TM 5-3895-374-24-2
FEBRUARY 1993
NORMAL BAGHOUSE OPERATION
DIRTY AIR INLET:
Dirty air enters at on end and flows down the center for the length of the baghouse, between two inner perforated
walls. The air passes thru the walls and bags, then up thru the tubesheet into the clean air plenum. The dust is collected
on the outside of the bags.
During the initial start-up the static differential pressure could be lower than normal, as the filter media is new and
quite porous. The high initial porosity could also be evidenced by visual emission at the exhaust stack. This condition is
only temporary and should cease after a few hours of operation. Some amount of dust will "cake" on the bags and
improve the filtration efficiency. When the "cake" is excessive the pressure drop will rise and the bags should be cleaned.
Inlet gas temperature should not exceed 375 deg. F. with singed aramid felt bags, for continuous operation.
Protection must be provided to prevent high temperature from damaging bags. An outlet temperature sensor is provided
to warn of high baghouse temperature.
STATIC PRESSURE DROP
Proper operation of a baghouse is best determined by monitoring the static pressure drop (inches water gauge)
across the tubesheet. It is recommended that accurate records of operating pressure drops be kept. High pressure
alarms should be used to warn the operator of an upset condition.
< 2" W.G. = New bags
2" - 6" W.G. = Normal Range
> 6" W.G. = Dirty bags - time to clean
> 8" W.G. = Blinded bags - time to replace
SCREW CONVEYORS/AIRLOCKS
Reference Wm. Meyer manual and drawing.
The conveyors and airlock are designed to operate while the baghouse is on line, to continuously discharge the
material collected in the hopper. The hopper is not intended to be used for storage purposes.
page 3-693
