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6.2.3. Rotary filters
The rotary filters installed in the TCF Air Treatment Units
come complete with control board and differential
pressure switch.
The MAINTENANCE OPERATIONS to be performed
periodically are as follows:
- cleaning and lubrication of the gears: every 6 months
- drive chain tension check: every week
- replacement of fouled filtration diaphragm: if the
equipment spare has been consumed.
To replace the diaphragm, proceed as follows (fig. 35):
- stop the system by turning off the control board master
switch:
- after retrieving the check pin (1 ). extract the empty
clean filter roller (2) and replace the filtration diaphragm
(3)
- refit the full clean filter roller (2), check the correct
direction of air flow and make sure that the pin (1) has
been reintroduced on the reduction gear motor side
- roll out the clean filtration diaphragm until the end of
the dirty diaphragm hooks onto it
- using the manual control, rewind the whole of the dirty
filter onto the relevant roller (4)
- after retrieving the check pin (5), extract the dirty filter
miler (4) and remove the diaphragm
- after replacing and blocking the empty dirty filter roller
(4), fasten the clean diaphragm (3) to it using the spring
- make sure that the system functions correctly using the
manual control. If it does not, check the operations
performed
- lastly. set the control panel switch to automatic.
6.2.4. Reconditionable bag filters
These are non-rigid filters with EU3-EU4 efficiency THEY
CAN BE RECONDITIONED using two different methods.
- With a vacuum cleaner, after removing the filter from
the Unit on the air inlet side.
- If this method is used the filter can be reconditioned
from 7 to 1 O times, after which the filter's efficiency and
accumulation capacity is impaired
If this method is not sufficient to remove impurities from
the filters, proceed as follows:
- extract the filters from the unit and, holding them with
the aperture uppermost, rinse them with a weak jet of
warm water (50°C max), letting the impurities run out at
the bottom through the filtration diaphragm
- let the filters dry thoroughly by evaporation before
refitting them. Do not use air jets to dry them.
In this way the filters can be cleaned 2-3 times, after
which the filter's characteristics will be compromised and
it will have to be replaced.
6.2.5. Non-reconditionable
medium-high
efficiency
filtration sections
This category includes BAG FILTERS with efficiency equal
to or in excess of EU5, and ABSOLUTE FILTERS.
They are characterised by an initial, clean filter loss and
by a final loss beyond which the filter loses its
accumulation capacity and original efficiency and must be
replaced. The filter must be replaced when it reaches a
loss level between the two points specified above. This
loss is fixed at the design stage on the basis of the
following considerations:
- it must not be high so as to prevent imbalances in the
system
- it must not be low to give the filters a sufficient service
life
THE REPLACEMENT LOSS CAN BE MEASURED WITH A
DIFFERENTIAL PRESSURE SWITCH. The recommended
values are shown in table 8.
6.2.5.1. Non-reconditionable bag—filters
These are filters with an efficiency of between EU5 and
EU9. THEY CANNOT BE RECONDITIONED as this would
damage their accumulation capacity and efficiency.
In order to preserve the filtration diaphragm for as long
as possible, the condition of the pre-filters must be
monitored carefully. Moreover, TCF recommends you
check the state of the gaskets on the frames and the
springs every week to prevent air passing the bag without
being filtered.
6.2.5.2. Absolute filters
These have an efficiency of between EU1O and EU14.
In order not to harm the very fine filtration capacity that
the filter in question is required to ensure, you must
check, on at least a weekly basis, the condition of the
gasket between filter and frame as well as the rigidity of
the
assembly.
ABSOLUTE
FILTERS
CANNOT
BE
RECONDITIONED and must be replaced when the preset
loss has been reached.
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