AN AERODYNAMIC RIFFLE DISTRIBUTOR TO MITIGATE PNEUMATICALLY-CONVEYED PULVERIZED COAL FLOW INSTABILITY

RIFFLE DISTRIBUTORS ARE INSTALLED AT PULVERIZED COAL-FIRED POWER GENERATING STATIONS TO DIVIDE THE FLOW OF PNEUMATICALLY CONVEYED COAL PARTICLES FROM THE PULVERIZER INTO TWO OR MORE STREAMS. THE DESIGN OF CONVENTIONAL RIFFLEDISTRIBUTORS HAS BEEN BASED ON SINGLE-PHASE FLOW CHARACTERISTICS. HOWEVER, WHEN PARTICLES ARE ADDED TO THE CONVEYING AIR, THE PRESSURE DROP CHARACTERISTICS CHANGE. WITH CONVENTIONAL RIFFLE DISTRIBUTOR DESIGNS, THE TWO-PHASE FLOW BECOMES UNSTABLE, RESULTING IN A DIVISION OF THE COAL AND AIR FLOWS THAT IS HIGHLY IMBALANCED. THE MAGNITUDE AND DIRECTION OF THE COAL AND AIR FLOWS BECOME UNPREDICTABLE. AN INNOVATIVE AERODYNAMIC DESIGN FOR RIFFLE DISTRIBUTORS THAT MITIGATES THIS FLOW INSTABILITY HAS BEEN DEVELOPED. RECENT ADVANCES IN COMPUTER MODELING OF PNEUMATICALLY CONVEYED PULVERIZED COAL PERMIT THE TWO-PHASE FLUID MECHANICAL INSTABILITY TO BE PREDICTED. THE PHASE I PROJECTCONSISTS OF THREE PARTS: (1) COMPUTER SIMULATION OF THE CONVENTIONAL AND AERODYNAMIC RIFFLE DISTRIBUTOR DESIGN IS BEING CARRIED OUT TO PREDICT THE IMPROVEMENT IN PERFORMANCE QUANTITATIVELY, (2) CONSTRUCTION AND LABORATORY TESTING OF A PHYSICAL MODEL OF THE AERODYNAMIC RIFFLE DISTRIBUTOR WILL BE CONDUCTED TO VERIFY THE PERFORMANCE OF THE INNOVATIVE DESIGN, AND (3) COMPARISON OF THEORETICAL AND EXPERIMENTAL RESULTS WILL BE PERFORMED TO OBTAIN AN IMPROVED VALUE FOR THE PARTICLE SHAPE FACTOR.