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Operation and maintenance, Discfilter HPF2200-series PFLC
6. FUNCTION
6.1 Intended use
The filter is designed and manufactured to remove solid particles in unpressurised water flow
systems. The filter is not a pressure vessel.
6.2 Non-intended use
Unless approved in writing by Hydrotech, the filter must not be used to filter liquids other than
water. The filter must not be installed in an environment with an explosive atmosphere or
another risk of explosion, such as high concentrations of dust.
6.3 Filtration and backwash process
A brief description of the process is given below.
1. The water to be filtered flows with gravity from the inside of the filter drum out to the filter
segments.
2. Solid particles are separated from the water using a filter medium attached to both sides of
the filter segments, whilst clean water passes through the filter medium to the outside of the
filter segment.
3. Operating mode AUTO – The solid particles trapped on the inside of the filter medium gra-
dually reduce the water flow through the filter panel. The water level on the inside of the drum
begins to rise. When the level difference between filtered and unfiltered water exceeds the set
value, drum rotation and backwashing start. Operating mode REMOTE – The filter is controlled
as in AUTO operating mode or using external control (e.g. time-controlled drum rotation and
backwashing). Operating mode HAND – Drum rotation and backwashing are started manually.
4. The backwash nozzles spray wash water on the outside of the filter panels. The solid particles
that accumulate are washed from the filter panels to the sludge channel, at the same time as
the drum rotates.
5. The removed particles and backwash water flow with gravity out of the filter.
Figure 6.1 Disc filter function.
