US2151007A - Device for separating carbonaceous materials - Google Patents

Description

March 21, 1939,. J R. BELKNAP DEVICE FOR SEPARATING CARBONACEOUS MATERIALS 3 SheetsSheet 1 Filed July 27, 1937 INVENTOR. Josz. A? BEL KN/JP ATTORNEY.

March 21, 1939.

J. R. BELKNAP DEVICE FOR SEPARATING CARBONACEOUS MATERIALS Filed ,July 27, 1937 3 Sheets-Sheet 2 QU-IZUZZ INVENT OR BY JOEL. A. BELKA/HP X ATTORNEY.

March 21, 1939. J. R. BELK NAP DEVICE FOR SEPARATING CARBONACEOUS MATERIALS Filed July 27, 1957 5 Sheets-Sheet 5 INVENT OR. JOEL 7?. BELKN/IP Patented Mar. 21, 1939 DEVICE FOR SEPARATING CARBONACEOUS MATERIALS Joel R. Belknap, South Charleston, W. Va.

Application July 27., 1937, Serial No. 155,958

4 Claims.

The invention relates particularly to mechanism adapted for separating carbonaceous materials. My copending application Serial Number 48,388 is intended for similar purposes. Hereto- 5 fore many different methods and kinds of apparatus and mechanism have been used for separating coal from slate, and other refuse in coal,

some of which utilize the difi'erences in specific gravities in the component parts of the aggregate run of mine coal. Others of them utilize a liquid having a relatively high specific gravity, whereby the relatively light weight coal will float on the surface and the heavier slate and other refuge will sink to the bottom of the liquid, because the specific gravity of the liquid is greater than the specific gravity of the coal but less than the specific gravity of the slate and other refuse. Such methods which utilize this latter method. known as floatation processes, are slow in opera- 20 tion and the cost of equipment and subsequent operation is relatively high.

Other classifications of methods and apparatus are utilized to effect a separation of coal from slate, and other refuse in coal, by passing a cur- 25 rent of water through compact masses of coal, causing the heavier slate and refuse to segregate and collect at the lower part of the whole mass, from which they are separated by specially designed mechanism. However, in many such 30 methods the separation is not as effectivev as in my method, and by use of my apparatus.

From experimentation and actual practice, I have determined that the relative differences in the velocities of sinking components of coal and 35 refuse is greater than indicated by a mathematical comparison of the specific gravities and velocities of sinking coal and refuse. For illustration, if a piece of coal which has a specific gravity of 1.4 is placed in water, the force acting to sink the coal is proportional to 1.4 less 1.0, or .4. If the coal is placed in a liquid having a specific gravity of 1.2 the sinking force is proportional to 1.4-1.2, or .2 which is half the force acting to sink the coal in water. Similarly consider refuse 45 (for example slate) having a specific gravity of 2.6, the sinking force in water is 1.6 and in liquid having a specific gravity of 1.2 is 1.4. Thus the sinking ratio as between refuse and coal would be 50 in water and in a liquid of 1.2 specific gravity. This larger ratio favors clean separation, particularly where the forms and specific gravities of the granules to be separated are subject to variation. However, actually the difference, when compared with coal and refuse, is appreciably greater, because refuse, such as slate, usually is fiat or streamline, whereas coal usually is of cubical shape, or somewhat spherical.

Using the term "rising current classification as meaning classification effected through the different settling rates of granular particles of different specific gravity, (or of different shape and specific gravity) in a rising stream of liquid, it 0 will be observed that the differentiation of settling rate can be intensified by using a liquid whose specific gravity is less than, but only moderately less than the specific gravity of the particles of lower specific gravity. This concept is an important feature of the present invention. Strict flotation requires solutions too concentrated for successful commercial use, but it is entirely practicable to use the relatively dilute solutions needed for a rising current process.

My invention differs particularly from the floatation methods because I utilize a liquid having a specific gravity less than the lightest com-' ponent of coal. Therefore, my liquid has a specific gravity of less than the heavier components slate and other refuse. My utilized liquid ranges in specific gravity from a maximum point which is less than the specific gravity of the lightest component of uncleaned coal to a minimum determined by economic considerations afiected by the problem of maintaining the concentration of the solution, etc., for the device will operate with water, but not so advantageously.

Another important difference between my process and apparatus and the past art is that the coal, as it comes from the mine, is not treated in a mass, but each piece of coal or refuse, or piece of coal containing refuse, is acted upon separately and sinks in an individual path depending on its size, specific gravity and shape. In other words, 40 the device operates on the rising current principle, and is sharply distinguished froma jig.

