US1610274A - Blasting method and apparatus - Google Patents

Description

Dee. 14,1926. 1,610,274

D. FERRELL ET AL BLASTING METHOD AND AFPARAT'US QQ Original Filed Feb. 1l, 1925 N Q N gw Patented Dec.l 14, 1926.

UNITED STATES PATENT OFFICE.

DENT FEBBELL, .ARTHUR W. HELMHOLTZ, AND JOHN H. CBAWFOBI), F HARRIS- .'BUBG, ILLINOIS, ASSIGNORS T0 SAFETY PRESSURE MINING & EQUIPMENT COM PANY, 0F HABRISBURG, ILLINOIS, A CORPORATION OIE' ILLINOIS.

BLASTINGj METHOD .ND APPARATUS.

Application'led February 11, 1925, Serial No. 8,328. Renewed lJecember 19, 1925.

This invention relates toa new and improved blasting method and to an apparatus adapted for carrying out the method.

In mine operation by blasting with the use of explosives as now commonly carried out, it is necessary to clear the mine of the operating personnel before setting oi the blast. This is due to the danger to personnel from fumes and gases evolved by the blast and also Ato the dangenof ignition of mine gases or powdered coal by the highly heated blast gases. These requirements prevent more than one blast in each head or room for each shift and consequently, slowing up production. Y

According to our present invention, we blast by means of apparatus giving o no dangerous gases and without the development of dangerous temperatures. The present invention is in the nature of a modification and improvement of our prior application, Serial' No. 710,724, liled May 3,.

l924.-l In that application, we have disclosed the rupture of a closed container by the gasification of a non-gaseous material by the means of heat.

According to the present invention, we provide heat producing means located within the container and adapted to not only produce heat but to violently agitate the carbon dioxide and thus facilitate the trans- :Eer of the heat.

It is an object of the present invention to provide a new and improved means and method forv blasting without the generation of dangerous heat or gases.

llt is a further object to provide a means and method of this character adapted for use by simple apparatus and which may be utilized without danger to mine personnel.

It is also an object to provide a means and method whereby the blasting force is supplied by the sudden gasification and liberation of a gas held in liquid form in a closed container.

It is an additional object to provide means wherein the heat necessary for gasiication is supplied internally of the container together with Violent agitation of the material. a v

Other and further objects will appear as the description proceeds.

lVe have illustrated a preferred embodimentpf our lnvention in the accompanying drawings in Which- Figure 1 is a longitudinal-section to one form of cartridge;

Figure 2 is a view of the cartridge as seen from the right of Figure l, and- Figure 3v is a fragmentary view similar to Figure l but showing a modified form of construction.

The cartridge comprises the cylindrical outer casing l1, into the right endvowhich 1s secured the ring 12. This ring has been shown as threaded into the casing l1, but it may be brazed or welded or otherwise permanently secured in place. The face 13 of the ring isrounded oli' to minimize the reslstance offered to the vpassage O gases outwardly through the ring. The outer axlal face of the ring is recessed to receive the packing 14. The outer ring 16 which is threaded into the casing 11, as best shown in Figure 2, is provided with the hexagonal opening 17 by means of which it may be Vsecured tightly in position by the use of a Wrench.

The disk 15 is held against the packing 14 by the ring 16 and is provided with the circular groove 18, which may be any desired depth. The thickness of the material left at the base of the groove 18 will determine the force required to rupture the disk on the line of the groove and consequently blow out the central part of the dlsk. The inner face ofthe disk is provided With a stud 19 and adapted to support the tubular member 20.

The ring 21 is screwed into the opposite end of the casing 11. This ring carries the insulating packing member 22 and supports the plug 23, which extends through the ring. The outer end of the plug 23 is threaded and receives the ring 24 which bears against the outer face of the packing 22 and retains the plug in place. The plug 23 is provided with the axial passage 25 communicating through passages 26 with the interior of the casing.

The needle Valve 27 is threaded into the outer end of the plug and receives the needle valve member 28. The housing is provided with the threaded opening 29 adapted to beconnected to a source of Huid supply. The valve is protected by a housing member 30 secured to the outer portion of plug 23 by means of disk 31.

The electrical conductor 32 is secured to the casing 11 and the conductor 33 is secured to the ring 24..` It will be noted that the plug and the associated rings and. valve housingare insulated from the housing.

The member 20 is formed of conducting material and consequently, current will pass through conductor 33 to the plug and thence through member 20 to disk 19 and to the housin 11. From the housing 11 it flows throng conductor 32 back to *the source of current supply.

In ythe form of construction shown in Figure 3 all of the elements are the same as described with the exception of the member 20, For the member 20 is substituted a tubular member 34 formed of non-conducting fluid-proof material. Enclosed within this member is the electrical conductor 35, the ends of which make electrical contact with the nipple 36 on the plug 23 and also with the stud 19 on the disk 15. The tubular member 34 is filled varound the conductor 35 with combustible material 37 adapted for combustion attended by large heat liberation. This material may be ordinary black powder. l

' In the use of either form of construction shown, after the parts have been put in place, a source of fluid under pressure is connected to the opening 29A in the needle valve. The valve is opened and liuid is introduced into the casing up to the desired pressure. The valve is then closed and the source of supply disconnected. The housing member 30 is then screwed in place to protect the valve against accidental injury or opening.

