US503585A

US503585A - Process of making smokeless explosives

Info

Publication number: US503585A
Authority: US
Publication date: 1893-08-22
Anticipated expiration: 1910-08-22

Description

2 Sheets-Sheet 1 L No Model.) v

,1 2. G. an P. s. DU PQNT; y PROCESS OF MAKING SMOKBLESS EXPLOSIVBS. 10,503,585

Ptented Aug. ZZA, .1893.y

` P776 dal@ (No Model.) 2 Sheets-'Sheet 2.

lF. G. 5 12.5. DU PONT. PROCESS 0F MAKING SMOKELESS EXPLOSIVES.

150,503,585. A K B55551155 Aug. 22, 189s.

Unirse Sterns FRANCS DU PONT AND Para @restent PIERRE S. DU PON", Ol* iVlLMlNG'lTlN,

DELAWARE.

PRGCESS OF iillAKlilG SMOKELESS EPLSiJ-ES.

ECIFICATON vformingpart o' Letters Patent No. 503,585 dated August 22, 1893.

Application tiled March 17, 1893. Serial No. 466,488. (No specimens.)

To @ZZ 'whom it may concern:

Beit known that we, FRANCIS G. DU PONT and PIERRE S. DU PONT, citizens of the United States, residing at iVilmington, in the county of New Castle and State of Delaware, have invented certain new and useful Improvements in Explosives; and We do hereby declare the flollowing to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it ap` pertains to make and use the same.

Our invention relates to improvements in explosives which are particularly adapted for imparting a high initial velocity to the projectiles of small bore riies, such as the Man n.- licher, the lrag-Jorgensen and the English 303, and it consists in an improved process for producing an explosive from nitro-cellulose, consisting of granulating the nitro-cellulose by agitatiug therewith, when suspend ed in a fluid, a solvent ot the saine in suitable proportions, which will be hereinafter fully described, and particularly pointed out in the claims. v

The main object of our invention is to prod ucc an explosive which will be smokeless, or nearly so, which will be unaffected by being kept for a considerable space of time, which, high muzzle velocity to the the gun barrel at the moment ot firing, and which can be eas-ily and safely handled and vrstored. Our invention has for its special aim,

however, the attainment of a higher'initia-l velocity than has formerly been attainable by the use ot'smokeless explosives, with the aim of adapting the explosive to use with small bore rifles, such as those mentionedabove.

lu our application for Letters Patent forA improvements-in explosives, filed December' 21,1392, Serial No. 455,001, we described a process for producing smokeless powder, the distinguishing feature of which was the granulation of pure nitro-cellulose by mixing therewith a solvent of the seme iusuitable proportions. Basing our process on the tendcncy which We found was inherent in the various solvents of the nitro-celluloses, and especially the nitro-derivatives of thcaromatic group, when mixed in a iiuid in which finely divided nitrocellulose is suspended, to seize the nitro-cellulose and leave the Water clear,

forming in thewater a more or less coherent mass, we discovered that when the solventis., added in proper proportions, (and we found that the proportions of three parts of the and forming a coating around the same. These grains,after they have undergone a process of hardening by rotation in a barrel, and removal of excess ofsolventl and water contained in the grains by boiling, or. by rotation in a barrel in an atmosphere of steam, in which case the removal of the excess of solvent and Water contained in the grains Will take place at the saine time as the rotation, become sut'iiciently rm to be graded as to size preparatory to being placed on the marhet, and constitute a valuable smokeless powder, the violence of whose explosiveaction can be diminished by varying the duration of the above processes, or it may be-still lfurther diminished-by the addition of a substancdto Amoderate itsvaction. We have found nitrated rosin and citi-ated turpentine especially suited forthis purpose, and we add them in the manner and proportion stated iu said application. We have discovered, however; that increased hardness and consolidation of the grains thus formed may be obtained by subjecting th z grains, either directly after they have been removed from the churn in which they were formed, or .after they have been subjected to partial treatment by rotatior iu an atmosphere of steam in order to remove" the excess of solvent, to the action' of la gentle heat, not suilicieut to cause vaporization of the solvent, but to remove some ef the yvavter condensed in the grains, thisl discover-,v being based upon the property, which we have found the Vgrain possesses, of giving/up. its

contained water before it parts with the solv- Y ent used in its preparation, and at a lower heat.

In the drawings accompanying and form- ICO- v rior at' the churn ened and prepared 5 imity to the bulkhead flzof the barrel.

sented the apparatus which we use in carrying out our process, Figure l, which is taken on the line'rcfc Fig. 1,lookingin thedirection of the arrow, illustrating the churn in which the mixture of the nitro-cellulose with the solvent takes place;"1"ig. 1n being a sectional view of the same; and Fig..2 being a representation of therotating barrel in which the grains formed in the churn shown in Fig. l are hardened and rounded, and thustitted for use. It is taken on the line y y Fig. 2". Fig. 2 is a view taken ou the line .a' .z Fig. 2, looking in the directionof the arrow. It shows the double series of apertures-infime inner bulkhead of the barrel, and Tsd the series of cycioidal chutes which conduct the water of condensation, received through the the bulkhead, to pipe forming the the said water is outer series of apertures in the apertures in the central axis of the barrel, by which conveyed away.`

' Before proceeding with a description of our process, we Awill descril-e the apparatus used in carrying it out.

