Design guidlines for RO membrane systeems

Index
1. System Design………………………………………………………………………………………………………………. 3
1.1 Introduction of RO System ……………………………………………………………………………………….. 3
1.1.1 Material Balance of RO System……………………………………………………………………… 3
1.1.2 Single-Module System ………………………………………………………………………………….. 3
1.1.3 Single-Stage System…………………………………………………………………………………….. 3
1.1.4 Multi-Stage System ………………………………………………………………………………………. 3
1.1.5 2 Pass RO System ……………………………………………………………………………………….. 4
1.1.6 Permeate Blending with Feed Water ………………………………………………………………. 4
1.1.7 Permeate Recirculation…………………………………………………………………………………. 4
1.2 Items of Water Analysis……………………………………………………………………………………………. 4
1.3 Basic Equations for RO Calculations …………………………………………………………………………. 5
1.3.1 Water Transport …………………………………………………………………………………………… 5
1.3.2 Solute Transport…………………………………………………………………………………………… 6
1.3.3 Correlation of Operating Conditions………………………………………………………………… 6
1.4 RO System Design Guidelines………………………………………………………………………………….. 6
1.4.1 Fouling Tendency with Operating Conditions …………………………………………………… 6
1.4.2 Recommended Range of Element Operating Conditions (Design Guideline) ………. 7
1.5 Steps to design RO membrane system ……………………………………………………………………… 9
1.5.1 System Design Information and Feed Water……………………………………………………. 9
1.5.2 Selection of Element Type and Average Permeate Flux……………………………………. 9
1.5.3 Calculation of Number of Total RO Elements…………………………………………………… 9
1.5.4 Decision of Recovery Rate…………………………………………………………………………….. 9
1.5.5 Decision of Number of Stages ……………………………………………………………………… 10
1.5.6 Decision of Number of RO Elements per Pressure Vessel ………………………………. 10
1.5.7 Decision of Element Arrangement ………………………………………………………………… 11
1.5.8 Relations between Nominal Performances and Field Results…………………………… 11
1.5.9 Comparing Actual Performance of Lewabrane® Elements to Projection Program. 12