US933532A - Apparatus for grading pulverulent materials. - Google Patents

Description

S. COOPER.

APPARATUS FOR. GRADING PUL'VBRULENT MATERIALS.

APPLICATION FILED JAN. 26. 1909.

933,532 Patented Sept. 7, 1909.

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UNITED STATES PATENT curios,

SIMON CC'GPER, OF NEW YQRK, "3., ASSIGNOR OF ONE-HALF TO CHARLES L. BERN- HEIM, 01" NE'W' YORK, N. Y.

Specification of Letters Patent.

Patented dept. 7, 1899.

Application filed January 26, 1909,, Serial No. 474,259.

T 0 all whom it only concern:

B it known that l, SIMON Coornu, a citizen ot' the United States, residing in the borough or lilanhattan, city, county, and litate ct Yew York, have. invented certain new and useful improvements in jipparas lus for Grading Pulwrulent iii-a terial, of which the following is a full,:true, and con-' vise specification, from which others skilled in the art will be able to'niahe, construct, and use the same.

The invention seeks to separate or assert pulverulent material into different grades of fineness, by means of an ascending air column which is made to actupon the material in opposition to the force of gravity thereon and to'select and carry out of the mass of the material such particles thereof as are sustainable upon the air current, and utter such selection, to carry the same forward for depositin any desired manner, or for further classification, for which purpose the current proceeds with a diminishing velocity whereby on becoming gradually and successively unsustainable on the current, according to their weight, the said particles fall into or are deposited in suitable receptacles successively arranged for that purpose. in this manner it is sought to grade and classify finely divided or impalpable material continuously and with precision, separating it into any desired number of true grades of fineness, that is to say, into grades whereof theparticles do not exceed in size a predetermined value and are substani' i ally un form.

The invention involves the disposition and relative arrangement of apparatus for accompl cling the above results and certain features of construction and operation there hereinafter explained and more pary pointed out in the accompanying In the drawings forming a part hereof, Figure l is a vertical side elevation of a form of my apparatus, with parts broken away and shown in section; Fig. 2 is a transverse sectional view through the several trunks of the apparatus; and 3 is a 1 diti d detail.

The apparatus comprises, in combination, an upright imperforate trunk l, designated herein the main separating or classifying trunk, which may be made of wooden boards,

as indicated, or of any suitable air-tight construction, and of any desired crosssect1onal shape, provided it is adapted for a certain portion of its length to conduct an upward admission means com rises a chamber 3 which as a matter of convenience is formed within and by the base-portion of the cylindrical wall of the trunk, with its floor formed as a hopper which leads to an in clined discharge spout 4. The air-chamber 3 is separated from the interior of the trunk proper by means of one or more transverse diaphragms 5, of perforated or foraminous construction adapted to admit air from the chamber to the trunk, as later explained. Such air is supplied to the chamber through an air-pipe 6 leading from a blower T or other suitable source of air pressure, andthe cubical capacity of the chamber is relatively large as compared with the delivery of the blower so that the chamber will serve as an air reservoir or collector of suilicient volume to absorb or neutralize slight variations in the blower, or the pulsations caused by its revolving fan-blades and so that the pressure of the air below the diaphragms shall be substantially or generally the same at all points in order to promote an even and uniform upward passage or" air through the latter. In the practical operation of the apparatus this consideration is important. F or increasing the capacity of the chamber, its dimensions may be extended farther than the boundaries of the trunk, or it may be connected with other air receptacles adapted for the stora 'e or air. The air thus passing upwardly tnrough the toraminous diaphragms is divided into a number of more orless equal jets, and such dillerences of pressure as may have previously existed beneath the diaphragms, if not equalized and diffused after passing the first of the diaphragms becomes so in any event in the region immediately above them, so that an ascending column of air is sooner or later produced which has a substantially unifornr motion. The total of the openings in at least one, preferably the upper, of the diaphragms should preferably not exceed more than twenty per cent. of its total exposed area, and the said openings should be of uniform size and uniformly distributed so that finely divided and uniform jets will be produced at all points. The other diaphragms may be somewhat coarser. The preferred and most serviceable size of the openings or per centage of total openings for the finest of the diaphragms will depend somewhat on the nature, the weight and size of the material under treatment, being preferably finer or a lower percentage of opening for less weight or size, and vice versa, coarse burlap being suitable for many materials. The region of pressure equalization or adjustment which exists immediately above the diaphragms extends upwardly more or less, depending upon the pressure of the air in the air-collecting chamber and the fineness and number of the diaphragms, and gradually merges into and forms the air column above referred to, of uniform and constant velocity, ascending within the trunk and passing out through the upper outlet. The material to be graded is fed into the air current and distributed, preferably in the line of the longitudinal axis of the trunk, at a point above the diaphragms, and in or above the aforesaid region of pressure adjustment where the multiplicity of fine jets from the upper diaphragm are becoming merged into the column of constant velocity.

