US593630A - Process of sifting granular material - Google Patents

Description

(NoModel.) 9 Sheets-Sheet 1.

' F. G. WINKLER.

`PROCESS 0F SIFTING GRANULAR MATERIALS.

(No Model.) 9 Sheets-Sheet 2.

- P. G. WINKLER.

PROCESS 0F SIFETINS GRANULAR SMTBRIALS.l No. 593,630. Patented Nov. 16,1897.

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(No Model.) 9 Sheets-Sheet 3.

F. G. WINKLER.

PROCESS 0F SIFTING GRANULAR MATERIALS. No. 593,630. Patented Nov. 16, 1897.

we Nonms PETERS co, PHo'roALrmo.. WASHINGTON, o. c.

9 Sheets-Sheet 4.

(No Model.)

P. G. WINKLER. PROCESS 0F SIPTING GRANULAR MATERIALS. No. 593,630.

Patented Nov. 16,1897.

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(No Model.)

. 9 Sheets-Sheet 5. F. G. WINKLER. PROCESS 0F SIFTING GRANULAR MATERIALS.

No. 593,630. Patented Nov. 16,1897.

/m/J J JJ y 5. mwl/wwwedm www (No Model.) 9 Sheets-Sheet 6.

F. G. WINKLER.

PROCESS 0F SIPTING. GRANULAR MATERIALS. I No, 593,630. Patented Nov. 16,1897.

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F. G. WINKLER.

I. PROCESS 0F SIFTING GRANULAR MATERIALS. No. 593,630. Patented Nov. 1'6, 1897.

hui-- WW1/mono 5 mato@ u mmm Gbtmm dem? MG/r (No Model.) 9 Shets-Sheet 8.

' F. G. WINKLER.

PROCESS 0F SIFTING GRANULAR MATERIALS.

No. 598,630. l Patented Nov. 16, 1897.

(No Model.) v -9 Sheets-Sheet 9.

. I'. G. WINKLER.

PROCESS 0F SIPTING GRANULAR MATERIALS.

No. 593,630. Patented Nov. 16, 1897.

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NITE` STATES I Enron..

PATENT A PROCESS OF SIFTING GRANULAR MATERIAL.

SPECIFICATION forming part of Letters Patent No. 593,630, dated November 16, 1897. Application filed August 14:, 1896. Renewed April 15, 1897. Serial No. 632,345. [No specimens.)

To all whom it may concern: Be. it known that I, FRrEDRIcH GEORG. WINKLER, a subject of. the Emperor of. Ger' `many, and a resident of AJersey City, Hudson county, State of New Jersey, have invented: certain newv and useful Improvements in Processes of Sifting GranularMaterials, ofl which the following is a specification.

This invention relates to a'proc'essof sifting granular material-such as iiour, meal, and other granular materials-through a sieve; and the process essentially consists in subjecting the said granular materials to the action of air-currents inthe following manner: First, the materials within the sieve are subjected: to the action of a long and strong inward aircu'rrent, the volume and distribution of which are accurately controlled and which frees the particles which are adhering to the inside of the sieve therefrom, and also brings large volumes of air into the sieve. Then immediately the materials are subjected to the action of a strong, sharp, and sudden outward current of air, which sifts the finer particles through the sieve. This outward sifting-current is then followed by a long and strong outward after-current, which blows the sifted particles far from the sieve, so that such partieles cannot be brought back by the next inward current.

I have'found that the effective sifting of iiour, meal, and other granularl substances through a sieve or homing-cloth requires that a large volume, of air (much larger, in fact, than that heretofore obtained) shall nbe made to pass both in and out of the sieve'or bolting-cloth, the volumepassing in and that passing out being of course equal, for in order to insure high sifting efficiencies sufficient air must be brought in to provide enough for a Very strong, swift, and sudden sifting impulse and also for a strong and long outward after-current, and if a large quantity of air is not brought in a sufficient supply for such an outward after-current cannot beobtained without taking away some of thev air that is needed for the strong sifting impulse.

. The air-wave must also be of such character th'e 'velocities of the fan.

succeeded at all they have proceeded upon sequent Aoutward currents, and also to clear the inside of the sieve of all particles of the material, and'thereby prepare it for the sucoeeding sifting impulse; second, this inward current must be immediately followed by a strong, swift, and sudden outward sifting-cur` rent, which propels thene particles of the material through the sieve; third, this sifting-current must be immediately followed by -or continued into a prolonged and strong outward after-current t0 project the iueparticles which passed through Vthe sieve` so far away that they cannot be caught by the next inward current. This outward after-current is indispensable, for if the first outward current be immediately followed by the next inward current more or less of the fine material whichhad passed through the sieve' will be carried back through, into, and upon the sieve, greatly reducing the output and'impairing the efciency of the apparatus.

