Evaluation of Mass Transfer coefficient in a wetted wall column
Objective: The rates of diffusion into gases flowing through pipes are studied in wetted wall column.
Mass transfer rates for fluids flowing through pipes have been studied more completely than other cases.
The rates of diffusion into gases flowing through pipes have been studied in wetted wall columns.
Here the mass transfer coefficient in the form of dimensionless group are plotted against the Reynolds number of the gas for the system air-water (Sc = 60). For gases, values of Re from 2000 to 35,000 were covered and from 0.6 to 2.5 with gas pressures varying from 0.1 to 3 atm.
Inter-phase Mass Transfer
Air flow rate from M2 Qa lpm
Water flow rate Qw lpm
Water temperature 0C
Air PD mm H20 across orifice
Partial pressure of water at outlet = PB KN/m2
9.22 X SQRTDP2/106 kgmoles/sec
Driving force at outlet of air
Amount of water evaporated
For each flow rate of air ,Kg can be calculated.
Kg * (d/DW)* (Pam/Pt) * (rADw/mair) 0.44 Vs Nre is plotted on a log –log sclae.
|Wetted Wall Column Set Up|
stored in a storage vessel and the vapors from the vessel are sucked by the blower and passed into the column or if the vapors are required to be mixed with air than an option at the discharge line of the blower which is facilitated with nozzle helps in mixing the vapor with air.
A heater is provided at the discharge line to supply heat to the vapor or air to maintain the temperature of the system and whole pipeline is insulated to prevent loss, by using the rotameter, flow rate of the vapor can be controlled.