High power impulse crushing tool and method

A tool for crushing rock by high power impulses, said too comprising a generator and a main pair of electrodes, said generator comprising a high voltage source electrically connected on the one hand to the ground and on the other hand in series at least with a bi-position switch, said switch being electrically connected to a first electrode of the main pair of electrodes, the second electrode of the main pair of electrodes being placed facing the first electrode and being spaced apart by a distance referred to as the “inter-electrode distance””, the tool comprises at least one energy recovery module comprising at least one capacitor and a secondary pair of electrodes, the at least one capacitor of the first energy recovery module being electrically connected on the one hand to the second electrode of the main pair of electrodes and on the other hand to the ground, the secondary pair of electrodes of the first energy recovery module comprising a first electrode, electrically connected at the midpoint located between the second electrode of the main pair of electrodes and the at least one capacitor, and a second electrode, placed facing the first electrode of the secondary pair of electrodes while being spaced apart by a second inter-electrode distance and electrically connected to the ground.

A method for recovering high power impulse energy for rock crushing, said method comprising the steps of:

• controlling a first electrical discharge between a first electrode and a second electrode of a main pair of electrodes,
• recovering a part of the energy of the first electrical discharge by at least one capacitor connected between the second electrode of the main pair of electrodes and a ground,
• triggering a second electrical discharge between a first electrode and a second electrode of a secondary pair of electrodes of a first energy recovery module.