C-MEMsupplier page

SFC Umwelttechnik GmbH supplies C-MEM Technology − organic hollow fiber membranes for ultrafiltration in water and wastewater treatment. The membranes, wound up around cartridges, which are combined to modules, are submerged into the filtration basin. The average pore size of 20.1 nanometer of the membranes allows for safe removal of bacteria and viruses without addition of disinfectants.

Applications:

1.1 C-MEM™ System

The basic principle of the filtration is that porous organic hollow fibre membranes with micro-pores are used as basic filtration media (Figure 1). The fibres (Figure 2) show outside diameters of less than 1 mm (0.3−0.5 mm depending on application).

In order to obtain sufficient surface area and to allow constant fluxes several hundred of parallel fibres (1−3m long depending on application) are combined to bundles and are wound up around a carrier cartridge (Figure 3).

The carrier cartridge has a suction connection for filtered water (top) and a pressure air connection for air scour (bottom) which allows cleaning the fibers from outside simultaneously to normal operation.

64 of such cartridges are combined in one module where air scour and filtered water connections are given and are connected to individual service pipes and valves.

In larger plants modules (Figure 4) are grouped together in order to allow economical operation and connection to the filtered water, backwash water, backwash air, air scour and CIP cleaning system.

Modules are finally submerged into a filter basin where raw water is filtered through the C-MEM™ system.

1.2 Description of Operation

During normal operation all modules are operated in the production mode: via the under pressure from the suction pump the membranes produce filtrate through the hollow fibres in 'outside−in operation'. Periodically the air scour system will prevent the fibres from clogging and will prolong the normal operation mode of a module (or a group of modules).

Once the filtration capacity of one module (group of modules) has arrived at a certain minimum value or transmembrane pressure has arrived at a certain maximum, the backwash procedure consisting of air and water backwash cycles will clean the clogged membranes in 'inside−out mode'.

Periodically (for example once a week) scaling of the membranes should be removed by using the clean in place CIP cleaning.

CIP cleaning will be done inside out module by module while other modules can remain in normal operation. Modules can be shifted into a separate chemical cleaning tank for that purpose or stay in the filtration tank.