US1778718A - Gelignite and gelatin dynamite - Google Patents

Description

Patented Oct. 21, 1930 UNITED STATES PATENT OFFICE BOY LINDEN BILL, OF WILMINGTON, DELAWARE, ASSIGNORTO ATLAS POWDER GOM- IPANY, OF WILMINGTON, DELAWARE, A CORPORATION OF DELAWARE' GELIGNI'IE AN D GELATIN DYNAMITE 1V0 Drawing.

The objects of my invention are to provide gelignites and gelatin dynamites of such composition that they will possess improved softness and plasticity, better keeping qualities 5 in storage, higher propagation sensitiveness,

and greater assurance of high rates of detonation than have heretofore been readily possible with known products of this nature.

My invention further contemplates the in provision of gelignites and gelatin dynamites that are more easily and economically handled in manufacturing operations than has heretofore been possible.

An additional feature of novelty and advantage resides in the fact that by the present invention I can more readily prepare satisfactory explosives of the types mentioned, with a lower nitroglycerin content than heretofore.

Broadly stated, the invention resides in the introduction of What I have chosen to call .pelleted sodium nitrate or pelleted potassium nitrate into the explosives concerned. To avoid any misinterpretation I may define my meaning as follows, using sodium nitrate as the example:

I am concerned with sodium nitrate which exists in the form of spherical or semi-spherical particles such as would be formed by submitting the molten material to shot towers or ejecting it through a spray gun by means of air or gas pressure. It is so special and peculiar in form that even a casual observation would indicate that it could not be formed by any grinding treatment of coarse sodium nitrate, or by any of the established methods of preparing this salt for use in explosives. Fortunately, for some of the objects of my invention many or all of the pellets are hollow to a greater or less extent. I place no limit of size on the spherical or semi-spherical particles. They may be so small that all will pass a 100 mesh screen or as large as conditions of application render desirable.

I have also found that potassium nitrate, pelleted into similar spherical or semispherical particles, exerts an advantage, similar to that of pelleted sodium nitrate, in gelignites and gelatin dynamites, and it is to be Application filed December 14, 1928. Serial No. 826,154.

understood that the use of this material constitutes a phase of my invention.

It is not necessary to use either pelleted sodium nitrate or pelleted potassium nitrate, as the entire content of these salts in my gelignites or gelatin dynamites. My compositions may include a. proportion of either one of these salts prepared in any well known way as by grinding, but, when using either of the pelleted salts, atleast five percent of the total content of such salts will be in the pelleted condition, because lesser amounts do not provide suificientl advantageous conditions.

There shoul be no misinterpretation of the meaning of gelignites and gelatin dynamites by those skilled in the art. They are explosives whose consistency has been effected by the use of more or less nitrated cellulose which has an appreciable degree of solubility in nitroglycerin.

Three examples will be given as follows, but it should be understood that I do not confine myself to these examples and that my invention covers the entire field of gelignites and gelatin dynamites in which potassium nitrate or sodium nitrate are used.

Example N o. 1

Per cent Nitroglyoerin 42 Nitrocottonuns 1 Pelleted sodium nitrate"; 45 Wood meal 5 Flour 6 Chalk 1 Example N o. 2

Per cent Nitroglycerin 51 Nitrocotton 2 Pelleted sodium nitrate 25 Ground sodium nitrate 12 Wood pulp 9 Chalk 1 Example N o. 3

Per cent Nitroglycerin 18 Nitrocotton 0.4 Pelleted potassium nitrate 50 Ground potassium nitrate 15 Flour l1 Sulphur 4.6 Zinc oxide 1 The advantages of the invention will be better appreciated after a consideration of the following facts: It is known that practically any explosive may be dead pressed, that is, pressed to a point where it will either detonate with a low order of detonation or merely burn. Obviously increased pressure means less or no air spaces between the particles. With this condition it is assumed that the failure of explosives to function properly when over-pressed is probably connected. A gelignite or gelatin dynamite may be looked upon as a honey comb of minute air particles surrounded by films of colloided nitro-cellulose. By insufiicient stirring in of air during mixing over pressing in packing, or submission to a series of temperature changes, the explosives noted are known to deteriorate in the properties mentioned. It is assumed that this is due to loss of aeration or the collapse of the minute air cells. Density increases during deterioration also point toward this.

