Installation, Operation and Maintenance Manual
Unimaster Dust Collectors – Series UMA 40-750
26
OPERATION
Unimaster standard collectors with dust container and
Unimaster hopper type collectors
Contaminated air from the dust generation source is drawn through the inlet to
the collector by the fan. Initially some pre-separation takes place as heavier dust
particles lose momentum and fall into the dust container or hopper. Finer dusts
are carried up to the filter elements where they are retained on the outer surface
of the filter fabric. The cleaned air is then passed through the filter fabric into
the fan chamber and discharged. When the fan is switched off the filter fabric
cleaning cycle is automatically activated. The collected dust is then dislodged
from the filter elements and falls into the dust container or hopper below. On most
applications the optimum interval between cleaning cycles is four hours.
Unimaster sack tipping units
When the quick-release sack tipping door is removed from the hopper, the unit fan
can be switched on. Air is entrained through the hatch preventing dust escaping
while sacks are being emptied. Airborne dust is carried up and retained on the
filter fabric. On completion of the sack tipping, the fan may then be switched off
and the door replaced. The cleaning cycle mechanism will then automatically be
activated – depositing the collected dust directly into a hopper chute or conveyor
beneath. Units fitted with explosion relief are fitted with a swing door that does
not require removal.
Unimaster venting type collectors
Venting type collectors usually operate above atmospheric pressure. No fan is
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The product laden air should enter the receiving vessel in a way that allows pre-
separation of the bulk product from the conveying air before it reaches the filter.
Dust is collected on the filter fabric as previously described. On completion of
the delivery operation, the blower or fan must be allowed to run down before the
cleaning mechanism is operated. Collected dust is deposited directly into the
silo or, on venting type collectors with dust container, the dust will be deposited
in the collection facility for disposal later.
Cleaning
Approximately every four hours or when operating pressure drop reaches
100-150 mm WG, depending on dust type and volume, the filter assembly should
be cleaned.
On all collectors, fans or blowers should be allowed to run down before cleaning
mechanism operation, otherwise dust penetration of the filter media can occur,
reducing media service life. The Donaldson controllers for all collectors except
venting type, have an automatic time delay after the cleaning cycle has been
initiated. The controllers on venting type collectors do not have this facility due to
