US1188245A - Nitro-starch explosive. - Google Patents

Description

. certain Improvementsin p a onion JESSE B. BBOIQ'S'XEIN AND CHARLES; E. VIALLEE, 0F ALLENTGWN, PENNSYLVANIA, ASSIGNOBS TO INDEYENDENT NON-FREEZING POWDER GOMEANY, 0T5 NEWARK, NEW JERSEY, A CORPOBA-TIDN OF NEW 3ER-SEY mrao-sraaon nxrrosivn.

lessees;

No Drawing.

To all whom it may concern:

Be it known that we, Jesse B. Bnons'r'nm and CHARLES E, lVALLERy citizens of the United States, and residents of Allentown, Lehigh county, Pennsylvania. have invented Nitro-Starch Explosives, of which the following is a specification.

Our invention relates to nitro-starch explosives.

Heretofore, nitro-starch explosives have been made containing nitrostarch as the explosivebase (and in using the term n1- tro-starch explosives we refer to explosives such as employ nitro-starch as an explosive base and are used for blasting purposes), nitrate of soda as the oxygen carrier and suitable quantities of an anti-acid such as calcium carbonate and of a waterproofing material such as paraffin oil These powders have been graded to, suit conditions encountered in practice, by varying the per centage of nitro-starch and nltrate of soda.

In varying the proportions of the nitro-' starch and nitrate of soda to secure the difi'erent grades, we have found it desirable, in order to avoid undue oxygen excess, to add an additional combustible, preferably carbon. or carbonaceous material in some form, and it is the object of our present invention to provide a suitable material for p the purpose mentioned.

A further object is to provide a nitrostarch powder having an additional com' bustible ingredient which will increase both the propellent force and brisance or shat- 'tering force of the explosive, without makhard and granular form,

ing any material increase in thecost and without any deleterious eifect.

A corbonaceous material for our purpose must answer several requirements. It must not have the efiect of unduly desensitizing. It must be sufficiently susceptible to oxida tion. it should be non-hygroscopic, and should be physically coarse and hard.

lVe have discovered that we can use to excellent advantage for the purpose above referred to, a carbonaceous material consisting of an ordinary cereal such, for example, as wheat, whcn'ground into a coarse, of such size that the granules will pass through a twenty mesh screen, but not through a' sixty-mesh screen, and having all of the finer particles Specification of Letters latent- Patented June 26 1916.

Application filed July 1, 1914. Serial No. 8483.46.

for use, and we have found that it does not desensmze the explosive as does a finelyground material, and at the same time it is very readily oxidized, is non-hygroscopic tand has all of the desired physical characer1s ics.

In order to illustrate the beneficial edectsmsof introducing a proper proportion. of this combustible carbonaceous materialinto nitro-starch explosives which would otherwise contain a considerable oxygen excess, it may be stated that we have ascertainedv by 'experiment that the addition of 8 per cent. of this material into an explosive containing 30 per cent. of nitro-starch has, the eflect of increasing the propellent force, as indicatetd by the ballistic mortar, about 10 per cen An illustration of one explosive mixture employing the carbonaceous material referred to may be given as follows:

/Ve have successfully used. mixtures con-v taining as high as ten per cent. by weight of the said carbonaceous material.

lVhile the formula above given can be successfully used for some purposes, experiment has shown that the brisance or shattering force of the explosive is not increased by the addition of the carbonaceous material to the same extent as the propellent force. It is desirable for most purposes that the shattering force should increase proportionately with the propellent force, and we have discovered that within certain limits, the use of small amounts of sulfur, together with the carbonaceous material will secure the desired increase in the shattering force. When using both ingredients, to wit, the carbonaceous material referred to, and sulfur, we prefer to use them in about equal parts, and it is also best to so proportion the two *ingredientsto the remainder of the Nitro-starch 3O Sodium nitrate 58.0% Calcium carbonate 1.5% Paraflin oil 0. 5% Carbonaceous material .5. 0% Sulfur 5. 0%

Total 100. 0%"

To further explain the effect of the carbonaceous material and the sulfur, it may be stated, that the presence of the carbonaceous material tends to increase the gaseous products of explosion, While the presence of sulfur tends to increase the temperature of explosion. The presence of sulfur in the quantities in which we usethis ingredient also tends to increase the sensitiveness of the explosive. Neither of the materials tends in any Way to reduce the stability of the explosive, nor do said materials haveany injurious effect on the physical condition of the explosive. duction of these ingredients in the proportions in Which we use them, tends to materially increase both the propellent force and brisance of the explosive without making any material increase in the cost of the explosive and Without having any injurious effect.

