(a)
(b)
(c)
(d)
(e)
(f)
(g)
(h)
Figure 2: Gas-liquid volume distribution during the blowing-off time from 5 s to 40 s: (a) 5 s, (b) 10 s, (c) 15 s, (d) 20 s, (e) 25 s, (f) 30 s, (g) 35 s, and (h) 40 s.