US3768411A

US3768411A - Safety blasting apparatus and method

Info

Publication number: US3768411A
Application number: US00202876A
Authority: US
Inventors: A Abbott; J Steffey; M Maes; J Friant
Original assignee: EXPLOSIVES CORP AMERICA
Current assignee: Explosives Corp of America; EXPLOSIVES CORP AMERICA
Priority date: 1971-11-29
Filing date: 1971-11-29
Publication date: 1973-10-30
Anticipated expiration: 1990-10-30
Also published as: ZM14972A1

Abstract

A two component explosive mix package having two component containing chambers separated by a rupturable wall. A detonating cord is arranged in sufficient proximity to the rupturable wall so that detonation of the cord ruptures the wall to cause mixing of the two components to make an explosive mixture. Thereafter activation of other detonating means causes the mixture to explode.

Description

Hit States Patent [1 1 Maes et a1.

[451 Oct. 30, 1973 SAFETY BLASTING APPARATUS AND METHOD [75] Inventors: Michel E. Maes, Bellevue; James E.

Friant, Renton; Albert F. Abbott, Seattle, all of Wash.; James R. Steffey, Paris, France [73] Assignee: Explosives Corporation of America,

lssaquah, Wash.

[22] Filed: Nov. 29, 1971 [21] Appl. No.: 202,876

[52] 11.8. C1. 102/24 R, 102/23, 102/70 R [51] int. Cl. F42b 3/00, F42d 1/06, F42d 3/04 [58] Field of Search 102/28, 57, 58, 24 R,

[56] References Cited UNITED STATES PATENTS 3,610,150 10/1971 Teichmann ..102/23 3,580,171 5/1971 0 Maes 102/28 Primary ExaminerBenjamin A. Borchelt Assistant Examiner-l V. Doramus Attorney-John O. Graybeal et al.

[57] ABSTRACT A two component explosive mix package having two component containing chambers separated by a rupturable wall. A detonating cord is arranged in suffi' cient proximity to the rupturable wall so that detonation of the cord ruptures the wall to cause mixing of the two components to make an explosive mixture. Thereafter activation of other detonating means causes the mixture to explode.

10 Claims, 9 Drawing Figures PATENIEBnmo 1975 3.768541 1 SHEET 2 OF 2 00 6 o a o SAFETY BLASTING APPARATUS AND METHOD In a first embodiment there are one or more packages, each having an inner and an outer annular component containing chamber. An elongate actuating member reaches through the center of the package or packages, and has along its length two detonating cords spaced from one another. Detonation of the first cord causes the rupturable wall to open to cause the two components to mix, and detonation of the second cord causes explosion of the mixture. The second embodiment is similar to the first embodiment, except that there is only a first detonating cord in the center passageway of the package to cause mixing of the two components, and a detonating well is provided in the package to detonate the explosive mixture.

In a third embodiment, there is a cylindrical container defining a first chamber, and a longitudinal rupturable wall member defining a second chamber formed in transverse section as an arcuate section of the cylindrical first chamber.

In a fourth embodiment, there is a cylindrical container defining a first chamber, and a coiled tubular member within the first container to contain a second explosive mix component. The detonating mixing cord is disposed along the length of the second coiled containing member.

In a fifth embodiment there are separate packages of the first and second explosive mix component stacked alternately. Each package has a center opening to receive an actuating member having two detonating cords as in the first embodiment.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to an apparatus and method for field mixing of a two component explosive, and more particularly to an apparatus and method for mixing of a two component explosive installation in a bore hole.

2. Description of the Prior Art Several prior art patents show containers or packages having two separate explosive mix components which by mechanical means are caused to be intermixed. Typical of these are: Lewis US. Pat. No. 2,929,325; Hopkins U.S. Pat. No. 2,426,269 and Maes US. Pat. No. 3,580,171.

SUMMARY OF THE INVENTION In the present invention, there is a blasting package assembly having first and second chambers containing respective first and second explosive mix components, and having explosively openable separating means for said two components. Actuation of a first explosive mixing means causes said separating means to open to permit intermixing of the two components to form an explosive mixture which can then be detonated by detonating means.

In a first embodiment, there is a blasting package having annular, circumjacent, longitudinally aligned first and second chambers separated by a rupturable wall or membrane. An elongate actuating member fits through a center opening in the package. This actuating member has two longitudinally aligned, circumferentially spaced detonating cords, one for rupturing the separating wall to cause mixing of the two components and the other to detonate the explosive mixture.

A second embodiment, similar to the first embodiment, has only a single detonating cord in a center opening, and a detonating well formed in the package for exploding the mixture.

