MANN+HUMMEL MICRODYN MD020 FP2N, Руководство пользователя

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MICRODYN CAPILLARY MODULES | USER MANUAL
MANN+HUMMEL Water & Fluid Solutions | REVISION DATE: 09/09/2021 20
6 Piloting
Pilot testing is usually required to determine the feasibility and process parameters of the filtration/concentration process utilizing
MICRODYN.
Please note that MANN+HUMMEL WFS offers compact pilot units (see Figure 17) and supervision of piloting. For more details,
please contact your MANN+HUMMEL WFS representative.
6.1 FILTRATION WITH CONSTANT CONCENTRATION
A typical pilot test starts with filtration at a constant concentration. The permeate and the concentrate flow back into the feed
tank, so there is no increase in concentration. Once the flux is not changing any more, the concentration step can start.
6.2 DETERMINING MAX CONCENTRATION FACTOR
By concentrating the feed, the influence of the growing filter cake can be seen and assessed for the process. The permeate flows
into a separate tank, the concentrate goes back to the feed tank. Please consider the increasing viscosity during concentration as
well as an increase in temperature. The max. temperature for MICRODYN modules is 60°C (140
°
F). Additionally, the pressure drop
- inlet pressure to outlet pressure - is increasing, so a pressure adjustment might be necessary.
6.3 SETTINGS FOR PERIODIC BACK PULSE
The tangential flow along the membrane surface reduces the speed of a cake build-up on the membrane but does not avoid the
cake formation itself. At some point, the filtration performance hits its limit, and the filter cake must be disturbed to stop further
compaction.
During the periodical back pulse (PBP) a part of the permeate is pressed back through the membrane. For each application, the
desired frequency and extent of the PBP needs to be determined to guarantee a stable process. As a starting point, a frequency of
every 5-15 minutes can be chosen. The default duration of the PBP is 2-3 seconds.
6.4 CLEANING TESTING
Depending on the fluid processed, a slow blockage of the filter modules takes place. A chemical cleaning might be necessary. The
chemicals to be used for the cleaning are related to the substances that are forming the cake on the membrane. In general, alkaline
or acids in combination with detergents, enzymes, etc. are good cleaning chemicals.
In principle, there are two different ways of cleaning, (a) cleaning in filtration direction and (b) cleaning from permeate side to feed
side. Please refer to section 5.6 for more details.
Figure 17.
Picture of compact MICRODYN pilot unit.