US1990129A - Apparatus for separating materials of different specific gravities - Google Patents

Description

Feb. 5, 193 5. w. c. MENZIES 1,990,129v

APPARATUS FOR SEPARATING MATERIALS OF DIFFERENT SPECIFIC GR-AVITIES Filed June 5, 1935 3 Sheets-Sheet l Feb. 5, 1935. w. z E 1,990,129

APPARATUS FOR SEPARATING MATERIALS OF DIFFERENT SPECIFIC GRAVITIE-S Filed June 5, 1953 5 Sheets-Shed 2 k Q lNVEN o WIM/W 4L ATTORNEYS F eb.'5, 1935. w. c. MENZIES APPARATUS FOR SEPARATING MATERIALS OF DIFFERENT SPECIFIC GRAVITIES Filed June 5, 1935 3 Sheets-Sheet 3 INVENTOR MZ/A/l a m z/a ATTORNEYS Patented Feb .5,1"935 I 1,990,129

UNITED STATES PATENT OFFICE APPARATUS FOR SEPARATING MATERIALS OF DIFFERENT SPECIFIC GRAVITIES William C. Menzies, Scranton, Pa. Application June 5, 1933, Serial No. 674,438.

16 Claims. (01. 209-161) My invention relates to apparatus for separatmeans just referred to are such as to produce a ing materials of difierent specific gravities. The variably hindered settling of the-materials fed invention pertains more particularly to apparato the classification chamber. For the maximum tus for separating coal orother' minerals from. resistance to downward settling, the upflow curmixtures containing them,- in which apparatus rent is at a predetermined maximum velocity '5 the mixture is subjected. to hydraulic classific'adesigned to float the good coal off into the distion and separation of the materials. charge at the top of the chamber while permitting While not confined to such use, the apparatus the ready downward settling of the heaviest refuse of my invention is particularly useful in the to the bottom discharge. Under this maximum separation of coal from the usual mined mixture velocity of current upflow and consequent hin- '10 v of coal and rock or other refuse; and as the drance to settling, the lighter refuse, such as the difliculties sought to be'overcome by my invenbony, tends to accumulate so near the top of tion are well illustrated in the case of separation the chamber under the stratum of good coal-that,

of coal, reference will primarily be made thereto if the maximum upflow current were continued, in explaining the principles and advantages of more or less of this refuse would be carried by 15 the invention. the upflow current over with the good coal into The impurities 'or' refuse in the usual mined the valve discharge. This is avoided by the means mixture are a. very poor grade of coal called automatically operating in response'to the inbony, and rock, pyrites, slate and the like.- creased density of the materials in the classifi- The material of value, the high-grade coal, is cation chamber to reduce the velocity of the 20 of the lowest specific gravity, the rock and pyrites upflow current.

are the materials of the highest specific gravity, Under the condition of less hindered settling the slate isof the next highest specific gravity, resulting from the reduction in velocity of the while the bony is material of an intermediate upflow current, of course all the materials in specific gravity, sufliciently approaching that of. the classification chamber settle more'rapidly 2fi the good coal to make it dimcult to effect subdownward so that if this condition were prostantially complete separation of the two by hylonged good coal, as the lightest material, would draulic classification. i settle down with the heavier refuse to the bottom A primary object of my invention is to" provide discharge. This is avoided by the means autoan apparatus for the hydraulic separation of matically operating in response to the decreased 30 coal and other minerals of value from mixtures density of the materials in the classification containing them which will automatically-operate, chamber to increase the velocity of the upflow with'a minimum of attention, to efiect substancurrent and thus restore the maximum resisttially complete separation of the coal or other ance to downward settling, which again forces mineral of value from the refuse even in cases the good coal upwardly while still permitting 35 where certain material of the refuse, such as the the heavier refuse to settle to the bottom disbonyin the case of the separation of coal, for charge. I example, is of a specific gravity sufiiciently ap- To thus make the density of the fluid mass in preaching that of the mineral-of value to ordi-' the classifying or separating chamber the factor 40 narily render the separation a difllcult and uncontrolling the velocity of-the upflow current, my 40 certain one so far as substantially complete sepinvention comprises means for supplying that aration is concerned. chamber with water at a predetermined maximum Another and more particular object of my involume and rate of flow sufiicient for the maxivention is to especially adapt an apparatus of mum velocity of upflow current through the chamthe foregoing character to the separation of 0091- her required for a given density of the materials 45 and to the overcomin Of h above-mentioned and associated means responsive to the increasing difliculty of substantially complete separation of Iresistance offered by th increasing density of th d coal from the ny by p vid materials to the upflow current to divert varyapparatus with means automatically operating ing ount of the supply liquid from the chamto vary the veloci y of e yd auli pfi w 11 her and thereby reduce the velocity of the classi- 50 rent in response to changes in density of the fluid' fying current.

mass in the classification chamber as the ma- Another object of the invention is the provision terials accumulate in or separate out therefrom. in a materials separating apparatus of the gen- The changes in the upflow current designed to eral character to which theinvention pertains of be brought about by the automatically operating a vertically adjustable feed-in chute which will 55 deliver the crude mixture to the classifying chamber in quantities and at levels so below its overflow rim as to ensure that none of the refusewill be swept over that rim by the hydraulic current upon entrance of the materials to the chamber.

A further object of the invention is the provision in such an apparatus of a mechanical agitator of the revolving blade type effective in maintaining the mixture in mobile condition in the classifying body of water without exerting a centrifugal force on the fluid mass disturbing the classifying action.

