US Patent 7887264 Apparatus for transferring particles

Method and apparatus are provided for transferring particles from an upper zone through an intermediate zone to a lower zone. The transfer of particles between the zones through valveless conduits is regulated by varying the pressure of the intermediate zone and the flow rate of gas passing through the valveless conduits. A body within the lower zone is in particle communication with a valveless conduit and obstructs the particle flow within the lower zone.