US1812071A - Apparatus for controlling air in dry separating tables - Google Patents

Description

June 30, 1931-. R. w. ARMS 7 APPARATUS FOR CONTROLLING AIR IN DRY SEPARATING mam-Is Filed Jan. 30, 1926 3 Sheets-Sheet 1 June 30, 1931. R. w. ARMS 1,812,071

APPARATUS FOR CONTROLLING AIR IN DRY SEPARATING TABLES Filed Jan. 30, 1926 3 Sheets-Sheet 2 fizvenior @Wa Z June 30, 1931. v R. w. ARMS APPARATUS FOR coumommq AIR IN DRY SEPARATING TABLES Filed Jan. 30, 1926' a Sheets-Sheet s Patented June 30; 1 931, A

" NIT D; STATES PATENT RAY W. ARMS, OF CHICAGO, ILLINOIS IASEIGHOB '10 ROI BEETS A; SCHAEFER COMPANY, I

OF CHICAGO, ILLINOIS, A

coaroaarron or rumors v arrm'rus ron couraomme AIR m DRY snrm'rme A Application filed January My invention relates to improvements in means for controlling and distributing air which is supplied to dry separating tables and has for one object to apply a new and 5 improved means for adjusting and controlling the airflow so as to insure a proper relation between the velocity of the air or gas current upon which a flowing sheet of finely divided material is partially floated as it passes over a separating table. Another object of my invention is to provide means for adjusting the air or gas with a minimum of difliculty and delay so that an unskilled operator may make the necessary adjustments to enable the table to satisfactorily handle different characters and quantities of material.

Experience shows that if the deck which carries the flowing stream or sheet of'divided material offers the same resistance to air flow throughout its entire area and if there are provided beneath the deck a series ofmanually adjustable shutters or bafiles strips which can be set to control the airflow, that satisfactory separating will take place. Experience further shows that these shutters or baflies are exceedingly sensitive and very slight changes beneath different parts of the deck may give rise to great differences in operation and it is desirable to provide means for decreasing the sensitiveness of these shutters so that a relatively unskilled operator may still be able to make correct adjustments.

Experience also shows that where the resistance to air flow afforded by the flowing sheet of material itself as distinguished from the resistance afforded by the deck is great, slight changes such as are always taking place in the character of the sheet of material as for instance,- the introduction of a flat piece of slate or the like may give rise to great difi'er-,

ences in action. It is desirable therefore to have the resistance to air flow of the flowing sheet relatively small with respect to the total resistance encountered by] the sheet. In order to take care of these various situations I propose to build into the deck in' addition to the normal pervious surface which carries the stream of material and through which the air passes, a series of reciprocating elements contion of the total resistance.

30, 19 26. aria" in. 84,834.

forming generally to the various parts of the deck surface,thus decreasing the total effect of change of the shutters and thereby makin them less sensitive. In addition to this ropose to provide beneath the manuallyfadjusted shutters a perforate plate or other suitable air flow resisting elements which will build up resistance to the air.

Experience shows that the resistance of the stream of coal or other material to air flow is approximately .3 inches water gauge. The resistance to flow of air 'afi'orded by the pervious surface of the deck itself is approximately .5 inches water gauge, thus the resistance without any additional resisting means of the coal sheet itself is a very large propor- When I have the perforate plate beneath the deck it can be given a resistance to air flow of approximately .9 inches water'gauge and we then get the resistance of the coal as related to the resistance of the total structure approximately in the proportions of one to three. When this is the caseslight temporary variations in the character of the coal or other bed of material if separated is of relatively less consequence and therefore as such slight changes are continually taking place, the adverse effect of these changes on the separator is reduced to a minimum. 1

Experience shows that in order to get the desired eflect it is necessary to provide other means for distributing the air and I do this by feeding the air to the area beneath the perforate plate to an vas chimney or gradually opening cone which more or less conforms to the cross sectional area of the table or deck and which therefore brings the air to the underside of the perforate plate in such manner that pressure beneath that plate is substantially constant throughout the entire area thereof.

