Factors Influencing Cell Hooding and Gas Collection Efficiencies

摘要

In modern aluminium electrolysis cells the hooding and gas collection efficiencies are important design parameters to improve productivity and reduce environmental pollution. Hooding efficiency is the result of a variety of design parameters for the anode superstructure. The factors that determine the gas collection efficiency are described by simple physical models. Measurements of HF emission rates into the potroom were made with our self-developed HF monitor. Forced gas suction rate during cell operations will in general reduce the HF emission from the potroom. By optimising the gas suction rate and operational routines it may be possible to reduce emissions from the anode changing operation by approximately 75%. Ventilation rates through the potroom were found to have a significant influence on the emission level, depending on the suction rate employed in the cells.