US1498318A - Apparatus for the production of powdered material - Google Patents

Description

c. A. BULKELEY APPARATUS FOR THE PRODUCTION OF POWERED MATERIAL June 17 1924.

Original Filed Dec. 9, 1919 Patented June 1,7,1924.

snare HST'EV CLAUDE A. BULKELEY, OF WILMINGTON, DELAWARE, A$SI GNOBTQ E. I. DU FONT DE nnnronns & comrANY, or WILMINGTON, DELAWARE, A co WARE.

arraaarus non rnn rnonnc'rron or rownnnni) Mara @BATION F DELA- Applicationv filed December 9, 1919, Serial No. 343,467. Renewed November 22, 1923.

To all whom it may concern:

Be it known that l, CLAUDE A. BULKE- LEY, a citizen of the United States, and a resident of \Vilmington, inthe county of New Castle and State of Delaware, have mvented a certain new and useful Apparatus for the Production of Powdered Material,

of which the following is a specification.

This invention relates to apparatus for the production of finely powdered material, and since the illustrated apparatus finds particular application in the art of produc ing bronze powder, although it is not restricted thereto, 1 describe it with more particular reference to that art.

In the making of bronze powder by hammering the metal to reduce it to small particles it is important that the finished fine powder be accurately separated from the unfinished larger particles, otherwise the powder will have its quality impaired by the presence of particles too large to be properly included therein. Also, it is important that when any particles have been reduced. to desired slze they be removed from the action of the reducing machine, otherwise suc particles ing their brilliancy, instead of remaining fiat, flake-like and brilliant. Various "apparatus have heretofore been proposed for the grinding and separation of certain materials but such apparatus are not well adapted to the production of bronze powder, for they do not separate the particles with suffic ent accuracy, and

have not suitable provisions for avoiding over-treatment. For example, it has been proposed to assemble together agrinding machine discharging into a hopper below terial leave the machine after it should and so is over-treated, but also much material leaves before it should and so -has"-to be rehandled and returned to the machine. Another difficult is that since the screen i screen.

become 1 over-' treated, thereby becoming granular and los-' is in the separator and an operative part thereof, it is subjected to forces tending to forcibly drive the particles through the screen, e. g., forces causing the separation, whereby the accuracy of the screening is destroyed, resulting in the presence in the supposedly fine powder of a large number of coarse particles driven through the Moreover, the screen of the apparatus, being stationary, has not that high degree of ability to screen the powdered material accurately which it is desirable to have present in a screening device used for screening bronze powder. I havedevised an apparatus by the use of which bronze powder of desired fineness and uniformity, and having its particles flat, flake-like and brilliant, can be conveniently produced.

An object-"of my invention isto provide" an apparatus for the production of pow-. dered material which apparatus shall provide for the removal of the material from the reducing machine upon the material reaching the desired degree of fineness, thereby avoiding over-treatment, and also provide for the accurate separation of the finished material from the unfinished.

To this end, and also to improve gener Figure 2 is a sectional view of the reducing machine included in the apparatus illustrated in Figure 1;

=Figure 3 is substantially a longitudinal sectional view of the rotary screen and adjacent parts, included in the apparatus illus- -tra ted 1n Figure 1, and

Figure 4 is a cross-sectional view substantially on the line. 4- of Figure 3, but with the partition wall of the casing omitted.

Referring now to the drawings, the illustrated apparatus comprises'a reducing machine 1, in the character of a stamping mill, acyclone separator 2, a rotary, horizontal, poly onal' screen 3, and a fan or blower 4. in air tight system of pipes 5, 6 and 7 provides for circulation of air from the mill 1, through the fan 4, to the separator 2, and back to the mill. A pipe 8 is provided for conducting to the rotary screen through the meshes of the screen; a pipe .tion -may be selectedfor each, independ till 10 returns unfinished material from the discharge end of' the screen to the ma chine, and the pipe 11, connected with the' pipe 10, return's'to themachine such mate rial as may by chance fail to enter, or to remain in, the entrance end of the screen. The machine, fan and screen are driven from any suitable source or sources of power (not shown), the drives. being independently controllable, as by changing the pulley sizes, so that the desired speed of operaentlyoi the others,