Still another object of the invention is the provision in the classifying chamber of deflector means effective to so divert and disperse the upflow current of water from the path axially of the chamber which it has a tendency to take as to avoid turbulence of upflow and improve the classifying action.

The foregoing objects, principles and advantages of my invention as well as other objects, principles and advantages thereof will more fully appear from the presentation hereinafter made by description and drawings of an apparatus embodying the invention in a form found particularly suitable for the separation of coal. It is to be understood, however, that the invention is not confined to this particular form of apparatus, nor its usefulness restricted to the separation of coal, and that the invention may include other forms of apparatus and applications of use within the scope of the appended claims.

' In the drawings, which are somewhat diagrammatic:

Fig. 1 is a side elevational view, with interior parts shown in interrupted lines, of one form of the apparatus of my invention, particularly adapted, as stated above, for the separation of coal;

Fig. 1a is a partial vertical sectional .view through the water-sorting chamber or tank of the apparatus shown in Fig. 1;

Fig. 2 is an end elevational view, with certain parts removed for clearness of illustration, of the apparatus shown in Fig. 1, the Fig. 2 view being that looking from left to right of the apparatus of Fig. 1;

Fig. 3 is a detailed'vertical sectional view, on an enlarged scale, of a portion of the apparatus along the line 33 of Fig. 1;

Fig. 4 is a top plan view of the portion of the apparatus shown in Fig. 3;

Fig. 5 is a vertical sectional view along the section line 5,-5 of Figs. 3 and 4; and

Figs. 6, 7 and 8 are diagrammatic views illustrating the functioning of the apparatus in the separation of coal.

Since the apparatus of my invention as applied to the separation of coal from-its impurities involves substantially the same principles as when applied to the separation of other minerals, the

present description will be confined to the separation of coal as a typical instance of use serving to present the essential principles of the invention.

The particular form of apparatus embodying my invention shown in the drawings includes a main receptacle or tank adapted to be so supplied with water as to function as a classification or sorting body for the coal mixture to be fed thereto. In the form shown, this tank has a cylindrical upper portion 1, an intermediate conical portion 2 with its walls converging downwardly to a tubular lower portion 3 of a substantially lesser diameterthan that of the uppermost portion. The sorting .tank is suitably supported adjacent its open top upon side rails-4 of a supporting frame, not further shown, and the lower tubular portion or member 3 of the tank is downwardly and laterally curved to connect, through a neck 5, with an upwardly inclined and elongated chamber 6, of tube-like form,-c1osed at the bottom and open at the top, through which the water for the upfiow current in the sorting tank is supplied in the manner hereinafter more fully set forth. A gate valve '7 in the tubular member 3 of the sorting column serves to open and close communication between the chamber 6 and the sorting tank. I

The chamber 6 is provided with a conveyor for the refuse material so that this chamber also functions as a conveyor boot, receiving from the sorting tank the refuse materials settling downward therethrough. As the conveyor, indicated by the numeral 8 on Fig. l, is the usual flight.

conveyor of well known construction, it is surficient to here state that its receiving end is journaled in the bottom portion of the chamber or boot 6 in the line of discharge of the refuse materials through the tubular member 3 of the sorting tank, and its delivery end extends beyond the upper open end of the boot in which it is located. It is driven through a head shaft 9 adjustably mounted in the brackets 10. v

Water is supplied to the sorting tank in the manner hereinafter set forth, not only to provide the upflow current of water hereinbefore referred to but also to provide a body of liquid to which the coal mixture can be fed and with which it forms a fluid mass.

In apparatus of this general type the only.

practical mode of feeding the coal mixture to the sorting tank is to feed it through the open top of the tank, but heretofore this has been attended with the disadvantage of some of the refuse of the fed-in mixture being swept over by the hydraulic current into the discharge for the good coal at the top of the tank before that refuse has time to settle downwardly away from that discharge. To avoid that disadvantage, the present invention contemplates a form of extended feed-in chute delivering the coal mixture well down into the tank below the water level therein, and well down into the fluid mass itself after the same has once been formed. The invention also proposes a. form of the extended feed-chute which is vertically adjustable so as to adjustably vary the depth of its delivery of the coal mixture within the sorting tank, as this avoids that reduction in the capacity of the apparatus to handle different coal mixtures which has been found to attend an unvaried depth of submergence of the delivery end of the feed-in chute.

In the illustrated apparatus, the feed-chute is of the form shown in Fig. 1, having a funnel shaped mouth and an elongated cylindrical chute portion 11 extending down into the sorting tank below its rim. To enable the chute to be vertically adjusted, it is bodily suspended from the .overhead flanged beams 12 by the rods 13 extending through the flanges of thebeams and through box lugs 14 on the outer circumference of the chute and nuts 15 engaging the threaded ends of the rods.

