US2165287A - Method of disintegration, dispersion, stabilization, and collection of solid materials - Google Patents

Description

L. M. McBRlDE nE'rHon oF DISINTEGRATION, msPERsIoN, sTABIILIzA'rIoN;

AND coLLEcTIoN oF soun MATERIALS Filed Aug. 12, 1935 EW/5M Mc SQ/01s' BY Wmw@ ATTORNEY.

2 Sheds-Sheet 1 July ll, 1939. M. MCBRIDE' 2,165,287 UETHOD 0F. DISINTEGRATION, DISPERSION. *STABILIZATIOK 1 AND COLLECTION OF SOLID MATERIALS Filed Aug. 12, 1935 2 Sheets-Sheet 2 INVENTOR. EW/s M Mc .5R/DE BY V4.

ATTORNEY.

UNITED STATES DISINTEGRATION, DISPER- METHOD OF PATENT OFFICE SION, STABILIZATION, AND COLLECTION 0F SOLID MATERIALS Lewis M. McBride, Corozal, C. Z.`

Application August 12, 1935, Serial No. 35,720

6 Claims.

(Granted under the act of March 3, 1883, as amended April 30, 1928; 370 0. G. '757) The invention described herein may be manufactured and used by or for the Government for governmental purposes, Without the payment to me of any royalty thereon.

This invention relates to the disintegration of solid substances, the dispersion thereof after disintegration, a means of stabilizing the fine particles of disintegrated and dispersed material to prevent recombining and a means of collecting 10 the disintegrated, dispersed and stabilized substance or substances.

One of the objects of this invention is to provide a method of producing a fine dust-like material that will retain its characteristics Without recombining into larger particles.

Another object is to provide a means of intensifying, increasing or enabling the capacity or ability of ne dust particles to adsorb upon themselves a nlm of air or other gas.

Another object is to provide a means to facilitate and augment the natural tendency of line dust particles to acquire a definite electrical charge. l

Another object is to provide a means of producing a substance consisting of one material as an active component and another material as an inert component, disintegrated simultaneously and intimately associated together, whereby the particles of inert material tend to assist in preventing the recombining or cohering of the active particles, the whole consisting of stabilized particles of active material with attached or adsorbed particles of inert material.

Another object is to provide a means of pro- 3 5 ducing a nely divided solid material consisting of two or more components of active material in a stabilized condition, such that the individual particles of one component will not recombine or cohere With other particles of the same component and, also, such that the particles of diiferent components will not combine with or adhere to each other.

In all processes of mechanical disintegration, the different particles into which the substance is divided have to be torn apart against the force of cohesion. Disintegration may be accomplished by shearing and tensile stresses grad'- ually applied, as in attrition mills, or by a crushing pressure applied gradually by means of rolls,

or by sudden blows, as in impact machines of come smaller, they form a loose dustthat yields more and more to the applied stress, so that the crushing effect is increasingly diminished. There comes a point, therefore, in all crushing operations at which the accumulated dbris is fine enough to accommodate itself tothe applied stress without the individual particles actually being stressed beyond their elastic limit. The rigidity of the mass is then too low for further crushing stresses to produce any eect.

To disintegrate the material further, it is evident that the nest particles of the dbris which are cushioning the larger remaining particles against the crushing effect of the process must be removedin order to allow the disintegration action to continue. To separate these nest particles from' the coarse and remove them from the crushing process and continue the ldisintegration of the remainder is one of the principal features of this invention.

The manner in which this is done contributes directly to another principal feature of the invention by disassociating any aggregates and dispersing the fine particles and isolating them in air or other gas whereby they are permitted and caused to adsorb upon their surfaces molecules or films of air or gas; also, by virtue of the process, ne particles of a particular type of material, according to its chemical nature, acquire an electrical charge of a definite sign, the adsorbed air or gas and/or the effect of the electrical charges produce a stabilized particle preventing recombining or the formation of aggregates of the individual particles. Further, the method used to accomplish these results is also used to provide a convenient means of retaining and collecting the processed material for use.

'I'he combination of the successive processes of disintegration, separation, dispersion, stabilization and collection constitute the basis of this invention and is accomplished by the methods and apparatus as follows.

In the drawings: l

Fig. 1 is a sectionalized side elevation of the disintegration mill.

Fig. 2 is an end view ofFig. `1 with end parts removed.

Fig. 3 is a side elevation of the assembly of the various apparatus of the system.

In Fig. 1 is shown the barrel or steel cylinder I, having heads 2, 2 provided with bearings 3, 3', rotatably mounted upon a stationary hollow shaft 4 clamped in the supports 5, 5', the .hollow shaft being closed by the plug 6 and V preferably near the interior ends of the cylinder. Plug 6 is held in place by a set screw 6. Enclosed within the barrel I are a number of steel rollers t arranged to roll freely on the lower interior circumference of the cylinder wall. Fig. 2 is an end elevation of Fig. 1 with the head 2 and the support 5 removed for clearness.