Experience a on'the deck where thesheet is fixed, it is desirable to provide means for increasing the supporting effect of the air. Under some I conditions it is" desirable to leave off the damping effect or perforate plate and; also to provide means for bringing an increased quantity of air to the deck, the reason for this lso shows'that at certain points i being that in the zone immediately adjacent the point where material is fed to the deck and before any appreciable separation has taken place-.andbefore the sheet has had time a to spread out, the sheet is of such thickness that the normal or supporting effect desirable in those parts of the deck removed from the supply is not suflcient and I therefore provide a partition in the vas chimney which may actually take the form of a reversed cone to concentrate rather than distribute the air flow and concentrate this air beneath that part of thesheet where it is at its maximum thickness.

My invention is illustrated more or less diagrammatically in the accompanying drawings, wherein Figure 1 is a plan view; 1

Figure 2 is a plan view of the cone in section through the bemis cloth which joins the cone and deck;

Figure 3 is 'a' section along the line 33 of Figure 1;

Figure 4 is a section along the line 44 of Figure 3.

Like parts are indicated by like characters throughout the specification and claims.

' A is a supporting frame. From it project upwardly brackets A A is a reciprocating frame supported by a link A on a hearing A on the bracket A and a link A on an adj ustable slide A on the bracket A whereby the angle of inclination of the frame A may be adjusted. A is a drive link whereby the frame A may be reciprocated on the pivot links A A A is a deck frame hinged on the frame A along a line generally parallel with the line of reciprocation. A is an adjusting screw associated with a hand wheel A and a bearing A onthe frame A whereby the frame A may be angularly adjusted about an axis at right angles to the adjustment axis of the frame A and thus the inclination of the deck may be controlled both in a direction parallel with. reciprocation and at right angles thereto.

B is a pervious deck of screen cloth or other suitable material mounted on the reciprocating slats B in the frame A". Mounted on these slats and adapted to control the space between them are manually adjusted shutters B of tin or other suitable easily bent material. B B and B B are rifles extending longitudinally of the perforate deck in the direction of reciprocation. The rifles B nearest the feed end of the deck are higher than the rifles B further removed therefrom. The rifles B decrease in height above the deck in the direction of reciprocation away from the feed end of the deck. The rifles B are as above indicated much higher than the rifles B and stop shortat a point slightly removed from the feed end of the deck and the rifles B continue at their normal height from the ends of the rifles B 13 is a chute mounted on the frame discharging to the deck against the high rifles B. -This chute reciprocatos with the deck and receives coal or other material from a fixed chute B so disposed that the two chutes are always in registcr independent of the reciprocation of the deck. The two sidewalls of the frame extending in both directions from the chute B as at B and B are higher than the maximum thickness of the bed so that there is never at any time any discharge of-the material over the walls B and 13 B is a guide wall inclined downwardly from the wall B at a point beyond the terminus of the high rifles. Coal does discharge over this wall onto an impervious part of the deck at B From Figure 1 it will be noted that the pervious part of the deck does not extend to the upper right hand corner of the deck but there is an impervious area B so that the shape of the pervious portion of the deck is an irregular hexagon.

C is a refuse trough discharging into a refuse chute C C is a middlings trough discharging into a middlings chute C 0 C are coal troughs discharging into a coal chute C. C C are extension plates bridging the gap between the deck and these troughs, and so arranged that they are always in register with the troughs independent of the reciprocation of the deck. 0 0

are deflector blades movable along the plate C so disposed as to separate the middlings, the refuse and the coal as they pass over the deck extensions into the troughs.

D is an air supply duct leading from any suitable air supply not here shown. It discharges into an upwardly expanding vas chimney D mounted on the frame A and terminating in a discharge mouth D underlying and of substantially the same shape and cross sectional area as the pervious part of the deck. D is a bemis cloth bellows bridging the gap between the mouth 1) and the underside of the pervious deck. D is a funnel or collector mounted Within the vas chimney and upwardly decreasing in cross sectional area. extends from the top of this deflector at D to the deck. Mounted within the frame A beneath the deck and out of contact with the An interior bellows D i manually adjustable shutters are a pair of sistance of the deck, that is,the resistance The resistance to air flow furnished by the resistance plate is fixed once and for all when the apparatus is built but is such that the air flow resistance exerted by the flowing film or sheet of material as it passes over the deck is much less than the resistance to air flow set up by the resistance plate, the manually adjusted shutters and the pervious deck itself. 1 1

Experience shows that if the internal reofthe deck'and its associated parts,.to air flow as distinguished from resistance to air flow of the material traveling across it is high, the expense of operation becomes extravagant because it is exceedingly expensive to pump air. On the other-hand, experience shows that if the internal resistance is too low in proportionto the resistance ofthe material, unsatisfactory operation results because slight changes in the thickness of the material bed or changes in the character of the material may radically increase or decrease the air resistance and cause difiiculty in distribution. Our experience has been that if the internal resistance of the deck is less than fivetimes the external resistance and not less than three times the external resistance, satisfactory operation results at an expense which is not prohibitive.