As is customary in apparatus of this type, means are also provided for mechanically agitating the fluid mass in the sorting tank, and the invention contemplates certain novel features of such agitating means which substantially conagitator comprises a rotatable shaft 16 on which coal handled by the apparatus, experience hav-- the agitator blades are mounted. It has been the customary practice heretofore in apparatus of this general type to employ a plurality of sets of blades spaced vertically apart through the sorting tank, withthe top set fairly close to the discharge rimof the tank, the bottom set in the lowermost portion of the tank and with at least one intermediate set, and with the blades of each set extending horizontally from the shaft and practically across the entire width of the tank. It has been found, however, that which such an arrangement, when the agitator is run at the higher speeds of the range employed for different coal mixtures, the top set of long blades produces excessive centrifugal action on the fluid mass which seriously interferes with the classification of the materials therein, and especially with the classification of the larger sizes of the materials. To avoid this, and at the same time maintain suflicient speed of the agitator for the proper classification, the apparatus of the present invention eliminates the customary top set of long blades and employs two sets' of relatively short horizontally extending blades in the lower and midway portions of the sorting tank, as indicated by the sets of blades 17 and 18 respectively in Fig. 1, and as a substitute for the top set 'of long blades the apparatus employs extremely thin blades having a stem portion 19 extending obliquely upwardly from the midway set of blades and short horizontally disposed spurs or blade portions 20, the uppermost of which are in approximately the location of the long top blades heretofore used. It has been found in the practical use of the apparatus that such blades sufliciently agitate the material near the upper part of the sorting tank to keep it in a fluent state while at the same time avoid that excessive centrifugal action hereinbefore referred to as interfering with the classification of the materials. 7

For a somewhat similar reason, the apparatus also employs extremely thin blades having a stem portion 21 extending obliquely downward from the lower-set of horizontal blades 17 and horizontal spurs or blade portions 22 so as to agitate the materials in the small-diameter bottom portion of the sorting tank adjacent its outlet to.

the tubular section 3. These blades, instead of producing centrifugal action enough to throw the materials in the bottom portion of the sorting tank forcibly against its side walls and thereby divert those materials from the bottom outlet, provide just sufficient agitation of the, materials to facilitate their discharge through that outlet.

The shaft 16 may be driven by any suitable means, preferably by a variable speed drive so that the speed of the agitator may be adjusfably varied in correspondence with the size of the ing shown that thegreater the size of the coal the greater the speed required of the agitator.

, unnecessary to describe the same in detail, and

it is suflicient here tosay that it comprises an adjustably mounted driving pulley 24 and a driver.

pulley 25 which latter in turn drives the gears 26 on the shaft 16.-

To supplement the work of the mechanical agitator in maintaining the mass of materials in the sorting tank in fluid condition, water inlet 5 nozzles 27 are disposed through opposite side walls of the sorting tank along its length, with each directed obliquely downwardly at an angle of approximately 45 to the horizontal and to the vertical axis of the tank, as shown in Figs. 1 and 2, 10 the effect being to assist the agitator blades in rotating the mixture in the sorting tank and therefore facilitate the classification of the materials according to their differing specific gravities. The nozzles may be supplied with water 15 from any suitable source, but in the illustrative Y apparatus each set of two oppositely disposed nozzles are connected to a ring pipe 28, and the ring pipes 28 are in turn connected to the water pipe 29 which is fed by the pump 30 as will here- 20 inafter be more fully pointed out. The connectionsbetween the water pipe 29 and the ring pipes 28 and the valves therein for the, control of the water to the inlet nozzles 2'7 are diagrammatically indicated at 31 and 32 in'Fig. 1. A pipe 25 34 of inverted U-shape, with one arm connected to the upper end of the water pipe 29 and its other freearm disposed over .the mouth of the chute 11, as shown in Fig. 1, serves to deliver water from the pipe 29 to the mouth of the chute m cylindrical extension 11 of the feed-in chute; 1 which would cause some of the refuse materials to be carried upwardly to the discharge for good coal over the rim of the tank. The provision to prevent this comprises a deflector plate 35 mounted on shaft 16 below the. delivery end of the feed-in chute and another deflector plate. 36, of ring shape, surrounding the cylindrical por- 50 tion of the feed-in chute. Each plate is so mounted as to be vertically adjustable. The plate 36 is vertically adjustable by reason of its suspension from the box lugs of the feed-in chute through the rods 3'7 and the nuts 38 engaging the threaded ends of those rods.

The'plate 35, which is vertically adjustable on the shaft 16 through the collar 39 and set screw 40, presents its flat circular base to the upflowing water current to divert the same away from the shaft, while its top face is beveled or cone-shaped to check the drop of the feed material from the delivery end of the chute-and thereby prevent the good coal from being forced down too deeply into the strata of refuse within the sorting tank. Another advantage of the beveled top face of plate 35 is that its disperses all materials from 'the delivery end of the feed-in chute outwardly into the classification areas of the sorting tank and prevents that accumulation, especially ofm the heavier refuse, on the top of the plate and consequent clogging of the delivery end of the chute which would occur if the top face of the plate were flat. Thus, the plates 35 and 36' divert the upflowing current of water away from the axis 7;,

of the agitator shaft and disperse it into the fluid mass in the sorting tank, while theupper face of the plate diverts the incoming material away from the axial center of the tank into the area of the classifying action of the water.

