MODELING GAS TRANSFER IN A SPRAY TOWER OXYGEN ABSORBER

A computer model characterizing the performance of a spray tower oxyge n absorption system was developed based on finite difference mass tran sfer calculations. Performance was assessed in terms of oxygen utiliza tion, transfer efficiency, and economy. Pilot scale tests verified mod el assumptions and performance predictions. Simulation runs indicated spray tower head and oxygen feed requirements for desired changes in d issolved oxygen (DO) exceeded those required for packed column equipme nt. Spray tower performance was improved by increasing hydraulic loadi ng from 35 to 85 kg m(-2) s(-1) and by increasing tower height from 1. 25 to 2.50 m. The effluent DO concentration that minimized variable co sts of oxygen transfer was lower in the spray tower than in the packed tower, indicating clean water use of the spray tower will be limited to moderate effluent DO requirement applications (DO <20 mg l(-1)). (C ) 1997 Elsevier Science B.V.