Integrated pressure and low control in SWRO with a HEMI turbo booster.

The high pressure hydraulic energy management integration (HP-HEMI) energy recovery device (ERD) centralizes brine hydraulic energy recovery, feed pressure and low control and brine pressure and low control into one compact and fully integrated unit. The objective is to dispense with feed pressure control valves (i.e. elimination of throttling losses) as well as a variable frequency drive (VFD) on the high pressure feed pump (HPP) resulting in the twin benefits of a substantial reduction in energy consumption and capital costs. This paper reports on test results of a production HP-HEMI coping with recoveries and pressures that accurately simulate an SWRO system dealing with typical feed temperature and membrane fouling variations. The paper further reports on development of a PLC control scheme that regulates feed low and brine low via adjustment of the HP-HEMI control features to meet a wide variety of membrane operating conditions. The paper also outlines future research concerning mitigation of equipment failure and further enhancements of system control. [ABSTRACT FROM AUTHOR]