In a third embodiment, there is a cylindrical container defining the first chamber, with a rupturable wall defining a longitudinal, arcuate section out of the cyindrical container as the second chamber. There is a centrally disposed explosive mixing cord, and a cord located proximate the outside wall of the container to detonate the explosive mixture.

In a fourth embodiment there is a cylindrical container defining the first chamber, and a tubular container coiled therein to define the second chamber. The explosive mixing cord is disposed lengthwise in the coiled tubular container.

In a fifth embodiment, a plurality of separate first and second packages containing, respectively, first and second explosive mix components, are stacked alternately on top of one another. An actuating member, similar to that of the first embodiment, extends through these packages for first mixing and then detonating the resulting explosive mixture.

In the process of the present invention, one or more two component package assemblies are inserted into a bore hole in their unmixed condition and can be stored there for a period of time. The explosive mixing means is then detonated to rupture the separating means to cause intermixing of the two explosive mix components. Then the explosive mixture is detonated.

In the particular process of the first embodiment, one or more of the two component packages are moved along the actuating member into the bore hole. In other embodiments, the one or more packages can be strung on the explosive mixing cord downwardly to a bore hole.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view illustrating the process of the present invention;

FIG. 2 is a longitudinal sectional view of the apparatus of the first embodiment of the present invention;

FIG. 3 is a sectional view taken on line 3-3 of FIG.

FIG. 4 is a partial longitudinal sectional view of a second embodiment of the present invention;

FIG. 5 is a transverse sectional view taken along line 5-5 of FIG. 4;

FIG. 6 is a sectional view similar to FIG. 5, illustrating a third embodiment of the present invention;

FIG. 7 is a view similar to FIG. 4, illustrating a fourth embodiment of the present invention;

FIG. 8 is a view similar to FIG. 7, illustrating yet a fifth embodiment of the present invention, and

FIG. 9 is a transverse sectional view taken along line 9-9 of FIG. 7.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The first embodiment of the invention is shown in FIGS. 1, 2 and 3. The main components are one or more component blasting packages 10 and an actuating member 12 to cause first mixing and then detonation of the explosive components in the package or packages 10.

One such blasting package is illustrated in detail in FIGS. 2 and 3. The blasting package 10 comprises concentric cylindrical walls, namely an outer wall 14, an intermediate wall 16, and an inner wall 18. The outer and intermediate walls 14 and 16 define a first annular chamber 20, containing a first solid explosive mix component, such as ammonium nitrate in powdered or granular form. The intermediate and inner walls 16 and 18 define a second annular inner chamber 22 containing a second liquid explosive mix component, such as hydrazine or a mixture of hydrazine and water. The two

chambers

20 and 22 are closed by front and rear closure caps 24 and 26, respectively. The entire package can be made of polyethylene or other suitable material, and can be a flexible package.

The inner wall 18 defines a center through opening 28 adapted to receive the aforementioned elongate actuating member 12. A locking collar 30 is mounted around the outer wall 14. This collar 30 has circumferentially spaced outwardly and rearwardly protruding ears 32, the function of the ears 32 being to hold the package in place after the package 10 is pushed into a bore hole.

The actuating member 12 has an elongate cylindrical configuration, is desirably made of flexible plastic, and has formed thereon two longitudinal grooves 34 and 36. In the groove 34 is a relatively small detonating cord 38 which serves the function of explosively mixing the two explosive mix components in the

chambers

22 and 20. In the groove 36 is a second larger detonating cord 40 which serves to detonate the resulting explosive mixture. The two detonating cords 38 and 40 are circumferentially spaced on the rod 12 (as shown herein in diametrically opposed relationship) so that detonation of the cord 38 will not cause premature detonation of the cord 40.

The operation of the present invention can best be described with reference to FIG. 1, wherein there is shown an upwardly directed drilled passageway or bore hole 42 in an ore formation. First, a length of actuating member 12 is taken from a spool 44 (shown porportionately smaller for convenience of illustration) on which the member 12 is wound, and this length 12 is inserted upwardly into the hole 42. Then one or more blasting packages 10 are slipped over the member 12 (with the member 12 extending through the package center opening 28), and the one or more packages 10 are pushed upwardly into the hole 42. This can be accomplished, for example, by means of a pipe fitting over the member 12 being used as a pusher or a ram. The ears 32 function to bear against the surrounding hole wall to hold the packages in place in the hole 42. In this condition, the explosive assembly is quite safe, since the two separate explosive mix components are separately non-detonable. This assembly can be left in place in the hole 42 for a period of months.

