Re: Column Pressure Control
Mr Mahesh Khanna
The column pressure control is done by controlling the condensing duty of the overhead gas. There are various variants for total condenser pressure control. A Pressure Control valve in the vapor outlet line upstream of the condenser or downstream of the condenser controls the column pressure and a Pressure differential valve or hot bypass valve ensures that there is enough diffenertial pressure for the condensed liquid to flow from column to the reflux drum. Unless there is a specific requirement for the tight control of reflux drum pressure(NPSH requiremnet of the pumps), Reflux drum pressure can be a resultant of the condensation.