Patent FR-2857005-A1 (FR)
Title: Distillation of sea water under vacuum at low temperature comprises use of turbine-pump assembly with common axle to send in and extract products
Inventor: SANCHEZ GOMEZ GINES
IPC: C02F1/00
Filed: 2003-07-03
Abstract: The product to be distilled enters and the distillation products are extracted at the same time, compensating for pressure differences by using a turbine-pump- assembly with a common axle. The solid residues are recovered when the volume of such residues is above a maximum value, maintaining the vacuum of the system by means of isolating valves : The product to be distilled is sea water and the distillation product is fresh water. The heat source is the sun and the coolant is sea water, with salt removed periodically. The distillation system has an evaporation zone and a condensation zone, with one or more condensation sub-zones, controlled by a computer with a local network. There are one or more sub-zones for residue in the evaporation zone, each condensation or residue subzone is equipped with a thermometer, a densimeter, means of measuring capacity and an isolation valve, and each residue subzone has an inlet valve and meter for the inlet flow. Each condensation subzone has an outlet valve, a meter for outlet flow and an extraction pump. The first residue subzone has an inlet turbine and an inlet densimeter. The turbine and extraction pump have a common axle and motor. The proportion between the capacity of the inlet turbine and the extraction pump is identical to that of the products transferred. The system also has a manometer and a vacuum pump. The thermometers, densimeters, manometers and measures of product are numeric or supplied with analog/numeric converters and are connected to the controlling computer by the local network. The isolation valves, inlet and outlet valves and the motor are supplied with controllers which are also connected to the controlling computer by the local network. The pressure, temperature and density for the vacuum pump and feed- recovery for the inlet valve, the isolation valves and the motor, the residue transfer and the calculation of residues are controlled by the computer. The evaporation zone is an evaporation reservoir, with a transparent cover and walls and floor which are thermally isolated. The condensation zone is a condensation reservoir which is submerged with thermally conducting walls. A steam pipe with an isolation valve connects the evaporation reservoir to the condensation reservoir. The vacuum pump is placed in the steam pipe, between the isolation valve and the condensation reservoir. The product measurements are made by buoys. The evaporation reservoir has a marine valve, and the marine valve and the isolation valve are controlled by the reading from the densimeter in the evaporation reservoir. To obtain different salts, the distillation system has several consecutive evaporation reservoirs, each being a residue subzone. The evaporation reservoirs are connected to the steam pipe via isolation valves. The system is assembled on a marine platform, with a device for recovering energy from waves. The evaporation reservoir is equipped with a movable receiver to remove the salt.