The invention includes and prefers a distributer apparatus which consists of an upright shaft 8, power-driven and appropriately journaled as indicated in the longitudinal axis of the trunk and carrying a number of fine beater-blades 9 designed to produce as slight air disturbance in the trunk as possible. These blades revolve directly beneath the delivery of the feed-ohute or spout 10, which leads from the feed hopper 11 through a suitable rotary feeding device 12, consisting, for example, of a usual conveyer wheel revolving within a casing and adapted to prevent back flow of air and powdered material through the spout. This feeding device is driven by suitable gearing, not specifically shown, and is susceptible of regulation so as to feed in material as required. The conveyer 13, of ordinary construction may supply the feed-hopper 11 with tailings from the tailings spout or any other source, the said conveyer, like the feeding wheel, being intended to be driven in any convenient manner and to be also susceptible of regulation. The material fed and distributed by the beater 9 as above described, is encountered by the upward air current and those particles which by reason of their size or weight or both, are not sustainable on the particular pretermined veteases locity of current, fall more or less promptly upon and through the fine apertures in the diaphragms and into the air-collecting chamber 3, from which they may pass out as tailing's through the spout 4, which latter is provided with fiap valve 14: or some equivalent arrangement to prevent also the escape of air. Some of the finer particles may adhere to the tailings and also pass into the hopper, on which account the deposit in the latter may be returned through the main trunk one or more times, as required for thorough separation. The remaining and finer particles, being those which are for the most part sustainable, on the particular cur rent velocity in the trunk and which succeed in reaching the point where the air column takes on its uniform and constant velocity, are carried upwardly thereby toward the upper outlet of the trunk, but those which are not indefinitely sustainable on the said current will fall back with the tailings before the outlet is reached so that only a certain definite maximum grade size can pass out from the upper outlet, as predetermined by the velocity of the constant air column, it being characteristic of this invention that the classifying trunk is so proportioned that the said column is of sufficient length and velocity as to allow all such undesirable particles to fall back of their own weight before the outlet is reached. After this selection has been fully accomplished, it is only essential that the velocity of the current shall not thereafter be diminished until the outlet has been passed. The proportions of the trunk, and particularly the length thereof, may be varied, according to the kind or quality of the material to be treated, and will have generally and desirably a greater length for materials of lighter specific gravity or in which the tailings and the air-selected particles are very closely related in size and considerable length will ordinarily be the most satisfactory. The proportions of trunk illustrated in the drawings are such as are suitable for material like ordinary talc powder or ground quartz. The velocity of the .air column may be regulated to control the maximum grade size which it is desired shall pass out of the upper outlet for further classification and assortment, the said velocity being the primary controlling factor of the classifying or separating process.

The column of air -with its burden of selected particles, on leaving the upper outlet 2, enters a filtering conduit wherein its velocity is gradually diminished by the continuing filtration of air through the textile material of which the walls of the said conduit are formed. This filtering conduit is arranged in a series of pairs of upright filtering trunks successively connected at top and bottom and supplied with hoppers at 1 their bottom connections. In the first pair,

then-ext pair if filter mg truinrs i:

