摘要:
A device for transporting particles of a magnetic material in a selected direction, the device comprising a support member having a support surface (21) for supporting the particles, the support surface extending in the selected direction, a magnet (28) arranged to generate a magnetic field retaining the magnetic particles on the support surface, the magnetic field having at least one region (32) of reduced field strength at the support surface relative to a field strength of the magnetic field at the support surface outside said region, and drive means (36) for moving each region of reduced field strength relative to the support surface in a direction having a component in the selected direction.
摘要:
A jet cutting device comprising a cutter head provided with at least one nozzle for ejecting a stream of fluid against a body so as to create a selected cut in said body, is discloded. For each nozzle, the cutter head is provided with a deflector having a deflection surface arranged to deflect the stream of fluid ejected by the nozzle into a selected direction in accordance with the position of said cut to be created.
摘要:
A drilling assembly for drilling a borehole into an earth formation is provided, comprising drill string extending into the borehole and a jetting device arranged at a lower part of the drill string, the jetting device being provided with a mixing chamber having a first inlet in fluid communication with a drilling fluid supply conduit, a second inlet for abrasive particles and an outlet which is in fluid communication with a jetting nozzle arranged to jet a stream of abrasive particles and drilling fluid against at least one of the borehole bottom and the borehole wall. The jetting device is further provided with an abrasive particles recirculation system for separating the abrasive particles from the drilling fluid at a selected location where the stream flows from said at least one of the borehole bottom and the borehole wall towards the upper end of the borehole and for supplying the separated abrasive particles to the second inlet.
摘要:
A drilling assembly for drilling a borehole into an earth formation is provided, comprising drill string extending into the borehole and a jetting device arranged at a lower part of the drill string, the jetting device being provided with a mixing chamber having a first inlet in fluid communication with a drilling fluid supply conduit, a second inlet for abrasive particles and an outlet which is in fluid communication with a jetting nozzle arranged to jet a stream of abrasive particles and drilling fluid against at least one of the borehole bottom and the borehole wall. The jetting device is further provided with an abrasive particles recirculation system for separating the abrasive particles from the drilling fluid at a selected location where the stream flows from said at least one of the borehole bottom and the borehole wall towards the upper end of the borehole and for supplying the separated abrasive particles to the second inlet.