Abstract: A distillation system has a degassing tank, a distiller for generating vapor of raw water taken from the degassing tank, a heater for heating the vapor from the distiller to convert the vapor into a high temperature and pressure vapor, a hydrophobic porous membrane through which the vapor from the heater flows, and a heat transfer unit provided in the distiller for effecting heat exchange between the vapor from the membrane member and the raw water from the degassing tank. The structural elements such as the heat exchange unit, piping, etc., with which the vapor from the membrane or the condensate thereof is brought into contact are made of titanium or titanium alloy.

Abstract: A distilling apparatus includes an evaporation section which heats raw water and causes the generation of vapor from said raw water, and a hydrophobic porous film through which the thus generated vapor is filtered. Because vapor separated from the raw water is supplied to one surface of the hydrophobic porous film, the proportion of the vapor relative to the fluid supplied to that surface of the film can be increased, thereby enabling the efficient filtering of a large amount of vapor through the film. In addition, because the temperature of condensed water obtained by cooling the vapor can be kept in the vicinity of the boiling point thereof, any gases and volatile substances contained in the raw water are prevented from dissolving in the distilled water, thereby enabling the production of extremely pure distilled water.

Abstract: The present invention relates to a process for producing ultra-pure water, an apparatus for producing said ultra-pure water and a process for using the ultra-pure water produced according to said process. More particularly, the present invention relates to a process for producing ultra-pure water which comprises boiling a raw water to vaporize off the volatile components from the raw water, subsequently generating steam from the water, contacting the steam with a hydrophobic, porous, gas-permeable and liquid-impermeable membrane to make the steam permeate the membrane, and then condensing the steam, as well as to an apparatus for producing said ultra-pure water and a process for using said ultra-pure water.