Abstract

The invention relates to a method for purification of feed liquid (F), the feed liquid (F) containing minerals or chemicals or both, the method having the followings steps of: - feeding feed liquid (F) into a tank (40) and pressurizing the feed liquid (F) to a high pressure using a piston (90) extending partially outside the tank (40), the piston (90) being attached to an actuator (32) located at least outside the tank (40) for pushing and pulling the piston (90), - cooling the feed liquid (F) near freezing point, - expanding the feed liquid (F) adiabatically to essentially normal pressure forming a mixture of ice and liquid brine (B), - removing and collecting the liquid brine (B), - feeding product liquid (P) forming a second mixture of ice and product liquid (P), - pressurizing the second mixture to high pressure, - using the second mixture to cool feed liquid (F) under high pressure expanding the second mixture adiabatically to essentially normal pressure, - removing the second mixture from the tank (40) as the product liquid (P). The invention relates also to a system for purification of feed liquid (F).

IPC Classes  ?

• B01D 9/00 - Crystallisation
• B01D 9/02 - Crystallisation from solutions
• B01D 9/04 - Crystallisation from solutions concentrating solutions by removing frozen solvent therefrom
• C02F 1/22 - Treatment of water, waste water, or sewage by freezing
• F15B 1/00 - Installations or systems with accumulatorsSupply reservoir or sump assemblies
• F15B 1/14 - Accumulators using a gas cushionGas charging devicesIndicators or floats therefor with flexible separating means attached at their periphery by means of a rigid annular supporting member
• F15B 15/14 - Fluid-actuated devices for displacing a member from one position to anotherGearing associated therewith characterised by the construction of the motor unit of the straight-cylinder type
• F16J 1/00 - PistonsTrunk pistonsPlungers
• C02F 103/08 - Seawater, e.g. for desalination