When it is desired to blast in the hole 42, first the explosive mixing detonating cord 38 is detonated. The explosive shock from the cord 38 travels outwardly against the liquid component in the chamber 22 rupturing the intermediate wall 16. The moderate explosive force also forces some of the liquid mix component into the outer chamber 20. In a short time (e.g. to 30 seconds) the liquid component soaks into the solid explosive mix component to make an explosive mixture. The detonating cord 40 is then detonated to cause the mixture of the first and second mix components to explode.

The second embodiment is shown in FIGS. 4 and 5. Since this second embodiment is quite similar to the first embodiment, like components will be given like numerical designations, with an a" suffix distinguishing those of the second embodiment.

There is a package 100 having a plurality of concentric

cylindrical walls

140, 16a and 18a defining two concentric chambers 20a and 2211. However, the center opening 28a is of a smaller diameter than in the first embodiment, and receives only an explosive mixing cord 380. In one end of the package 10a there is formed a detonator well 46 to receive either a detonating cord or other detonator, such as an electric or fuse type detonator.

As in the first embodiment, one or more packages 10a are placed in a bore hole, with a mixing detonating cord in the center thereof. The mixing cord 38a is detonated to cause mixing of the two components, and the explosive mixture can then be detonated in a suitable manner by means of a detonator in the well 46.

The third embodiment is illustrated in FIG. 6. There is a cylindrical container 48 defining a first component chamber 50. Within the container 48 is a longitudinal wall member 52 defining an elongate arcuate chamber 54, which is the second component chamber. In a center opening of the container 48, adjacent the longitudinal apex of the wall member 52 is a first detonating cord 56, which serves as the explosive mixing means. A second detonating cord 58 adjacent the outer wall of the container 48, serves to detonate the explosive mixture. The mode of operation is substantially the same as in the second embodiment.

The fourth embodiment is shown in FIGS. 7 and 9. There is a cylindrical container 60 defining a first component chamber 62. Coiled in the chamber 62 is a tubular container 64 containing the second explosive mix component. Running the length of the tubular container 64 and adjacent the wall thereof, is an explosive mixing cord 66. Detonating the cord 66 causes the two components to mix to form an explosive mixture. Then other detonating means can be used to cause explosion of the mixture.

The fifth embodiment is illustrated in FIG. 8. In the fifth embodiment there is a cylindrical actuating member 12b, similar in configuration and function to the aforementioned actuating member 12 of the first embodiment. Thus this member 12b has running the length thereof two spaced detonating cords, similar to those shown in FIG. 3, one for mixing the two components and the other for causing detonation of the explosive mixture.

In this fifth embodiment, there are first and second

annular packages

68 and 70, respectively. The one or more packages 68 contain the first explosive mix component and the one or more packages 70 contain the second explosive mix component. Either one set of

packages

68 and 70, or several sets of the

packages

68 and 70 are placed in the bore hole onto the actuating member 12b. When

several packages

68 and 70 are used, they are stacked in alternate relationship. If desired, these

packages

68 and 70 can be encased in a cylindrical container 72. In other respects, the mode of operating is substantially the same as in the first embodiment.

What is claimed is:

1. A safety two component explosive assembly adapted for down hole mixing and subsequent detonation, said assembly comprising:

a. blasting package means having first and second containing means contiguous to one another, in-

cluding separating means for said containing means,

b. first and second separately non-explosive mix components in, respectively, said first and second containing means,

c. an explosive mixing means positioned in said package means in a manner to explosively open said separating means upon activation of said explosive mixing means to cause mixing of the said two components into an explosive mixture, and

d. a detonating means operable separately from said explosive mixing means and spaced sufficiently from said explosive mixing means so that activation of said explosive mixing means does not cause premature activation of said detonating means, said detonating means being so disposed in said assembly as to cause detonation of said explosive mixture upon activation thereof,

whereby initial activation of said explosive mixing means causes formation of said explosive mixture, and subsequent independent activation of said detonating means causes said explosive mixture to detonate.

2. The assembly as recited in claim 1, further comprising an elongate actuating member positioned in proximity with said package means, said explosive mixing means comprising a first detonating cord positioned along the length of said actuating member, and said detonating means comprising a second detonating cord positioned along said actuating member in spaced relationship with respect to said first detonating cord.

3. The assembly as recited in claim 2, wherein said package means has an annular configuration with an internal through opening, and said actuating means is positioned in said opening.

