US2620067A - Apparatus for separating materials - Google Patents

Description

J. T. HALZA APPARATUS FOR SEPARATING MATERIALS ,1 Dec. 2, 1952 2 SHEETS-SHEET l Filed Oct. 30, 1947 JOHN T. HALZA .A m M M 0 m M H S .I@ T M 2 m w E J. N 2 A I R E T A M A m 8 2m N. M m m. H mm l EE T. s my R Il FA J m .I LA* EW S AS. Ro S G ON I w D N .VCH A A U l D WE R .r ,D LD OT Mm ETI-S M M S MNA w ww 7 Mm om M AT L.. CW 2 E P w R W 1 DI 2, nw n D .F

Patented Dec. 2, 1952 UNITED STATES PATENT OFFICE APPARATUS FOR SEPARATING MATERIALS .lohn T. Halza, Hazleton, Pa.

Application October 30, 1947, Serial No. 783,101

2 Claims.

My invention has to do particularly with the art of separating materials of different specific gravities and different coefficients of friction in a current of water flowing down `an inclined plane `and particularly over a deep natural refuse bed. The invention relates more particularly to a method and apparatus for classifying and separating coarse or fine coal (silt) or other minerals in which mixtures of materials of this character are subjected to selective forces `applied to the solids in a current of water flowing over a controlled natural refuse bed.

The invention is adapted to the separation of both coarse and fine Anthracite and Bituminous coals as well :as metallic ores, but, for the purpose of clearness, this method and apparatus will be described as it relates to the separation of fine coal from its impurities.

In the trough or launder portion of the apparatus, the principle of `alluviation operates to stratify the unsized materials according to specic gravity differences, while friction becomes effective as the stratified mixture passes over the subsiding surface of the natural refuse bed above the refuse compartment, where the lower layer, composed of particles of high density 'and particles of lower density but of a high coefficient of friction, is retarded and drawn in. For example, boiler ashes or cinders, some of which Iare of a lower specific gravity than high-grade coal, but of a higher coeflicient of friction in relation to coal, as well as bone and slate, will be retarded and drawn into the refuse compartment. ri`hus my method is applicable to many otherwise valuable Anthracite silt and culm banks or deposits which are seriously poluted with these boiler ashes and cannot economically be separated with methods available heretofore.

As compared with heretofore known appliances which depend on alluviation, my method shows some improvement in producing stratication, but the chief difference is in the method of removing refuse. For example, on a concentrating table the mechanical agitation of the pulp spread over the riiiied plane assists in the process of stratification and it is also the principal means of removing the refuse in a direction at right angles to the water current but only the heavier constituents are diverted. Furthermore, concentrating tables have the defect that they cannot deal satisfactorly with feeds containing widely variable proportions of refuse to coal. For, if the percentage of refuse drops, coal is lost in it. And, if the percentage of refuse rises abnormally, then the coal is polluted with refuse. In trough washers or launders of the endless belt or endless chain type, coal is separated by a current of water flowing down `an inclined plane land the dirt is removed in a direction opposite to the current of water by means of a belt, drag or screw conveyor, but such devices are unsatisfactory for separating boiler ash and other light refuse. Also, endless chain and belt appliances require preliminary classification of feed within relatively close sizing ratios, they are of low capacity, and they have the defect of mechanical entanglement of coal with the refuse with no means for correcting the defect save by rewashing.

In Rheolaveur washers, as in simple trough washers, stratification is caused by Ialluviation while the refuse falls through apertures in the bottom of the trough into a series of receptacles through which an upward current of water is admitted into the trough to prevent most of the coal particles from being discharged with the refuse. This is disadvantageous because particles distinctly stratified according to density differences and flowing over the apertures, are repeatedly disturbed by this upward current of water. To overcome this tendency, a series of troughs and, in the treatment of lines, and to a lesser extent when treating coarse materials, a great numb-er of such upward current receptacles ,are used, and the mixture is thereby unnecessarily subjected to restratiiication and rewashing. The reason why these defects lare present in appliances of this class heretofore known and operated is largely because they do not employ adequate means for discharging refuse and intermediate products, or because they operate upon the wrong principle of strata separation and, also, because they lack means for the complete and final separation of the coal or other product of value from the refuse products at the moment when stratification is complete.