The barrel I is provided with openings A, B and C spaced 120 degrees apart around the circumference and equidistant longitudinally, the middle opening B being preferably at about the center of the cylinder and opening A being toward the rear head 2 and leading opening B (by 120) when the direction of rotation of the cylinder is as shown by the arrow or counter-clockwise as shown in Fig. 2, while opening C is toward'the front head 2 `and`fcllowing opening B by 120. These openings may be closed or opened by means of plugs as shown at B Fig. 1.

In Fig. 3 is shown a side elevation of the assembly of the disintegrating, dispersing, separating and collecting system in which I is the mill of Figures 1 and 42, I0 is a motor or other means of rotatably driving the mill, II is a vacuum exhaust fan driven. by the motor Ilm or other suitable means, the suction side of the fan being connected to the open end of the hollow shaft outside of the support 5 and arranged to discharge into the centrifugal separator I2 through the pipe I3, the centrifugal separator being provided with a removably mounted collecting receptacle I2a at its lower end and an outlet` at I2b communicating with the top of the dust settling and collecting chamber Id through the pipe I5, the dust chamber I having 'a removably mounted collecting receptacle Ilia at its lower end. The walls of the dust chamber It consist of one or more layers of a suitable fabric filter which will permit the escape of the discharged and spent air or gas but which retains the fine dust particles, -the area of the walls being proportioned to the volume of air or gas delivered by thel vacuum exhaust fan II, so that the velocity of airl or gas through the illter will be relatively low.

With reference to Figures 1 and 2, a predetermined charge of materiaLto be disintegrated is placed within the cylinder I through one of the openings as at B, and initially the openings A, B and C are closed with plugs, the charge being represented at I6. Upon rotation of the cylinder I upon the stationary hollow shaft 4, the rollers 8, roll over the material I6 crushing and breaking it down to a certain extent; some of the material I6 is carried around with and over the rollers, which, rising on the side of rotation, are carried up by friction with the inside of the cylinder I of the mill until they are overbalanced above the axis of the cylinder and fall back upon the top of following rollers as shown by the line of arrows, giving several impacts upon the top of succeeding rollers, further crushing the material I6 by impact. Continuous rotation of the cylinder I produces a continuous falling and impacting of the rollers 8. However, a point is soon reached where the accumulated line material acts as a cushion, as hereinbefore explained, and this condition is overcome as follows: First, withthe end fla of the hollow shaft Il open, the vacuum exhauster is started and draws air through lla, and the pipe l and,A across through the top `of the interior of the cylinder and Iout through pipe removing the fine dust carried into the air by the continuing action of the cylinder and rollers.

This, however, removes only a portion of the extremely fine dust and to complete the process, the cylinder is stopped and with the vacuum exhauster still operating, one or all of the plugs A', B and C are removed and the rotation of the cylinder again started. (The opening la may or may not 'be closed depending upon the extent of vacuum produced by the exhauster.)

The vacuum exhauster now draws air in through the openings A, B and C, preventing any of the material from falling out, and removes the fine material from under and between the rollers carrying it through the pipe 'l allowing only the comparatively coarse uncrushed material to remain, upon which the action of the disintegrating process continues unobstructed.

The uniform angular spacing of the openings and the manner in which they lead one another successively from rear to front tends to agitata the material under and between the entire surface of the rollers and to carry the i'lnes from the rear to the front and-out of the pipe l. The constant and continuous removal of the fine particles permits the disintegrating action of the mill to reduce the last remaining material to the nest proportions.

Referring to Fig. 3, the vacuum exhauster I I is preferably a multibladed high speed type, and serves a triple purpose; first, for producing a partial vacuum through the mill and removing the ne particles as described; second, to break up any aggregates of fine particles and to agitate and isolate individual particles/in the air stream; and, third,to maintain the particles in the air stream for a definite period of time by discharging through a considerable length of pipe I3 into a centrifugal separator I2 specially proportioned with reference to the fine nature of the material handled. Although this separator is similar to a standard type of centrifuging collector as used commercially for various purposes it is used in this process as a separator rather than a collector in that the direction of the stream of high velocity, dust laden air being suddenly diverted causes any aggregation of ne particles, that may have escaped separation previously in the process, to be torn apart and isolated.

The receptacle I2a is arranged for the collection and removal of such material as gravitates to it, while at I2b is a central opening from the separator connected to the pipe I5 which carries the dust laden air to the collector I4, allowing the dust to be filtered out of the air by the walls of filter fabric I4, the finely divided and stabilized particles being nally collected in the removable receptacle Ida. as an impalpable powder which will not cake or form aggregates.

In some instances it has been found advantageous to mix an inert agent with the material to be disintegrated and stabilized. Preferably theA inert agent and the material are mixed prior to disintegration and then are fed into the mill. The fine particles are thus thoroughly mixed and are carried forward in the gaseous medium. Although the invention is not limited to this theory, I believe that the inert particles collect around the surface of each particle of the active materiaL'thus positively separating the particles of active material. Y

In the preparation of stabilized tear gas, the chloracetophenone 'has been mixed with such stabilizers as fullers earth, chalk, magnesium oxide (calcined) or zinc oxide. I have found that not over 5% by weight cf these stabilizing mateand diphenylamine chlorarsine may be disinterials effectively prevents cohesion, coalescence or recombining of the tear gas when collected in bulk after treatment in accordance with this invention.

