Membrane Filter Press Plates have a chamber
below the drainage surface that may be inflated. The common method
used is water pressure, which is generated by pumping into the squeeze
cavity to inflate the face of the plate against the filter cake.
Air may also be used.
Membrane Plates are used to reduce the cake moisture content or
shorten the filtration cycle time. Two types of membrane plate designs
are used; fixed and replaceable.
Mixed pack
membranes are the most common configuration -(one recessed plate
then one membrane plate alternate in the press plate pack). The final
product produces savings in the overall plate pack cost.
Membrane plates usually operate at a feed pressure of up to 7 bar
and squeeze pressure to 15 bar. Special plates can be designed to
accept higher feed and squeeze pressures.
Fixed Membranes
are most commonly 100% polypropylene but, thermoplastic is also available.
The plate is manufactured by molding a face membrane and a core plate
separately. The face membranes are then joined into the core by heat
welding to form a homogeneous plate. Although this type of membrane
is suitable for many designs, it has particular advantages in food
applications where the lack of joints will prevent contamination.
Replaceable membranes
use a polypropylene core, which is machined to accept the connection
and seal of a rubber membrane. These faces are easily changed. EPDM
thermoplastic and other compounds are used for specific conditions.
Savings in operation can be achieved in difficult environments and
the membrane's superior flexibility make it the best design for many
installations.