Abstract: A simple to operate personal water purification device using membrane type filtration with almost constant pressure exerted to the membrane filter during the operation. The water inlet is connected to the high pressure chamber via a non-return valve. The water from the chamber is injected via the piston into the already pressurized circuit which maintenance filter working pressure. A pressurized circuit is formed in the concentrate cylinder and the filtration unit. The fluid circulation within the pressurized circuit is enabled via motion of a circulation piston. The permeate outlet produces potable water while the remaining concentrate is returned to the return chamber. The circulation piston and high pressure piston are connected via piston coupling and operated, preferably, by hand activating reciprocal motion of the piston rod. The membrane type filtration can be a ultra-filtration membrane, a nano-filtration membrane or a reverse osmosis membrane.

Abstract: A simple to operate personal water purification device using membrane type filtration with almost constant pressure exerted to the membrane filter during the operation. The water inlet is connected to the high pressure chamber via a non-return valve. The water from the chamber is injected via the piston into the already pressurized circuit which maintenance filter working pressure. A pressurized circuit is formed in the concentrate cylinder and the filtration unit. The fluid circulation within the pressurized circuit is enabled via motion of a circulation piston. The permeate outlet produces potable water while the remaining concentrate is returned to the return chamber. The circulation piston and high pressure piston are connected via piston coupling and operated, preferably, by hand activating reciprocal motion of the piston rod. The membrane type filtration can be a ultra-filtration membrane, a nano-filtration membrane or a reverse osmosis membrane.