BLASTING CARTRIDGE, BLASTING APPARATUS, AND BLASTING METHOD

• US 20120180684A1
• Filed: 09/01/2010
• Published: 07/19/2012
• Est. Priority Date: 09/28/2009
• Status: Active Grant

• Current Assignee: Hitachi Zosen Corporation
• Original Assignee: Hitachi Zosen Corporation
• Inventors: Sasaki, Katsuya, Kitajima, Hideaki, Sakamoto, Ryo, Ohnishi, Takaaki
• Granted Patent: US 8,904,938 B2
• Time in Patent Office: Days
• US Class Current: 102/322
• CPC Class Codes: E04G 23/083 using vaporising wire technique particular applications of blasting techniques F42D3/00
• CPC Class Codes: F42B 3/00 Blasting cartridges, i.e. case and explosive fuse cords, e.g. detonating fuse cords C06C5/00; chemical aspects of detonators, blasting caps or primers C06C7/00
• CPC Class Codes: F42B 3/11 characterised by the material used, e.g. for initiator case or electric leads F42B3/107 takes precedence
• CPC Class Codes: F42B 3/124 characterised by the configuration or material of the bridge F42B3/13 takes precedence
• CPC Class Codes: F42B 3/128 characterised by the composition of the pyrotechnic material
• CPC Class Codes: F42D 3/04 for rock blasting

Abstract

A blasting cartridge includes a generally cylindrical blasting container, a blasting substance filled in the blasting container, a pair of leadwires contained in the blasting container, and a single thin metal wire connected to tip portions of the pair of leadwires. The leadwires and the thin metal wire are positioned within the blasting substance within the blasting container. The blasting substance is nitromethane, and the thin metal wire is formed of tungsten. With an electric discharge impact blasting apparatus, since the thin metal wire has a higher heating value than a copper wire because of its higher resistance and vaporizes at higher temperatures, it is possible to obtain a greater blasting force at lower voltages than with a blasting apparatus using a copper wire.

Claims

1. A blasting cartridge to be used in a blasting apparatus that blasts an object, comprising:

a self-reactive blasting substance;

a container that contains said blasting substance;

a thin tungsten wire disposed within said blasting substance; and

a pair of leadwires whose one ends are connected to both ends of said thin tungsten wire and whose other ends are connected to a power supply device outside said container.

2. The blasting cartridge according to claim 1, wherein,

said thin tungsten wire is formed of a single thin metal wire or two or three stranded thin metal wires.

3. The blasting cartridge according to claim 1, wherein

said thin tungsten wire has a length greater than or equal to 10 mm and less than or equal to 120 mm and a cross-sectional area greater than or equal to 0.03 mm² and less than or equal to 0.13 mm².

4. The blasting cartridge according to claim 1, wherein

said blasting substance is nitromethane.

5. The blasting cartridge according to claim 2, wherein

said blasting substance is nitromethane.

6. The blasting cartridge according to claim 3, wherein

said blasting substance is nitromethane.

7. A blasting apparatus for blasting an object, comprising:

a blasting cartridge; and

a power supply device, wherein

said blasting cartridge comprises;

a self-reactive blasting substance;

a container that contains said blasting substance;

a thin tungsten wire disposed within said blasting substance; and

a pair of leadwires whose one ends are connected to both ends of said thin tungsten wire and whose other ends are connected to said power supply device outside said container, and

said power supply device comprises;

a capacitor connected to said pair of leadwires;

a power supply part that supplies electric energy to said capacitor; and

a discharge switch that discharges electric energy accumulated in said capacitor to said thin tungsten wire through said pair of leadwires.

8. The blasting apparatus according to claim 7, wherein,

said thin tungsten wire is formed of a single thin metal wire or two or three stranded thin metal wires.

9. The blasting apparatus according to claim 7, wherein

said thin tungsten wire has a length greater than or equal to 10 mm and less than or equal to 120 mm and a cross-sectional area greater than or equal to 0.03 mm² and less than or equal to 0.13 mm².

10. The blasting apparatus according to claim 7, wherein

said blasting substance is nitromethane.

11. The blasting apparatus according to claim 7, wherein

a discharge voltage applied to said thin tungsten wire is greater than or equal to 1500 V and less than or equal to 3000 V.

12. The blasting apparatus according to claim 7, wherein

said capacitor has an electrostatic capacitance greater than or equal to 100 μ

F and less than or equal to 1000 μ

F.

13. A blasting method for blasting an object, comprising the steps of:

a) housing a self-reactive blasting substance in a recessed portion formed in an object, such that a thin tungsten wire whose both ends are connected to a pair of leadwires is positioned within said blasting substance; and

b) causing said thin tungsten wire to melt and vaporize by supplying electric energy to said pair of leadwires and blasting said object by an impact force caused by said blasting substance.

14. The blasting method according to claim 13, wherein,

said thin tungsten wire is formed of a single thin metal wire or two or three stranded thin metal wires.

15. The blasting method according to claim 13, wherein

said thin tungsten wire has a length greater than or equal to 10 mm and less than or equal to 120 mm and a cross-sectional area greater than or equal to 0.03 mm² and less than or equal to 0.13 mm².

16. The blasting method according to claim 13, wherein said blasting substance is nitromethane.

17. The blasting method according to claim 13, wherein

a discharge voltage applied to said thin tungsten wire is greater than or equal to 1500 V and less than or equal to 3000 V.

18. The blasting method according to claim 13, wherein

said capacitor has an electrostatic capacitance greater than or equal to 100 μ

F and less than or equal to 1000 μ

F.