sectional area of the column and its connection must be large enough so that the friction head of a small amount of water passing through them will be negligible.

. The height of the overflow of the column is then made such that the hydraulic pressure maintained at the opening between the teeter and discharge chambers is equal to the hydraulic pressure due to a column of pulp, the height of the teeter chamber and of the density desired to be maintained in the teeter chamber plus the column of less dense pulp above'the top of the teeter chamber. The density of the pulp above the top of the teeter chamber will remain practically constant, so that it is evident that under the conditions described, whether there is a movement of liquid from the discharge chamber into the teeter chamber or in the opposite direction will depend on the density of the pulp in the teeter chamber. If this density exceeds the amount necessary to balance the constant hydraulic pressure in the discharge chamber. there will be a movement from the teeter chamber into the discharge chamber. The movement from the teeter chamber into the discharge chamber will thin the pulp in the teeter chamber until equilibrium is again restored. The movement of the water into the teeter chamber from the discharge chamber will hinder the particles from leaving'the teeter chamber so that the density of the pulp in the teeter chamber will be thereby increased, and this Will continue untilequilibrium is again restored. In this way the density of the pulp in the teeter chamber will be kept practically constant, rovided only that the area of the opening etween the teeter and the discharge chambers is equal to or less than the area through which the coarse ore particles in the pulp being treated will pass simply by free settling, and without a move-- ment of liquid either way, and provided, also, that this opening is not so small'but what a slight increase of density of the pulp will produce movement enough to discharge the pulp as fast as it is formed by the ore particles fed to the teeter chamber.

In practice, the area of this opening, that is, the opening between the teeter and discharge chambers,-should be something less than the area which will discharge the particles b-y freesettling, say, for instance, half such area. Then the density of the pulp in the teeter chamber will increase until a steady stream of pulp is discharged into the discharge chamber, at a velocity equal to twice the average, free. settling velocity of the particles; In' this way the -machine will IOU provided that the area of the teeter chamber is large enough for the overload.

Echarge chamber if there is the proper density of pulp in the teeter chamber. If this density exceeds the amount necessary to bal- .ance the pressure in the discharge chamber there will be movement from the teeter chamber into the discharge chamber, while if the density is less than the amount necessary to balance the pressure in the discharge chamber there willl be movement in the opposite direction. From the discharge chamber the pulp passes through the valves 8, 29 and .38 for further treatment.

The embodiment of the invention shown in Figures 5 to 10, inclusive, is characterized by the addition of a feed water chamber arranged above the classifier and from which all the water used by the classifier is derived. In the said embodiment of the invention two discharge chambers 50 and'51 are provided, separated from a partition 52, and thechamber rated from the waste chamber 53 tion 54 and from the chamber 51 is sepaby a parti- 53 leads a waste pipe 55. The water is fed into thefeed water chamber 56 which is above the discharge chambers, and to which water is delivered from a pipe 57 having a valve 58 for controlling the flow of the water.

'Spigots 59 lead from the feed water cham-' her and deliver to pipes 60, which pass downward through the discharge chambers, delivering to the hydraulic chambers 61, one of which is arranged beneath each pulp or teeter chamber 62, of which there are two,

corresponding to the number of discharge,

chambers and number of hydraulic chambers. Each teeter or pulp chamber '62 is separated from the ad acent hydraulic chamber by a partition 63 having openings for permitting the water to flow from the hydraulic chamber to the teeter or pulp .chamber. The excess water from the feed chamber 56 over and above that passing through the spigots 59, flows over the end 64 of the feed water chamber into a passage 65, which opens intoa passage 66 communicating with the discharge chamber 50 through an opening 67. Each discharge column or chamber communicates with the adjacentpulp chamber through an opening 68, whose extent may be varied by means of a valve or gate 69, mounted to'slide in guides-7O on the chamber wall. These'ports or openeach other by I ings 68 are adjacent'to the pipes which lead the feed water from the spigots to the hydraulic chambers. A screen 71 is arranged between the feed water chamber proper and the spigots, to prevent the pas.- sage of sediment. Spigots 72 lead from the bottom of the

discharge chambers

50 and 51 to deliver the pulp, and each hydraulic chamber is provided with a drain pipe 73,

which can pass through the spigots 59, and

the. excess flows ever the the

passages

65 and 67 into the first dischargechamber 50. The chamber 50 is the discharge column and dispartition 64 through charge chamber regulating the dischar' e of pulp from the first or adjacent teeter c 1amthis discharge ber 62. The overflow from column or chamber is by way of the parti tion 52 separating the discharge chambers,