Also, I provide a container for said liquid which has two compartments, communicating with each other. One of said compartments contains refuse and the other said compartment contains sinking coal and refuse. I control the sinking velocity of the coal and refuse, as slate, by providing adjustable means which can be regulated to vary the velocity of upward currents of liquid from one compartment and into the other and through which currents coal and refuse is sinking and, at the same time, cross or transverse currents are produced in the liquid in one of said compartments for the purpose of transporting the coal,

which sinks at a lesser velocity than the refuse,

' to a predetermined area or to mechanism adapted refuse in coal by allowing the particles to sink.

through two currents which combine to create a current of liquid which moves vertically and horizontally, said liquid being lighter in specific gravity than the lightest component of the aggregate whereby the heavier components shall deposit in a predetermined space and the lighter components shall deposit in a different space; to provide mechanism to convey said coal and slate; and to provide means to produce upward and horizontal currents of said liquid and to regulate the velocity of said currents.

Other objects of the invention are apparent by reference to the hereinafter description, and drawings.

The invention consists in the combination of the elements, arrangement of the parts and in the details of the construction, as hereinafter fully explained.

In the drawings:

Fig. 1 is a side view of the container, and mechanism with parts broken away, having the invention incorporated therein;

Fig. 2 is a plan view of the same, with parts broken away, and showing the invention incorporated therewith; I

Fig. 3 is a section taken on a line corresponding to 8-8 in Fig. 2 with parts broken away;

Fig. 4 is a section taken on a line corresponding to 44 in Fig. l, with parts broken away;

Fig. 5 is a section taken on a line corresponding to 55 in Fig. 1;

Fig. 6 is a fragmentary side elevation at the discharge end of the tank, with parts removed and broken away, showing the mechanism for controlling the flow of water and solution;

Fig. 7 is a side elevational view of a sprocket, or pulley, and conveyor, with parts broken away;

Fig. 8 is a diagrammatic view of the conveyor drives; and

Fig. 9 is a plan view of the valve mechanism, and tank with parts broken away.

In the preferred construction of the invention I provide the tank or container I which is supported by the platform 2, and supports 2.

The tank I has a horizontal bottom 8 and vertical side walls 4 and 5 rising from thebottom and integrally connected therewith. The inlet end wall 6 inclines upwardly and outwardly at an obtuse angle with respect to the bottom and is integrally connected with the side walls 4 and 5. The outlet end wall I is integrally connected with the bottom and side walls.

Formed in the bottom 8, of the tank I, is the trough 8 which extends transversely and across the tank. The width of the opening 8 of the open top of the trough and its location is predetermined by calculation and in consideration of all the factors involved in the operation of the invention. As will be hereinafter explained the trough 8 receives the heavier or impure components of the mined coal, as slate, rock, and other impurities, which will be referred to as refuse 9,

which are separated from the pure coal III. A screw conveyor II is positioned in and operates in the trough 8 to convey the refuse to the outside of the tank I. The shaft I2, which revolves the conveyor I I, has one end I8 joumaled in the end wall I4 of. the trough 8.

On the side wall 4 of the tank I is secured a conveyor casing I5 and the lower end thereof opens into the discharge end I8 of the trough 8. The casing I5 is inclined upwardly from the trough 8 to the discharge end of the tank, and forms a water-tight chamber from the trough 8 to a point above the liquid level in the tank where it is open to receive the endless refuse conveyor I! which travels in the casing I5. The screw conveyor shaft I2 has an extension on the end I8 journaled in the end wall I8 of the trough 8. On this extension is rotatably mounted the lower sprocket pulley 20 about which the lower end of the refuse conveyor belt 2I, of the conveyor I1, is trained. There are transverse cleats 22 on the conveyor belt 2I which wipe against the bottom inclined wall 28 of casing I1 and slide the refuse 8' up the inclined wall 28. The refuse is pushed into the casing I! by the screw conveyor I I. The conveyor conveys the refuse up the bottom of the casing and discharges this retuse into the chute 24 which is separate from the discharge chute 25 for the coal I0.

The shaft 28 is journaled in a bracket 21 at one end and in the bracket 28 at the other end. This shaft 28 has a pulley 28 thereon similar to the pulley 20, and about this pulley 28 is trained the upper end of the refuse conveyor I'I.

Fixed to the upper end of the discharge end wall are aligned bearing brackets 29 and 88in which are iournaled the ends of the shaft 8I, on which is secured a sprocket pulley 82, around which is trained the upper end of the endless coal conveyor 88. The shaft 8I drives the coal conveyor 88 in a direction opposite to the refuse conveyor II. The lower coal conveyor sprocket pulley 84 is fixed to a shaft 85, the ends of which are journaled in the side wall 5 of the tank. The conveyor 88 is perforated and has substantially the same width as the tank I.