The significance of the defects in prior known appliances and the advance in the art attributable to my invention, `and the principles on which it operates, exemplified by a suitable design of apparatus, will more fully appear from the description that follows, taken in connection with the accompanying drawings. It should be understood, however, that while these specifications describe one mode of practicing the method and one form of apparatus found most desirable,l the -invention is not limited thereto, and that it includes other modes of practicing the method :and other forms and constructions of the apparatus within the scope of the `appended claims.

n the illustrative drawings wherein like charasados? acters represent the same parts -in the several views, Figure l is a side elevation and cross-section of a preferred form of apparatus for practicing the invention, the section being taken in the line I-I in Figure 2, showing the materials therein as they appear under the condition of complete stratication, and alluvium comprising the two substrata being separated While the low density top strata is in suspension;

Figure 2 is a top plan View of the apparatus shown in Figure l;

Figure 3 is a plan vand Figure 4 a side view, on a larger scale than that of Figures l and 2, of the stream-flow float used in my apparatus, which forms ya part of the servo-mechanism (not shown) for regulating the speed of the drive mechanism and thereby controlling the sag in the horizontal plane of the bed surfaces;

Figure 5 is a side elevation and Figure 6 is a front view, on a larger scale than that inv Figures l and 2, of the Weir adjusting mechanism for controlling the gradient of the bed;

Figure 7 isv a View similar to Figure 1, illustrating a portion of ya modified form of apparatus provided with two final refuse compartments and one middlings compartment for dealing in one operation with an abnormally dirty and difiicult feed; and` Figurel 8 is a diagram or ow sheet illustrating the flow or circulation of water and solid materials 4as they pass through the form of apparatus shown in Figures 1 and 2,

The illustrated apparatus is adapted to the benei'iciation of both coal and metallic ores, but thedescription which follows will be conned to the separation of coal as a typical instance of use serving to p'res'ent. the essential principles of the invention.`

Referring to Figures 1 to 6.0i the drawings, the apparatus therein illustratedv comprises an inclined trough orllaunder, Il, which is adjustable in height -at its inflow end (not shown) and is provided at its discharge end with ya hinge I2 and suitable exible side and bottom joints VI3 connecting it 'to the housing I4 of. the separator, whereby thestreamoffmaterials owing down it is separated into layers by gravity and discharged intothe'receiving chamberxl, which has Ian approximately level bottom I6, ending in `a steep discharge chute I'Ifin the bottom of which are two successiveY openings I8, I9, leading to the refuse compartment 2i! Iand middling compartment-2 I, respectively.

Atth'e. lower endof the discharge chute I'I is.

an adjustable gate or Weir 22 provided with means for raising and lowering rit and holding it in adjustedposition comprising two verticalgracks 23 (see'Figure 5) secured to the back of the gate and meshing with a pair of spur gears 24, fixed on a shaft 25 mounted Ain bearings in the side Walls of the housing I4 andprovided with a ratchet disc 26 onitsouter end and a hand wheel 21. A pawl 28, pivotally mounted on the housing, is provided for engaging the ratchet teeth and retaining the shaft and gatein vertically adjusted position.

In the apparatusshownin Figure 1 there are two compartments 202I over and beyond which the stream` of stratified materials flows on its Way to the control weir 22 and into which the heavier materialssink and are withdrawn. The housing has -a horizontal bottom 29 adjacent to the Weir and a third compartment 30 beyond the Weir into which the coal and lighter portion of the material being separated are discharged and Where the water and light refuse and other materials form a suspensoid separate from the coal. The overow from the compartment 3D passes over a fixed wall or weir 3| into the vertical chamber 32 where the Water and lighter materials which are more affected by surface tension or other factors than by gravity are separated, the former being drawn off through the discharge pipe 33 for reuse and the latter escaping through the overflow duct 34. A baille 35 prevents mixing of the clean coal with lighter materials and water leaving the compartment 3B.