66 and the openingand the chamber 51 is the discharge column of the second teeterchamber. The water coming through the; opening 67 supplies what is needed for the spigot 72 of the chamber 50, the excess of water overflowing the partition 52, as above stated, for supplying the spigot 72 of the chamber 51, from which flows the pulp delivered by the said chamber 51 from the second teeter chamber 62. The final execess of water overflows the partition 54 and runs to waste through the pipe 55.

The essential function of the feed water chamber'56 and the spigots 59 leading there from is to furnish a means whereby the amount of water running to the teeter chambers may be accurately adjusted ,to the correct amount when the classifier is first put into use, and this amount of water may thereafter be continuously furnished to each teeter chamber without the necessity for readjusting the Water except to see that the required level of water is maintained in the feed water chamber. In the construction which I show, the level ofthe water in the feed water chamber is maintained at the desired point by providing thefeed water chamber with an overflow, but it is obvious that any means for maintaining this water level would be equally as effective, as, for instance, a feed water chamber having no overflow and having the valve 58 controlled by a float in the chamber 56, so that ias the water in the said chamber 56 would be maintained at a constant level. With this construction another water supply for the

discharge chambers

50 and 51 would be providedI' This construction would not be a departure from the spirit of my invention, but I prefer the construction which I show in the drawings as it requires only one water supply.

It will be noticed that the top of the pipe 60 is high enough above the level of the pulp-in the pulp chambers, which is indicated by the dotted lines oi. Figures 9 and 10, so that the water may rise in the said pipe high enough to force itself into the teeter chamber against any bed of pulp which can form therein, and this insures at all times a constant feed of Water to do the classifying, the amount being determined by the size of the spigots 59 and the head of water maintained in the feed water chamber, and independent of the density of the pulp bed in the teeter chambers. The screen '71 prevents any solid matter from finding teeter chamber are its way into the sp-igots and thence to the hydraulic Water chambers, where" it might stop the restricted openings in the partition 63.

In use, the unclassified pulp is fed into the extension 77 at the front of the classifier, from whence it fiows into" the first teeter chamber 62. The pulp rejected by thefirst teeter chamber flows to the second teeter chamber, passing over the partition 7 8 which separates the two chambers, and the lightest particles which are rejected by the second contained in the pulp which flows over the partition 79 between the second pulp chamber and the outlet 82.

ll claim:

1. A device of the character specified, comprising a casing, an inclined transverse partition near the bottom of the casing, an approximately vertical partition between the transverse partition and the bottom, said partitions dividing the easing into an uper ulp or teeter chamber and lower hyrau ic and discharge chambers, means for supplying water under pressure to the hydraulic cham er, a discharge valve for the discharge chamber, a stand pipe communicating with the dischargephamber and extending above the discharge chamber commimicating with thepulp chamber by arestricted opening, the i inclined transverse partition having openthe pulp level'in the pulp chamber and having an overflow above the said level,

the pulp chamber and communicating with the hydraulic chamber.

3. In a device of the character described,

a teeter chamber, a hydraulic chamber there beneath and separated therefrom by a partition through which highly restricted openings are formed, means for supplying water through the partition to the teeter chamber in such a quantity that a predetermined pressure head may be maintained across the partition to effect even distribution of the water to all parts of the teeter chamber, means for supplying unclassified pulp to the teeter chamber, means for regulating the discharge of classified pulp therefrom and means controlled by'the changing of pulp density for regulating the discharge of pulp from the teeter chamber. I

4. In a device of the character described, a teeter chamber in all parts of which a unitormhindered settling bed of pulp is maintained by water entering the teeter chamber through numerous restricted openings in the bottom thereof and under sufiicient pressure to overcome the tendency of the pulp to form a bank or solid mass upon the bottom of the teeter chamber, and means in connection therewith and controlled by the changing of the pulp ,densit whereby the discharge of the heavy classi ed portion of the pulp will be effected.