The hydraulic state of the entire fluid mass in the sorting tank, that is, its condition of motion, has an effect onthe settling of the materials according to their different specific gravities, and both the mechanical agitator and the water inlets 27 in the wall of that tank are factors in this matter. But, since the speed of the mechanical agitator is adjusted to a predetermined constant rate and the water supplied through the inlets 27 is also adjusted to a predetermined amount by the valvesin the pipe connections, for any given coal mixture, depending principally upon the size of the coal therein, the mechanical agitator and the water inlets 27 are constant factors in the classification of any given coal mixture. The other factor affecting the hydraulic state or condition of motion of the fluid mass in the sorting tank, and the one directly eifecting the separation of the good coal from the refuse and its discharge over the rim of that tank, is the upflowing current of water which has been mentioned but which, together with the means in the illustrated apparatus for producing it, have not yet been described in detail. That factor, as hereinbefore pointed out, is made a variable one responsive to variations in the downwardly with the refuse through the discharge at the bottom of the tank. Broadly considered, the means for doing this comprises means for supplying the sorting tank with water at a predetermined maximum volume rate of. flow sufficient for the required maximum velocity of I upfiow current thrbugh that tank, and associated means responsive tothe resistance offered by the materials to the upflow current to divert varying amounts of the supply water from that tank. Preferably, the diverting means is of a character operative to divert the supply water from the sorting tank in a proportion of greater increase of quantity diverted than the increase in the density of the materials in the sorting tank.

While the foregoing water-supply and diverting means may take, other forms, the form employed in the illustrative apparatus, whichis the preferred embodiment of the invention, comprises the chamber or boot 6 through which the water supply is delivered to the sorting tank for the unflow current therein, and a variable overflow device connected to that chamber. As will more fully appear as the description of this feature of the invention proceeds, the chamber 6 and the associated overflow device are so arranged as to produce an overflow of water from that chamber and a consequent diverting of the liquid from the sorting tank only upon a rise abovea predetermined lower limit of the liquid level in the chamber 6,which.rise is in turn dependent on the density of and consequently the resistance offered by the materials in the sorting tank to the charge rim .of the sorting tank. Water is fed from the pump 30 through the water pipe 29 and the branch pipe 41 to the chamber 6 at a point therein also substantially above the discharge rim of the sorting tank. The branch pipe 41 is provided with a gate valve, diagrammatically indicated at 42, to control the feed of the water to the chamber 6.

The overflow device associated with the chamber or boot 6 comprises a standpipe 43 connected to andsupported upon that chamber at a point substantially below the overflow rim of the sorting tank and extending upwardly to a point substantially above the overflow rim of the sorting tank. The open upper end of the standpipe 43 is surmounted by the casing or box of an overflow weir indicated generally by the numeral 44. That casi'ng, which has an open top, is divided by an interior partition wall 45 into a water receiving chamber 46 and a water discharge chamber 4'7. The floor of the water receiving chamber is apertured and provided with a cylindrical extension 48 defining the boundary of the aperture and extendingdownwardly to fit within the upper end portion of the standpipe 43 so as to mount the entire casing or box of the weir on that standpipe and provide a free passage for the rise of water from the standpipe into the receiving chamber 46 of the casing, as shown in Fig. 3. The discharge chamber is provided a with a discharge spout 49 extending downwardly into the launder 50 to discharge the overflow water into the launder between its boundary wall and the upper rim edge of the sorting tank, as shown in Fig. 3.

The overflow weir is designed of a form to present a progressively increasing area of overflow as the water rises in the receiving chamber of the weir box. One suitable form of the weir for this purpose is presented by the partition wall 45 in the weir casing, which wall is cut away in a V-shaped notch with the opposed edges of the V forming an angle of approximately and with the apex of the V at the base of the water receiving chamber 46 and therefore at approximately the upper end of the standpipe 43, as shown in Fig. 5. It is to be understood, of course, that the angle of spread of the opposed overflow edges of the weir need not necessarily be 60, as the angle of spread will depend upon the increase in the amount of overflow found advisable to provide for as the water-rises in the receiving chamber of the weir casing. But a 60 angle of spread has been found suitable in the practical operation of the illustrative apparatus in the separation of coal. tent of the V-shaped notch is not necessarily restricted thereto, -a vertical extent of approximately 3 inches has been found to give good results in the use of .the apparatus for the separation of coal. It is to be understood, of course,

Also, while the vertical ex-' that there is no partition wall between the water i.

receiving and discharge chambers 46 and 47 above the v-notch of the weir. In other words, the weir occupies the lower portion only of the casing.

A further feature of the overflow device of some practical advantage is its vertical adjustability. This is attained by making the standpipe 43 in two sections with their adjacent opposed end portions exteriorly screw threaded with right and left hand threads as indicated at 51 and 52 in Fig. 3, to be engaged by a complementary threaded sleeve 54 which, when slipped over the opposed ends of the standpipe sections and rotated, draws from the screen to a suitable conveyor or recep-. tacle while the water drains from the screen the two sections'toward one another to the extent desired for adjusting the height of the stand pipe. In Fig. 3, the standpipe is adjusted to its minimum height with the opposed ends of the two sections in contact. When the adjustment has been made, threaded collars are screwed into engagement with the opposite ends of the sleeve 54 to secure the adjustment and to prevent leakage cfwater from the standpipeoutwardly between the opposed: sections. It is evident that this adjustability of the height of the standpipe 43 is in effect an adjustability of the overflow weir as to its height above the normal level of the water in the water chamber 6 and in the standpipe 43. By this arrangement, the overflow device can be adjustably regulated with respect to the degrees of increase and decrease in the density of the materials in the sorting tank required to'begin and discontinue the overflow through the weir and conmquent diversion of water from the sorting tank.

.As already stated, the water overflowing the weir into the chamber'47 of the weir casing discharges from that chamber through the spout 49 into the launder 50. The fluent mixture of coal and water overflowing the rim of the sorting tank also goes into that launder, and the launder in turn discharges its burden of water and coal upon the dehydrating'screen 56 which is of the usual vibrating or shaker type not necessary to 'fully illustrate here and therefore only diagrammatically. illustrated in-F'ig. l. The coal passes on through the chute 57, also diagrammatically illustrated in Fig. 1, into the water storage tank 58,. from which tank it is drawn by the pump 30 through the pipe 59 for re-use in the apparatus.

