Time (t) = 30 min = 1800 s
Dia of drains (Dd) = 0.0525 m
Dia of bleeder vents on CWR (Db) = 0.0525 m
No. of drains operated (Nd) = 4 drains
No. of bleeders on CWR (Nb) = 2
Volume of tank (V) = 5.7 m3
Density of water (ρw) = 1000 kg/m3
Density of air (ρa) = 1000 kg/m3

Area of Drain (Ad) = 0.00864 m2
Flow-rate (Q) =0.00316 m3/s
Velocity of water (vw) =0.36 m/s > 3m/s within erosion velocity range
I need to calculate no. of bleeder vents required for the following data. i m stuck here. the vents are to be of 0.0525 mm. Also i want to calculate how much vacuum is created in our current condition if we are using 2 bleeder vents (this is the no currently being used but causing vacuum creation)