Water desalination
First Claim
1. A method of desalinating water which comprises pumping water to be desalinated to a filter element consisting of reverse osmosis membranes defining salt retention passages, characterized in that the water is pumped through an obstruction having a plurality of passages of different areas so that the water is divided by the obstruction into a plurality of water streams of different areas which streams are turbulent and emerge from said passages on the downstream side of the obstruction at a lower pressure than the pressure upstream of said obstruction whereby gases dissolved in the water come out of solution as bubbles, and feeding the turbulent streams with the bubbles in them into the salt retention passages of the filter element.
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Accused Products
Abstract
A desalination plant is disclosed which includes a pump for pumping water at a pressure of between 50 and 65 Bar to a generally cylindrical filter element which includes a plurality of reverse osmosis membranes defining salt passages. Immediately upstream of the filter element there is a disc with a plurality of holes in it. The disc forms an obstruction which causes a pressure drop between the upstream side thereof and the downstream side. It also divides the water flow into a series of separate streams which impinge on the end of the filter element and flow into the salt passages. The water downstream of the obstruction is not only at a lower pressure than the water upstream of the obstruction but also is flowing turbulently. The disc and filter element are in a cylindrical casing. The brine which emerges from the filter element, and which is still at a substantial pressure, can be fed through a device such as a Pelton wheel to recover some of the residual energy therefrom.
78 Citations
5 Claims
- 1. A method of desalinating water which comprises pumping water to be desalinated to a filter element consisting of reverse osmosis membranes defining salt retention passages, characterized in that the water is pumped through an obstruction having a plurality of passages of different areas so that the water is divided by the obstruction into a plurality of water streams of different areas which streams are turbulent and emerge from said passages on the downstream side of the obstruction at a lower pressure than the pressure upstream of said obstruction whereby gases dissolved in the water come out of solution as bubbles, and feeding the turbulent streams with the bubbles in them into the salt retention passages of the filter element.
Specification