THE REFERENCE AND ANALYSIS OF A DOUBLE-ELEMENT TYPE HOLLOW-FIBER RO MODULE IN SEAWATER DESALINATION

Toyobo succeeded in developing a single-pass seawater desalination RO module composed of hollow fiber type membranes made of cellulose triac etate in 1978, and then in 1979 began production of the first commerci ally available double-element module. This double-element module has m any advantages suitable for seawater desalination. It has high chlorin e tolerance and high salt rejection, derived from the properties of th e membrane material, and it is highly resistant to fouling and scaling matters due to the unique flow pattern and fiber bundle configuration . These advantages help to explain why the Toyobo double-element modul e has been used so successfully at the many seawater desalination plan ts around the world. In this report we show the simulated water flow r ate, bulk concentration, concentration polarization coefficient and co ncentration at the membrane surface in double-element modules and pres ent actual operating data from desalination plants in Chigasaki (Japan ), Seraya (Singapore) and Helgoland (Germany). Using these monitoring data we analyzed RO performance, A value and B value, thereby demonstr ating the advantages of the Toyobo double-element module.