The Equation of the Mixing Time
According to Eq. 5, the blowing positions should be converted to dimensionless values. In this study, we used the graphic method to making the blowing position dimensionless [10]. Table 2 showed all of the nondimensionalized blowing position.
In this study, Through stepwise regression analyzing of the data, a relationship between H_{0} and H/D, W, Fr' were found. The equation was described as follows:
Equation (11) was also represented in the following dimensionless form:
Equation (12) clearly indicated the index of every influence factor. The size of the index determined the importance of the factor to H_{0}. It could be seen here that the significant of the influence factor to H_{0} were in order of the blowing position, the aspect ratio, the modified Froude number and the liquidgas density ratio. Among them, the blowing position was the most remarkable.
Table 2 The dimensionless of the blowing positions
Positions 
Case 
Case 
Case 
Case 
Case 
Case 
Case 
Case 
A 
B 
C 
D 
E 
F 
H 
I 

lgH0 
2.717 
2.665 
2.640 
2.696 
2.682 
2.740 
2.723 
2.820 
lgW 
0.401 
0.196 
0.100 
0.317 
0.263 
0.490 
0.423 
0.800 
W 
2.517 
1.570 
1.259 
2.076 
1.832 
3.088 
2.651 
6.310 