Water desalination equipment and cleaning method for water desalination equipment

摘要

Water desalination equipment comprises pretreatment equipment (13) having a pretreatment membrane (12) for filtering the turbid components in raw water (11), reverse osmosis membrane equipment (17) having a reverse osmosis membrane (16) for producing permeated water (15) by removing salt content from filtrated water (14) output from the pretreatment equipment (13), a first control valve (31) which is interposed between a high-pressure pump (21), that is installed in a filtrated water line (23) for supplying filtrated water (14) from the pretreatment equipment (13) to the reverse osmosis membrane equipment (17), and the reverse osmosis membrane equipment (17) in order to lower the supply pressure of filtrated water temporarily, and a controller (30) which operates the first control valve (31) to perform a suck-back control that effects an operation for lowering a pressure at the inlet of the reverse osmosis membrane equipment (17) in a pulsed manner during the operation.