US2291661A - Apparatus for dedusting and cleaning coal and the like - Google Patents

Description

Aug. 4, 1942.- E. STUMP 2,291,661

APPARATUS FOR DEDUSTING AND CLEANING COAL AND THE LIKE I Filed April 27, 1939 2 Sheets- Sheet l Aug. 4, 1942.

x E. STUMP APPARATUS FOR DEDUSTING AND CLEANING COAL AND THE LIKE 2 Sheets-Sheet '2 Filed Abril 27, 1939 orra'e y wherein- Patented Aug. 4, 1942 APPARATUS FOR DEDUSTING AND CLEANING COAL THE LIKE Earl Stump, Harvey, Ill., assignorto Roberts and Schaeier Company, Chicago, 111., a corporation of Illinois Application April 27, 1939, Serial No. 270,391

'7 Claims.

My invention relates to improvements in apparatus for dedusting and cleaning coal and the like, and has for one object to provide an apparatus and process whereby, in connection with apparatus suchas that illustrated in United States Patent No. 2,245,942,. dated June 17, 1 941, the coal will be dedusted as apart of the gravitational separation or air ,washing process before the separation of coaljand slate is commenced.

'While I am concerning myself in the present invention more especially with the dry cleaning of coal it will be understood that the separating and dedusting apparatus and process is applicable to any situation where it is desired to dedust or withdraw from any minerals or solids of the connecting rod 25 and crank- 2l, which crank is driven by a pinion 28 and sprocket chain j the dust which adheres to or is mixed with the larger particles.

This application is filed as'a continuation in part of my prior. application, Serial No. 165,129, filed September 22, 1937, which has become abandoned.

My invention is illustratedmore or less diagrammatically Figure .1- is a side elevation of the apparatus in part section;

Figure 2 is a section along the line 2-2 of Figurel; and I Figure 3 is a longitudinal part device.

section of the in the accompanying drawings,

29 from the gear 30 on the flutter valve drive shaft. Thereciprocating plate 23 forms the bottom of a feed box 3| which receives coal or other material to be treated, from a hopper 32.. The manually adjusted valve 33 controls the thickness of the sheet of material fed forwardly and to the v left in Fig. 1 by the reciprocating plate 23. "-The box 3| is open into the separating chamber 34,

bounded at the bottom bythe perforateplate I9, I

at the sides byplates 35, and at the top'by a cover 36. ..This cover throughout the majorjpart Q of its area is generally parallel with the perforate plate l9, but at the feed end the cover is asso-'- ciated with a dust and air funnel 31 which discharges into an air duct 38, above that part of the box into which the coal is first introduced.

The air duct 38 extends to an exhaust' fan, and

thence to a dust separator, "both of which 'a re f known in the art and hence are not shown herein. P

The exhaust fan should be ofsuflicient capacity to maintain the pressure above the coal entering the separating chamber 34 below the ,atmos: pheric pressure outside the chamber.

At the end of the separating chambe which 1. I is beneath'the box 3| there is pro ided opm ing 5ll for the admission'of air. The size'cf this Like parts are indicated by like characters throughout the specification and claims.

A main supporting frame is indicated at II Numeral 2 indicates a blower which discharges air into a 'pipe 3, controlled by a'butterfiy valve 4, adapted for manual adjustment by means of lever 5, quadrant Gand thumb screw 1. The flutter valve housing 8 is in alignment with the pipe 3 and contains a butterfly valve 9 mounted for rotation in the housing and driven bya pulley l0 and belt H from any suitable source of power. The flutter valve, when in its transverse position, may substantially close the pipe. When in its horizontal position, the pipe is open. The pipe 12 receives air from the flutter valve box and discharges it into an air box l3 which is closed at'bottom, sides and forward end by plates l4, l5 and I6. At its top, this box .is'closed by a marble pack 11, constrained between perforate the l opening may be regulated by means of the adjustable gate or valve 5|, which is suspended on a pair of hangers such as 52.

Two adjustable separating blades 39 and 40 are provided, which may be adjustable vertically to separate the sheet of material as it flows along the plate l9, coal going over the top of the blade 39, middlings moving between 39 and 40, and refuse being discharged below 40. The partieu lar means for adjustment, support, and handling" of the coal is not illustrated here becauseit has no connection with my present invention.

When the fan motor is started, and when the manually adjustable butterfly valve has been set for thedesired operation, the motor which drives the flutter valve is also started,-or the flutter valve may be driven by the same motor that drives the fan. This causes a continuous rotation of the flutter valve. so 'as to open and close the air supply to permit the discharge into the discharge. pipe38. At the same timethe feed' plate is reciprocated and feeds the material to be. on the rollers 24 and to be reciprocated by means separated forwardly toward thei left into the air box of a pulsating current .of air, which pulsating current of air passes up through the mar-. ble pack into ,the separating chamber above it and thence out through the funnel 3l and,the

separating chamber. The velocity at which this supplied through the marble pack, anda powerful upward air current is established at the upper end of the separating chamber where the coal is delivered from the feed plate. This air current is composed partly of air pulsations coming through the marble pack, greatly augmented, however, by air admitted through the opening 50, which is adjusted to admit the required amount of air depending on the conditiorrof the coal an other factors. The upward air current thus created tends to support the sheet of coal or similar material discharged into the separating box and causes it to travel further toward the left, thatis, further toward the discharge end than it otherpended sheet of coal is in the neighborhood of 2000 feet per minute. It increases gradually upwardly along the contracting funnel until at the entrance to the discharge pipe, its velocity may be in the neighborhood of 3000 feet per minute. These velocities might be increased if larger dust particles were to be handled, or decreased if smaller dust particleswere to be removed. Again, these velocities. may be increased or decreased, depending upon the specific gravity of the dust material.