As the pure coal III sinks through the liquid 84 in the tank I it deposits on the upper flight of the conveyor 88 at the lower end, as will be hereinafter explained, where it is carried upwardly on an incline and discharged over end wall I and into the coal chute 25, at a point separate from the refuse.

Extending transversely of the tank I, at the 'over the tank. Water is sprayed on the coal from this pipe 86 as the coal emerges from the tank and the coal is washed. Moreover, a portion of the liquid 84 which adheres to the coal is thereby returned to the tank.

For the purpose of causing an internal movement of the liquid 84 in the tank I an apron or bridge wall 81 is provided which extends across the tank with flanges 88 on the sides thereof bolted to the side walls 4 and 5 of the tank. The bridge wall is located at the end of the conveyor 88 and above the vertex of the obtuse angle formed between the outlet end wall I and the bottom 8 of the tank. The impeller chamber 89 is formed as by the end wall 48, and the upper and lower horizontal walls 4I and 42. The end 48 of the wall H is connected with the bridge wall. 81 and the end 44 of the wall 42 is connected with the outlet end wall I. The other ends of the walls 4| and 42 have connected therewith the vertical end plate 45 in which is journaled the propeller shafts 46 and 46' having fixed to their ends 41 the propellers 48 and 48. The other end of the shaft 46 has a wheel 48 and a pulley 58 fixed thereto. The wheel 49 is in contact with the wheel 5| which is connected with and operated by the usual electric motor 52 supported by the support 53 which is mounted upon the platform 2. 1 1

The shaft 46' has a pulley 58' thereon which is in alignment with the pulley whereby a belt 53 causes rotation of the shaft 46 and pulley 50', when the Wheel 5| imparts rotary movement to the wheel 48, shaft 46 and propeller 48.

In relatively small tanks only one impeller is necessary but in the apparatus illustrated a pair of propellers are shown. An intermediate portion of the impeller shafts 46 and 46' are journaled in water-tight bearings 54, in the end plate 45, and the outer portion of these shafts extends outwardly of the tank.

The tank I has two compartments, the upper compartment and the lower compartment 56. The compartments are divided by the partition 51 which comprises the buttress plate, or side, 58, the apron or bridge wall 31, and the upper flight of the conveyor 33 which has the spaced apart perforations 59 therein to permit liquid to drain from the coal into the tank 'I. The opening or separating slot or passage68 is provided in the partition 51 and which is a passage for refuse, as will be hereinafter explained.

For the purpose of insuring that the heavier components of the aggregate will fall into the trough 8, in the event that there is not complete coordination of the operating elements, such as sudden changes in the rate of raw coal feed, specific gravity of the liquid, or other such factors, the buttress plate or side 58, which bridges the width of the tank I, is positioned adjacent the inlet end wall 6 and arranged to swing on horizontal pivot bolts 6|, one for each side of the plate. The ends of these bolts are anchored to the side walls 4 and 5. These bolts 6| extend through apertured ears 62 fixed to the upper corners of the plate. The plate 58 extends the major portion of the depth of the tank and terminates at a point substantially in alignment with the upper half of the bottom sprocket pulley 20 so as to be aligned with the lower end of the upper flight of the conveyor 11.. All coal and refuse falling on the plate 58 are directed toward the passage 68.

The angle of plate 58 may be adjusted by the I use of a bolt 63 having a threaded intermediate portion extending through a slightly elongated aperture in the end wall 6 and threadably engaged by a pair of nuts 64, one bearing on each side of the end wall 6. The inner end of the bolt 63 extends through an opening in the plate 58. A pair of nuts 65 are mounted on the inner end of the bolt 63, one bearing on each side of the plate 58. Thus by changing the gripping positions of the nuts 64, the angle of the plate 58 may be changed as desired.

Fixed to the lower end of the wall 48 is the plate 40' which has-a plurality of slots 40" therein. The plate 40 is inclined downwardly and toward the outlet wall 1.

Due to the rotatable movement of the propellers 48 and 48', the liquid is caused to move, and

' a current is created in the liquid. For the reason compartments 55 and 56, and the current of liquid is created in the lower compartment 56, this current must travel through the perforations 48 in the plate 40, and below the plate 40' and then upwardly through the passage at a rate of speed dependent, and capable of being regulated, upon the revolving speed of the propellers 48 and 48' and the width or area of the passage 68. The position of the hinged plate 58 controls the area of the passage 60, W1 ereby if the plate 58 is raised the area of the passage is reduced and thawlocity of upward current of liquid, in consideration of the propellers having a regular rotatable speed, is increased. On the other hand, if the plate 58 is lowered the area of the passage 68 is increased and, since the area of the path of the current of liquid is increased, the speed or velocity of the current is decreased. Obviously, with the passage 60 having a predetermined area, or width and length, the velocity of the current of the liquid which passes upwardly through the passage 60 can be increased or decreased by varyingthe rotatable speed of the propellers.