In the operation of the apparatus, coarse bronze powder is supplied at intervals to the hopper 12 on an extension 10* of the pipe 10 and is reduced by series of hammers as 13 and 1d. The particles as they become suficiently reduced, are carried up the pipe 5' by the air current, separated from the air by the separator, and discharged into the screen; the air returning from the separator to the machine through the pipe 7. Finishcdpowder is discharged from the screen through the piped), unfinished material is discharged through the pipe 10 back to the machine, and spilled material is discharged through the pipes 11 and 10,

back to the machine, Thus the action is continuous, coarse material being sup lied as required to the hopper 12 and finished material removed at the lower end of the pipe-9.

1 As shown more particularly in Figure 2, the pipes 5 and 7 communicate with the reducing chamber 15 of the. machine 1 above the anv'ils 16, 16, whereby the material being reduced is not directly discharged into the pipe 5, that is, is not discharged by gravity, for example, and the air entering at the pipe 7 does not blow up throughthe charge C, but, instead, blows over it. With this arrangement, with the hammers, as 13 and 1d, keeping the charge in a constant state of agitation the smaller .parti cles float in the air current. The strength of the air current is so regulated that these finer lighter particles are carried upward to the screen, while the coarser heavier particles are left behind for further treatment, and an initial separation of the particles is made. The finer particles are removed from the machine as soon as they are suficiently reduced and therefore are not subjected to over-treatment that would tend to render them granularinstead of fiat, fiakelilre and brilliant For practical reasons, It prefer not to attempt to make the separation at the reducing machine absolutely enact, but, rather, use an air current sntliciently strong to carry away ea ers a certain amount ofslightly' oversize particles, and I make the final separat on at the screen 3.

As previously pointed out the screen is separate and distinct from the cycloneseparator 2. With the screen thus separate and distinct from the separator, there is no forcible driving of oversize particles through the screen-an action that would of course introduce inaccuracies into the screening. Also, by having the screen separate from the separator 11 am able to use as fine and delicate a screen as l desire, not having to considerwhat might be the efi'ect on such a screen were it to be placed in the separator to be subjected to swirling particles and so forth. Again, by having thescreen separate from the separator 11 am enabled to use a rotary screen, which I could not feasibly do were the screen'within the separator; and so can get a more accurate separation than would be conveniently possible with a stationary screen;

It will be noted also that, since the air current is created, not by the action of the reducing machine, but by an independent element, the 1 fan, the stren h of the current can beregulated as desired, without regard to what the desired speed of the machine may be, Also, the etl'ect of the screen is determinable. by its speed of rotation and so iorth and is not dependent upon the strength of theair current or forces acting within the separator, and, so,

can be regulated to exactly meet desired conditions; and the air current can. be regulated withouthaving to consider its efiect at the screen, Thus the effect of each element of the apparatus can be accurately regulated, independently of the others, to

secure the best results.

The details ofthe various elements of the apparatus may be of any suitable or preferred character. As here illustrated the reducing machine is of the type commonly called a sixteener machine its series of hammers, as 13, being driven by cams, 17, carried by a shaft 18; and its series of hammers, as 1 1, being driven by cams, as 19, carried by a shaft 20. Qne shaft, as 18, is driven by the belt pulley 21, and the motion is transmitted by gearing 22 22'" to the shaft 20, The fan is oi the usual type driven by the belt pulley 23 from, say, an electric motor (not shown).

leaving at 25; The screen 3 comprises 1 frame composed of theelements 26 which are carried by, the spider 27 and the end plate 28 mounted to rotate with the shaft 29 driven by the pulley 30. @n the elements 26 is preferably carried Zllil mesh,

lllll ill) : claim eaders silk bolting cloth. The receiving end of the screen is open, while the end plate 28 closes the discharge and except for exit apertures, 31. Desirably the pipe 5 -is,

as shown, of relatively large diameter adjacent the machine 1 and of relatively small diameter along'the major portion of its length. Desirably, too, the lower portion of the pipe 7 is of smaller diameter than the portion thereof adjacent the separator. Conveniently a portion 7 of the pipe 7 may be flexible, as of canvas, to facilitate the opening of the door 1 of themachine, for inspection or any desired purpose. It will be understood that proper brackets, supports, and so forth, for the various 'elements of the apparatus are provided, but to avoid confusion no attempt is made to illustrate such parts. Also, although for simplicity in the drawings but one entrance pipe 7 and one exit pipe 5, and but one separ'ator, one screen, etc, have been shown, it will be understood that asmany entrance and exit pipes spaced along the chamber 15, and as many separators, screens, etc., can be used as are desirable for the objects sought.