' Itis desirable th at the air-waves which generate theafore'said currents through the sieve shall Abe producedat comparatively low velo'cities of the fan or pulsator, for high velocities-such, for example, as twelve hundred or fteen hundred revolutions per minute-involve an excessive power cost and wear and tear.

The attempts heretofore made to produce a commercial sifting apparatus have been unsuccessful, particularly in respect of the volumeof air passed through the sieve and in respect ofthe character of the air-waves and So far as they have the principle of generating an air-wave that Was intended to subject the material successively to the influence alternately of a relatively strong current of air moving outward through a small area of the sieve and a relatively weak current moving inward through a larger area of the sieve and following immediately upon the outward current; but in practice neither the relatively weak and long inward'curreut nor the relatively short and strong outward current was ever obtained, because an air-cushion was produced between the deflecting-grate and the sieve before the.

real sifting impulse began, which materially impaired the sifting effect. The result also of following up thesifting-current by the inward current, without an intermediate outward after-'current of 'considerable force and volume, was that a considerable part of the ne material that had just been sifted through the sieve was carried back through, into, and upon the sieve, the output greatly reduced, and the action of the/apparatus rendered very uncertain at moderate speed. This has compelled the employment of Very high velocities, with consequent great power cost and wear and tear, and even then the action has been uncertain, and to obtain a large siftingvv effect it has been necessary to employ comparatively long sieves and-correspondingly" long pulsators and other parts. This has also greatly increased the power necessary to drive the machine, as well as the size :an'd'wei'ght of the machine. Such apparatus 'was :also constructed with cells open onlytoward the periphery of the fan but'closedv inwardly and laterally. The consequence-was 'the crowding of the incoming air rand 4genera-tion ofreturn currents which'shortened and then destroyed 'the inward current soon afterfi-t vwas .generated by creating a :gentle outward cury ren'tof the air which formed the :aforesaid 'air-cushion between the deiiecting-.grate :and

sieve long before the intended short 'and -strong outward sifting-current 4began to :act and lessened greatly the volume of fair fand tlrelefiiciency of the machine. These defects forced a resort Ito very highvelocities inthe attempt to develop p'roperinward volume and distribution of the currents; but-theattempt was unsuccessful, because thefdistribution of the air inside of 'the -sieve was ywrong'in principle and could not be'control'led. lheprocess, however, which @is tlresubject of -thefpresenit :application succeeds for `the first iti me in the art Yin the vperfect control both of the' incoming'and the outgoing ai'r -currents #and also in bringing very large volumes of air int-o the machine, Aand -I havebeen enabled-toreduce the power cost both by a materialredu'ction invelocities of revolution/andiabove all by thev great 'reduction of -the I'length of "the sieve,` fan, "and other parts 'of 5the preferred form of y machine by which theprocessvis 'operated. These two facts combined have'refv resulted insolgreat aredu-ction'of thepowen cost and wear and tear that myzpresent invention attains -an Veconomy of operation siftingfeect.

panying drawings, and which consists, essentially, of a sieve and outer defieeting-grate in proximity to the sieve and a plurality of pressure land vacuum -generators independent of each other within the said outer delectinggrate arranged concentrically to each other,

r so that the vacuums are developed in any succession determined upon and are regulated to maintain the inward ycurrent practically up to the instant when the sudden sifting impulse begi-ns to operate. The efficiency of this apparatus for operating lthe process depends upon the facts, iirst, that the machine isy so formed that there are open spaces in the interior which-are connected together laterfally in such lmanner that the `total inward current or volume of vair has `suiiicient room without :generating return currents, which would :greatly reduce the volume of air and impair @the effectof the inward current. Sec- -ond,\that'the wave-'generator contains or is 'combined with a Vplu ral ity of vacuum-making ydevices .arranged concentrically within and 'successively behind Aeach other, so'that the inner vacuum-making devices successively -act uponand increase or maintain Ithe'inward current previouslygenerated almost up .'currentwhi'ch is developed and controlled by :the-'successive vacuums rebounds or deiiects outward with immense velocity'and powerful The intensity and force of this reboundare r,greatly increased by the aforesaid movement of the inner gratings in a direction opposte'to the movement'of the inner pressure-fans,'for the effect of these opposite nrotionsis'that the incoming airis defiected iandfimpelled in a direction opposite to `that oft'h'efanblades lwhich generate the sifting impulse, andthe air'encounters no Aresistance untilitisaetually upon the said fan-blade. The'consequence is 'an extremely powerful 'outward-sifting impulse or current following almostv immediately upon the stoppage of the inwardfcurrent. Third, that thesifting-impulse :generator is succeeded by blades or :groups offans lwhich generate a prolonged fand -strong=outward after-current which projects'thelsifted materialfar from the sieve.