In the instance given the propellent force and the shattering force are so proportioned one to the other as to give the best results in all that class of work which involves moving great masses of rock in very large quantities. This class of Work is exemplified in any of the large quarry or excavation operations where blasts comprising thousands of pounds of explosives are frequently made and Where thousands of tons of stone are brought down with each blast. In suchwork in order to get the best results from the energy of the explosive, it is necessary that neither the shattering force nor the propel-- lent force of the explosive be unduly preponderant. For instance, if the explosive has too great a brisance or shattering force,

toolarge a proportion of its total energy is.

consumed in pulverlzing and burning the rock in immediate contact With the charge,

thus resulting not only in a useless waste of energy, but also having another bad effect, in that under these. conditions the charge chamber is instantaneousy enlarged at the moment of explosion, before the main mass of rock or earth begins to move and before the gases have developed their full pressure,

In short, the introdle in quarry or excavation operations. It.

is for this reason that in ordinary cases we prefer to balance the propellent and shat-' tering forces by employing the carbonaceous material and sulfur in substantially equal proportions. ever, that We do not wish to confine ourselves, in this aspect of our invention, to the use of the two ingredients in equal proportions, as in some cases the advantages of our-- invention or some of them can be secured by the employment of either ingredient in lesser proportion than the other.

It will also be understoodthat the shattering force and propellent force of the explosive can be varied in ratio otherwise than by a mere variation of the proportions of carbonaceous material and sulfur employed. For example, we have found that other ingredients, such as barium nitrate,

, may be substituted for a portion of the so- It is to be understood, howbe made, the subject of another application.

It is also to be understood that in the broader aspect of our invention, We do not Wish to be confined to the employment of" the described carbonaceous material, with or Without sulfur, solely for the purpose of overcoming an oxygen excess due to the particular proportions of nitro-starch and nitrate of soda employed in the mixture,.as said carbonaceous material, or carbonaceous material and sulfur, can be usefully employed in nitro-starch powderswhere oxygen excess is due to other causes. For example, in our application filed August 7-, 1913, Serial No. 783,601, we have described the use of a mixture of nitrate of ammonia and trinitrotoluene as a substitute for a portion of the nitro-starch in nitro-starch explosives, and in certain cases such substitution leads to undue oxygen excess, and our present invention may be very usefully employed in mixtures in which the nitrate of ammonia and trinitrotoluene are also employed.

As this application possesses matter in common with an application filed by us August 7, 1913, Serial No. 783,601, it is to be treated as a continuation of said prior application as far as the common subject-mat ter is concerned.

rise,

We clainl: L A detonatmg explosive containing n1- trc-starch as an explosive base, and combustible carbonaceous materlal comprising cereal. screenings 1n the form of hard granules; said carbonaceous materlal not exceed- 3. A detonating explosive containing ni-' tro-starch as an explosive base, an oxygen .carricr in such proportion to said nitrostarch to result in oxygen excess, and combustible carbonaceous material comprising cereal screenings in the form of hard granules; such carbonaceous material being proportioned to proper y balance the oxygen content of the mixture.

4-. A detonatingexplosive containing nitro-starch as an explosive base, combustible carbonaceous mate 'ial comprising cereal screenings in the form or hard granules,

and sulfur. 7 1- dctonatmg explosive containmg n1- s this pa-tent may be obtained for five cents each, by addressing the are 5 tro-starch as an explosive base, an oxygen carrier in such proportion to said nitrosta'rch as to result in oxygen excess, combustible carbonaceous material comprising cereal screenings in the form of hard granules, and sulfur.

6. A detonating explosive containing nitro-starch as an explosive base, an oxygen carrier in such proportion to said nitrostarch as to result in oxygen excess, combustible carbonaceous material comprising cereal screenings in the form of hard granules, and sulfur; the carbonaceous material and sulfur being proportioned to properly balance the oxygen content of the mixture.

7. A detonating explosive containing nitro-starch as an explosive base, combustible carbonaceous material comprising cereal screenings in the form of hard granules, and sulfur; the carbonaceous material and sulfur being used in substantially equal parts by Weight.

In testimony whereof, We have signed our names to this specification, in the presence of two subscribing Witnesses.

JESSE B. BRONSTEIN. CHARLES E. "WALLER.

\Jitnesses M. ELEANOR ROBERTS, J os. H. KLEIN.

"Commissioner or Eatents,

Washington, I9. 3.