Method for blasting object to be treated in pressure vessel

Patent metadata

Field	Value
Publication number	US-9618311-B2
Application number	US-201314371602-A
Country	US
Kind code	B2
Filing date	Jan 22, 2013
Priority date	Feb 6, 2012
Publication date	Apr 11, 2017
Grant date	Apr 11, 2017

Abstract

A blast treatment method for blasting an object includes: a step in which an explosive is detonated inside a pressure vessel ( 30 ) which has an elasto-plastic metal, thereby imparting to the pressure vessel ( 30 ) an initial load wherein the primary and secondary stress generated in at least a portion of the pressure vessel becomes high enough to be in a plastic region exceeding the elastic region, thereby generating a shakedown state in the pressure vessel ( 30 ); and a subsequent step in which a treatment explosive ( 50 ) is detonated within the pressure vessel ( 30 ), thereby blasting the object ( 10 ).

First claim

The invention claimed is:

1. A method for blasting an object to be treated, including:
preparing a pressure vessel that comprises a metal having elasto-plasticity, has a shape allowing the object to be treated to be contained in a closed state, and has an inner circumferential surface to receive detonation energy generated when the object to be treated is blasted in a contained state;
giving an initial load to the pressure vessel to the extent that the sum of a primary stress and a secondary stress generated in the pressure vessel exceeds an elastic limit and reaches a plastic region at least at a part of a structural part excluding a local structural discontinuous part of the pressure vessel and generating a shakedown state to the pressure vessel by containing an explosive, sealing the pressure vessel, and detonating the explosive to give the initial load; and
blasting the object to be treated in the pressure vessel by containing the object to be treated and a treatment explosive in the pressure vessel after the initial load is given, sealing the pressure vessel, and detonating the treatment explosive.

2. A method according to claim 1 , wherein the treatment process includes a process of detonating the treatment explosive to the extent that a load smaller than the initial load is applied to the pressure vessel and the treatment process is carried out several times after the process giving the initial load.

3. A method according to claim 2 , wherein: the method further includes a strain measurement process to measure a residual strain at a predetermined measurement point in the structural part of the pressure vessel after the treatment process; and the treatment process for another object to be treated is continued when the specific condition that the accumulated quantity of the measured residual strains is smaller than a predetermined reference quantity is satisfied and in contrast the treatment process is prohibited from continuing when the specific condition is unsatisfied.

4. A method according to claim 1 ,
wherein the initial load is set so that, on all the cross-sections of the structural part of the pressure vessel, the stress at least at a part on each of the cross-sections may be smaller than a yield strength.

5. A method according to claim 2 ,
wherein the initial load is set so that, on all the cross-sections of the structural part of the pressure vessel, the stress at least at a part on each of the cross-sections may be smaller than a yield strength.

6. A method according to claim 3 ,
wherein the initial load is set so that, on all the cross-sections of the structural part of the pressure vessel, the stress at least at a part on each of the cross-sections may be smaller than a yield strength.

Assignees

• Kobe Steel Ltd

Inventors

• Hayashi Koichi
• Shirakura Takao
• Asahina Kiyoshi

Classifications

• C21D7/10

  of the whole cross-section, e.g. of concrete reinforcing bars · CPC title

• F42D3/00

  Particular applications of blasting techniques {(explosive welding B23K20/08; explosive bolts or actuators F42B3/006; explosive valves F16K13/06; cutting devices actuated by explosion B23D15/145; pyrotechnical actuators F15B15/19; switching devices actuated by explosion H01H39/00)} · CPC title

• B21D26/08

  generated by explosives, e.g. chemical explosives · CPC title

• F42B33/06 Primary

  Dismantling fuzes, cartridges, projectiles, missiles, rockets or bombs ({F42B33/004 and} F42B33/04 take precedence; {elimination of undesirable components of explosives C06B21/0091}) · CPC title

• C21D9/0068

  for particular articles not mentioned below · CPC title