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ling as does the machine shown in Fig. 1.

Fourth, that the wave-generator is so opened on the interior that the devices for said out, ward after-current get their air from the inward current, thereby preventing the crowding of the incoming air and aiding to maintain the inward currents. Fifth, that the air which passes from the inward currentsto the outward after-currents,as aforesaid, sweeps under and keeps the inner surfaces of the 4blades or fans thoroughly clean and prevents the accumulation of fine dust in the interior ofthe wave-generator.

Referring to the drawings which accompany the specification to aid in explaining how the process is operated, Figure 1 is a longitudinal vertical section of vthe preferred form of machine. Fig. 2 is avertical crosssection on a larger scale and on the line 2 2 of Fig. 1. Fig-3 is averticalcross-section, partly broken, on the line 3 3 of Fig. 1 and on the scale of Fig. 2. Fig. 4 is an elevation of the left end of Fig. 1. Fig. 4a is a detail of the preferred device for driving the pulsator.` Fig. 5 is a vertical section, on a large scale, showing the preferred shape and relative positions of the gratings, suction-blocks, and fans. This figure illustrates parts of the same machine that is shownin Fig. 1. Figs. 7, 8,'and 9 are cross-sectional viewsA illustrating modifications in the arrangement of gratings, suction-blocks, and fans, but all arranged to operate the same process of sift- Referring to Figs. 1. to 5, inclusive, A is the bolting-chest, within which-are arrangedy the sieve B, the concentricv gratings C C C2 C3, the vacuum-generators or suction-blocks d cl didi and the fans E E E2. Said sieve B may either revolve or be stationary. The said gratings preferably revolve in the direction of the arrow -1 Fig. 5--7. c., in the direction opposite to the revolution of the sieve B, if said sieve revolves-and the said suction-blocks and fans (which, taken together, I term the pulsators, since they produce the pulsations of the air which Yare instrumental in developing the currents and distribution of the volumes of airthrough the machine whereby the working of the process is effected) preferably revolve at'comparatively high ,velocities in the direction opposite to the revolution of the deflecting-grates. Said sieve B is a cylindrical vreel having its peripheral wall formed of a suitable screen Vor bolting-cloth stretched in any known and usual manner on frames 1 2, Fig. 2. At one end the said frames are. fastened to rims 4, Fig. 1, carried on the ends of radial arms 5 5 of a. circular head 6,` Fig. 3, and the other end of said frame lis fastened to a circular head 7, which is bent and flanged at its outer part, as shown in Fig. 1. Openings 8 S between said arms 5 5 permit the tailings'to pass out` to the discharge-chute WV. A iianged rim 9 on said head 6 revolves with dust-tight fit in a circular groove 10, formedvin the frame in the usual manner, and said head 6 carries a carry the suction-blocks and fans.

lof the outer circle of deiiecting-grates C, howhollow hub 1.1, which turns in boxes 12, carried by the frame. The hollow hub 15 of the head 7, and which is of sufficient diameter to serve as the inlet for the material to be septoo coarse for the mesh of the basket will be retained thereby; Removable plugs 18 19 are provided to give access to said basket.

The aforesaid gratings are preferably arranged in concentric circles C C C2 C3, as shown in Fig. 5. The gra-tes or bars of each circle are arranged in two parts or halves, one part being fastened to vthe head 2O and the other partto the head 21, and, if desired, the number and shape of the bars in the one part may differ from those in the other part. The bars of the outer circle C are each preferably'bent, as shown in cross-section, Fig. 5, to give the air-currents a direction approximately radially outward, and the bars of the inner circles of gratings C' G2 C3 may be either curved, bent, or fiat. circles C C2 C3 extend from their respective heads 20 or 21 nearly to the middle of themachine; but sufficient space is leftbetween the inner ends of said bars to permit of the free revolution ofV the wings 2525, Fig. 2, which ever, extend entirely across from the head 2O to the head 21, and said bars are preferably held in Vframes secured on said heads, as in dicated in Fig. 1.

