US1385674A - Method and apparatus for treating pulverized material - Google Patents

Description

G. H. FRASER. METHOD AND APPARATUS FOR TREATING PULVERIZED MATERIAL.

I918- Patented July APPLICATION FILED SEPT.25 I912. RENEWED AUG. 1,385,67.

.1 In I I I w S m I WITNESSES:

UNITED STATES PATENT OFFICE.-

GEORGE HOLT FRASER, OF BROOKLYN, NEW YORK.

METHOD AND APPARATUS FOR TREATING PULVERIZED MATERIAL.

1,385,674. Application filed September 25, 1912,

To all whom it may concern:

Be it known that I, Gnoner. HOLT FRAsER, a citizen of the United States, residing in the borough of Brooklyn, county of Kings, city and btate of New York, United States of America, have invented certain new an useful Improvements in Methods and Apparatus for Treating which the following is a specification.

This invention relates to means for treating finely divided material, or mixtures of various pulverized substances, and to grinding, screening and mixing the same, and aims to provide improved methods for such treatment, and improved means especially applicable to carrying out the improved methods provided.

Heretofore it has been common to pul verize mixed materials of different physical characteristics or difierent specific gravity, to grade the material according to size so that material too large for pulverizlng should be separated from that to be fed to the pulverizer, and that sufficiently pulverized should be separated for subsequent treatment. Ordinarily a coarse screen or grizzly is used to remove the coarsest material, and a fine screen or air separator is used to extract the powder, the intermediatematerial being returned to the pulverizer for further screening. The coarse screen is used to prevent the coarser material from wearing the finer separator, and its product ma be mixed with the reject of the latter for return to the pulverizer after the fine sep arator has operated on the material.

The coarse material or mixture is supplied from a bin or suitable source, and the fine material is removed as made to a bin or suitable discharge. The various successive operations are effected by suitable apparatus arranged in the desired order and connected by any usual means for delivering from one to another.

In such operations difficulties have arisen from the liability of the mixture to change in proportions at different times, especially when one ingredient is lighter than another or of different physical characteristics. This changing of the relative percentages of the different materials in the mixture affects the chemical qualities of the mass, and. where subsequent chemical treatment is required it is very disadvantageous.

In pulverizing, difficulty sometimes results from the liability of material of intermedi Specification of Letters Patent.

Pulverized Material, of

Patented July 26-, 1921.

Serial No. 722,233. Renewed August 15, 1918. Serial No. 250,079.

ate fineness occurring in irregular quantitles, and variations 1n the proportions of coarse material and intermediate material injuriously affect the operation of the apparatus, as well as causing variations in the proportions of the mixture.

This invention aims to provide a method whereby material can be pulverized Without materially altering the character of the mixture, whereby pulverization' can be effected with great uniformity, and whereby the operation of pulverizing material may be automatically regulated by the material being treated. I

t also aims to provide improved apparatus for pulverizing, separating and treating finely divided material or mixtures.

To this end in carrying out the preferred form of the improved process, the pulverized material is withdrawn from treatment as finished in quantitiescorresponding with the quantities of fresh material introduced for terial, and the intermediate material present regulates the entrance of fresh material. The effect of this is that the quantity of material being treated is maintained so uniformly that substantially the same conditions prevail throughout treatment, and its treatment must be completed before additional material can enter, thus precluding important changes in the percentages of the-materials constituting the mixture, since the charge under treatment must be disposed of before additional material can be treated,

while the materialas finished is continuously withdrawn and is continuously replaced by the automatic control of the fresh supply. I

Where the is effected by a fluid current or air separator and the materials differ greatly in specific gravity, this precaution againstchanging of the mixture is especially important, as in separation of finished material pulverizer,

such instances the air separation would tend to remove the lighter material from the heavier regardless of fineness, in case a continuing supply of material were available before all of the material present had been pulverized.

This invention also provides improved means for carrying out the improved process, which means preferably comprise a pulverizer, a coarse screen, a fine separator, a supply bin, an elevator, and means connecting these parts in succession to effect the desired results.