It will be evident that while I have shown in my. drawings an operative device, still many changes might be made. in the size, shape, arrangement and disposition of parts without departing. materially from the spirit of my invention and I- wish, therefore, that my showing be taken as, in asense diagrammatic.

It is obvious that while I have suggested a preferred rangeof numerical relation between the internal resistance to the deck and the external resistance of the sheet of material fiowing' over it, nevertheless any range wherein the conical resistance was sufiiciently greater than the external resistance to make the deck in its operation essentially independent of temporary variations in flow is satlsfactory. .;Unde r some conditions the internal resistance might be even less in proportion to theexternal resistance thanabove stated or it might 1 be much greater but in any event. the; internal resistance .must. -be such I that variation in the external resistance inoperation jbears's'uc'harelation to the total resistance that such variation does not exert a deleterious effect. The benefit o'f this that it makes it possible to designthe equipment for 'a-given' set 'of; conc'lit'ions and nstall it with aminimum ofadjustment-in the field. Since whatever adjustment is 'fneeessary 'mu'st be made-by skilled :operatorsas a result" of ;the long tedious cut and dried method under ordinary conditions anything a that makes it possible or tends to make it possible todesign' without special adjustment in the field is manifestly of the utmost importance.

The use and operation of my invention are as follows:

The engineer who installs the plant determines the dimensions once and for all. He selects the type of resistance plate to be used and he bends the separate shutters to the proper angle to give a satisfactory distribution of the air throughout the. entire surface. The operator may from time to time during the operation change the angle of inclination in both directions of the deck. The dimensions of the rifles and the relation between them and the pervious surface will not, however, be chan ed though the position of the deflector bla es dividing the coal, middlings and refuse discharge zonesmay be changed.

The machine is started and the deck is reciprocated. Coal is fed into the fixed chute, thence through the reciprocating chute onto the deck. The coal. until it builds up above the high rifles is free to move only 1n a direction parallel with the direction of reciprocation. As soon as it builds up above the high deep bed is exposed to the action of the concentrated stream of air traveling in the direc tion of the arrows, X X in Figure 3. As soon as the coal orcoal and refuse gets away from the high rifle zone, it spreads out as indicated by'the arrows on Figure 1 and is subjected to the influence of the air traveling in the direc-.

tion ofthe arrows Y through the retarding lates. The refuse being heavier-will stay eneath the rifles and travel in the'direction" of the arrows Z Z in Figure 1. The coal be- I ing lighter will gravitate to the'top of'the sheet and tra-velacrossthe rifles down toward the lower edge ofthe deck in Figure 1. The.- refuse together with some coal perhaps traveling out beyond the end of the rifles will move in the direction of the arrows Q toward the refuse trough. The resistance furnished by the resisting or retardingplates' is so great that slight variations in thickness or air resisting quality of the-sheet away from the high rifle zone will not exert an appreciable I change on the air flow because no variation can bemore than a comparatively small percent of. the total air resistance. In. the high rifle zo'nethebed is so thick thata piece of slate or a slight change in the charaeterwill 3 1y effect the" characteror quan-- not apprecia tity-of airresistance and therefore at all times the air distribution will remain substantially constant as set by the installation engineer I *w'hen'he initially sets up the apparatus. The

05 andbuild a plant goes into' operation air caught by therev'e'rse-funnel and [dis-1 charged to the high rifle zone will, of course, exert a greater lifting force than the air on the balance of the deck and this is necessary because it is desired in the thick bed held by the high rifles to get quick support. This separation must be as accurate as the separation in the balance of the deck but the quick initial separation results in concentrating the material somewhat so as to permit more accurate separation on the balance of the deck. It will be noted from Figure 4 that the rifle in the roup of rifles furthest removed from tie feeding means is substantiallv higher than any of the others. It will further be noted that the resisting means, that is,the means which resists the air flow in addition to or separate from the resistance set up by the deck and the burden of material on the deck is formed by two perforate plates D; and that these plates are close together and that the distance between them 1s less than the distance between the uppermost of the two and the deck itself.

