Patent ID: 6841076

Claim:
A method for desalting water, comprising: salt water is introduced into a membrane module and is separated into desalted water and concentrated salt water; the salt water is conveyed at an increased pressure level from the pressure-compensating device, which comprises several piston devices, to the membrane module; the concentrated salt water is discharged from the pressure-compensating device, transferring its pressure energy in the process; salt water is introduced into the pressure-compensating device at a pressure level by means of a feed pump; in front of the piston, the piston devices contain an intake chamber, which is connected to the feed pump and the membrane module, and in the rear of the piston they contain a discharge chamber, which is connected to the membrane module and a discharge line for concentrated salt water; and the pressure chambers of each piston device are fluidly connected by a single pre-charged hydraulic connecting line, the pre-charged hydraulic connecting line in combination with the pressure chambers forms a closed fluid system of preset pressure acting on the pistons, the pressure chambers are located at the piston rear sides of the piston devices, to assist the pressure level, which is exerted on the piston by the concentrated salt water that has been introduced into the discharge chambers.