Fluid treatment apparatus with semi-permeable membranes

Fluid treatment apparatus comprising:

• means for enabling said fluid to be introduced and discharged on the same side of the apparatus, including,
• (a) - a stack of superposed essentially imperforate plates, the stack having plates of a type A alternating with plates of type B;
• (b) - opposite major faces on each plate;
• (c) - a semi-permeable membrane overlying each of said faces of each plate of the stack, the semi-permeable membrane being folded around one edge of each said plate, each edge being superposed in the stack and forming a lateral face of the stack;
• (d) - means defining an exchange zone (3,3a) on each of said faces of each plate;
• (e) - means defining distribution zones (5,5a) on each of said faces of each plate, with a distribution zone at each opposite end of each exchange zone;
• (f) - two first grooves, (8,9 and 8a, 9a) formed in each of said faces of each of said plates and emerging from and perpendicular to the side of the edge of each of said plates around which a membrane is folded, each semi-permeable membrane overlying and extending into said first grooves of each of the associated plates, the first grooves (8,9) of one face of a plate being in back to back superposed relation to the first grooves (8a,9a) of the opposite face, the first grooves of a plate of type A being superposed with the first grooves of a plate of type B, one group of first grooves (8,8a) constituting a flow path for the liquid to be treated which is introduced from the said lateral face of the stack between the membranes, located between adjacent plates and one group of first grooves (9,9a) constituting a flow path for the treated liquid which is removed from the said lateral face of the stack between the membranes, said first grooves communicating with said exchange zones (3,3a) via said distribution zones (5,6);
• (g) - a first passage (12) extending through each plate and connecting one of said distribution zones on one face of that plate with a distribution zone on the opposite face of that plate;
• (h) - a second groove (13) located on one face of each plate and communicating with said first passage;
• (i) - a second passage (14) extending through each plate and communicating with said second groove;
• (j) - a third groove (15) located on the opposite face of each plate to said one face on which the second groove (13) is located and communicating with said second passage (14), the first and second passages of a plate of type A being superposed with the first and second passages respectively of a plate of type B, the second and third grooves of a plate of type A being of the opposite faces of those of a plate of type B, the first passage, second groove, second passage and third groove enabling the withdrawing of a fluid being in contact with the faces of the plates;
• (k) - means for enabling the introduction of a fluid being in contact with the faces of the plates;
• (l) - means for arranging said location where a fluid to be treated is introduced and location where the treated fluid is discharged on said distribution zones at diagonally opposite ends of each exchange zone.