Referringv to Figsx] and l, A represents a churn, in which, by a shaft l, are rotated the blades b, each of which is formed with a notched outer surface to promote currents from side to side in the contents of the churn during rotation. Steam inlet pipes C are provided' which arerelativelysmall in diameter, so that the steam will be well distributed through the contents of the churn,and a singie steam outlet pipe D, which leads to the refrigerating coils E, where the vapors which it conducts may be condensed. `An opening F is provided for the-admission of material, and an opening C when desired. Test cocks l l are also provided, in order that the condition of the contents of thc churn may at any time be inspected.

In Figs. 2 and 2, the rotating barrel is represented in which the grains of explosive produced in the churn just described are hardfor use. This barrel, II, is provided with a tubular axis I, journaled in the supports i, to which axis steam is con- ,ducted by the pipe 2, and from which steam is conveyed away by the pipe 8. 'This barrel is designed to facilitate the escape of 'both water and steam, the latter carrying oif the solvent used, and to this end is formed with an innerbulkhead K,which is placed in close prox- In this inner bulkhead are formed two series of apertures, one around its periphery S, for the ,separation of water from the contents of the barrel, and que nearits center 9, for the escape of steam from the same. Between the two bulkheads K and K are arranged a- .scries of cycloidal chutes or guides` L, ail ot which converge toward `the central axis. In the operation of the barrel, steam is admitted to its interior through the aperture f' in the central axis, passing outthrough thc apertures 9 in tho bulkhead K, from which it passes to aid in ushing the inte.

4solvent of great extent in the liquid uscdto suspend.

through the axis I and the pipe 3. W'atcrof conde sation, as fast as formed, and also the water separated. from thc grains ot' explosive, passes through the outer' series ot' apertures in the bulkhead K at the lower part of the revolution of the barrel into the space botween the said bulkhead K and bulkhead K", and is conducted by the cycloidal chutes towaid the axis of the barrel, then passing fout through the apertures 6 formed at this point.

Proceeding now with our process, we place inl-the churn A about ninety liters of Water, or other liquid, whichl may either be pure, or mixed with any salt. When w'ater is used, we sometimes dissolve ci um, common salt, saltpeter or other salt, as we can thus modify in many ways the characteristics of the grains formed. We addto the water about six kilograms ot gun cotton, beating it up with the water in the churn until a thorough mixture has taken place. When this has been accomplished, we add to the mixture nitro benzole, or other. suitable gun cotton not miscible to any nitro-toluol and nitroabout three times the the gun cotton, such as xylol, to the extent of weightot the gun cotton. tion of the contents of. the churn is continued, the gun cotton assumes a well'detined granular state, the grains formed, being soft" and containing considerable water. .During this agitation. steam may be admitted through the bottom of the churn,an'd this as it passes out through the refrigerating coils `carries with it a portion of the solvent, which is ro-l coveredin the said'coils. This action of the steam is not, however, essential to ,they production of the grains, though it assists in their formation, and may be omitted without detriment to the product., The 4sire of the grains may be varied by changing the proL.

portions ofthe ingredients and thefduration.

of treatment. Tho-above is an example'of proportions which give good results. Instead of placing the grains thus forined'direct'ly into the rotating barrels shown in Figs. 2 and 2, and rotating said barrel with ingress of steam until theexcessof volatile solventhas been entirely evaporate'tfrom the grains, as we doin the process described in the applica.` tion for Letters Patent for improvements in explosives already referred to, we have found that better results as to the hardness and d'egree of consolidation of the resulting grains may be obtained hysubjectingthe grains lto a gentle heat,'ranging say from 120 to 180 l-`ahrenheit, either placed in the rotating barrel, or after they have been partiz'tllytreated in the saine. This result is due to aproperty which 1the grains possess of parting with the water condensed in their fiber before they part with the Solv? ent used in tlicir preparation. liy heating tle said grains to afpoint not sufficient to carry away tno solvent, but only to evaporate When the agitabefore thehgrains are in it chloride of cali the condition of thegrains and consolidation required, the grain is vin the steam cess for ivhich application for 'Cotton in the dense, and thus become tted to produce the high initial `velocity to the projectile which is the object of this'process. It is not Vmaterial whether the grains be subjected to this gentle heat before they have been treated by boiling for removal of excess of solvent, or

after they have been partially so treated, it only being necessary that they be so treated before the outer envelope of the grains becomes so hard as not to permit the passage of Water through the same.

We do not confine ourselves to the temratures mentioned, although we nd them good for the purpose intended, nor do we coniine ourselves to any particular method of exposing the grains Ito heat, using a rotating driersueli as is used in sugar refineries, or spreading the grains upon sieves, or adopting any other method for the desired purpose.