The water storage tank 58 is provided with an overflow pipe 60 which has its open and within the tank near the top thereof and which extends through the bottom of the tank to discharge outside the same. This is the usual overflow pipe to provide for any sudden rush of water to the tank beyond its capacity; The water storage tank is also provided with the usual bottom hoppers 61 and valved outlets 62 for drainage of sediment from the tank.

4 The pump 30 is driven bythe motor 63, and the pump and the pipe connections to the water chamber are of a designed capacity amply sufllcient, when the gate-valve 42 in the pipe connection' 41 to the water chamber 6 and the gate valve 7 in the pipe connection to the sorting tank are open, to feed water to the chamber 6- at a uniform volume'rate sufficient to maintain a head therein and in the connected standpipe 43 at a level above the point of entrance of the pipe 41 to the chamher 6 and below the apex of the weir notch whileproducing the maximum velocityof upflow current required in the sorting tank.

' maximum velocity of upflow current required under that condition to sustain the good coal above the outlet for refuse into the tubular sec- I tion 3 can be determined by varying the opening of the valve 42 and consequently the velocity of the current upflow through the tubular section 3 into the sorting tank from a low point which prethe tubular section 3 to the sorting tank at substantially the rate at which it is supplied to the chamber 6, and the water level wm stand ata constant height in that chamber and in the connected standpipe 43 above the point of supply of water to the chamber 6 through the pipe 41 and below the apex of th" V-notch of the weir. This is the condition of no discharge over the weir diagrammatically illustrated in Fig. 6.

Under the foregoing condition of maximum' volume rate of water upflow through the tubular section 3 to the sorting tank, the heaviest refuse, such as rock and pyrites, readily settle downwardly to and through the discharge outlet at" is such that, if the coal mixture being fed to the tank should contain an unusually large amount of refuse, or even with the normal proportion of refuse if the maximum velocity of upflow current continues for some time, there is a tendency for both the slate and the still lighter bony to so accumulate in the tank, with the slate at the bottom and the bony above it, as to form a bed of refuse in the bottom of the'sorting tank over the outlet therefrom to the tubular section below it. This bed of refuse presents a very substantially increased resistance to the upflow of water from the water chamber 6 through the tubular connection to the sorting tank. Were'it not for the overflow device this increased resistance to the upflow of water through the tubular section '3 to the sorting tank would be counterbalanced by the constant feed' of water to thewater chamber'6 and the rise 0 the pressure head therein so that the upflow curr nt through the tubular connection 3 to the sorting tank would continue substantially undiminished with a consequent forcing of some of the bony with' the good coal over the rim of the tank.

When the foregoing condition in the sorting tank occurs, however, although the increase in the density of the materials in the sorting tank may be comparatively slight, if it is substantial.

enough to cause an undiminished water upflow to force an appreciable amount of refuse with the good coal over the rim of the sorting tank, .the water will rise through thestandpipe 43 sufficiently above the apex of the v-notch of the weir to produce an overflow diverting a sufficient amount ofwaterfrom the sorting tank to reduce the upflow current therein to a degree causing the refuse to settle downwardly away from the rim of the tank. The diverting of the water over the -weir under this condition is diagrammatically is used for separation of coal. In each of these views, the particles of good coal, as the material of lowest specific gravity, are represented in solid black. The particles of the heaviest refuse, such as rock and pyrites, are represented in circular outline with a clear center and the-particles of the lighter refuse, such as the slate and the bony, are represented in circular outline with a single line through the center. r

Fig. 6 illustrates the condition of minimum density of materials within the sorting tank and the consequently required maximum volume rate or velocity of water flow from the water chamber 6 upwardly through the tubular connection 3 to the sorting tank as determined by thesetting of the control valve in the feed line tothe chamber -6 in the manner hereinabove explained. Under this condition, the sorting tank contains a comparatively small amount of refuse, and there is comparatively little resistance to the upward current of water, with the result that the head of the water in the chamber 6 and in the standpipe 43 is below the apex of the V-shaped notch of the overflow weir.

Under the foregoing condition, let it be as sumed that the maximum volume rateof'water for the upflow current through the tubular connection 3 to the sorting tank which will allow heavy refuse to drop out of the tank but will sustain the good coal therein amounts to 370 gallons per .minute, for example. Then, as long as there is no discharge through the 'V-notch of the weir, the total of 370 gallons per minute passes through the tubular connection to the sorting tank. Fig. 7 shows a slight increase in density of materials in the sorting tank which has resulted from a continued feed to that tank of the coal mixture while the maximum upflow ance to the upflow current through tubular con-.

nection '3 to the sorting tank to cause, under the constant feed of water to the water chamber. 6. a rise of the water level therein elevating the water through the standpipe 43 to a point slightly above the apex of the V-notch of the overflow weir. There is consequently a slight discharge through the V-notch of the weir, and the water passing through the tubular connection 3 into the sorting tank is slightly decreased, which permits a slight increase in discharge of the refuse but suflicient to prevent its lightest particles, such as the bony, from going with the good coal over the rim of the sorting tank. I

As an illustration of the last foregoing condition, and under the assumption above of a feed of water to the water chamber 6 at the rate of 370 gallons per minute, if the density of the materials in the sorting tank has sufficiently increased to cause a rise in the water through the standpipe 43 to a point, say, one inch above the apex of the V-notch of the weir, this will permit a discharge over the weir of approximately 2 gallons of water per minute. Then, there will be 370-2 or a total of 368 gallons of water per minute upflowing through the tubular section 3 into the sorting tank.

