FCC combustion zone catalyst cooling apparatus

摘要

An apparatus for the cooling of hot fluidized solid particles such as catalyst of an FCC petroleum refining process includes a conduit in which particles flow downward from a first dense phase fluidized bed into a cooling chamber and contact the shell side of a vertically oriented shell and tube heat exchanger where cooling occurs via indirect heat exchange with a cooling medium circulating in the tubes. The extent of cooling is controlled by the varying of the heat transfer coefficient between the tubes and particles in the heat exchanger. The coefficient is varied by changing the quantity of fluidizing gas fed to the fluidized bed in the heat exchanger. The heat exchanger is located within a lower portion of the cooling chamber totally below the particle inlet and outlet conduits. The heat exchanger can therefore be removed from service and protected by being buried under unfluidized relatively cool catalyst. The fluidizing gas supports combustion within a lower combustion zone.