Particle-delivery in abrasive-jet systems

A particle-delivery device, comprising:

• a hopper configured to contain abrasive particles;
• an elongate fluidizing chamber having a first end portion and an opposite second end portion, wherein the fluidizing chamber is positioned to receive abrasive particles from the hopper via the first end portion;
• an outlet conduit downstream from the fluidizing chamber, wherein abrasive particles travel along a flow path extending from the fluidizing chamber to the outlet conduit;
• and
• a metering assembly positioned along the flow path between the fluidizing chamber and the outlet conduit, wherein the metering assembly includes:
• a metering opening at the second end portion of the fluidizing chamber,
• a plurality of injection orifices, wherein individual injection orifices within the plurality of injection orifices are distributed around the metering opening at the second end portion of the fluidizing chamber,
• a regulator configured to change a steady-state pressure, a steady-state flow rate, or both of carrier gas entering the fluidizing chamber via the plurality of injection orifices, and
• a manifold chamber extending around the flow path, wherein the manifold chamber is configured to distribute carrier gas among the individual injection orifices.

A method of supplying abrasive particles to an abrasive jet, the method comprising:

• flowing a first quantity of non-fluidized abrasive particles at a first steady-state flow rate from a container through a metering opening of a metering assembly operably connected to the container;
• introducing carrier gas at a first carrier-gas pressure and a first carrier-gas flow rate into a second quantity of abrasive particles within the container to fluidized the second quantity of abrasive particles;
• flowing the second quantity of abrasive particles at a second steady-state flow rate from the container through the metering opening while the second quantity of abrasive particles is fluidized;
• introducing carrier gas at a second carrier-gas pressure and a second carrier-gas flow rate into a third quantity of abrasive particles within the container to fluidized the third quantity of abrasive particles;
• and
• flowing the third quantity of abrasive particles at a third steady-state flow rate from the container through the metering opening while the third quantity of abrasive particles is fluidized,
• wherein:
• the second carrier-gas pressure is greater than the first carrier-gas pressure, the second carrier-gas flow rate is greater than the first carrier-gas flow rate, or both, and
• the first, second, and third steady-state flow rates are different.

A method of supplying abrasive particles to an abrasive jet, the method comprising:

• moving abrasive particles from a hopper into an elongate fluidizing chamber operably connected to the hopper;
• injecting carrier gas into the fluidizing chamber to fluidize abrasive particles within the fluidizing chamber while other abrasive particles within the fluidizing chamber upstream from the fluidized abrasive particles are non-fluidized;
• flowing fluidized abrasive particles from the fluidizing chamber through a metering opening of a metering assembly operably connected to the fluidizing chamber;
• and
• operating a regulator to change a steady-state pressure, a steady-state flow rate, or both of carrier gas injected into the fluidizing chamber to change a flow rate of abrasive particles moving through the metering opening.