ULTRAFILTRATION
SYSTEMS
What Is An Ultrafiltration System
Ultra-Filtration (UF) is a kind of membrane filtration method. It is a filtration process which utilizes trans-membrane pressure differential to separate particles according to molecular weights. Puritech UF membrane pore size is designed for molecular size of 0.01um.
Generally, it is used to remove high molecular-weight substances, colloidal materials, bacteria, organic and inorganic polymeric molecules.UF system requires. ONLY 20% energy consumption of reverse osmosis system. Low operating pressures are sufficient to achieve high flux rates from UF membrane.
Puritech UF systems are suitable for removing high turbidity peaks, particles and microbiological impurities (bacteria, viruses, parasites). Even with temporary or microbiological contamination after heavy precipitation the systems provide a constant filtrate quality – free of turbidity and pathogens.
The extremely robust sprial wound membranes are operated in the dead-end or cross-flow process. Timer relay control allows adjustable in flush and filtration duration. A variety of control options ensures the highest possible degree of flexibility and operational reliability. Adapted to the untreated water quality, chemicals can be optimally added to support the cleaning process.
The UF Membrane Process
The UF process is used in a wide variety of applications and industries and typical feed sources include seawater, surface, well and waste waters.
The main separation mechanism of UF membrane filtration is size exclusion or sieving and the graphic illustrates that UF effectively removes particles in the size range of less than 0.01 to 0.1 mm. Effective removal of these contaminants in a source water results in a filtrate well suited for further treatment by downstream reverse osmosis (RO).
The following steps are for a hollow fiber uf membrane
Filtration
Feedwater flows inside the hollow fiber uf membrane. The particulate and colidal particles are filtered through the inner skin of the hollow fibers. The filtered water comes out through the outer skin of the fibers which flows into the central permeate colctal tube of the uf membrane. The duration of filtration release is between 20 minutes to 60 minutes.
Forward Flush A (For The Hollow Fiber UF Membrane)
There are two steps in the backwash process, ie., top drain and bottom drain.
One (Top Drain): In the top drain mode, the backwash is done in out-to-in method.
The UF permeate flows in the reverse direction, ie, from the out skin and flows out into permeate collector similar to PSF Backwash. In the top drain mode, the backwash water comes out through the top drain nozzle and flows out.
Two (Bottom Drain): After completing the backwash in the top drain mode, the backwash now takes place and the backwash water comes out through the bottom drain nozzle.
Forward Flush B
Forward flush be is done after both top and bottom drain of the backwash cycle is completed for flushing of particles is collected through the fiber capillary.