Now it is obvious that not all of the currents, or agitated liquid, pass through the passage 60, whereby a secondary current of the liquid travels past the passage 60 and contacts the inlet wall 6 and is deflected upwardly and in contact with the plate 58. This latter mentioned or secondary current carries liquid through the perforations in the plate 58 and after this secondary current passes through the perforations, and through the coal and refuse on the plate 58, this secondary current drifts or moves horizontally or toward the outlet end 1 of the tank I and meets the upward current which previously has passed through the passage 60. The meeting of the up ward current with the horizontal current produces a current or drift of the liquid in a direction which is substantially at an angle upwardly and toward the outlet wall or end 1 of the tank.

Since the specific gravity of the pure coal is only moderately greater than the specific gravity of the liquid, the lifting effect of the upward current of liquid keeps the coal in suspension for a considerable time. -This action can be modified by varying the specific gravity of the liquid or by varying the velocity of the rising current, but in any event, the coal which remains in suspension after it leaves the supply chute is kept in suspension until the cross-current produced by fiow through the perforations 65 in the plate 51 carries the coal over the barrier 31. Refuse settling on the plate 51 will slide to the throat, and if any coal should be trapped with the refuse and slide with it to the throat it will be elevated by the rising current and carried over the barrier 31. Consequently, while the separation occurs almost exclusively with the coal in suspension, any coal which may move to the throat over the plate 51 together with the settling refuse, will be recovered by being again brought into suspension in the zone where the rising current of liquid is most active.

The liquid 34 substantially fills the tank to the level indicated at 61. This liquid may vary in specific gravity within the limits of pure water and a liquid having a specific gravity equal to the specific gravity of the lighter component coal. When it is desired to increase the specific gravity of the liquid above water any of the cheaper grades of salts that will not disintegrate the coal or adversely effect its burning properties may be used. Common salt or sodium chloride has been used with excellent result, as well as calcium chloride, magnesium chloride, or any of the salts of the alkali earth metal group taken separately or in combinations, depending on their relative economy and desired effects.

It is, of course, advantageous to maintain a substantially constant predetermined density or specific gravity of the liquid in tank I and to compensate for the volume absorbed by the refuse 8 and the coal I8, salt or other materials heretofore mentioned is automatically introduced for increasing the density, either in granular or concentrated liquid form through conveyor pipe 68 by any suitable pressure, gravity or otherwise. This pipe 68 deposits the liquid or granular material in the tank above the liquid level 61 thereof. In the pipe 88 is a control valve 68 having a lever 10 to turn the valve.

On the wash-water pipe 88 there is a control valve 1| outwardly of the perforated end that is positioned over the tank. On one side wall I of tank I is a bracket 12 to which is pivoted as at 13 the apex of a bell crank lever and one leg 14 of this lever is formed with a series of openings 15 continuous with its length. The other leg 16 of this lever has the free end pivoted at H to an upstanding arm I8 on the float 18. The float moves as the liquid level 84 in the tank varies.

The valve arm 18 is connected by a link rod 88 to any predetermined point on the arm H by a bolt 8| inserted in the selected opening of the series 15.

series of openings 15 on the arm 14. The variation of the liquid level is therefore transmitted through the fioat 18, the bell crank 18, link rods 80 and 82, to the water valve II and the density increasing material pipe valve 88. Since the stroke of the link rods 88 and 82 may be regulated, and these link rods move in response to the variation of the liquid level in the tank, the volume of water and the density increasing material may be controlled.

Any suitable means may be used to drive the conveyors 88 and I1, and in Fig. 2 is shown the electrically operated motor 88 which has the driving shaft 84 on which is connected the gear 85 and the sprocket 88. On the sprocket 86 is meshed the chain 81 which is meshed with the sprocket 88 fixed to the shaft 8| which operates the conveyer 88 by means of the sprockets 82.

Fixed to the end of the shaft 84 is the gear 85 which meshes with the gear 88 fixed to shaft 88 which is fixed to the casing ID, as by the bolts 8| and 82. On the shaft 88 is the sprocket 88 on which is meshed the chain 84 which also meshes with the sprocket 85 fixed to the shaft 86 which has sprockets thereon that operate the conveyor II.