I claim:

1. In an air separating table, a pervious deck, means for reciprocating it, means for discharging air upwardly through it, rifles projecting upwardly from it, extending in the direction of reciprocation and decreasing in height from one end to the other, means for feeding material to be treated to the deck and a plurality of high rifles of constant height throughout their length extending in the same direction as, of substantially greater height than, and located at the high end of, the tapering rifles.

2. In an air separating table, a pervious deck, means for reciprocating it, means for discharging air upwardly through it, rifles projecting upwardly from it, extending in the direction of reciprocation and decreasing in height from one end to the other, means for feeding material to be treated to the deck and a plurality of high rifles of constant height throughout their length extending in the same direction as, of substantially greater height than, and located at the high end of, the tapering rifles, and terminating at a point intermediate the feeding means and the discharge end of the deck.

3. In an air separating table, a pervious deck, means for reciprocating it, means for discharging air upwardly through it, rifles projectin upwardly from it, extending in the direction of reciprocation and decreasing in height from one end to the other, means for feeding material to be treated to the deck and a plurality of high rifles of constant height throughout their length extending in the same direction as, of substantially greater height than, and located at the high end of, the tapering rifles, and extending from the feeding end to a point short of the discharge end of the deck.

4. In an air separating table, a pervious deck, means for-reciprocating it, means for discharging air upwardly through it, rifles projecting upwardly from it, extending in the directlon of reciprocation and decreasing in height from one end to the other, means for feeding material to be treated to the deck and a plurality of hi h rifles of substantially greater height tiian,'and located at the high end of, the tapering rifles.

5. In an air separating table, a pervious deck, means for reciprocating it, means for discharging air upwardly through it, rifles projecting upwardly from it, extending in the direction of reciprocation and decreasing in height from one end to the other, means for feeding material to be treated to the deck and a plurality of high rifles of constant height throughout their length extending in the same direction as, of substantially greater height than, and located at the high end of, the tapering rifles, the feeding means being located at one corner of the deck, the high rifles being located only on that side of the deck adjacent the feeding means.

6. In an air separatingtable, a pervious deck, means for reciprocating it, means for discharging air upwardly through it, rifles projecting upwardly from it, extending in the direction of reciprocation and decreasing in height from one end to the other, means for feeding material to be treated to the deck and a plurality of high rifles of constant height throughout their length extending in the same direction as, of substantially greater height than, and located at the high end of, the tapering rifles, the feeding means beinglocated at one corner of the deck, the high rifles being located only on that side of the deck adjacent the feeding means, the high rifles furthest removed from the feeding means being substantially higher than any of the others.

7. In an air separating table, a pervious deck, means for discharging air upwardly through it, means for propelling a sheet of finely divided material across it, means immediately adjacent the deck and interposed between it and the air discharging means for resisting the flow of air toward it, said resisting means comprising a plurality of perforate plates spaced more closely together than the distance between the uppermost plate and the deck.

8. In an air separating table, a pervious deck, means for discharging air upwardly through it, means for propelling a sheet of finely divided material across it, and means independent of the deck for concentrating a part of the air flow and discharging it through the deck to give an area of increased air activity.

9. In an air separating table, a pervious deck, means for discharging air upwardly through it, means for propelling a sheet of finely divided material across it, and means independent of the deck for concentrating a part of the air flow and discharging it through the deck to give an area of increased air activity, rifles projecting upwardly from the deck and a plurality of high rifles in addition thereto located in line with the area of increased air activity.

10. In an air separating table, a pervious deck, means for propelling a sheet of finely divided material across it, an vas chim.- ney terminating at the deck and means for dischar ing air upwardly through it against the un erside of the deck, a funnel located within the chimney, upwardly tapered and discharging against a portion of the deck.