The chambers 2l), 2| and 30 are closed at their lower ends by star valves or vaned drums 36, 31, 38, respectively, which are caused to rotate slowly by electric motors 39, 40 and suitable belts or chain gearing 4I, 42, 43, as shown in Figures 1 and 2. The speed of the motor 39 which drives the valves 33, 31 controlling the discharge of solid materials from the chambers 2, 2 I, is controlled by a oat 45 mounted on a pivoted arm 46 suspended from the top of the housing t4, and-counterbalanced by a weighted lever 41towhich the arm, 46 is Vconnected at its free end by a link 48. A dash pot 49 is provided which is connected to the free end of the armv 41 by arodffor preventing rapidV iiuMctuations-in` the position of the float due to variations in the amount and character of the material` under treatment. Adjustable stops 5I on the link ,48' engagethe operating arm 52 of the rheostat 53 for. turning on-andsoi the current to the motor starting and stopping switch 54 of the motor SS'asVdeterrnined by the iioat 45. Y

The speedof the motor 451 whichgoperatesrthe valve38 in the discharge passage from the chamber `3Ilvis controlled by a float 55 mounted for vertical movement in a tube 51 which projects into the chamber 30 from above, the float being suspendedfrom a'counterbalanced lever 58,'by a rod 59 uponwhich are adjustable stops Iii]v for actuating the operating arm 6I ofthe rheostat 6'2 which controls the electric current suppliedto the motor starting and stopping. switch A(i3.

Electric vibrators Y(i5, 65Lareprovided for shaking the inclined bottom ofthe chute Il and -freeing it from heavy particles of slate 4or stone that tend to collect on any supporting surface not scoured by the stream of water and suspended solid material, as is wellunderstood in this art- The apparatus illustrated in Figure 7 is similar to that shown in Figures 1 and -2 in the general arrangement of the'actuating and control devices, which areidentied-by the same-reference numbers corresponding to the same parts in-both forms of apparatus,A that illustratedV in Figure 7 having an additional refuse chamber 'I0-posi tioned between the chambers 20 and 2| The chamber 1I) is provided with a discharge'valve controlled bythe oat 45 or by an independent float asmay be desirable for treating some materiali,

My invention avoids the defects of other Washers depending on the principle. of alluviation, by treating the materials to be separated inr a deep and compact natural .refuse` bed c which automatically subsides to accommodate freshly introduced refuse which slides down the steeply inclined end Il' from the v.horizontal bottom I6..of the receiving chamber'Vl5-after rst beingstratifled in the current-of Awater owing Ydov'vnthe launder II. Important factors in producingthis result arethe automatic means and method of removing refuse; the inclination of theflaun'der. and the change in Width and slope of the launder at the approach to the refuse bed a; and controlling the depth and contour of the bed by means oi the adjustable Weir 22, and the float 45. The heavy refuse, which is continuously deposited on the subsiding surface of the bed over the final dirt compartment 20 and the middlings compartment 2 I, continues to sink at a controlled rate as it is being withdrawn at the bottom by means of valves 36, 31, which may be of the form shown or in the form of a drum with plane or concave blades xed around its circumference and rotated in a vertical plane transverse to the direction of flow over the bed. The stratified materials flowing over compartments 2|] and 2l, where the actual separation takes place, are never disturbed beyond hindering the flow of and holding down the lower layer of high specific gravity refuse and other materials with a higher frictional value, while the coal, suspended in the top layer, continues to go forward rapidly over a protective layer b of bony coal of intermediate density which concentrates over the middlings compartment 2 I, is discharged into a sump (not shown) and returned to the launder Il by means of a pump or elevator for recirculation in order to build up a thick intermediate layer to function as a protective barrier between the low density materials in the top layers and the high density materials in the bottom layer a.

The reaction between the lower layer e and the bottom surface It of the i'lrst receiving chamber I5 is suddenly increased because of the abrupt reduction in the inclination and a slight widening of the launder trough as it approaches the horizontal bottom surface I6. Most of the suspended refuse subsides when it rst comes in contact with the bed over refuse compartment 2! and the remainder, composed largely of particles of intermediate density, is held down and drawn into the middlings compartment 2| while the coal and light refuse are held in suspension in layers c and d and pass over the weir spillway 22. The bed deposited over the horizontal section 2S in front of the Weir 22 is composed very largely of coal in the area nearest the Weir, while that portion nearest to the middlings compartment 2| containing some coal slowly recedes into the more rapidly subsiding central portion and passes into the middlings compartment to be recirculated.

