FLUIDIZED BEDS: AN ENERGY EFFICIENT ALTERNATIVE TO CONVENTIONAL HEAT TREATMENT OPERATIONS

摘要

Heat treatment of metallic alloys is often essential in order to achieve improved mechanical properties. However, the conventional heat treatment process remains a major constraint to production flow in manufacturing operations since it must be performed off-line in labor intensive batch processing systems and thus may require cycle times as long as 30 hours. Fluidized beds have been demonstrated to be a far more efficient means of energy transfer than conventional furnaces and have been shown to reduce the overall heat treatment cycle time to less than 3 hours. However, typical fluidized bed units are batch systems; therefore, further reductions in cycle time may be possible by using in-line continuous fluidized beds. In this paper, we will review the fundamentals of fluidized beds, highlight an in-line continuous fluidized bed that has been recently constructed, and examine the application of fluidized beds to heat treatment of metallic components with emphasis on the heat treatment of aluminum alloy components for automotive applications.