Ultrafiltration (UF) is a variety of membrane filtration in which forces like pressure or concentration gradients lead to a separation through a semipermeable membrane. Suspended solids and solutes of high molecular weight are retained in the so-called retentate, while water and low molecular weight solutes pass through the membrane in the permeate. This separation process is used in industry and research for purifying and concentrating macromolecular (103 - 106 Da) solutions, especially protein solutions. Ultra filtration Plants that are reusable and cleanable with standard chemicals and are designed using advanced process technology with the purpose of removing micro bacterial counts. These Ultra filtration Control Systems act as advanced Industrial Filtration System and find application as pre treatment step to the next in step reverse osmosis process.
This design tries to maximize surface area in a minimum amount of space. It is the less expensive but more sensitive to pollution due to its manufacturing process. It consists of consecutive layers of large membrane and support material in an envelope type design rolled up around a perforated steel tube.
It is normally used for bad quality water. They are set up with a stack of membranes and support plates.
Generally used for viscous or bad quality fluids. These modules do not need a preliminary pre-treatment of the water. As the feed solution flows through the membrane core, the permeate passes through the membrane and is collected in the tubular housing.
The main drawback is that the system is not very compact and has a high cost per m2 installed and it is not very compact. Diameter’s tube is generally between 4 and 25mm.
The modules contain several small (0.6 to 2 mm diameter) tubes or fibers. As the feed solution flows through the open cores of the fibers, the permeate is collected in the cartridge area surrounding the fibers. It can carry out the filtration in two ways, either “inside-out” or “outside-in”.