CONTROL AND MONITORING OF REVERSE OSMOSIS DESALINATION PROCESS

Abstract

The growing demand for making the seawater desalination process more and more cost effective call for the two leading desalination technologies namely Multi-Stage Flash brine recirculation (MSF-BR) and Reverse Osmosis (RO) to be hybridized at various levels to complement each other. The hybridization concept is relatively new and acquires only 0.7 % of the present desalination market share. Presently available hybridization of multi stage flash and reverse osmosis is limited to common intake/outlet and hybridization of common power supply. This work demonstrates development of supervisory control and data acquisition (SCADA) based process control and instrumentation of the hybridized system. It can be taken as a primary step to make the conventional MSF-BR plant cost effective. Steady state modeling is used for determination of various plant parameters and flow rates of multi stage flash plant. A TDM matrix model is followed for steady state modeling and the corresponding results were analyzed. The hybridized system focuses on the use of MSF reject cooling seawater to feed reverse osmosis unit. FactoryTalk View Site Edition (SE), a real time platform for industrial automation by Rockwell Automation, is used for development and simulation of entire process. All the typical SCADA functions like data acquisition, continuous monitoring, remote control, online fault detection, report generation etc were implemented on process mimic using human machine interface (HMI).