Membrane distiller and operation method therefore

A use of an air channel membrane distiller in a semiconductor production plant, said channel membrane comprising:

• a hot surface;
• a cooling section;
• a hydrophobic membrane with pores of diameters less than 1 μm;
• wherein said hot surface being mechanically arranged to said hydrophobic membrane separated by a sealed evaporation channel;
• wherein a surface of said cooling section being mechanically arranged to said hydrophobic membrane separated by a sealed condensation channel;
• a water supply tubing connected to a water inlet of said sealed evaporation channel;
• a water discharge tubing connected to a water outlet of said sealed evaporation channel;
• a purified-water discharge tubing connected to a water outlet of said sealed condensation channel;
• and
• a cooling equipment arranged for cooling said surface of said cooling section to a temperature lower than a temperature of water in said sealed evaporation channel;
• a gas supply arrangement for inert gas;
• said gas supply arrangement comprising a heater arranged for heating said inert gas;
• a gas pipe system connected to said gas supply arrangement and arranged to a gas inlet of said sealed condensation channel for enabling flushing of at least said sealed condensation channel with said inert gas;
• and
• a controller, said controller being arranged for, upon finishing a first purified-water production period, controlling said gas supply arrangement to supply said inert gas by said gas pipe system and controlling said gas supply arrangement to stop supply said inert gas before starting a second purified-water production period;
• passing purified water directly from said purified-water discharge tubing into a production stage of a semiconductor production plant.

A method for operating an air channel membrane distiller, comprising the steps of:

• providing, during a purified-water production period, water to an evaporation channel;
• cooling, during said purified-water production period, a condensation channel to a temperature lower than a temperature of said water;
• said evaporation channel being separated from said condensation channel by a hydrophobic membrane with pores of diameters less than 1 μm;
• whereby water vapour passes from said evaporation channel through said hydrophobic membrane to said condensation channel;
• and
• discharging, during said purified-water production period, water being condensed in said condensation channel;
• heating an inert gas;
• and
• streaming, upon finishing said purified-water production period, said heated inert gas through at least said condensation channel, thereby causing a removal of any remaining water;
• said heating and streaming being stopped before a next said purified-water production period.