In the accompanying drawings Figure 1 shows the preferred utilization of the im-' proved process, and. the preferred embodiment of the improved apparatus, and is a vertical axial section of a. pulverizing, screening, separating, feeding and discharging system especially applicable for carrying out these lmprovements, the view being cut approximately on the line 1-1 of F i s. 2 and 3 and looking in the direction of t e arrows; Fig. 2 is a fragmentary vertical section thereof cut at right angles to Fig. 1 approximately on the line2-2 of Fig. 3 and looking in the direction of the arrows, and Fig. 3 is a fragmentary horizontal section thereof cut approximately on the line 33 of Fig. 2 and looking in the direction of the arrows.

ReferringBto the drawing, A indicates a v a drive pulley therefor, G the grinding chamber thereof, l) the outlet coilduitthereof, E the inlet conduit thereof, F a coarse screen, (Jr its tailings spout, H an air separator, I its tailings s out, J its fine chamber, K its fine spout, the fine discharge, M the coarse rock supply or feed bin, N the feed hopper, O the feedregulating or controlling chamber, P the elevator or other means communicating between the parts 0 and E, and Q the supply regulator.

The parts of the device shown may be of any suitable or usual construction and connected in any desired order or manner, but it is preferred to use a pulverizer of the ring and roll type in which the material is centrifugally carried by the ring and free to discharge therefrom regardless of the fineness of the material, and to drive the pulverizer from a suitable source of power, and to drive the other parts from the pulverizer, connecting the parts in succession so that the operation of all will be coincident.

As shown, the coarse screen or grizzly immediately succeeds the pulverizer, and is disposed below the latter to receive the discharge therefrom, having a revolving distributing disk R on which this discharge falls and by which it is thrown centrifugally to the outer upper edge of the screen, which is a vlbratorynon-rotative member.

It is preferable to construct the screen in the shape of an inverted cone elastically suspended from above by. a spring S, so that it may descend under load or shock and will rise when released, and its upward movement will be suddenly arrested to give it a vibration or upward bumpto jar material out of its meshes. A'lever or arm T hinged to the casing a above the screen and in the path of a projection on the disk R serves to depress the screen when struck by the, disk, thus vibrating the screen.

Preferably the screen is provided with swinging or spring strikers U shown'as both extending toward the shaft ,of the disk R and movable into the path of swinging hammers W thereon, so that they will be struck thereby when the screen is depressed to agitate it for cleaning.

The screen F is preferably extended within and discharges its fines onto the inner face of a revolving distributer X, which is preferably an inverted cone mounted on and revolving with the shaft V, and having an outlet surroundingand spaced apart from the outlet of the screen F. The distributer X revolves with sufficient speed to raise and distribute over its upper edgethe material fine enough to pass the screen F, which material is thrown against a deflector Y, from which it falls onto the receiving cone Z of the air separator, crossing Lthe outlet thereof, so that the outflowing air current can blow the powdered material of desired fineness out of the falling material and into the settling chamber J of the air separator, the air from which returns within the apron .7), over the tailings cone 0, through the outlet 01 of the receiving cone, to the blades 6 of the blower 7, which latter is a conical wall surrounding the cone distributer X and revolving therewith, and having radial blades between its inner face and the adjacent face of the distributer. The receiving cone Z is yieldingly supported by springs 9 so that it can be depressed until it are brought into the path of revolving strikers i to jar it.

The t'ailings cone 0 communicates with the cylindrical upper end of the spout I, which end surrounds and is concentric of the coarse spout G, which latter receives the coarse material from the coarse screen F. The distributer X has bottom outlets j for. any material failing to rise in that this material may drop through the bottom of the distributer and into the receiving coneZ and flow through the bottom out-' let 03 thereof to the spout I. All material too large to be floated slides down the receiving cone Z and escapes through its outlet to the spout I.

The spout G discharges above and preferably vertically down through the material being discharged from the spout I, which latter discharges laterally into the regulatg'ch m er 0. If. i d sired to use the its inner projections the distributer, so

"material flowing through the spout I, in-

stead of to further grind it, the door is in the bottom of this spout is turned up so as to let the material in the spout I escape through the chute Z, but if this material is to be reground, this door is closed as shown'and the material enters the regulating chamber with the coarse material from the spout G.

The regulating chamber 0 discharges its material through a bottom outlet m to the boot of the elevator P, which raises the material to the feed inlet E, so that there is an past a gate n and endless circuit communicating through the pulverizer, the screen, elevator back to the pulverizer, through which the coarse reject from the screen and the intermediate reject from the separator may be continuallyre-fed to the pulverizer, so that this material will be. reground.