The relatively quiescent condition at the surface of the refuse bed, accompanied by the slight seepage of water through the fine interstices of the particles, tends to draw in, hold down and entrap the finest particles of slate or cinders when friction oifers insufficient resistance to their movement, but any such particles discharged with the coal, are rejected through the classificatory action caused by the turbulence existing over the regulated coal bed in the dewatering compartment 3Q. The tendency of this slight seepage apparently is to complement the forces of friction, and at the same time, to assist in keeping the bed in a more compact condition. To further accentuate this condition the electro magnetic vibrating mechanism 65 is employed under the steeply inclined approaches to the refuse and middling compartments 2d and 2 I. These vibrators 65 constitute a desirable component of my apparatus in so far as they assist in the entrapment of the iiner impurities which are already in contact with the bed at this point and, more particularly, when the feed is polluted with boiler ashes. The intense vibration and sharp percussive impact provided by these vibrators compact the lower layer of high density materials and at the same time hinder the escape of the low density particles with a high coeiiicient of friction.

The approach to the heavy refuse opening I8 drops abruptly from the horizontal section I6 to an inclination of 45. This is desirable in order to provide a deeper concentration of refuse at this zone of the bed which serves as a protective barrier against the intermediate layer b above and more particularly to prevent coal in the top layers c and d from being drawn into the refuse cornpartrnent 25. When the withdrawal of refuse is proportional to the quantity of feed being introduced, any excess flows over to the middlings compartment 2 I, where it forms a fraction of the recirculating mixture. If the introduction of refuse falls below a predetermined normal quantity, the depth of the refuse accumulation at this point will remain uniform for the iloat 45 will respond to the resultant lowering of the bed at this point and actua-te the servomechanism to slow up the motor 39 controlling rotation of the discharge valves Se, 3T; and thus by means of the up and down variations of the bed level between the two refuse compartments the apparatus maintains the desired balance between the refuse being withdrawn and that beign introduced. This streamiiow float l5 can actuate any suitable servomechanism, preferably in a direct current system producing fast response and accurate speed control of the motor S9 and having full power available at a high starting torque and ruiming load at all speeds of the rotor drive.

When a stoppage of the feed occurs all discharge ports are automatically shut off. The cavity or depression maintained between the two ref use compartments is kept within certain predetermined limits. If this depression were too deep, swirling counter-currents would form and cause a contamination of the products particularly if the feed volume is light, coal being trapped among the refuse and dirt among the coal. It is, therefore, to eliminate this condition that the feed is maintained at full capacity and the float is placed between the two refuse compartments, the rate of discharge 0f the middlings and the heavy refuse compartments being equal. The variations in the level of the bed in this reference zone are under close control. When the extreme high and low limits are reached the circuit is opened or closed, while `the movement of the lever arm actuated by the oat within these limits varies the speed of the motor. Thus, the refuse concentration over compartment 29 is maintained at a uniform and unvarying depth regardless of varia tions and irregularities of feed in quality Products of intermediate density, together with some high and some low specific gravity materials, are withdrawn by the middlings compartment 2l to be recirculated, incidentally for rewashing but primarily to build up a thick layer b of intermediate density between the coal and dirt strata. The bed contour within the housing is given a steeper inclination than in the launder by lowering the adjustable Weir 2B in order to accelerate the velocity of the coal or other value product in the upper strata c and d as it ows over the receding intermediate layer into the coal compartment Sil. In this compartment, the coal bed is held at a predetermined level by the cylindrical icat 55, the lower end of which projects below the float chamber 51, and which actuates a lever arm and mercury switch to open and close a circuit at adjustable points on the float rod. The coal bed is maintained at a level suiiciently below the baiiie 35 to permit the dirty water to 'overflow `the Weir 3l into the water compartment 32 from where it is drawn olf by pipe 33 into a water recirculating sump of a suitable type. If a blockage of the compartment at the ope ing to pipe 33 occurs, the overflow pipe 3d which connects with the recirculating sump draws off the surplus water until nor-mal conditions are restored. The product discharged from the coal port Vby the rotor valve 33 can be collected by any suitable means such as a conveyor belt, elevator or gravity, and fed to the classifying and rinsing screens. VThe products from all discharge ports, if nes are being treated, can also be collected into suitable sumps and conveyed hydraulically.

