Method and apparatus for controlling the bed temperature in a circulating fluidised bed reactor

摘要

Bed temperature in a circulating fluidised bed (CFB) reactor (6) is controlled by varying a re-circulation rate of particles collected by a secondary particle separator (22) back to the CFB reactor (6). Particle storage means (40), sized to contain sufficient inventory required for bed inventory/temperature control due to fuel/sorbent variations and/or load changes, stores particles collected by the secondary particle separator (22). The storage means (40) can be either directly below the secondary particle separator or at a remote location. Particles collected by the secondary particle separator (22) rather than by the primary particle separator (20) are preferred due to their smaller size and lower temperature. A bed temperature control system (80) controls the re-circulation rate of these particles back to the reactor (6). Level sensing devices (44) are provided on the storage means. A solids storage level control system (81) that interacts with the bed temperature control system (80) controls the solids inventory in the storage means via a purge system (46).