Different Relief Load Scenarios Analysis in a Distillation Column

Dr. G. S. Zamre, D. S. Semwal

Abstract: Pressure Relief Valves for protecting Distillation Column are installed on the top of distillation Column or its overhead vapor line. Pressure relief valves are sized to protect the entire distillation column circuit i.e., distillation column, distillation column condenser tube side, Distillation Column Reboiler shell side and distillation column reflux drum. Before the tower relief valve opens, the material flows in and out of the column are equal but there is more heat going into the column than being removed causing the tower to pressurize. The source of this heat may be loss of condensing, loss of a cool feed stream, loss of reflux. Locating pressure relief valves on reflux drums, to protect the associated tower, is undesirable because loss of reflux flow can result in the drum overfilling which in turn creates a liquid seal in the relief path. A pressure relief valve, if required on reflux drums for fire relief or liquid overfilling, should have a higher set pressure than tower pressure relief valve set pressure. The present investigation addresses to find applicable relief scenarios and analyze relief load for various relief scenarios.

Keywords: Pressure Relief Valve, Distillation Column, Relief Load, Relief Scenarios, Overpressure