Obviously, spherical or semi-spherical particles will not pack like a fine powder or irregular particles, and automatically provide sturdy walled air spaces in the explosives. The hollow nature of the pellets further provides such a condition. The result is an aeration of the explosives which is maintained under very severe conditions and excellent keeping qualities are effected. Since the explosives manufactured in accordance with this invention represent the greatest departure from the dead pressed phenomena they will detonate with maximum orders of detonation and so show excellent propagation sensitiveness and-rate of detonation conditions. Their resistance to loss of aeration will also keep them most effective in use under conditions of hard tamping and high pressure, as in deep holes filled with water. There is actually provided a new form of aeration to augment the aeration caused by stirring air into the colloided nitrocellulose.

The spherical or semi-spherical particles will roll readily within the mass of gelatin, as compared with fine powder or irregularly shaped particles. This tends toward easier packing into cartridges and greater conditions of softness and plasticity. Easier packing into cartridges means less pressure exerted and less loss of aeration, showing the interlocking nature of the effects.

Also the spherical or semi-spherical particles, most of which have no opening into the hollow interior, present less surface to which nitroglycerin may adhere, as compared to particles of other shapes and fine powders. Thig obviously presents the possibility of preparing moist, soft, plastic masses of gelatin with less nitroglycerin than usual. There is thus rendered possible the manufacture of lower strength, cheaper gelatinous explosives,

arrears for which there is acbroad demand among consumers.

My experience, derived from extended experimentation, has demonstrated that explosives prepared as described herein possess better keeping qualities, higher propagation sensitiveness, higher rates of detonation and greater softness and plasticity than explosives made with ordinary ground sodium nitrate, and that such explosives maybe more easily and economically manufactured, and may be made with a lower nitroglycerine content in the production of a good gelatinized mass, than has been possible by any method of manufacture heretofore practiced. F urther, by virtue of the use of the im roved sodium nitrate in pelleted form, as erein-' before described, I am able to secure increased densities in gelignites and gelatin dynamites, without corresponding decrease of aeration. I wish to specifically disclaim the use of ammonium nitrate in pelleted form of the nature of that disclosed in the patent to Symmes, No. 1,613,335, because such ammonium nitrate yields a lower density than even ordinary granular ammonium nitrate or Chilean sodium nitrate. 3

Lower density is desirable in those explo sives of the permissible type while gelatin dynamites and gelignites from the very nature of their ap lication require a high density. The intro notion of ethylene glycol dinitrate in the manufacture of dynamites has tended to reduce their density and has been a source of worry and trouble to explosive manufacturers. Consequently, thing tending to further lower theirdensity is to be avoided.

It, is understood that the invention applies only to gelatinous ex losives, commonly nown as gelignites an gelatin dynamites. They are very different from non-gelatinous dynamites in structure and in the effects of various conditions upon them.

It is further to be understood that the invention is not limited to the particular proportions recited, but that it includes within lts purview any composition coming within either the terms or the spirit of the appended claims.

Having thus clearly set forth theessential features of the invention, and shown by example how it may be applied, I claim: Y

1. Pelleted alkali metal nitrate in geli n1tes and gelatin dynamites as herein (1%- scribed. i

' 2. Alkali metal nitrate in particles of sub,- stantially spherical form in gelignites and gelatin ynamites. I

3. Gelignites and gelatin dynamites which contain substantially spherical particles of sodium nitrate.

4. Gelatinous explosives which, contain al-' kali metal nitrate which has been converted to a spherical form from a molten condition.

any-

its

5. A gelatinous explosive containing an alkali metal nitrate in particles of substantially spherical form.

6. A gelatinous explosive containing an alkali metal nitrate in the form of distinct pellets.

7. A gelatinous explosive containing an alkali metal nitrate in the form of hollow pellets.

8. A gelatinous explosive containing substantially spherical pellets of sodium nitrate. 9. A'gelatinous explosive containing hollow pellets of sodium nitrate.

10. A gelatinous explosive containing hol- 15. low pellets of an alkali metal nitrate of substantially spherical form.

11. A gelatinous explosive of greatly increased aeration characteristics, having as an ingredient thereof substantially spherical hollow pellets of sodium nitrate.

12. A gelatinous explosive of greatly increased, aeration characteristics, having as an ingredient thereof substantially spherical hollow pellets of sodium nitrate in the form produced by discharging molten sodium nitrate into the atmosphere.

In testimony whereof I aflix my signature.

ROY LINDEN HILL.