Question 1. A toxic liquid stream is flowing through two stirred tanks in series. In each tank, the outlet flow rate from the tank is proportional to the tank volume (Vi =KiVi), where Vi is the tank voluem and Vi is the outlet flow rate from the tank. For tank1, which has a capacity of 15m3, the constant K1=0.3. For tank 2, which has a capacity of 5m3, the constant K2=0.67. Initially, the liquid flow into tank 1 is V0 =2.0 m3/min and the system is operating at steady state.

A) Determine the quantities of liquid in each tank at this initial steady state. Because of a flow controller failure, the liquid flow rate into tank 1 is suddenly doubled to VN=4 m3/min. The operator recognizes this disturbance exactly five minutes after change occurs and returns the inlet flow to tank 1 back to its original flow rate of 2 m3/min.

B) Determine what the volume of liquid in each tank would have been if the system would have been allowed to reach a new steady state at a flow of Vn=4m3/min?

C) Did the operator recognize the process disturbance soon enough to prevent any damage to or danger in the vicinity of the process?