Fig. 8 shows a still further accumulation of refuse in the sorting tank which has resulted from a continued feed to that tank of the coal mixture while the only slightly reduced upflow current established by the conditions illustrated in Fig. 7 was on, and in consequence of the increased resistance ofiered by the accumulated materials 1,990,129 the materials in the sorting tank as the apparatus I in the tank to the upflow current'the water has risen through the standpipe 43 to a further ex'-' tent above the apex of the V-notch of the weir. Let it be assumed, for example, that the water has risen another inch above its level shown in Fig. 7, so that it now stands two inches above the apex of the V-notch of the weir. Due to the spread of the notch or overflow edges of the weir there is now a considerably greater overflow than resulted from the first rise of one inch as in the Fig. 7 example. The discharge over the weir for the second rise illustrated in Fig. 8 may be taken, for example, as 12 gallons per minute, and there is thehefore 370-12 or a' total of 358 gallons per minute of upward flow of water through the tubular section 3 into the sorting tank. This marks a substantial reduction in the velocity of the upflow current and a consequent substantially less hindered settling which substantially increases the discharge of refuse from the tank and avoids that forcing of the lighter refuse, such as the bony, with the good coal over the rim of the tank which would occur had not the'upflow current into the sorting tank been sosubstantially reduced.

,Under usual working conditions, where the refuse contained in the feed is'of normal amount, j

to the amount of refuse accumulated in the sorting tank, so as to cause a further rise of 1 inch,

for example, of the water through the standpipe '43 and over the weir, there would, because of the spread of the V-notch of the weir, be a substantially greater overflow than occurred on the last rise of the water in the Fig. 8 example. The third rise may be taken,to give a discharge over the weir of 70 gallons per minute. There would therefore be a reduction from the originally a'ssumed rate of 3'70 gallons per minute to 300 gallons per minute of water upflow into the sortingv tank, with a correspondingly more rapid downward settling of the materials in the tank and discharge of the refuse.

Even under the foregoing example vof extreme reduction in volume rate of upflow current of water into the sorting tank, there would not,

however, be a dropping of good coal to any substantial amount with the refuse through the discharge outlet at the bottom of that tank. This is so because of the substantial ,bed of refuse which has accumulated in the lower part of the sorting tank and which must discharge through the outlet from the tank into the tubular section 3 below it before the good coal above it is in position to be discharged, and by the time the refuse has settled through the discharge outlet sufliciently to enable the coal to follow, the density of the materials and consequent resistance to the upflow of water into the sorting tank'has so decreased as to drop the water level in the overflow device below the apex of the V-shaped notch of the weir, and substantially the initial full volume flow of water to the sorting tank is restored, which, as hereinbefore explained, is sufficient to sustain the good coal within the sorting tank.

The cone shape of the sorting tank and its termination below in the tubular member 3 also assists in preventing a dropping of good coal downwardly with the refuse from the tank into the tubular section below it. As already stated, the heaviest refuse, such as rock and pyrites, settles so rapidly downward under all conditions of the hydraulic current that they do not accumuate in the sorting an, and it is the lighterrefuse,

such as the slate and the still lighter bony,

which-accumulates as a body of materials-in the bottom of the tank. With the cone shape of the sorting tank and its relatively restricted bottom discharge outlet at the apex of the cone, the discharge of the slate and bony at the bottom of the tank is sufliciently delayed to present a bar- 'rier against the drop of good coal into the refuse outlet to any substantial extent; and, as already stated, by the time the bony and slate materials of the refuse have dropped out of the sorting tank down through the tubular section 3, the upfiow current is restored to substantially its initial velocity or volume rate of flow of water.

In the foregoing description, the chamber 6 has been variously termed a water supply chamber and a boot because of its diiferent functions. That chamber, under the feed of water from the pump thereto, serves as a water supply chamber for the hydraulic current to the sorting tank. It

'also serves as a boot for the refuse conveyor. That chamber, in association with the standpipe 43 connected thereto, also functions as a water expansion chamber since the water level rises and falls therein in response to increase and decrease in density of the materials in the sorting tank.

As shown in the diagrammatic view of Fig. 6, the inlet connection of the pipe i1 to the water expansion chamber 6 is but slightly below the minimum-water level in that chamber, and as shown in the diagrammatic views of Figs. 7 and far below 8 that inlet connection is never very the water level. With such a disposal of the water inlet to the chamber 6 but slightly below the els maintained therein, any air trapped iz l fe zirculating water from the pump 18 very readily dispelled to the surface of the water in the chamber 6, thus ensuring the feed of a continuous solid mass of water, without air bubbles, from the water chamber 6 upwardly through the tubular connection to the sorting tank. This is a feature of considerable practical advantage, for

' therethrough into said water-sorting chamber of water at a sufficient volume rate to produce a materials-classifying upflow current of water through said chamber a waterexpansion chamber connected to said hydraulic inlet and extending above said overflow discharge, means for continuously feeding water to said expansion chamber at a uniform volume rate s ufliciently high to produce a materials-classifying upfiow current in said sorting chamber at all times preventing settling of the coal downward to said lowerdischarge, said expansion chamber being so arranged that when thus fed with water the water level therein rises from and falls to a minimum height in response to increase and decrease in density of the materials in said sorting chamber, and a variable overflow device forsaid expansion chamber operating over the ,range of said rise and fall of the water level in said expansion chamber and arranged to deliver overflow water at a point outside the boundary walls of said water-sorting chamber at variable volume rates correspondingly reducing the volume rate of -flow of the materials-classifying current of water through said sorting chamber.

