Desalination Systems, Inc.

Larry A Lien

A method of reclaiming spent aqueous brine solutions used in the regeneration of water-softening resins. An aqueous solution chloride or other brine is acidified with HCl to a pH of between about 0.5 and 6 and a soluble sulfate salt, preferably Na.sub.2 SO.sub.4 is added, together with a precipitation inhibitor of the type polyacrylamide. Following such treatment, the spent brine is pumped at high pressure axially through a spirally-wound nanofiltration-type membrane device which is effective to remove at least about 90% of the divalent hardness while allowing passage therethrough of at least about 90% of the monovalent cations. As a result of such treatment, about 90 to 95% of the volume of spent brine can be efficiently and effectively reclaimed in a form in which it is suitable for use again in regenerating water-softening resins or the like.

Spent brine reclamation

Apparatus for the supply of decontaminated fuel to a diesel engine including two filtering stages, the first being a spiral wound, cross flow ultrafiltration unit and the second being a spiral wound deadheaded ultrafiltration unit with a pressure operated alarm connected to respond to the build-up of contaminants in said second stage.

Method and apparatus for supply of decontaminated fuel to diesel engine

Disclosed are spiral-wound membrane cartridge constructions for use in ultrafiltration and reverse-osmosis separation equipment, each of which include a feed layer, a membrane layer and a permeate carrier layer. By using a feed layer in the form of a channel material having a plurality of parallel ribs extending in an axial direction, interconnected by a matrix of smaller filaments which may be generally perpendicular thereto, this construction advantageously reduces resistance to liquid frlow axially through the cartridge, registering only very low pressure drops. Such cartridges of 40 to 70 inches in length and 8 inches in diameter may be employed in series, even within a single outer casing or pressure vessel. Such constructions are especially useful in separating liquids having high levels of particulate contamination using ultrafiltration membranes where clogging of the cartridge is a common problem and also in concentrating solutions of fairly viscous water-soluble polymers.

Spiral-wound membrane cartridge with ribbed and spaced carrier layer

Disclosed are spiral-wound membrane cartridge constructions for use in ultrafiltration and reverse-osmosis separation equipment. The membrane constructions include a membrane layer directly bonded to a permeate carrier layer characterized by a channel material having a plurality of parallel ribs extending in a transverse permeate-carrying direction, interconnected by a relatively thin matrix of smaller fibrils. It advantageously reduces resistance to permeate flow to a central collection point, and can be employed to separate both liquid and gaseous fluids.

Spiral-wound membrane with improved permeate carrier

Membranes of highly crystalline PTFE having an average pore size between about 0.01 micron and about 0.5 micron ordinarily reject any passage of water while allowing an organic nonpolar liquid to flow therethrough. By thoroughly wetting an expanded polytetrafluroethylene membrane with isopropyl alcohol, such a membrane will selectively allow the passage of a polar liquid, for example water, therethrough while rejecting other components, including nonpolar organic liquids, such as oil, kerosene or the like, and dissolved components of fairly large molecular size. Such IPA-wetted membranes are used to separate oil-water mixtures by allowing the water to selectively permeate through the membrane. The membrane may include a 5 mil thick backing layer of nonwoven synthetic fibers. The mixture is supplied to the membrane at a pressure not greater than about 90 psig., and often very low pressures of about 5-20 psig. can be used.

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Solana Beach, CA, United States of America

Larry A Lien