In the machine illustrated in the drawings all the gratings are of course driven from the same shaft or hub; but each circle of gratings may, ifdesired, be constructed so as to be driven independently of all the others. Referring to-Fig. 1, the hollow hub 27 on head 20 passes through hollow hub "11 and turns in boxes 29, and the hollow hub 30 of'head 21 passes through hollow hub 15, there being a good space between saidhubs 30 and 15, and turns in boxes 32. A spiral conveyer 34 on hub V30 works the materials toward and into the aforesaid basket G.

The aforesaid suction-generators D D D2D3 are preferably formed as blocks d CZ (Z2 d3, which I term suction-blocksand .which are preferably curved on their rear or. suction side, as shown in Fig. 5. Said suction-blocks d d d2 d3 are arranged and fastened inthe following manner on the wings25 25, Figs. 1 and 2, which are iixed on the sleeve 35, that Wings 25 25 are provided withA transversearms 3l, anged at their outer ends, as shown. '0n said arms 3l are fastened the concentric rings 37 38 39 and the center plate 40. Said suction-blocks d d Pds are each made in halves, and said halves are fastened at opposite sides of said wings 25 25, respectively, between said The' bars The bars of said inner IOO IIO4

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vis keyed to the swift-running shaft K: Said I d3 and fans G2 64 revolve inside of the innermost circle of gratings. and 5.)

The aforesaid pressure-fans EE' Ezare fastened to their respective rings 37 3S 39. The outer fans E consist of main blades 45 45, which generate the swift, strong, and sudden sifting impulse in combination with the outer deflecting-grate C, and said main fan-blades are bent forward at a considerable angle from the radius-to effect thepowerful outward rebound of the air-currents, which is a very important factor in generating the desired sudden and powerful outward impulse of the sifting-current, as hereinbefore mentioned. Each ,of `the said main blades 45 is followed by -a group of auxiliary fan-blades, certain of which blades are preferably bent forward at a less angle than the main fan-blades 45. The number of-said auxiliary blades 4S may be increased or diminished according to circumstances, and said auxiliary blades are disposed between the main fans 45 and the advancing side ofthe suction-blocks d. The purpose of said auxiliary blades 4S is to take up the air furnished by the inner fan-blades 55 57 and the front curve 60 of the suctionblock cl3 and deliver it in a strong outward after-current of large volume between said main fan 45 and the advancing face of said suction-block d. Said inner fan-blades 55 57 and curve 60 may each be either used singly, as shown, or be followed or even replaced by groups of fan-blades, as indicated by reference to letter N, Fig. 6. The .air delivered by said fans 55 57 and curved surface 60 to the auxiliary fans 48, and by said fans 48 sent through the sieve as a strong outward after-current of large volume, blows the material which has been sifted by the main outward sifting-current which `was developed by the main fans 45 so far from the sieve that it cannot be caught and brought back by the next inward current. Said fan-blades 55 57 and curved surface G0 (or their corresponding groups of fan-blades) are so shaped and disposed in the machine as to provide the largest possible area for the outflowing air and to offer the least possible resistance thereto. Therefore, as will be observed on (Compare Figs. 1

inspection of the drawings, the passages between the fan-blades are preferably enlarged in the direction of the air-How, and in this manner not only does a large volume of air pass to the point of discharge of and form the outward after-current, but said air also powerfully sweeps the under sides of the fanblades and prevents the accumulation of line particles of material in the interior of the machine.

Suction-blades 62 64, auxiliary to the innermost suction-block d3, may be xed between the center plates 40 in any desired manner, or such auxiliary blades may be omitted and the shape of the block d3 correspondingly changed without affecting materially the re,- sult.

Any suitable drivin g-gear may of course be used, and I prefer the following arrangement: A shaft S0, provided in the usual manner with fast and loose driven pulleys 8l, respectively, carries a cone S4 and driving-pulleys SG. A half-turn belt S8 from said pulley S5 drives a worm 90, which meshes with a worm-gear 01 of the sieve B, thereby imparting a slow rotation to said sieve. A belt 95 from pulley S6 drives a pulley 98, fixed on the hub 27 of the gratings. A cone 100 is driven from cone 84 through the medium of the shiftable endless belt 101, which is equipped with any suitable belt-shipper, and a p ulley 102, fixed on the shaft 103 of said cone 100, drives pulley 105 on the aforesaid swift-running shaft K, on which are fixed, as hereinbefore described, the pulsators, (fans and vacuum -generators.) Thus by `shifting belt 101 the speed of said fans and vacuum-generators may be varied according to the nature of the material without varying the speed of the sieve or the gratings.