In my specification and claims, where I refer to coal and the like, it will be understood that this reference is for convenience only, that this wise would without the air support. This sheet of material traveling through the air on a path inclined to the vertical and supported as it is by the air blast is in an ideal condition for dedusting. The air blast at this point has a dual function. It supports the sheet of flowing material and as it passes up through that sheet of loosely suspended material in motion in space, it entrains the adhering and mixed dust and carries it upwardly away from the stream of coal. Depending upon the air velocity and the design of the parts, coarser or finer dust may be removed. The apparatus shown is ideally adapted to pick up minus 48 dust. That is, dust that is fine enough to pass through a screen having 48 meshes to the inch, which is the size of dust most desired to remove.

The coal, after the dedusting operation, falls to the floor of the separating chamber and then flows downwardly along the inclined floor, the floor and box being at rest, but the coal is agitated by the pulsating current of air which passes upwardly through it, the marble packing offering "1a resistance to the flow of air which is greater apparatus and process is applicable to a wide range of materials in the ore dressing or material treating field and it is understood that where this language is used in the specification and claims, it is intended to cover any type of material which may be dedusted.

While it is, of course a fact that the major portion of the dedusting operation takes place while the bed of coal is on its way from the feed plate 23 to the point where it contacts the floor l9, nevertheless the dedusting operation may continue as long as any of the coal is passing through the machine. For instance, a small residue of dust may have remained in the coal and dust may perhaps, under some circumstances, even be generated as the coal travels along the floor. Such dust will be blown upwardly through the mass of coal and projected above such mass by the high velocity air currents in the interstices between the coalparticles. Such dust particles,

if flne enough, may be suspended in the air and carried back to the hood 31 by the lateral current of air travelling across the upper surface of the coal bed from the discharge end of the deck backward and upward toward the air discharge hood 31.

The invention having been described, that which is considered to be new and for which the protection of Letters Patent is desired will be pointed out in the appended claims.

I claim:

1. In a combined coal separator and deduster, a fixed inclined air-pervious'deck having a resistance bed beneath it, a chute above the upper end of said deck for delivering raw coal thereto by gravity, means for forcing air up through said resistance bed and deck to cause the coal properly controlled. The agitation caused by the pulsating air column as the coal stream flows downwardly causes stratification of the .coal, heavy refuse at the bottom, lighter coal at the top,

w and some mixed coal and refuse or middlings in the center. Because the air stream at the upper end of the box has had a chance to work on the coal while it was suspended in the air and before it was supported by the floor of the box, the dust has been substantially removed, and so the gravitational separation is applied to coal and refuse only without interference from dust.- The result is that a better separating effect, is obtained and a clean,dustless product is discharged.

The air which passes up through the coal bed is guided by the cover or hood back along the and refuse mixed therewith to flow down the inclined deck and separate into parallel strata, means including a suitable hood and an exhaust pipe connected thereto at a point above the upper end of the deck for withdrawing the air from above the coal, said exhaust pipe having a substantially greater capacity than is required to remove the air which comes through the deck, whereby a partial vacuum is established, and

an opening communicating directly with the atmosphere outside of the separator for admitting air-underneath the stream of coal as it flows from the chuteto the deck, whereby a current of air is drawn through said stream of coal at high velocity to dedust the same before it reaches the deck. v

2. A coal separator and deduster as claimed in claim 1, characterized by the provision of means for adjusting the size of the air opening to regulate the volume of air admitted and thereby control the dedusting operation.

3. A coal separator and deduster as claimed in claim 1, characterized by the peculiar shape of the hood, which above the-lower half of the deck is substantially parallel to the deck and above the upper half of the deck has sloping sides which terminate in the walls of the exhaust pipe.

4. In a combined separator and de-duster, a fixed inclined air-pervious deck having a resistance bed beneath it, a casing enclosing said deck and including an air chamber beneath the resistance bed and a hood above the deck, means for delivering a stream of mixed materials to the upper end of the deck by gravity, an opening in said casing above the deck and adjacent the stream-of descending coal, means for delivering air under pressure'to said chamber to force air currents through said bed and deck to cause the said materials to flow down the deck, and means for exhausting the air from said hood at such a rate that a stream of air is caused to flow through said opening from outside the casing and through the descending stream of materials to dedust the same.

5. In a combined separator and de-duster, a fixed inclined trough having an air-pervious bot- .tom, means including a chute for delivering a stream of material to the upper end of said trough by gravity, means for supplying air at greater than atmospheric pressure to the bottom of said trough, means for supplying air at atmospheric pressure at a point between the upper end of the trough and said chute and beneath the descending stream of material, and means for maintaining the air above the material in the trough and said stream below atmospheric pressure to assist the flow ofair through the trough and material therein and to create a current 01 air from said point through the descending stream of material to de-dust the same.

for delivering said raw coal to the deck, and.

means for actuating said feeder means to impart to. the raw coal to be delivered to the deck adefinite mechanical movement in a direction generally parallel to the plane of the deck.

7. The structure and combination defined in claim 4, wherein said means for delivering a stream of mixed materials includes a feeder device. and means for actuating said feeder device to impart to the stream of descending material a definite mechanical movement in a direction generally parallel-to the plane of the deck.

EARL B'I'UMP.

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