2. Anapparatus for the hydraulic separation of materials of different specific gravities comprising, in co'mbination, a water-sorting cham'-.

ber having discharges at different levels for classified materials, an hydraulic inlet at the bottom.

of said chamber formed for the delivery therethrough into said water-sorting chamber of water at a sumcient volume rate to produce a materials-classifying upfiow current of waterthrough said chamber, awater-supply chamber connected to said hydraulic inlet for the supply of water thereto and extending upwardly from said connection to an open top, said water-sortmg chamber being arranged to receive its supply of water wholly from said water-supply chamber, means comprising a pump and a pipe leading from said pump to said water supply chamber below the open top thereof for feeding water to said water-supply chamber at a volume rate sufiiciently high to produce an upflow current of sufficient velocity in said sorting chamber for I the classification of materials therein and to maintain the water level in said water-supplychamber at all times above the water-feed inlet thereto but sufliciently near said water feed inlet to permit the ready escape of entrained air from said pipe upwardly through the water in said water-supply chamber to atmosphere. I

3. An apparatus for. the hydraulic separation of materials of differing specific gravities comprising, in combination, a watersorting 'chamher having discharges 'at difierent levels for.

classified materials, means supplying water to said sorting chamber, and means for mechanically agitating the fluid mass of water and materials comprising a rotatable shaft extending along the vertical axis of said chamber and a set of blades having a mounting on said shaft substantially below .the uppermost discharge of saidchamber and horizontally disposed blade portions above said mounting in the region of the upper discharge and spaced radially from the axis of said chamber.

4. An apparatus for the hydraulic separation of materials of diifering specific'gravities comprising, in combination, a water-sorting chamber having an open top for the discharge thereover of water'and the lightest of "said materials and a bottom discharge for heavier materials, a

feed-in chute for said materials extending concentrically of said chamber through its top to a delivery end substantially below said top, means supplying water to said chamber, and means for mechanically agitating the fluid mass of water and materials comprising a rotatable shaft extending along the vertical axis of said chamber I materials to said chamber through its top, means and a setof blades having a mounting on said for supplying water to said chamber through its 1 open bottom, and means for mechanically agitating the'fluid mass of water and materials in the bottom portion of said chamber comprising a rotatable shaft extending along the vertical axis of said chamber and a set of blades having a mounting on said shaft substantially above the opening at the bottom of said chamber and horiprising, in combination, a cone-shaped water,- sorting chamber having its small end at the bottom and open and its larger end at the top and open, means for feeding a mixture of said materials into said chamber through its open top, meansjsupplying water tothe open bottom of said chamber in a constantly flowing stream under suflicient head to provide a materials-classifying flow of water upwardlytherethrough of constant velocity for a constant density of materials in said chamber and at all times sufficient to sustain the coal as the lightest material above.

I the open bottom of said, chamber, and means responsive to an increase in resistance offered to the entrance of said supply water to said chamber by accumulation of refuse in the bottom thereof to divert water of said stream from a point therein on the supply sides of said chamber directly to a pointoutwardly of the outer boundary wall thereof at such a volume rate and so progressivelyincreasing with increase in said resistance as to progressively reduce the velocity of said materials-classifyingflow of water upwardly through said water-sorting chamber and thereby speed the discharge of refuse materials through the open bottom of said chamber while still sustaining the coal as the lightest material above the discharge refuse withinsaid chamber.

7. An apparatus for the hydraulic separation of materials of differing specific gravities comprising in combination, a water-sorting chamber having discharges at different levels for classifled materials, means for feeding a mixture of said materials to said chamber, an hydraulic inlet to said chamber at its bottom, means comprising a water-supply duct connected to said hydraulic inlet and supply means delivering water to said duct at a predetermined volume rate providing a constantly flowing stream of upflow current to divert water of said stream away from said chamber at a volume rate increasing with increase in density of said materials and sufficient to progressively reduce the velocity of said upflow current through said chamber below said predetermined velocity.

8, An apparatus for the hydraulic separation of coal or other mineral of lower specific gravity than the refuse materials mixed therewith comprising, in combination, ,a' cone-shaped waters'orting chamber having its small end at the bottom and open'and its larger end at the top and open, means for feeding a mixture -of said materials into said chamber through its open top,

a water-expansion chamber connected to thethrough the open bottom of said sorting cham-' ber, said expansion chamber being so arranged that when thus fed with water the water level therein rises from and falls ,to a minimum height in response to increase and decrease in density of the materials in said sorting chamber, and a standpipe connected with said waterexp'ansion chamber having a V-shapedover-flow outlet out of delivery relation to said water-sorting chamber with the apex of said outlet downward and so slightly above said minimum level of the water in said expansion chamber as to cause no discharge of water through said outlet at said minimum level of water but to cause variable discharge of water through said outlet during said rise and fall of the water level in said expansion chamber. L v

