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User manual | Filter E-PURE ASPRA P10000
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Figure 3.3: Automated coarse filter cleaning
Brush
Dust collection
Automatic cleaning of the coarse filter (P10000-4C only)
Over time, the number of particles on the coarse filter will increase until the coarse
filter is saturated with a cake-like layer. The coarse filter is therefore periodically
automatically cleaned. A brush moves up and down several times, causing the “cake”
to fall into the dust collection box. Figure 3.3 shows the automatic cleaning of the
coarse filter.
The self-cleaning frequency is set in the factory (usually an interval of 24 or 48 hours).
More coarse dust will result in faster cake formation. This cake formation is a desirable
process, as it significantly increased the efficiency of the coarse dust filter. However, of
the cake thickness increases too much the airflow will decrease, furthermore, the cake
might become very hard to remove if left too long. The cleaning frequency is therefore
strongly dependent on the conditions in which the P10000-4C operates. Clean too
frequently, and the coarse dust will end up in the collectors, decreasing filter lifespan
and reducing the amount of dust in the dust collection box. With a too large cleaning
interval however the airflow through the P10000-4C will be reduced too much. This is
the reason that the cleaning interval often needs fine-tuning at the customers’ site in
the weeks and months after installation.
To prevent re-entrainment of dust from the collection box when the fan restarts after
a cleaning interval, the box is closed off using a valve register, multiple long blades
which rotate around their longitudinal axis (comparable to a multi bladed volume
control damper). During the downward stroke of the brush these blades open. Thus,
any dust which, due to the brush, falls on both the inside and outside of the coarse dust
filter, drops into the dust collection box. During the brush down stroke the valve register
is open, under all other conditions, i.e. during the upstroke and when the fan is running
the valve register is closed.
Valve register (open during cleaning)
3. Functional overview