The fine material settling in the dust chamber J flows into its spout K and escapes therefrom to the fine bin L.

The fresh feed from the chamber M flows a rock crusher or crushing roll 0 to the feed chamber N, from W'hlCll it passes through outlets p to the regulating chamber 0. These outlets preferably have adjustable lips 9 within the chamber 0 which extend inwardly, so that the angle from the top of the outlet 79 to the edge of the lip or shelf 9 is adjustable to control flow of the material escaping from the feed bin. The feed bin surrounds one or more sides of the regulating bin and has several outlets thereto, preferably one on each of two sides, for example as shown in the drawmgs wherein the chamber or bin 0 is shown as a vertically extending pipe or tubulanmember having an imperforate Wall opposlte each outlet p from the fresh feed hopper N, the openings ;0 entering the bin 0 laterally intermediate of its bottom outlet m and its upper super osed fine and coarse tailings inlets I and Theregulating bin is similar to a vertical conduit or chute, and its inlet for intermedlate and coarse material is above the inlets for fresh material, and its outlet is below these inlets. The intermediate material falls into the regulating chamber, and if it is not removed through the outlet therefrom by the elevator as rapidly as it enters, it fills up this chamber until it rises above the outlets p of the feed bin, whereupon the intermediate material in front of these outlets arrests flow of fresh material from the feed bin, WlllCll it does by closing the outlets therefrom. The removal of the intermediate material below these outlets permits this fiow to automatically occur until it has sufii-i ciently filled the regulating chamber to again prevent inflow thereto. The removal of material by the elevator through the outlet from the regulating chamber progresses uniformly, and so long as there s any material the separator, and thebin, and vice versa.

mum necessary to control fresh feed will continue to be carried through the circuitof the system until it is pulverized before additional fresh material can enter.

In this manner it is assured that the charge of material being treated will be finished before more material can enter, and the excessive removal of a lighter ingredient from the mixture by the air separator will be precluded, since the heavier ingredients left in the system will prevent infeed of fresh material until the air separator has removed a' sufficient quantity to permit the infeed of fresh material to automatically resume.

Should the escape of uninterrupted, the entrance of fresh material .can be automatically controlled by the arrangement described, but it is preferred to further insure that the fresh material supplied to the system shall accord with the removal of finished material therefrom. This preferably is accomplished by utilizing the weight of fine material removed to control the supply of fresh material to the feed I As shown, the'finished material spout K discharges into a Weighing bucket 1 through agate which is controlled by a weighing device t, and this finished material be bucket and gate are connected by a lever u with a gate w and a bucket w for the feed bin, which are controlled by a weighing device y. The bucket 03 is shown assupported from its weighing device by the tri catch .2, so that the gate to is open and fres material for the feed bin is entering the bucket w. "When the desired quantity has entered the bucket its weight tilts the beam until the trip catch releases, whereupon the bucket rapidly falls, lowering the gate w to prevent further infeed of fresh material, tilting the lever u to raise the bucket 1' and open the gate 8 until its trip catch 2 engages and supports this bucket, the bucket m dumping and the bucket 1' closing. all according to any well known method of automatic weighing, of which the parts illustrated are intended to be diagrammatic representations. bucket x will discharge its weight load of fresh feed into the feed bin N and the bucket 1' will collect an equal load of finished material from the spout K, after. which the operation will be reversed, the bucket 1- dumping its load into the fine bin L and closing the fine outlet and restoring the bucket m and opening the feed outlet.

As shown, the elevator is driven from the pulverizer by a belt a, and the distributer attained to for the coarse screen and blower for the air separator, as Well as the feeder for the fresh rock, are driven by a belt b therefrom, so that all movable parts of the system coincide with the pulverizer in operation, thus insuring stoppage of all in case of stoppage of the pulverizer, which prevents undue accumulation in any part of the system.

In this manner an automatic mechanical uniformity prevent variations in operating conditions and minimize resulting changes.

