Method and device for the production of pure water

Abstract

Input water is preheated in a heat exchanger ( ), pumped ( ) through another heat exchanger ( ) into a heating unit ( ). The heating unit heats the water to a temperature of above 100° C., preferably 140-150° C., while maintaining the water in a liquid state without vaporization. A pump ( ) feeds the heated water under sufficient pressure to prevent vaporization to at least one crossflow filtration unit ( ). A portion of the heated water passes through a thermally stable filtration material having a pore size of 1-20 nanometers for filtering endotoxins and pyrogens, 4-10 nanometers for filtering viruses, or 100 nanometers−30 &mgr;m for filtering bacteria. Heated water which has passed through the filtration material is fed through a pure water product outlet of the filtration unit to a pure water outlet ( ). A retenate portion of the heated water flows past the filtration material to carry filtered impurities through a retenate output line ( ). To conserve energy, the retenate output line passes through the heat exchanger ( ) and the pure water product line passes through the heat exchanger ( ) to preheat the incoming water. A backflushing valve ( ) selectively passes pure water product backward through the filtration material to backflush impurities trapped in the filtration material.