Moving bed heat exchanger for circulating fluidized bed boiler

A moving bed heat exchanger, comprising:

• a vessel including an upper portion having a feed opening, a lower portion having a floor including a discharge opening therein, and an intermediate portion disposed between said upper portion and said lower portion, said vessel being configured so as to thereby direct a gravity flow from said upper portion through said intermediate portion to said floor of said lower portion of said vessel of hot ash particles received in said vessel via said feed opening and to effect the collection of said hot ash particles on said floor of said lower portion of said vessel;
• a plurality of tubes disposed in said intermediate portion of said vessel and configured so as to thereby direct a flow of working fluid in a direction substantially orthogonal to the direction of the directed gravity flow of said hot ash particles through said intermediate portion of said vessel, such that heat from said hot ash particles is transferred to said working fluid to thereby cool said hot ash particles as the gravity flow of said hot ash particles is directed to said lower portion of said vessel;
• and
• a plurality of air inlets configured to inject air into said lower portion of said vessel to control the amount of said collected cooled hot ash particles that are discharged through said discharge opening of said vessel.