Method and system for washing

摘要

A washing system for use in cleaning or washing a soiled substrate or substrates, the system comprising: a. a washing zone for contacting the soiled substrate with wash liquor; b. a feed supply for providing hot or cold feed water to the washing zone; c. a water-softening zone intermediate the feed supply and washing zone and in fluid communication therewith; d. an effluent storage and/or discharge zone; and e. a product dispensing zone intermediate the water softening zone and washing zone; and wherein the water-softening zone is effective to soften the water to a residual Ca²⁺ hardness of 1 mmol/L or less with a soft water flux of at least about 2 L/h, preferably at least about 10 L/h at a feed water pressure in the range from about 100 to about 1000 kP (1-10 bar). The water-softening zone is preferably a nanofiltration device having a cut-off in the range from about 100 to about 1000 Daltons, a clean water flux of at least 3 L/m².h.100 kp (RO water at 25° C.), and a magnesium ion rejection of at least 50%. The washing system is preferably used for washing laundry.