9. An apparatus for the'separation of coal or the like mineral of lower specific gravity than the refuse materials mixedtherewith comprising, in combination, a,water-sorting tank having a 'main body portion of cone shape with smaller en'd downward and an upper cylindrical portion with an openrim at the top for the discharge thereover of separated coal, said cylindrical portion being of suflicient depth to effect the accumulation therein of a substantial body of coal when separated from the mixture, means supplying water to said tank at its bottom and in line with its vertical axis for upflow therethrough and over its rim for separation of the coal and overflow discharge of the same, a cylindrical feed-in chute for the coal mixture disposed concentrically of the vertical axis of said tank at the top thereof and having its delivery end portion extending below'but sufficiently close to the lower level of said cylindrical portion of said tank to avoid substantially limiting the cross-sectional flow area of classifying current in the cone-shaped portion of said tank, a rotary 'deflector member disposed concentrically with the vertical axis of said tank immediately below the delivery end of said chute and spaced therefrom a less distance than its spacing from the bottom of said cone-shaped portion of said tank, said deflector member havinga bottom face adapted to deflect the upflowi'ng water away from the vertical axis of said tank and to paths of travel avoiding the delivery end of said chute and a top face adapted to deflect the materials delivered from said chute into the path of the deflected water, and an additional deflector member disposed about said feed-in chute above its delivery end, spaced from the side boundary walls of said tank and adapted to deflectthe upflowing water away from said feed-in chute toward the side walls of said cylindrical portion of the tank.,

10. An apparatus as defined in claim 9 and further characterized by said additional deflector member being verticallyadjustable to different levels including a position substantially at the delivery end of said feed-in chute.

11. An apparatus for the hydraulic separation of coal or other mineral of lower specific gravity than the refuse materials mixed therewith comprising, in combination, a water-sorting chamber having an overflow outlet at its top for the coal and a discharge outlet in its lower part for the refuse materials, a water-supply conduit connected to the bottom of said chamberfor the supply of water thereto to form the classifying current, means automatically operating to continuously feed water to said conduit at a uniform volume rate producing a stream of water flowing through said conduit toward said chamber and at a sufficient volume rate of flow into said chamber for a given density of materials therein to form a materials-classifying upflow current separating coal from the refuse and discharging said coal over said overflow outlet, and means automatically operating in response to changes in density of said materials through a range of densities above said given density to divert water of said stream from a point therein in said conduit directly to a point of delivery located outwardly of said conduit and outwardly of the boundary walls of said sorting chamber at a volume rate so progressively increasing and decreasing with increase and decrease in density of said materials as to reduce in varying de-.

grees dependent on the changes in density of said materials the velocity of said upflow current through said chamber.

12. An apparatus for the hydraulic separation of coal or other mineral of lower specific gravity than the refuse materials mixed therewith comprising, in combination, a water-sorting chamber having an overflow outlet at its top for the coal and a discharge outlet in its lower'part for the refuse materials, a water-supply conduit connected to the bottom of said chamber for the supply of water thereto to form the classifying current, means automatically operating to continuously feed water to said conduit at a uniform volume rate producing a constantly flowing stream of water through said conduit into said chamber at a sufficient volume rate to produce a materialsclassifying upward current therein at all times preventing settling of substantial amounts of coal downward to said lower discharge, stand-pipe means connected to said water-supply conduit and so arranged that when said conduit is thus fed with water the water level rises from and falls to a minimum height in said stand-pipe means in response-to increase and decrease in density of the materials in said sorting chambenand vari-- able-overflow means for said stand-pipe means automatically operating over the range of said rise and fall of water level to divert water from said stream at a point therein on the supply side of said sorting chamber through said stand-pipe means and overflow therefrom directly to a point outside said conduit and outside the boundary walls of said sorting chamber at volume rates so progressively increasing and decreasing with said rise and fall of said water level as to reduce the velocity of the materials-classifying current of water through said sorting chamber in varying degrees dependent upon the extent of change in density of said materials.

13. An apparatus for the hydraulic separation of materials of differing specific gravities comprising, in combination, a water-sorting chamber having discharges at different levels for classified materials and an hydraulic inlet atits bottom for the supply of water for the classifying current, a water-supply column connected to said hydraulic inlet and extending above the uppermost discharge from said chamber, means automatically operating to continuously feed water to said column at a uniform volume rate suflicient to maintain said column at a given head level for a given density of materials in said chamber and produce for said given density of materials an upward classifying current separating out material of lowest specific gravity and discharging the same from said chamber, and overflow means for said water-supply column comprising an overflow wall disposed above said given head level in'said column within the range of rise of water therein consequent on increase in density of materials in said sorting chamber and having an overflow boundary of increasing area in the direction of the water rise, said overflow means having its point of delivery located outwardly of the outer boundary of said sorting chamber.

14. An apparatus as defined in claim 13 and further characterized by said overflow wall having its overflow boundary or rim extending in opposed lines diverging upwardly from a common point.

15. An apparatus as defined in claim 13 and further characterized by said overflow wall having its overflow boundary or rim of V-shape.

16. An apparatus as defined in claim 13 and further characterized by means for vertically adjusting said overflow wall.

C. MENZIES.

t CERTIFICATE OFiCORRECTlON.

Patent No. 1,990,129.. February 5, 1935.

WILLIAM c. MENZIES.

II is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 1, second, column, line 17, for "valve'-' read value; and that the said Letters Patent; should be read with this correction therein that the same may conform to the record of thecase in the Patent Office.

Signed and sealed this 23rd day of A r-u. A. n. 1935.

- Leslie Frazer

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