The machine operates as follows: The material to be sifted having been fed through the chute X works into the basket G, and falling from thence is worked by the spiral blade 75 into the annular space between the deflectinggrate and sieve. Now the long andstrong inward air-cu rrent clears the sieve of adhering particles of the material and brings a large volume of air into the machine. A certain proportion of this air is crowded upon and rebounds powerfully outward from the main fan-blades 45, developing a very strong, swift, and sudden outward current, which sifts the finer particles of the material through the sieve. The remaining part of the in brought air iows freely into the interior of the machine, as described, and to the auxiliary fans 48, between the said main sifting-fans 45 and the front side of suctionblocks d, and is here expelled as a long and strong outward after-current, blowing the sifted particles far from the sieve. Then follows the next inward current, and so the cycle repeats itself continuously all around the sieve. The aforesaid inward and outward currents may be considered to be due to the crests of high pressure and the hollows of low pressure of an air-wave of peculiar nature, which is produced by my apparatus and propelled around the sieve, a wave which I believe to be essentially unlike any heretofore generated in sifting-machines.

As hereinbefore stated, the process which ICO IIO

is the subject of my present application-is not limited to any'particular form of apparatus, and the apparatus herein shown and described are only used as illustrations of good forms of machines for operating the process. Said machines are not herein claimed,but are severally the subject of claims in other of\my applications for patents of the United States.

and N inner blades which cooperate with the `grating J2 to deliver the air to the said auxiliary fans M. O O2 are auxiliary suctionblades xed on the heads which carry the blocks F F2. The airburrents generated by this machine agree in their general character with those generated by the machine illustrated in Figs. `1 to 5 and operate the same process of sifting.

In the machine shown in Fig. 7 I employ` l only one set of suction-blocks F3 and one defleeting-grate J3. L is thev main fan; M', the auxiliary fans for aiding in generating the outward after-current, as hereinbefore described. P P are blades revolving in the same direction as the deilecting-grate J 3 and either driven from the same hub or separately, as desired. I now prolong the suction-blocks F2 backwardly by plates f3, as shown, whereby I increase and prolong the inward current, and in cooperation with said blades P P prevent the injurious action of the return currents hereinbefore referred to.

The machine shown in Fig. 8 is analogous to that shown in Fig. 7 but I now replace the blades P by the grating P, which revolves in the same direction as deiiectin'g-grate J3 and may be driven from the same hub or separately, as desired, and the bars of said grating P may be wider than shown in any desired degree. Both these machines generate substantially the same air-wave as the machine shown in Figs. 1 to 5 and operate the same process. l

Fig. 9 illustrates a cross-section of the preferred machine, whereinA the arrangement of pulsators is in general similar t-o that of'Fig. 5. It differs, however, from the lastenamed machine in two respects. First, the suctionblocks d6 dl d8 019 are lengthened out, as shown, to effect the control of the volume and distribution of the air referred to above, and, second, the center of the machine is open between the inner suction-block and the hub, with only a single grating between said suction-block and hub. The opening in the center was also shown in Fig. 8, and the machines of Figs. 8 and 9 both demonstrate the fact that the use of pockets or cells open only toward the periphery, but closed toward the center, which were an essential characteristic of all machines that have been heretofore known as wave-generators, is not essential in Vmy new machines.

Thus comparison of Figs. 5 to 9, inclusive, proves that my process is, as before stated, independent of any special machine and depends upon the generation in any manner of suitable air-currents and the subjecting to such currents of the materials to be sifted in the manner hereinbefore described. In each of said figures I have indicated the direction of the air-currents and approximately their strength by arrows on'one-half the figures. The distribution of the aircurrents is the same on the other half of the figures, but the arrows are there omitted to permit clear representation of the parts of the machines.

Now, having described my improvements, I claim as my invention- The process of sifting granular materials hereinbefore described, consisting in first clearing the sieve by long and strong inward currents of air of large volume, then propelling a part of this air in a strong, swift and sudden blast outward through the sieve, whereby the finer particles of the material are sifted through the sieve, and following this blast with a long and strong outward Lafter-current'of the remainder of the air whereby the sifted particles 'are blown far from the sieve and out of reach of the next inward curf rent, and causing said several currents to travel successively over all parts of the sieve.

In testimony that I claim the foregoing as my invention I have signed my name, in presence of two witnesses, this 12th day of August, 1896.

FRIEDRICH GEORG WINKLER.

Witnesses: A BERNARD J. IsEcxE, HENRY V. BRowN.

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