Research Of Dual Membrane Process Applied To Reusing Recirculating Cooling Water Blowdown Of Thermal Power Plant

The recirculating cooling water blowdown will be reused to become boiler makeup in a power plant of Shanxi. Dual Membrane process (microfiltration,MF + reverse osmosis,RO) was applied as predesalination process in the reuse system. The pilot plant study on the spot was conducted to determine the feasibility of dual membrane process reusing cooling tower blowdown and the system operation parameter. The result of experiment showed that, water quality indexes of filtrate from recycling water treated by MF, SDI < 4,turbidity<0.30NTU, can meet the requirement of RO feed water. RO desalination rate was over 98%. RO permeate conductivity was between 20～60 μS/cm, which helped to reduce load of the following ionic exchange system greatly. Application of dual membrane process to reusing recirculating cooling water blowdown is a new and effective way to solve water shortage and realize zero discharge strategy in thermal power plants. The technology is of a promising prospect.