INSTRUMENT FOR BORING OBJECT Russian patent published in 2009 - IPC E21B7/18 

FIELD: mining.

SUBSTANCE: present invention pertains to a boring instrument, particularly to a water jet apparatus for bore-hole drilling. The instrument has a water jet system, meant for applying onto the bored object, a stream of boring fluid, mixed with abrasive particles. The water jet system has a mixing chamber with a first inlet channel for boring fluid, a second inlet channel for abrasive particles and an outlet nozzle for the boring fluid, mixed with abrasive particles. The water jet system of the instrument is meant for re-circulating, at least, some of the abrasive particles from the returning current of boring fluid, mixed with abrasive particles, down along the surface where the jets hit the object, back into the jet system. The abrasive particles contain a magnetic material. The recirculation system has a separator magnet for separating abrasive particles from the returning current and for moving particles to the second inlet channel. The instrument also has a component made from magnetic material, fitted in the mixing chamber or near it, which is meant for drawing part of magnetic field, formed by the separator magnet, into the mixing chamber.

EFFECT: increased efficiency of the boring instrument.

6 cl, 7 dwg