17 | 24
MICRODYN BIO-CEL XS-1 Pilot Plant Manual // Revision: A // Date: Jul. 25, 2018
7
Operation
The MICRODYN BIO-CEL
®
XS-1 module is operated as dead end filtration, but with air crossflow,
which is induced by a blower. The permeate pump is controlled by the given flow. The cycle of
filtration is:
•
Filtration
(510 s standard operation)
•
Relax 1
(50 s standard operation)
•
Back washing
(30 s standard operation)
•
Relax 2
(10 s standard operation)
The above listed intervals are freely adjustable within a certain range, so that a flexible adaptation
to the operational conditions on site is possible. Plesae note, that usually a regular de-aeration
is necessary for propper function of the filtration stage. Due to the position of the permeate tank,
the permeate system de-aerates trough the tank automatically, so that no separate de-aeration
step is necessary.
For backwashing the conveying direction of the permeate pump is changed. Filtrate from the
permeate tank is pressed into the membrane pockets, reversing the flow and removing the filter
cake and all particles that have entered the membrane pores. In addition to the back washing,
the air crossflow remains on to clear the removed particles off the membrane surface. For this,
the permeate tank must always be filled. The allowable pressure during backwashing is limited
to avoid membrane damage.
An accumulation of air bubbles in the permeate line due to outgassing can occcur, especially
during high transmembrane pressures. To avoid this effect, the permeate tank is situated at the
highes point of the permeate line so the air can easily escape.
The pilot plant runs fully automated after the initial start up.
The power supply of the plant can be interrupted by means of a master switch at the switch
cabinet in the control cabinet.
In emergency cases the plant can be shut down as follows:
Shutdown of the feed pump (P1) and shutdown of the permeate pump (P2) at the control
computer. To switch off the power supply turn the master switch in position “0”.
Operational Sequence and PLC Settings
The operation sequence starts with filling the filtration tank with waste water. The filling sequence
is triggered by the level sensor in the filtration tank. Filling ends when the max level in the filtration
tank is reached and starts again when the min level is reached.
The next step is the denitrification phase (if required). During this phase, the aeration is mainly
switched off to maintain anoxic conditions in the filtration tank. The blower is only running for
short amounts of time to ensure the sludge is properly mixed. The duration of the denitrification
phase is controlled by a timer and can be adjusted to match the local requirements, if not required
set T
DN
to 0.
master switch