23, and in commnnicution adi-iering to the inner side of renchii a velocity so diminished the nitration that the maximum Elf- 36 particles which it capable of sustaining and carrying over to somewha' finer grade s r-ze then the 1mm; ium that cussed through the outlet The particles or filtered from the air during falling out the p sage through the tint pair of trunks constitute the first and largest grade size and full or are collected in the hopper 17 disposed at the bottom of the trunks for that purpose and from which withdrawal may be made as inoiciited. in the next pair of filtering trunks. 18 and 19, a similar selecrepeated, a still snniller naxinnun particles being sustainable at the outof tile t "unit if) and of each of the folowing upwurd filtering trunks, and so on, sothet successively liner grades are. collected in the hopper '20 and in the successive hoppers, until the motion of the original uir current has been practically dissipated in a final trur 21, where the finest of the is depoa ted in its hopper The particles filtered on o the air which escapes through I in the several l fil'ering walls trunle l which may cling to the fabric, are disloc .by means of a series of clez'u'iers and fall into the hoppers. 'lhese cleaners are shown in Figs. 1 and as consisting of hoois or rin s 23 embracing each of the filtering trunks and assembled in a supporting frame and mechanically guided and reciprocate t in light rubbin contact with the outside of the textile walls of the trunss. T he drawing illust ates a harness of cords end sheaves operated fron'i a Windlass by which the frame and cleaner rings can be raised {and Lowered either by hand or power, but any suitable method may be employed for this purpose. T he cleaner ring or member 2-3 is former of sufficient width or dinienrion in the direction of its movement to trap 1 him of air between it and the textile well upon uover which it mo es,

and by "he compression of the said air film the ring up the counter pressure acting 1st ind through the fabric which el lect form 0 2 dislodgnient. A. n'eferrtd cleaner apparatu consists of circular or 4 'herwise reciprocating frame 2%, inste the material the walls by inc-ans of :-ounter pressure. butv withoiiit physical contact or wear thereupon.

The relation of the several grade sizes produced by the T'21l)'O"9tleSCllbed =appa' 'atus will and down, tl-icreby dislodging r A L i under tr rials, less than 200 niet-eln and, by virtue of the constant movement: and uniform velocity of the air column and the mode of introduction of the material, as above described, enables such materials to be s pia 'ated into a series of I tinct grades of fineness having uniformity of size then has hitherto been possible with air-flotation apparatus.

I claim as my invention the following 1. In apparatus for grading pulverulent materials, an upright trunk having air-admission 'means at its base, comprising one or more air-diffusing and pressure-equalizing diaphragms, and an outlet for dust-laden ai at its top and being closed against the entrance or escape of air between said diaphragm and air-outlet and being further of uniform crosssectional area and of sufficient length between said diaphragm and outlet to enable a classifying current of air admitted, and rising therein, to assume a constant and uniform velocity within the trunk in combination with means for feeding the material to be graded into the air current, above the said diuphagm, an airliltering conduit connected with the outlet at the top of said trunk for gradually diminishing the velocity of said air current and comprising a series of classifying trunks formed with air-filtering walls and successively connected in tandem relation with each other and with said upper outlet, and receptacles at the ends of said trunks adapted to receive successively smaller grades of the classified material.

2. In apparatus for grading pulverulent material an upright trunk having an air inlet and tailings receptacle at its bottom and an outlet for dust -laden air at its top, and being closed against the entrance or escape of air between said 'air inlet and outlet, and being further of uniform crosssectional area and 0f sutlicient length between said inlet and outlet to enable a classifying current of air introduced and rising therein to assume a constant and uniform velocity within the t unk, in combination with a feeding means comprising a chute closed against the passage of mi air current and mounted to conduct the material to be graded into the interior of said trunk at or above the place therein where the air currentbeoomes constant and uniform a posimaterials, an upright imperforate separating trunk having a tailings hopper and air inlet at its bottom and an upper outlet for dust-laden air and being closed against entrance or escape of air between said inlet I and outlet and being of uniform cross-sectional area between said inlet and outlet, in combination with means for producing an ascending current of constant and uniform velocity through said trunk, comprising a blower pipe, an air chamber in the base of the trunk of relatively large cubical capacity with reference to said pipe, and a foraminous air-difiusing and pressure-equalizing diaphragm, dividing said chamber from the trunk and transmitting the air therefrom upwardly into the trunk, and means, closed against the passage of air currents, for introducing the material to be graded into the path of said upwardly ascending air.