It will be understood that the disk 15 fitted into the cartridge will be adapted to rupture at the desired blasting pressure. The liquid introduced into the cartridge will be brought to a pressure Suiiiciently less than the rupturing pressure of the disk, so as to render the cartridge entirely safe for handling. The conductors 32 and 33 are connected to a suitable source of electric current, the switch controlling which, however, is held open.' The cartridge is then introduced into the drill hole and is tamped in place in the same manner as a charge of dynamite.

In the form of construction shown in Figure 1, it will be necessary to supply a relatively large amount of electricity. It is desired to supply suilicient current so as to cause the member 20 to blow out, or to be substantially instantaneously fused and atomized by the current. This vaporized or asified metal passing into the liquid in all irections very quickly heats the whole body of liquid and raises it to such temperature as to raise its rassure above that re uired for rupturing t e disk l5, The disk lows out and releases the imprisoned liquid which has been gasiied by the heat and which has a blasting effect in the drill hole.

In the form of construction shown in Figure 3, only a small amount of current is necessary. The conductor 35 need merely be heated to such a temperature as to cause the detonation of the black powder or other explosive'37. The explosion of this powder raises the temperature of the surrounding liquid suiciently to gasify it and cause the rupture of the disk l5 and the consequent desired blasting action.

The liquid which is preferably used is carbon dioxide. This liquid when gasiied will form so smalla portion of the air in the mine as to have no harmful eiects. The sudden expansion of the gas will have a refrigerating action and consequently, there will be no dangerous heat evolved from the blasting action. With thel form of construction involving the use of black powder, it will be possible lto use such a small portion of powder vas to have no appreciable defect upon the air. The heat from the powder will be dissipated through a large volume of carbon'dioxide gas evolved upon the blasting rupture of the container. Consequently, either method of gasifying the carbon dioxide may be used without danger to persons in the mine. It will simply be necessary for the personnel to move far enough away from the working face to be out of danger from iying :tiragments.

After the blast, the cylinders may be recovered and the only parts destroyed will be the member 20, or its equivalent in the forni of Figure 3, and the disk 15. The outer ring 16 may be removed and a new member 2O and disk l5 inserted. The casing may then be filled with liquides before and used again. The cost of operation is therefore kept very low since the parts to be replaced are relatively inexpensive and the carbon dioxide may be cheaply secured. While We have mentioned carbon dioxide as a suitable substance to. be used, it will be understood that we .may employ other material in the non-gaseous state, such as air, nitrogen, etc.

While We have illustrated certain preferred forms by way of example, it is to be understood that `we contemplate such changes and modifications as come within the spirit and scope of the appended claims.

We claim:

1. The method of blasting which comprises coniining in a closed container a compressible fluid not a liquid under atmospheric temperatures and pressures, and applying to said Huid a gasitying heat by means of the vaporization of an electrical llo igeiaa'm conductor in the container, the gasification producing a pressure suilicient to rupture a Wall of the container.

2. The method of blastin which comprises confining carbon dioxi e in the non-- gaseous state in a closed container, and applying to said carbon dioxide a gasifying heat by means of the vaporization of an electrical conductor inthe container, the gasification producing a pressure suiiicient to rupture a Wall of the container.

3. 'l`he method of blasting which coniprises coniningin a closed container a compressible fluid not a liquid under atmospheric temperatures and pressures, and applying to said fluid a gasifying heat by means of the vaporization of an electrical conductor and the detonation of. an explosive in the container, the gasification producing a pressure sufficient to rupture a wall of the container.` f

4. The method of blasting which comprises coniining .carbon dioxide in a closed container, and applying to said carbon dioxide a gasifying heat by means of the fu; sion of an electrical conductor and the combustion of material accompaniedby large heat liberation in the container, the gasiiication producing a pressure sufficient to rupture a wall of the container.

5. 'lhe blasting cartridge comprising a casing, means whereby a Huid under pressure may be introduced into the casing, a fusible electrical conductor n the casing and electrical connections for the conductor extending exteriorly of the casing.

6. A blasting cartridge comprising a casing, a removable and replaceable Wall section in the casing, said section being rupturable at less pressure than the remainder i.

of the casing, means whereby ra. Huid under pressure may be introduced into the casing, a fusible electrical conductor in tlie casing, and electrical connections for the conductor extendino exteriorly of the casing.

7. A blasting cartridgeJ comprising a casing, means whereby a li-uid under pressure may be introduced into the casing7 a vaporizable electrical conductor extending length- Wise of the casing and having one end secured to the casing and the other end secured to a plug insulated from the casing and extending through a wall thereof.

8. A blasting cartridge comprising a casing, means whereby a. Huid under pressure may be introduced into the casing, a fusible .electrical conductor in the casing, a body of material located adjacent the fusible conductor, said material being ignitable by neat and adapted for combustion attended by large heat liberation, and electrical connections for the conductor extending exteriorly of the casing..

9. A blasting cartridge comprising a casing, means Whei'eby a iluid under pressure may be introduced into the casing, an innercasing extending longitudinally or' the casing, a material in said inner "casing, said material being ignitible by heat and adapted for combustion attended by large heat liberation, a. fusible electrical conductor extenuinginto the inner casing and having one end secured to tn'e outer casing and the other end secured to a plug insulated from the outer casing and extending through a wail thereof. y

Signed at Harrisburg,"lllinois, this 7th day or' February, 1925. y

DENT FERRELL. A. W. HELMHOLTZ.- JOHN CRAWFORD.

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