Table 7. Change of Pressure and the Exit Volumetric Flow Rates of Gas Removal Over Time.

time (min)	pressure drop	exit gas flow
0–2	from 1000 to 500 mbar	constant
2–12	held at 500 mbar	Qg gradually decreased
12–14	from 500 to 300 mbar	Constant
14–24	held at 300 mbar	Qg gradually decreased
24–26	from 300 to 100 mbar	Constant
26–36	held at 100 mbar	Qg gradually decreased
36–38	from 100 to 50 mbar	Constant
38–293	held at 50 mbar	Qg gradually decreased