Reference has been made herein to the use of i l through the pipe 1', the interior of the cylinder l and out of the pipe 1 and to the vacuum exhauster Il, the operation of which is continued to agitate and separate the particles' as hereinbefore explained.

In the event that it is desired to mix an amount I of air with any particular kind of gas used, one or more of the plugged openings A, B and C may be opened to the atmosphere and the gas pressure so regulated that the vacuum exhauster will maintain a partial vacuum within the barrel I.

Carbon dioxide or nitrogen may be used as the stabilizing gas. If it is desired that no air be admitted, the rotating drum may be placed in a chamber to which the gas is admitted, whereby openings A, B and C will draw gas only through the material. However, as above indicated, air may be drawn through the openings A, B and C and gas through the hollow shaft, the proportions being easily varied by varying the gas pressure.

Although not shown in the drawings, ports d ,may bedrilled in the hollow shaft i under the i specific material, it. has been found especially useful in disintegrating, stabilizing and collecting normally solid materials used as disabling and incapacitating agents such as chloracetophenone and `diphenylamine chlorarsine. Chloracetophenone, commonly called teargas, is normally a solid and has heretofore been dispersed by dissolving it in an inert liquid, or by mixing it with powder and slowly burning the powder, or by an explosive charge.

Diphenylamine chlorarsine is also normally a solidv which will decompose at a relatively low temperature, so that dispersion by a burning munition results in loss of the diphenylamine chlorarsine. Some loss by decomposition also occurs when diphenylamine chlorarsine is dispersed by explosion due to the high temperature.

Chloracetophenone and diphenylamine chlorarsine disintegrated and stabilized in accordance with this invention may be dispersed directly as very fine dust, since these materials may be loaded in various munitions and containers and will not cake or recombine.

Furthermore, two or more of these or similary materials may be disintegrated andmixed for use together. For` example, chloracetophenone grated separately in my mill and then mixed in proper proportions, or the mixture maybe made prior to disintegration. Such a mixture will not cake and may be stored and dispersed in any suitable manner such as by air pressure or from airplane spray or dusting apparatus. Also by' means of artillery or mortar shell, bombs, 'grenades and other projectiles, static containers or land mines and other devices all of which may be loaded with a bursting charge only suflicient to rupture the body of the projectile or other container and disperse its contents.

Although certain specific materials have been mentioned herein which may be disintegrated, stabilized and collected by this method and apparatus, it is to be understood that there are many other material vused in the various industries, sciences and arts, either separately or compounded,I mixed or otherwise embodied in or with other materials, that may be advantageously prepared as a finely divided and stabilized material by this method. A few of such instances are appended by way of illustration, as follows: medicines, foods, fuels, ceramics, cements, cosmetics, paints, lubricants, abrasives, insecticides, disinfectants, paper, pencils, polishes, powder, rubber and other materials.

It is also to be understood that the apparatus of this invention has been described and shown in its simplest form for the purpose of illustration, however, it is apparent that modifications and refinements may be made, without departing from the principles involved, such, for example, as providing a meansof feeding the material, which isto be disintegrated, into the revolving cylinder of the mill, and for opening.A

and closing the varous nlets of the apparatus without stopping the mill, thereby providing for continuous operation instead of intermittent operation as described herein. l

In the following claims the term gaseous medium is intended to include air or gas or a mixture of air and gas.

While I have shown and described the preferred embodiment of this invention, I wish it to be understood that I do notY confine myself to the precise details herein set forth by way of illustration, as it will be apparent that many changes and variations may be made therein by those skilled in the art without departing from the invention nor exceeding the scope of the appended claims.

I claim:

1. The method of disintegrating and stabilizing normally solid irritant chemical agents material which normally cakes during storage, which comprises disintegrating the material and a mag'- nesium oxide to fine dust particles continuously extracting only the finest dust particles, suspending and transporting the extracted dust particles of the materials in a moving stream of air, and collecting the fine dust particles vtl'ius stabilized.

2. The method of disintegrating and stabilizing lchloracetophenone to form a fine dust which and diphenylamine chlorarsine in stabilized powder form for use as an offensive chemicalagent chloracetophenone and diphenylamine chlorarsine together to ine dust particles, intimately mixed, continuously extracting only thefinest dust particles, suspending the mixed dust particles in air until they are stabilized, and co1- lecting the mixed ne particles.

4. The method of disintegrating and stabilizing chloracetophenone and/or diphenylaminechlorarsine into fine dust particles which will not cake together during storage by the use of a rotary disintegrating impact mill, which comprises disintegrating the chloracetophenone and/or diphenylaminechlorarsine to ne dust, continuously withdrawing the very nely ground particles from an area spaced a substantial distance above the disintegrating area, and away from the turbulence of such area whereby only the iinest oating Vparticles are withdrawn, keeping said arenas? particles suspended in a gaseous medium until each particle is surrounded by attached molecules of the gaseous medium, and collecting the stabilized particles.

5. The invention as dened in. claim .4, the

additional step of withdrawing the nely ground LEwIs MMCBRIDE.

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