Ia operating according to my improved process, one or several grades of the treated material, or of the material in process of treatment, will be utilized to control the feed of other grades of material or of fresh material, according to the requirements of the particular process or conditions of use. The coarser material being projected through the intermediate material, will ma-v terially reduce the tendency of the material to segregate according to size within the regulating chamber. The control of flow of the fresh or coarse material by the intermediate material will insure precedence to e the latter in treatment, and greatly diminish kept from clogging,

i tion,

tendency to variations in the percentage of ingredients in the mixture if a mixed material is being treated.

In using my improved apparatus the circular or conical vibrator movably and yieldingly mounted in the screen'wlllbe easily and being nested or positioned within the conical redistributing disk, will occupy comparatively little space, and the distributing disk being likewise nested within the receiving cone of the air separator, and the blower of the latter bemg disposed in conical arrangement between the distributing cone and the receiving cone, will further minimize the space required for these several parts. The revolving striker in conjunction with the yielding and movably mounted receiving cone, will aid in keeping the cone clean, thus reducing the steepness necessary therefor.

It will be seen that this invention provides improvements in processes of treating materials which can be variously arid advantageously availed of in whole or in 'part, and it will be understood that the invention is not limited to the particular details of arrangement, application or use set forthas constituting its preferred adaptation, since it can be employed in whole or in part according to such modifications and in connection with such devices as circumstances or the-judgment of those skilled in the art may dictate, without departing from the spirit of the invention; and it will also be understood that the improvements in apparatus this invention provides are not lim-- ited to the particular details of construcarrangement and combination set forth of supply and removal may be.

as constituting the preferred form thereof,, since these improvements may be used in whole or in part according to such modifications as circumstances or the judgment of those skilled in the art may dictate, without departing from the spirit of the invention. v v

For example in practising the improved process it is not essential that the screen be either beneath or directly following the pulverizer, as any suitable means for communicating between the parts in any desired successive stage .may be employed.

While these improvements in apparatus include in their preferred form screens and separators located next following the pulverizer, and circular or conical devices nested within one another for compactness, and having annular communicating ducts and contracting annular outlets, it will be understood that it is not essential that these be used in practising parts of the invention, since the elements may be individualized and connected in any suitable arrangement, or any suitable grizzlies or separators may be employed, if desired.

VVlule. the regulating ho per or bin is shown as disposed below al the parts and as feeding from its bottom to the mill through the medium of the elevator, and the plurality of hoppers or bins for different grades of material to be fed are shown as beneath the mill, and the feed bin as sur-' rounding the regulating bin, instead of these parts being above the mill and the regulatmg bin discharging directly into the latter, it will be understood that the arrangement shown is not essential, being preferred for compactness and convenience of access, and that the plurality of bins may be located as desired, and the connections correspondingly arranged to dispose them in any manner so that fee-d to the pulverizer may be controlled by any of the .several grades of material which it is desired shall govern the operation, the bins and theirinlets and out- I lets being constructed and connected in proper manner to enable the grade of material whichis to have precedence to interrupt or control the inflow of the other grade or grades.

What I claim is 1. The improved process of reducing material which consists in subjecting it to a crushing treatment, removing the material of the desired fineness as formed, separating the coarser material, again subjecting the separated material to crushing treatment, and utilizingthe weight of such separated material to control entrance of fresh mate- '125 rial to the mass.

2. The improved process of reducing material which consists in subjecting it to crushutilizing the weight of the removed material to control entrance of fresh material to the mass.

3. In apparatus for grinding materials, a pulverizer, a separator, passages for fines, intermediate and coarse materials in communication with said parts, means operated by the weight of the fine material removed from said separator, means measuring the fresh material supplied to said pulverizer, and means controlled by said weight operated means and controlling the supply of freshmaterial to said separator.

' 4. In combination, means affording an endless path for material, means for returning coarse material to said path by gravity comprising a downwardly extending gravity chute or passage having an upper inlet and a confined downwardly extending chamber for such material and having a lower outlet, and having a lateral inlet in the side of said chamber for fresh material intermediate of said upper inlet and said lower outlet, and means for feeding by gravity fresh material to said path through said lateral inlet to 'said chamber laterally of the direction of flow of said coarse material therein.

5. In combination, means affording an endless path for material, means for feeding fresh material to said path, and means for returning coarse material to said path comprising a passage or chute having an upper inlet and a lower outlet in vertical alinement and having intermediate thereof a down wardly extending'chamber between and in vertical alinement with said inlet and said outlet having a lateral inlet between said upper inlet and said lower outlet, and a gravity chute communicating with said fresh feeding means and discharging through said lateral inlet into said chamber.