Although I have described my invention with more particular reference to the illustrated embodiment, it will. be understood that Iydo not restrict it thereto, for it may be embodied in many other and different apparatus. I

Having thus described my invention, '1

1. In an apparatus'for the production of powder, in combination, a reducing machine aving a chamber for holding the material to be acted on, and means in. said chamber for acting on the material, conductors providing an air circuit with said chamber included therein, means for movin air through said circuit, a separator in luded in said circuit, vand a screen located without said circuit and operatively distinct from the separator, said separator and screenbeing arranged for the discharge of material from the separator to the screen.

2. In an apparatus for the production of powder, in combination, a reducing machine having a chamber for holding the material to be acted on, and'located to support such material upon the bottom thereof, and means in said chamber for acting on the material, conductors providing an air circuit with said chamber included therein, with the'entrance conductor and the exit conductor communicating therewith above the bottom thereof, thereby to provide that the air circulating through said chamber shall pass across the material, means for moving air through said circuit, a separator included insaid circuit, and a screen, said separator and screen being arranged for the discharge of material from the separator to the screen,

3. In an apparatus for the production of powder in combination, a reducing machine aving a chamber for holding the material to be actedfon, andlocated to support such material upon the bottom thereof, and means in said chamber for actingon the material, conductors providing an air circuit with said chamber included therein, with the entrance conductor and the exit conductor communicating therewith above the bottomthereof, thereby to provide that the air circulating through said chamber shall pass across the material I means for moving air through said circuit, a separator included in said circuit, and a screen located without said circuit and operatively distinct from the separator, said separator and screen being arranged for the dischargeof material from the separator to the screen.

' 4. In an apparatus for the production of 'throuh said circuit, a separator included 1n sai circuit, and a screen located without" and agitating the material, conductors providing an air circuit with said chamber included therein, with the entrance conductor and the exit conductor to and from said chamber communicating therewith above the bottom thereof, means for moving air through said circuit, a separator included in said circuit, and a screen, said screen being.

operatively distinct from said separator,

said separator and screen being arranged for the discharge of material from one to the other,

6. In an ap aratus for the production of terial, said chamber having anvil means at its bottom, said mill also embodying stamp.-

ing means operative in said chamber] and cooperating with said anvil means to reduce the materlal, conductors providin an air circuit with said chamber include therein with the entrance conductor and the exit lit!) conductor to and from said chamberv communicating therewith above said anvil means with said stamping means substantially in the line of the air current, driven means for moving air through said circuit, a separator included in said circuit, a screen, a conductor from said separator to said screen, a conductor from said screen to said mill for returning unfinished powder there to, a conductor for discharging finished gowder from the screen, and means for c riving said mill and said moving means.

7. In an apparatus for the production of powder, in combination, a driven stamping mill embodying a chamber for material, said chamber having anvil means at its bottom, said mill also embodying stamping means operative in said chamber and cooperative with said anvil means to reduce neeaere the material, conductors providing an air circuit with said chamber included therein With the entrance conductor and the exit conductor to and from said chamber communicating therewith above said anvil means with said stamping means substantially in the line of the air current, driven means for moving air through Saidcircuit, a separator included in said circuit, a driven rotaryscreen, a conductor from said se arator to said screen, a conductor irom sai screen to said mill-for returning unfinished oWder thereto, a conductor for discharging finished mowder from the screen, and means Whereoy said driven mill, moving means, and screen can be driven each at a speed. independent Or that of the others.

In testimony whereof I affix my signature.

CLAUDE A. BULKELEY.

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