Optimization of Key Parameters in Casing Process Based on Casing Effect

The casing process was assessed on the basis of casing uniformity coefficient and the effective utilization rate, the parameters including hot air temperature, the opening of the exhausted valve, the opening of circulation air valve, the speed ratio of motor for hot air, compressed air pressure for the nozzle were studied with uniform design method. The results showed that: 1) The relationship model established with stepwise regression fitted pretty well and accurately described the relationship between each parameter and casing effect with the correlation coefficients(R²) of 0.988 9 for casing uniformity and 0.992 2 for effective utilization rate, respectively. Contribution rate analysis indicated that hot air temperature made the greatest contribution to casing uniformity with the contribution rate of 1.829 5, as did the velocity ratio of hot air motor to the effective utilization rate of casing with the contribution rate of 2.338 6. 2) The optimal casing parameters were hot air temperature 45.0℃, the opening of circulation air valve 45.0%, the opening of the exhausted valve 50.0%, the velocity ratio of hot air motor70.0%, compressed air pressure for the nozzle 0.35 MPa. Production validation showed that casing uniformity coefficient and the effective utilization rate of casing reached 95.03% and 65.90%, increased by 2.60% and 5.80%, respectively comparing with the control.