6. In combination, means affording an endless path for material, means for feeding fresh material to said path, and means for returning coarse material to said path comprising a tubular member or spout having a lower outlet and having an upper inlet for said coarse material spaced above said outlet, and having intermediate of said'lower outlet an upper inlet, a lateral gravity inlet communicating with said fresh feeding means, and having a wall opposite said lateral inlet forsustaining material descending through said member from said upper inlet against inflowof freshfeed through said lateral inlet.

7. In combination, means for feeding different grades of material comprising a downwardly extending chamber or chute having an upper inlet for material of one grade, a lower outlet, and intermediate thereof a confined chamber and a lateral inlet for another grade of material, and a second chute or member at theside of and communicating with the lateral inlet of said downwardly extendin chute for feeding another grade of material laterally into the latter.

'8. In'combination, means for feeding material comprising a chamber or chute having a downwardly extending tubular portion having an upper inlet, a lower outlet, and having a downwardly extending chamber between said inlet and said outlet, and hava lateral inlet to said chamber below said upper inlet and above said lower outlet, a gravity chute communicating with said lateral'inlet, and means for adjusting said lateral inlet to regulate flow through the latter.

9. In combination, means for producing pulverized material affording an endless circuit or path for material to be pulverized andcomprising means having a vertically extending crushing chamber affording a complementary portion of such path constituting a downward way for such material and having a lower outlet, an air separator below and successive to said chamber and having a downwardly extending chamber affording a successive complementary portion of such path and a downward way for such material, and having means surrounding such way for freeing such material of fines, an elevator affording a complementary part of said path and having a lower inlet below and communicating with the outlet of such air separator for such material for receiving and elevating such material, and having. an upper outlet above and communicating with such crushing chamber for delivering such material thereto, .and means for operating said parts in correlation, and means for supplying material to be pulverized to such circuit.

,10. In combination, means for producing pulverized material affording an endless circuit or path for material to be pulverized and comprising means having a vertically extending, crushing chamber affording a complementary portion of such path censtr tuting a downward way for such material and having a loweroutlet, an air separator below and successive to said chamber and having a downwardly extending chamber affording a successive complementary portion of such path and a downward way for such material, and having means surrounding such way-for freeing such material of fines, an elevator affording a complementary part of said path and having a lower inlet below and communicating with the outlet of such air separator for such material for re ceiving and elevating such material, and having an upper outlet above and communicating with such crushing chamber for delivering such material thereto, means for operating said parts in correlat1on, and

. complementary portion of such path constituting tutin a downward way for such material and Iiaving a lower outlet, a separator below and successive to said chamber and havin a downwardly extending chamber affordlng a successive complementary portion of such path and a downward way for' such material, and having means surrounding. such way .for freeing such material of fines, an elevator affording a complementary part of said path and having a lower inlet below and communicating with the outlet of such air separator for such material for receiving and elevating such material, and having an upper outlet above and communicating with such crushing chamber for delivering such material thereto, means for operating said parts in correlation, and means for supplying material to be pulverized to such circuit as fines are separated from said separator.

12. In combination, means for producing pulverized material affording an endless circuit or path for material to be pulverized and comprising means having a vertically extending crushing chamber affording a complementary portion of such path constia ,downward way for such material and having a lower outlet, a separator below and successive to said chamber and having a downwardly extending chamber affording a successive complementary portion of such path and a downward way for such material,

and having means surrounding such way for freeing such material of fines, an elevator affordlng a complementary part of said path and having a lower inlet below and communicating with the outlet of such separator for such material for receiving and elevating such material, and having an upper outlet above and communicating with such crushlng chamber for delivering such material thereto, means for operating said parts in correlation, and means for supplying material to be pulverized to said circuit in like quantity of fines separated from said circuit. 13. In combination, means for producin pulverized material comprisin means a fording an endless path afl'or 'ng an inlet for material to be pulverized and an outlet for pulverized material and comprising means having a chamber affording a complementary portion of said ath and constitutmg a way for material in said path, means for causing materialuto .circulate through said ath, means for withdrawing fine material fgom said path, means for progressing the residue of partially pulverized.

