An Experiment Study on Pneumatic Control Valve in Circulating Fluidized Bed

External heat exchanger is generally used in large-scale circulating fluidized bed boiler to adjust furnace temperature and working material temperature.The characteristics of a new type pneumatic control valve with varies structure size applied to control the circulating solids flow rate into external heat exchanger in circulating fluidized bed was investigated in this paper.Influence of the height of clapboard fixed on the outlet of the pneumatic valve on the relation of control air and solids flow rate was given.The relation of controlling air and solid flow rate in the pneumatic valve with an extended plane segment was also given.Influence of the height of the inlet tube on the control characteristics was discussed as well.