Abstract: Fluidized bed reactor method and apparatus for removal of coarse material from the reactor. The apparatus comprises a discharge device including a substantially vertical pipe portion connected at one end with an outlet opening in the reactor grid, and at another end to an aeration chamber containing a discharge opening located below the level of the grid outlet opening; and a device for supplying pressurized air in short blasts of 30 to 100 milliseconds, preferably at pressures of from 2.5 to 7.0 bar, into the aeration chamber in the direction of the discharge opening to remove the coarse material from the reactor. Low pressure fluidizing air may be supplied to the vertical pipe portion as well as the aeration chamber to return small particles in the discharge device to the fluidization zone of the reactor.