4. In apparatus for grading pulverulent materials, an upright imperforate separating trunk having a tailings hopper chamber in its base and an upper outlet for dustladen air, and being closed against entrance or escape of air between said hopper chamber and upper outlet and being of uniform cross-sectional area between said hopper chamber and outlet, means for producing an ascending current of uniform and constant velocity upwardly within said trunk, comprising an air inlet pipe leading from a suitable fan or blower to the hopper chamber, the latter being of relatively greater diameter than said air inlet pipe, and one or more foraminous air-diffusing and pressure-equalizing diaphragms dividing said trunk from the said hopper chamber and admitting air from said chamber upwardly into and through said trunk, in combination with a filtering conduit connected with the said upper outlet.

In an apparatus for grading pulverulent materials, an upright imperforate separating trunk having an outlet for dustladen air at its top and a tailings hopper at its base, and two or more foraminous diaphragins superposed one above the other and separating said hopper and trunk, said trunk being of uniform cross-sectional area and also closed against the entrance or escape of air between said upper outlet and the said superposed diaphragms and being of sufficient length between said outlet and diaphragms to enable the air rising through the latter to assume a constant and uniform velocity within said trunk, in combination with means for feeding the material to be graded into said trunk above the said superposed diaphragms.

6. In apparatus for grading pulverulent materials, an upright separating trunk, having air admission means at its base and an outlet for dust laden air at its top, and being closed against the entrance or escape of air bet-ween said air admission means and outllet, and being further of uniform crosssectional area between said parts and of sufficient length between said parts to enable a classifying current of air entering therein to assume constant and uniform velocity within the trunk, the said air admission means comprising one or more air-diffusing and pressure-equalizing foraminous dia phragms through which the air issues upwardly into said trunk, in combination with means closed against the entrance or escape of air for feeding the material to be graded into said trunk and a filtering conduit connected with said upper outlet, comprised of a plurality of upright classifying trunks formed with textile filtering walls alternately connected by their tops and bases in tandem relation, and grade receptacles at the junctions of the bases of said trunks.

7. In an apparatus for grading pulverulent materials, a separating trunk having an outlet for dust-laden air at the top and one or more air diffusing and pressure equalizing diaphragms at its base forming a partition between the main part of said trunk and an air inlet chamber, the said trunk above the said chamber and below the upper air outlet being closed against the entrance or escape of air, and the said diaphragm having not more than 20% of its total exposed area constituted of uniformly distributed openings, through which the air passes from said chamber upwardly into the said trunk,

in combination with means for feeding the material to be graded into the main part of said trunk above the said diaphragm therein.

8. In apparatus for grading pulverulent material, an upright separating trunk having an air outlet at its top and an air inlet at its bottom and being of uniform crosssectional area and also closed against the entrance or escape of air between said inlet and outlet, one or more air-diffusing and pressure-equalizing diaphragms disposed across said trunk and dividing the lower part thereof into an air chamber, in combination with a feed chute closed against the passage of air and leading from the exterior of said trunk to approximately the central axis thereof and a power-driven distributer revoluble beneath the delivery of said chute.

9. In apparatus for grading pulverulent material, an upright separating trunk having an air outlet at its top and air inlet at its bottom and being of uniform crossseotional area and closed against escape or entrance of air between said inlet and outlet, one or more air-diffusing and pressureequalizing diaphragms disposed across said trunk, dividing the lower part thereof into an air chamber, and having 20% or less of their total exposed area constituted of air o]oenin; 2;.s, and means for feeding the material to be graded into said trunk above said diaphragm or diaphragms, in combination with an air filtering conduit comprising a series of upright filtering trunks having textile walls and connected in tandem relation with said upper outlet of the trunk and means for the reception of the different grades at the bases of said upright filtering trunks.

10. In apparatus for grading pulverulent material, the combination with an air-filtering trunk, formed with textile walls, of

a cleansing device, for said walls comprising a movable, tubular member, embracing the exterior of said trunk, and provided with one or more orifices directed toward said trunk, means for supplying compressed air to said member, and means for reciprocating the same over, but not in contact with the surface of said walls.

In testimony whereof, I have signed my name to the specification in the presence of two subscribing witnesses.

SIMON COOPER. iVitnesses CLIFFORD H. KLos, H. G. KIMBALL.

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