The general control of the apparatus according to my invention is effected by adjusting the elevation of the weir 22 at the spillway into chamber 3i! to determine the gradient of the refuse bed; a float 55 automatically controls the level of the coal bed by measuring their variations within predetermined high and low limits and through suitable servo-mechanism regulates the speed of the discharge valve motor 40; a launder hinged in sections having water-tight joints 9, to permit the inclination to be adjusted in order to increase or decrease the velocity of the current as demanded lby volume or quality of feed; and a level and speed control servomechanism actuated by a stream-flow float 45 to control, within predetermined limits, the depression depth in the refuse bed over the middlings compartment. The Ipurpose of varying or regulating Ithe inclination of the plane of the refuse bed is to increase or decrease frictional resistance overits surface. The correct gradient is determined by the character ofthe feed and the viscous density of the water. Any suitable hinged joint with a Iwater-tight rubber or other flexible seal at the junction lof the launder I l and the horizontal approach I6 to the refuse bed, enables `adjustment of the launder inclination. The launder is elevated at the feeder end by any suitable means.

The correct inclination of the launder is also determined by experiment with the type of feed to be treated and the density of the medium to be used. The inclination of the launder is given 'a somewhat higher value for a highly heterogeneous feed and a lower value for one of a more homogeneous character or quality. These values also determine the velocity of the current and the capacity of the apparatus. If a particular feed to be processed contains a greater proportion of refuse to coal, apparatus with a second refuse compartment 'I0 (Figure '7) ahead of the middlings compartment 2l would be preferred. Since the stratification is never disturbed before final separation is attempted, the introduction of a second refuse compartment to form a threestage 4unit facilitates sepa-ration of a very dirty and diicult feed in one continuous operation without resort to rewashing.

In employing my apparatus for the separation of coal from its impurities, the coal mixture is preferably vunsized when subjected to the separation treatment and sized after treatment.

The invention is not restricted to the details of construction or forms of apparatus illustrated.

W hat is claimed is:

1. Apparatus for separating coal particles from boiler ash, ybone coal, slate and other impurities found in culm banks which comprises a launder having means for adjusting its slope, an elongated separator into which said launder discharges, said separator having a portion of its 'bottom sloping in `the direction of flow and provided with at least two openings through its bottom, a chamber beneath each said opening `provided with a discharge valve, a float in said separator above said openings, said float being adjustable vto ride on the heavy refuse bed carried by vthe discharge lfrom said launder, means controlled by the position of said oat for governing the discharge passing through said valves, means for recirculating the discharge through on'eiof said valves to the feed to the launder, a weir in said separator and a coal settling chamber rinto which the discharge over said Weir passes, said settling chamber being provided with a discharge valve, a second float in said settling chamber, said second float being adjustable to ride on the coal bed in said settling chamber, and 'means controlled by Athe position of said second iioat for governing the discharge passing through said coal settling chamber discharge valve.

2. Apparatus for separating coal particles from boiler ash, bone coal, sla-te and other impurities found in culm banks which comprises a launder having means for adjusting its slope, an elongated separator into which said launder discharges, said separator having a portion of its bottom sloping in the direction of flow and provided with at least two openings through its bottom, a chamber beneath each of said openings, said oat being adjustable to ride on the heavy refuse bed carried by the discharge from said launder, means controlled by the position of said float for governing the discharge passing through said valves, means for recirculating the discharge through one of said valves to the feed launder, an adjustable weir in said separator and a coal settling chamber into which the discharge over said Weir passes, said settling chamber being provided with a discharge Valve, a second float in said settling chamber, said second float being adjustable to ride on the coal bed in said settling chamber, and means controlled by the position of said second float for governing the discharge passing through said coal settling chamber discharge valve, and a froth separating chamber into which water and light refuse from said coal settling chamber passes, said froth separating chamber being provided with separate outlets for water and light refuse.

JOHN T. HALZA.

REFERENCES CITED The following references `are of vrecord in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,065,288 Whitten June 17, 1913 1,561,919 France Nov. 17, 1925 1,897,545 Bird Feb. 14, 1933 1,906,916 Mitchell May 2, 1933 2,074,977 Bird Mar. 23, 1937 2,132,380 Attwood Oct. 11, 1938 2,211,895 Hayois Aug. 20, 1940 2,286,067 Davis June 9, 1942 2,312,865 Bird Mar. ,2, 1943 FOREIGN PATENTS Number Country Date 40,685 France May .10, 1932 v840,665 `France Jan. 23, 1939

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