After this roasting process has been carried to a greater or less extent, dependent upon the degree of treated in the sblvent being boiled ott the usual manner,

a still, or in the barrel, or in open air.

We .have found that better results are obtained in the use of the barrel by creating a vacuum atA the steam outlet pipe, as the vapors are thereby more rapidly conveyed away,

and the amount of time required for the treatment in the barrel is reduced.-

The explosive force of the explosive thus produced maybe tempered in the same manner as was the explosive produced by our pro- Letters Patent has already been made, namely, by adding from two and one-halt per centi to ten per cent. of a inoderatingagcnt, such asnitrated rosn or nitrated turpentine, 'e'. c., rosin or `v'cnice turpentine treated with nitric acid, although wc do not conline ourselves to the use of these substances, nor to the proportions mentioned. We add`this moderating agent by dissolvingthe saine in the solvent used in the granulation process, or by adding it to the finished grain, or in any other suitable manner, but' it must be added in the proportion which it is to bear to the finished proj duet as it is non-volatile at thc tenipcratuics used.

We have described thegun cotton as being.'` diilusedin water, but it is evident that an) other (luid, which will cause a better, or as good a distribution ot the particles of gunchui'n may be used instead; and

while gun cotton has been described as the- Lform of nitro-cellulose employed in the process, it is evident that other forms ofinitrocellulose may beused instead if desired.A

-We do not confine ourselves tof the exact4 proportions mentioned, nor to the particular apparatus described, as these .can bevat-led and changed without affecting the merits of our process.

What we claim as new, and desire to secure f by Letters Patent, is-

1. The herein described process for producing a smokeless explosive, which consists in suspending nitro-cellulose in a liquid not a solvent of the saine,'granulating the nitrocellulose by agitati n g therewith in proper proportions a suitable'solvent of the saine not miscible to any great extent in the liquid used to suspend the nitrocellulose, and so! lidifyingthe grains thus formed by subjecting the saine to a heat insufcient to vaporize the solvent but sutiicient to vaporize the liquid for removal of the liquid contained in the grains, and vthen removing the excess of solvent, substantially as described.

, boiling them for nitro-cellulose,

- portions a 2. The herein described process for producing a smokeless explosive, wl'iich consists i'nsuspending nitro-cellulose in a liquid not a solvent of the same, gran'ulating the nitrocellulose by agitatingjtherewith in proper p'roportions asuitable solvent not iniscible to any great extent in the liquid used to suspend the andsolidifyin g the grains thus formed by subjecting the saine to a heat in= sufficient tf' vaporize the solventabut Sullicient to vaporize the liquid tor removal ofthe liquid contained in the grains, and then to a heat sufiicient to vaporize the solvent for removal ofA the excess of solvent, substantidarly as described.

3. The liereindcseribed process for producing a smokeless explosive, which consists in suspending nitro-cellulose in a liquid not a solvent of the same, granulating the nitrocellulose by agitatirg therewith in properprol portions a suitable solventnot miscibletoauy great extent inthe liquid used to suspend the nitro-cellulose, and solidifying the granstiis formed with removal of liquid contained in the saine and excess of solvent by s .-bjeetingu them toaheat ranging from to 180 Fahr-f enlieit for removal et the liquid, and then removal of excess ot' solvent,- substantially as dcscrilvedf,A f L 'lhe herein described process for producf ing a smokeless explosive, whic'nconsists in tog IKO

susnending nitrocellulose iii-'a liquid vnot a solvent of the same, gra-nulating the nitrocellulose by agitating therewith in proper prosuitable solvent not iniscible to any great extent in the liquid used to suspend the nitrocollnlose, and soldif ying the grains thus formed by subjecting the same'to'aheat insul'lcient to vaporzc Vthe solvent but'- suili cient to vapori/.c the-.liquid forri'gmovalof the liquid contained in heut sullieicni to vapor-izo thcsolve'nt for rcthc-grains, and 'their to ai moval of the excess of solvent, the latter opsolvent but sufficient to vaporize the liquid eration being.,r accompanied by agitation, subfor removal of the liquid contained in the 15 stnntially' as described. grans,'and thenrotating the grains iu an at- 5. The herein describedprocess for producmosphere of steam forv removal of the excess 5 ing as'rnokeless explosive, which consists" of soivextsubstnntinlly as described. v suspending nitro-ce11ulosefin a liquidv not a' f5' In testimony whereof we ax our signatures sofelnt of the same, granulaltiug the nitro- 'in pesenceof two witnesses. ce u ose by agitating t xerewit 1 in proper proportions n, suitable solvent of the samenot r' xo tmiseible to any great extentin the liquid used to suspend the nitro-ceiluose, and solidify` Witnesses: ing` the grains thus formed by subjecting the HENRY J. CRIPPEN, same to a heat insufficient to yaporize the` FRANCIS II. IIOFFECKER.