It is, therefore, quite apparent that I have invented a highly desirable device for the heretofore fully described purposes and which may be utilized to separate carbonaceous materials eificiently, dependably, and economically." Furthermore, the simplicity of the invention enables and assures its economical manufacture and, at the same time, minimizes possibility of the various parts of the invention getting out of order or developing defects which are likely to prevent its usage or lessen its efiiclent operation.

While I believe that the form of the invention illustrated in the drawings and referred to in the above description, as the preferred embodiment, is efficient and practical, yet realizing that the conditions concurrent with the adoption of the device will necessarily vary, I desire to emphasize the fast that changes in the details may The valve II is likewise connected by a. link rod 82 by means of a bolt to any one of the 1 be resorted to, when required, without sacrificing any of the advantages of the invention as defined in the claims.

For example, the impure or mined coal may be fed'onto the plate 58, and into the tank I by any kind of conveyor or feeding device. The,pure coal conveyor 88 may be any conventional dsign, such as a single or double chain with open metal flights. The refuse conveyor I! may be a ram or plate feeding to an elevator of either screw or bucket type, or flight conveyor. The circulating propellers may be placed at different angles to the position shown to favor various conditions of installation, in which cases suitable housing or casing may be used The speed of the propellers may be adjusted by any variable speed transmission device other than those shown, or the speed-changing devices may be discarded when the best speed for a particular constant operating condition is determined. Furthermore, the design of the plate 58, as well as the partition 51 may be changed to meet various conditions.

What I claim as new and desire to secure by Letters Patent is:

1. In a device for separating mixtures of granular solids having different settling rates through a liquid and characterized by different specific gravities, the combination of a tank containing a liquid whose specific gravity is greater than one and only moderately less than the solid of .lower specific gravity said tank having an entrance side; a barrier extending across said tank approximately parallel with said entrance side with its top substantially horizontal and below the liquid level in the tank and its lower margin above the bottom of the tank; a foraminous guide partition sloping downward from approxi: mately the liquid level along the entrance side of the tank toward the lower margin of said barrier from which it is spaced horizontally, the

'lower margin of the guide partition beingformed to produce with the barrier a narrow approximately vertical throat; means for circulating liquid in the tank from the space beyond the barrier beneath the barrier and then upward, part passing upward through said throat and part upward through said foraminous guide partition, the structure being so arranged that the guide partition delivers any solids sliding down it into the throat and the liquid flowing upward through the guide partition flows with a substantial horizontal component toward the stream of liquid rising through the throat, and joining therewith, flows over the barrier; means for feeding solids to be separated to the guide partition at the entrance side of the tank; means for intercepting and withdrawing the lighter granular solids which tend to settle in that part of the tank beyond the barrier; and other means for collecting and withdrawing from the bottom of the tank the heavier granular solids which settle through said throat.

2. In a device for separating mixtures of granular solids havingdifierent settling rates through a liquid and characterized by different specific gravities, the combination of a tank containing a liquid whose specific gravity is greater than one and only moderately less than the solid of lower specific gravity, said tank having an entrance side; a barrier extending across said tank approximately parallel with said entrance side and inclined upwardly and away therefrom with its top substantially horizontal and below the liquid level in the tank and its lower margin above the bottom of the tank; a foraminous guide partition sloping from approximately the liquid level along the entrance side of the tank downward toward the lower margin of said barrier from which it is spaced horizontally, the lower margin of the guide partition being formed to produce with the barrier a narrow throat; means for circulating liquid in the tank from the space beyond the barrier, beneath the barrier and then upward, part passing rapidly upwardthrough said throat and part less rapidly upward through said foraminous partition, the structure being so arranged that the guide partition delivers any solids sliding down it into the throat and the liquid flowing upward through the guide partition flows with a substantial horizontal component toward the stream of liquid rising through the throat, and joining therewith, flows over the barrier; means for feeding solids to be separated to the guide partition at the entrance side of the tank; means for intercepting and withdrawing lighter solids which tend to settle in that part of the tank beyond the barrier; and other means for collecting and withdrawing from the bottom of the tank solids settling through said throat.

3. The combination defined in claim 1 in which the lower end of the guide partition is imperforate and curved downwardly and in which the barrier is curved at its upper portion away from the entrance side of the tank whereby the upper end of the throat formed between the guide partition and the barrier is gradually flaring and consequently adapted to minimize eddying while favoring horizontal flow away from the entrance side over the top of the barrier.

4. The combination with the structure defined in claim 1 of means for so adjusting said guide partition relatively to said barrier as to vary the width of the intervening throat.

JOEL R. BELKNAP.

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