Hollow sheet membranes
Alfa Laval manufactures hollow sheet membranes for use in our membrane bioreactor (MBR) modules. Combining the best of two distinct membrane technologies, hollow fiber and flat sheet, the hollow sheet membranes are widely used for waste water and sludge treatment. Hollow sheet membranes from Alfa Laval have a unique structure of hollow spacers between the membranes and are available in cassettes which can be stacked up to three high to produce a MBR module
The Alfa Laval hollow sheet PVDF membrane is ultrasonically welded to a polypropylene frame which provides a strong bonding compared to e.g. glued membranes. Moreover, it is the only flat sheet membrane with a hollow spacer behind which allows cleaning with recirculation and thereby a real even cleaning of the full surface. This reduces fouling on the membrane, increases the lifetime of the membrane and reduces the use of chemicals.
The Alfa Laval Membrane Filtration Module (MFM) consists of standardized packages of hollow sheet membranes placed inside a stainless steel frame fitted with the appropriate connections, the socalled Membrane Bioreactor (MBR) module. Alfa Laval offers MBR modules with one, two or three cassettes (single, double or triple modules).
The unique feature of the MFM design is that it operates with an exceptionally low TMP across the entire surface of the membrane. This means that mixed liquor passing across the membrane does not accumulate or adhere to the surface. This significantly reduces fouling, which is also one of the major constraints on the effective implementation of MBR technology. The low TMP results in a considerable reduction of the need for cleaning, thus reducing both costs and downtime.
- Even utilization of the full membrane surface
- Ultralow trans membrane pressure (TMP)
- Robust module design
- Fully stackable design, better utilization of scouring air
- Less chemical cleaning requirements
- Easier maintenance
- Lower auxiliary equipment requirements