Method and apparatus for circulating fluidized bed scrubber automated temperature setpoint control

In a circulating fluidized bed (CFB) scrubber for removing sulfur oxides from a flue gas produced during the combustion of a sulfur-bearing fuel in a reactor vessel, the CFB further comprising a flue gas inlet duct leading to said reactor vessel, a water spray infeed for spraying cooling water into said reactor vessel, and an exhaust outlet duct leading from said reactor vessel to a downstream particulate collector, an improvement comprising:

• a probe mounted in the exhaust outlet duct proximate said reactor vessel or downstream particulate collector for sensing the temperature of the flue gas leaving the CFB scrubber;
• a temperature monitor for monitoring the temperature at said probe;
• a programmable controller for comparing said sensed temperature to at least one predetermined setpoint and for selectively outputting a cooling water adjustment signal in response thereto;
• an actuator coupled to said water spray infeed for adjusting an amount of cooling water sprayed into said reactor vessel, said actuator being electrically connected to said programmable controller;
• whereby whenever said sensed temperature level is differs from the predetermined setpoint said programmable controller outputs a cooling water adjustment signal to said actuator to adjust the amount of cooling water sprayed into said reactor vessel.