Although we could find out the influences of various experimental parameters on CIP degradation efficiencies via variable-controlling approach, there were impacts of interactions between many factors, which would make the single-factor tests unable to accurately analyze the results. Hence, orthogonal experiments were conducted to study the influencing factors. Four experimental factors of milling rotational speed, RGM, grinding ball type, and pH value were set as A, B, C, and D in orthogonal experimental design. Each experimental factor had three values, and Table 2 shows the factors and levels of orthogonal experiment.
Orthogonal experiment factor level table
Level . | Factor A . | Factor B . | Factor C . | Factor D . |
---|---|---|---|---|
milling rotational speed (rpm) . | RGM . | grinding ball type . | pH value . | |
1 | 300 | 3:1 | steel ball | 5 |
2 | 400 | 4:1 | agate ball | 7 |
3 | 500 | 5:1 | zirconia ball | 9 |
Level . | Factor A . | Factor B . | Factor C . | Factor D . |
---|---|---|---|---|
milling rotational speed (rpm) . | RGM . | grinding ball type . | pH value . | |
1 | 300 | 3:1 | steel ball | 5 |
2 | 400 | 4:1 | agate ball | 7 |
3 | 500 | 5:1 | zirconia ball | 9 |