for material in said path, means for causing material to circulate through said path, means for withdrawing fine material from said path, means for progressing a residue of coarse material in said path past said inlet, means for supplying through said inlet additional pulverulent material, and

means for causing such residue material in said ath to control inflow through said inlet of such additional material. f

15. In combination, meansafl'ording an endless path for pulverulent material afmaterial fording an inlet and an outlet and comprismg conveying means having a chamber at fording a complementary portion of said a path and constituting a way for such material in said path, means for causing material to circulate through such path, means for withdrawing from said path a portion of such material circulating through said path, means for progressing in said path the residue of such material therein past said inlet, means for supplying through said inlet additional means for causing such residue material in said path to control inflow through said inlet of such additional material.

16. Incombination, means affording an endless path for pulverulent material affording an inlet and an outlet and comprlsing elevating means having a vertically extending chamber affording a complementary path and constituting a way portion of said for such materlal in said path, means for causing material to circulate through said path, means for withdrawing through said material to said path, and

outlet a portion of such material from said path, means for progressing the residue of such materialinsaid path ast said inlet, means for supplying throug said inlet additional materialto said path, and means for causing such residue material in said through said inlet mg chamber afl'ording a complementary portlo-n of said path and constituting a way for material in said path, means for causing material to circulate through saidpath, means for separating fine material from such material-in said path, means affording an outlet for fine material from said path, means in said path between said crushing chamber and elevator affording an inlet to said path for additional material, means for progressing such residue of material in said path ast,,said inlet, means for supplying throng said inlet additional material to said path, and means for causingsuch residue material in said path to control inflow through said inlet of, such additional materiaL' a 18. In combination, means .for separating fine material comprising means afiording an endless path for pulverulent material to be separated and comprisinga separator having a separating chamber affording a complementary portion of said path and constituting a way for such material in said path,

velevating means for elevating material 1n said path comprising a vertically extending chamber affording a complementary portion of said path and constituting a way for such material in said p'ath, means for causing such material to circulate through said path, means afl'ording an outlet for fine material from said path communicating with said path between said separatorand said elevator for'withdrawing from said path fine material separated from the material in said path, means afi'ording an inlet to said path between said elevator and said separator, means for progressing the residue of such material in said path past said inlet, means for supplying to said path through said inlet additional pulverulent material, and means for causing such residue material .in said path to control inflow through said inlet of such additional material.

19. In combination, means affording an endless path affording an inlet for pulverulent material and an outlet for fine material and comprising elevating means having a chamber affording a complementary portion of said path and constituting a vertically extending way for such material in said path, separating means for separating material from the material in said path having a downwardly extending chamber affording a complementary portion of said path and constituting a gravity way for downward flow of materialnin said path, means for progressing the residue of matefrom such material in mi ,pulverulent material to rial in said path by gravity past said inlet for controlling inflow through said inlet, and means for introducing additional material into said path by gravity through said inlet. I

20. In combination, means aflording an endless path for pulverulent material and comprising elevating means for elevating such material having a vertically extending chamber affording a complementary portion of-said path and constituting an upward way for such material in said path, separating means for separating coarse material path having a chamber affording a complementary portlon of said path and constituting a gravity way for material said elevating means and said separating means affording a conduit for coarse material afl'ording a complementary portion of said path, means for withdrawin from said path the residue of such materlal in said path through said outlet, means for progressing suchcoarse material in said path ast said inlet, means for introducing into said path through said inlet additional material, and means for causing such coarse material in said path to control inflow through said inlet of such additional material. 21. In combination, a separator for separating fine material from ulverulent material having an inlet and aving an outlet for fine material and an outlet-for coarser material, an elevator communicating between said latter outlet and said inlet for raising coarser material discharged through said latter outlet and returning it to said inlet, and means for feeding additional pulverulent material to be separated to said separator controlled by the material discharged through said outlet f or coarser material. L

22. In'combination, a separator for separating fine material from pulverulent material having an inlet and having an outlet for discharging fine material and an outlet for coarser material, and means. for feeding be separated to said separator controlled by the fine material discharged through said outlet for fine material.

In witness whereof, I have hereunto signed my name in the presence of two subscribing wltnesses.

, GEORGE HOLT FRASER. 1 Witnesses: 4 v

FRED WHITE THOMAS F. WALLACE.

in said path, means between

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