5. In a device of the character specified, a teeter chamber, means for supplying hydraulic'water to produce hindered settling classification therein, means for maintaining the even distribution of the h draulic water over the teeter chamber area y forcing it to enter the teeter chamber through numerous small openings distributed over the bottom of the tester chamber, the said openings being so restricted that they formenough resistance to the passage of the water that the distribution of thewater is thereby maintained regardless of slight inequalities in the weight of the pulp bed at different points in the teeter chamber, and means in connection therewith. and controlled by the changing of the pulp density for regulating the discharge of the heavy classified portion of the pulp therefrom. A

6. In a device of thecharacter specified, a teeter chamber, a discharge chamber with which the teeter chamber communicates by a restricted opening, means for supplying water under pressure to the bottom/of the teeter chamber to produce hindered settling classification therein, a stand pipe commu nicating with the discharge chamber and extending above the pulp level in the pulp chamber and having an overflow above the pulp level, and means for removing the heavy classified material chamber otherwise than nicating therewith by of the first teeter chamber, each discharge column having an overflow leading to the succeeding discharge column.

8. In a device of the character specified, apulp or teeter chamber, a hydraulic chamber below the pulp chamber and communieating therewith b restricted openings, a

dischar e column a jacent to the pulp chamber an having a restricted communication therewith, a feed water chamber above the discharge column discharge chamber and communicating with the hydraulic chamber, the feed water'chamher having an overflow leading to the dischar e column.

9. n a device-of the character specified, a pulp or teeter chamber, a hydraulic chamber below the pulp chamber and communicating therewith by restricted openings, 9. adjacent to the teeter chamber and having a valved communication therewith, a feed water chamber above the discharge chamber and communicating with the hydraulic chamber, the feed water chamber having an overflow leading to the discharge column.

10. A device of the character specified, comprising a casing having an n per pulp chamber and lower discharge and ydraulic chambers communicating with the pulp chamber, means for supplying water under pressure to the hydraulic chamber, a stand pipe communicating with the discharge chamb level of the pulp in the pul chamber and filled to this overflow leve with nearly static clear water. and means the classified pulp from the discharge chamber otherwise than through the stand 11. In a device of the character-specified,

- a teeter chamber, a hydraulic chamber beneath the teeter chamber and communicating therewith by restricted opemngs, means for supplying water under pressure to the hydraulic chamber, a discharge chamber chamber communiproducing in the discharge chamber at the discharge opening a constant hydrostatic pressure-greater than that of a column of er, having an overflow level above the for removing ht to the. vertical arge openin and pulp in the teeter 0 am clear water equal in hei distance between the disc the surface of the her.

12. In a hvdraulic classifier, a pulp chamber provide(. with feed and overflow means and a perforated bottom, a hydraulic chamber communicatin with the pulp chamber through vided with awater feed, a discharge chamber in direct communication with said pulp chamber adjacent said perforated bottom a pressure column in communication w1th said discharage chamber and rovided with an overflow above the level of the overflow of the pulp chamber, and a water feed to said pressure column independent of the water feed to' said hydraulic chamber.

13. In a hydraulic classifier, a ulp chamber provided with feed and over ow means, a hydraulic chamber communicatin with the pulp chamber through a plur ity of' smallapertures in the bottom chamber, a discharge chamber in communication with the pulp chamber adjacent its bottom, a pressure column in communication with the discharge chamber and provided with an overflow above the level of the overflow in the pulp chamber, and independent water feeds to the hydraulic chamber and to the discharge chamber pressure column.

14. In a hydraulic classi of pulp chambers, each pro 'ded with feed and overflow means and a perforated bot tom and a hydraulic chamber on the other side of the said perforated bottom provided with water feed, .a discharge chamber in communication with each pulp chamber a of the pulp er, a plurality pressfire column in communication t with each discharge chamber and provided with an overflow above the level of the overflow of its pulp chamber, and water feed means to the pressure column independentof the water feed to the hydraulic chamber.

15. In a hydraulic classifier, a pulp chamber provided with feed and overflow means and a perforated bottom, a'hydraulic chamber on the other side tom and pulp chamber, a pressure column in communication with the discharge chamber and ROBERT BAXTER ELDER.

' Witnesses:

A. 0.. Emma, Sm Pom; Hm.

said per orated bottom, and pro-.

I of the perforated botprovided with water feed, a discharge chamber in communication withtheprovided with an overflow above the level "of" the pulp chamber overflow, and water means .to the pressure column mde-