11. In an air separating table, a pervious deck, means for propelling a sheet of finely divided material across it, an vas chimney terminating at the deck and means for discharging air upwardly through it against the underside of the deck, a funnel located with-' in the chimney, upwardly tapered and discharging a ainst a portion of the deck, a plurality of ri es projecting upwardly from the deck and rifles substantially higher than the remainder projecting upwardly :from that part of the deckwhich is in register with the funnel.

12. In an air separating table, a pervious deck, means for propelling a sheet of finely divided material across it, an vas chimney terminating at the deck and means for discharging air upwardly through it against the underside of the deck, a funnel located within the chimney, upwardly tapered and discharging against a portion of the deck, means immediately adjacent the deck, interposed between it and the chimney, outside the funnel for resisting the flow of air toward the deck.

13. In an air separating table, a pervious deck, means for propelling a sheet of finely divided material across it, an vas chimney terminating at the deck and means for discharging air upwardly through it against the underside of the'deck, a funnel located Within the chimney, upwardly tapered and discharging against a portion of the deck, a plurality of ri es projecting upwardly from the deck and rifles substantially higher than the remainder projecting upwardly from that part of the deck which 1s in register with the funnel, means immediately adjacent the deck, interposed between-it and the chimney, out side the funnel for resisting the flow of air toward the deck. I

14. In an air separating table, a pervious deck, means for propelling a sheet of finely divided material across it, an vas chimney terminating at the deck and means for dis-.

ume of air flowing through the deck.

15. In an air separating table, a pervious deck, means for propelling a sheet of finely divided material across it, an vas chimney terminating at the deck and means for discharging air upwardly throughv it against the underside of the deck, a funnel located within the chimney, upwardly ta 'ered and discharging a 'ainst a portion 0 the deck, a plurality of rifles projecting upwardlyfrom the deck, and rifles substantlally higher than the remainder projecting upwardly from that part of the deck which is in register with the funnel, manually adjusted shutters immediately beneath the deck adapted to be set to control the volume of air flowing through the deck.

16. In an air separating table, a pervious deck, means for propelling a sheet of finely divided material across it, an vas chimney terminating at the deck and means for discharging air upwardly through it against the underside of the deck, a funnel located within the chimney, upwardly tapered and discharging against a portion of the deck, means immediately adjacent the deck, interposed between it and the chimney, outside the funnel for resisting the flow of air to ward the deck, manually adjusted shutters immediately beneath the deck adaptedto be set to cont-r01 the volume of air flowing through the deck." 7

17. In an air separating table, a pervious deck, means for propelling a sheet of finely divided material across it, an vas chimney terminating at the deck and means for discharging air upwardly through it against the underside of the deck, a funnel located within the chimney, upwardly tapered and the deck adapted to be set to control the vol- 1 discharging against a portion of the deck, 7

a plurality of rifles projecting upwardly from. the deck and rifles substantially higher 7 the flow of air toward the deck, manually adjusted shutters immediately beneath the deck adapted to be set to control the volume of air flowing through the deck.

18. In an air separating table, a pervious deck, means for propelling a sheet of finely divided material across it, an vas chimney terminating at the deck and means for discharging air upwardly through it against the underside of the deck, a conduit located within the chimney and adapted to receive air at a point therein intermediate the two ends of the chimney to discharge it upwardly against a portion of the deck.

19. In an air separating table, a pervious deck, means for propelling a sheet of finely divided material across it, an vas chimney llo terminating at the deck and means for discharging air upwardly through it against the underside of the deck, a conduit located within the chimney and adapted to receive air at a point therein intermediate the two ends of the chimney to discharge it upwardly against a portion of the deck, a plurality of riflles projecting upwardly from the deck and riflies substantially higher than the remainder projecting upwardly from that part of the deck which is in register with the conduit. 20. In an air separating table, a pervious deck means for propelling a sheet of finely divided material across it, an vas chimney terminating at the deck and means for discharging air upwardly through it against the underside of the deck, a conduit located within the chimney and adapted to receive air at a oint therein'intermediate the two ends of t e chimney to discharge it upwardly against a portion of the deck, means immediatel ad ace-nt the deck interposed between 'it an the chimney outside the conduit for resisting the flow of air toward the deck.

Signed at Chicago county of Cook and State of Illinois, this 26th day of January RAY W. ARMS.

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