4. The assembly as recited in claim 3, wherein said package means has an annular configuration with an interior through opening, and said explosive mixing means comprises a detonating cord positioned in said through opening, and said detonating means comprises a second detonating cord positioned in proximity to said package means at a location spaced outwardly from said first detonating cord.

5. The assembly as recited in claim 2, wherein said first and second containing means comprises first and second packages in stacked relationship along the length of said actuating member.

6. The assembly as recited in claim 5, wherein there is a plurality of stacked first and second packages with said first and second packages being stacked alternately.

7. A method of in-hole mixing and detonation of an explosive composition, said method comprising:

a. placing in a hole a blasting package means having first and second containing means contiguous to one another, containing, respectively, first and second independently non-explosive mix components, with separating means separating said components,

b. also placing in proximity to said package means a first explosive mixing means and a second detonating means spaced from said explosive mixing means,

c. activating said explosive mixing means to open said separating means and effect intermixing of said first and second components to form an explosive mixture,

d. subsequent to the mixing of the two components to form an explosive mixture, activating the detonating means to cause detonation of said explosive mixture.

8. The method as recited in claim 7, wherein one of said components comprises ammonium nitrate, and the other component comprises a liquid selected from a group consisting of hydrazine and a mixture of hydrazine and water, and said mixing of said two components is accomplished by explosively opening said containing means to cause said liquid component to wet said ammonium nitrate.

9. A method of mixing a two-component explosive in a relatively narrow passageway and detonating the same, said method comprising:

a. inserting in said passageway an elongate actuating member having mounted thereto an explosive mixing detonating cord,

b. mounting to said actuating member explosive package means having first and second containing means containing, respectively to a position where said first and second containing means are contiguous to one another, first and second independently non-explosive components,

0. moving said package means along said member into said passageway,

d. actuating said detonating cord to cause mixing of said first and second components to form an explosive mixture, and

e. subsequent to said mixing, detonating said explosive mixture.

10. The method as recited in claim 9, wherein said actuating member is inserted into said hole with second detonating cord.

I UNI'I'ED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 768,4l l Dated October 304 1973 m Michel E. Maes et al It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 6, lines 34, 35, and 36, beginning on line 34, after "respectively" delete -"to a position where said first and second containing means are contiguous to one another"-.-

Column 6, line 39, after "passageway insert to a position where said first and second containing means are contiguous to one another.

Signed andsealed this 29th day of April 1975.

(SEAL) Attest: A

C. MARSHALL DANN RUTH C. MASON Commissioner of Patents -Attesting Officer and Trademarks

Claims

1. A safety two component explosive assembly adapted for down hole mixing and subsequent detonation, said assembly comprising: a. blasting package means having first and second containing means contiguous to one another, including separating means for said containing means, b. first and second separately non-explosive mix components in, respectively, said first and second containing means, c. an explosive mixing means positioned in said package means in a manner to explosively open said separating means upon activation of said explosive mixing means to cause mixing of the said two components into an explosive mixture, and d. a detonating means operable separately from said explosive mixing means and spaced sufficiently from said explosive mixing means so that activation of said explosive mixing means does not cause premature activation of said detonating means, said detonating means being so disposed in said assembly as to cause detonation of said explosive mixture upon activation thereof, whereby initial activation of said explosive mixing means causes formation of said explosive mixture, and subsequent independent activation of said detonating means causes said explosive mixture to detonate.

7. A method of in-hole mixing and detonation of an explosive composition, said method comprising: a. placing in a hole a blasting package means having first and second containing means contiguous to one another, containing, respectively, first and second independently non-explosive mix components, with separating means separating said components, b. also placing in proximity to said package means a first explosive mixing means and a second detonating means spaced from said explosive mixing means, c. activating said explosive mixing means to open said separating means and effect intermixing of said first and second components to form an explosive mixture, d. subsequent to the mixing of the two components to form an explosive mixture, activating the detonating means to cause detonation of said explosive mixture.

9. A method of mixing a two-component explosive in a relatively narrow passageway and detonating the same, said method comprising: a. inserting in said passageway an elongate actuating member having mounted thereto an explosive mixing detonating cord, b. mounting to said actuating member explosive package means having first and second containing means containing, respectively ''''to a position where said first and second containing means are contiguous to one another'''', first and second independently non-explosive components, c. moving said package means along said member into said passageway, d. actuating said detonating cord to cause mixing of said first and second components to form an explosive mixture, and e. subsequent to said mixing, detonating said explosive mixture.

10. The method as recited in claim 9, wherein said actuating member is inserted into said hole with second detonating cord means mounted thereon in spaced relationship to said first named detonating cord, and detonating said explosive mixture by actuating said second detonating cord.