This invention relates generally to fluid treatment systems, and more particularly to a system, method and dual configuration check valve for the continuous cleansing of reverse osmosis membranes contained within the system.
The reverse osmosis membrane is well suited to, and accepted for, purifying a variety of liquids, including sea water, ground water, and the like. However, the input surface of the membrane against which the pressurized input fluid to be purified is forced against and through becomes clogged of solid materials which have been filtered out to produce product liquid. As the deposit on the input surface of the membrane increase, efficiency of the membrane decreases rapidly.
A number of U.S. patents attempt to address the issue of cleansing of the filter or reverse osmosis membrane either during use or in conjunction with the interruption of the purifying process as follows:
U.S. Pat. Nos. 4,642,188 DeVisser, et al. PA1 4,629,568 Ellis, III PA1 4,632,754 Wood PA1 4,705,625 Hart, Jr. PA1 3,398,834 Nuttall, et al. PA1 3,959,146 Bray PA1 4,218,317 Kirschmann PA1 3,922,301 Shippey, et al. PA1 3,282,432 Greenleaf, Jr. PA1 4,814,086 Bratt PA1 4,744,895 Gales, et al.
However, none of these references disclose the present system or method, nor do these references approach the relatively high efficiency achieved with the present system, both in terms of being devoid of downtime, as well as the unique and highly efficient and conserving arrangement of utilizing product liquid to accomplish cleansing of the membrane.