Apparatus and Method for Sintering Proppants

A method for sintering green pellets to make proppant particles comprising the steps of:

• providing an apparatus comprising:
• a vessel having an overflow disposed in a first end, an underflow disposed in a second end, a middle portion having a circular cross-section disposed between the first end and the second end, and a tangential inlet proximate to the first end,
• a first electrode extending through the overflow and a second electrode extending through the underflow, wherein both electrodes are at least partially disposed within the vessel, spaced apart from one another, and axially aligned with another along a central axis of the vessel from the first end to the second end, and
• one or more feed tubes extending through the overflow proximate to the first electrode;
• directing a gas into the tangential inlet to flow in a vortex path from the first end to the second end of the vessel;
• creating an open electrical arc between the first electrode and the second electrode;
• and
• dropping the green pellets from the one or more feed tubes, such that the green pellets are sintered or partially sintered in a selected temperature range to form proppant particles as the green pellets pass between the electrical arc and the gas flowing in the vortex path and exit the underflow.

A method for sintering green pellets to make proppant particles comprising the steps of:

• providing an apparatus comprising:
• a vessel having an overflow disposed in a first end, an underflow disposed in a second end, a middle portion having a circular cross-section disposed between the first end and the second end, and a tangential inlet proximate to the first end,
• a first electrode extending through the overflow and a second electrode extending through the underflow, wherein both electrodes are at least partially disposed within the vessel, spaced apart from one another, and axially aligned with one another along a central axis of the vessel from the first end to the second end,
• a linear actuator connected to the first electrode or the second electrode,
• a DC power source connected to the first and second electrodes,
• one or more feed tubes extending through the overflow proximate to the first electrode, and
• a heated gas source connected to the one or more feed tubes;
• directing a gas into the tangential inlet to flow in a vortex path from the first end to the second end of the vessel;
• creating an open electrical arc between the first electrode and the second electrode by moving the first electrode or the second electrode to strike the electrical arc between first electrode and the second electrode using the linear actuator;
• pre-heating the green pellets within the one or more feed tubes using the heated gas source;
• and
• dropping the green pellets from the one or more feed tubes, such that the green pellets are sintered or partially sintered to form proppant particles as the green pellets pass between the electrical arc and the gas flowing in the vortex path and exit the underflow.