Water hammer simulation in spiral wound reverse osmosis membranes

The purpose of this work is the development of a mathematical model for the formation and the propagation velocity of water hammer in spiral wound reverse osmosis (RO) membranes. Unexpected shutdowns of the RO plants and failure of the check valves can cause water hammer formation and its propagation as a pressure wave inside the membrane envelope resulting in membrane destruction. The model is based on energy and mass balances at flow conditions inside the membrane envelope. The mathematical analysis results in explicit equations for the local permeate pressure in steady state conditions and the increase of pressure in unsteady situations. During the water hammer formation the permeate pressure may increase so as to cause damaging results to the RO membranes.