AAF International Millennium - Manual (Page 8)

8
4.0 Initial Startup Instructions
4.1 Preparation for Startup
1. Check the compressed air lines to ensure they are properly
connected to the manifold. Turn on the compressed air supply
and adjust the pressure to 80 to 100 psig. BEFORE PULSING,
CONDENSATE BLEED VALVES SHOULD BE FULLY OPENED
TO PURGE AIR LINES AND MANIFOLDS OF DIRT AND WATER.
GOOD PRACTICE DICTATES THAT ALL PIPING BE BLOWN
DOWN TO REMOVE ANY SCALE, RUST OR OTHER DEBRIS
PRIOR TO PULSING THE UNIT. This can be done by removing
the plug in the manifold furthest from the air supply connection
and supplying compressed air to the manifold.
2. Check the bags to ensure they are in sealed position in the
collector. Verify doors are closed and tightly secured.
3. Ensure the hopper discharge device is operating properly. Efficient
fan sizing includes an allowance for pressure drop across filter
media with a thin residual cake as the normal operating condition.
During the initial dust caking period for new media, unit airflow
may have to be restricted to avoid fan motor overload. This may
be achieved by partial blank off of the inlet or outlet. Fan motor
amperage will indicate need and adequacy.
4.2 DCT-1000 Series Timer Control
1. Energize the solid state timer control panel. The “POWER ON”
and the “PROCESS” light inside the enclosure will illuminate. At
this time the digital inputs on the control panel must be set. Refer
to the AAF connection diagram for initial settings on control. SEE
BULLETIN E-97 FOR FURTHER INSTRUCTIONS.
2 Listen for diaphragm valve and pilot solenoid firing, to determine
that they are working properly.
WARNING: Before introducing any dust to the collector, turn off the
power to the timer panel.
3. Start the fan with the fan damper or duct blast gates partially open.
At the same time, observe the differential pressure indication on
the board, which indicates the pressure drop across the dust cake
and fabric. Rising pressure on the gauge shows that dust is being
collected on the bag. When the gauge shows 2" to 5" w.g., the fan
damper or duct blast gates may be opened to the full normal
position.
4. Check the pressure gauge again. It should read a minimum of
2" to 5" w.g. with slight fluctuations each time a pulse occurs.
If the pressure drop is not 2" to 5" w.g., the pulse interval (Time
Off) of 30 seconds must be changed. Decrease the interval for
high pressure readings and increase the interval for low pressure
readings. If it is not possible to maintain the nominal 2" to 5" w.g.,
contact your AAF representative.
CAUTION: Do not adjust the pulse (Time On) duration before
consulting an AAF representative.
CAUTION: Any decrease in “Time Off” will significantly increase
compressed air requirements.
5. Follow Section 4.1, steps 1 through 3 and Section 4.2, steps 1
through 4 after installing new filter bags in the unit.
4.3 Pressure Demand Control Option
1. Energize the solid state panel. The “POWER ON” and the
“PROCESS” light and digital LED will illuminate to indicate an
initial 0.0” w.g. reading for the differential pressure. At this time, the
digital inputs on the control panel must be set. Refer to the AAF
connection diagram for initial settings on the control. SEE
BULLETIN E-97 FOR FURTHER INSTRUCTIONS.
2. Momentarily set the pressure switch settings to zero to check
pulsing. Listen for the diaphragm valve and pilot solenoid firing, to
determine that they are working properly.
3. Reset the pressure switch with a low limit point of 2" w.g. and a
high limit point of 5" w.g. and start the fan with the fan damper or
duct blast gates partially open. At the same time, observe the
pressure gauge, which indicates the pressure drop across the dust
cake and fabric. Rising pressure on the gauge shows that dust is
being collected on the bag. When the gauge shows 2" to 5" w.g.,
the fan damper or duct blast gates may be opened to the full
normal position. Power to the control panel may be turned on
from startup.
4. When the pressure gauge reaches 5" w.g., the unit will begin to
pulse and will continue to do so until the pressure indicates 2" w.g.
5. Repeat Section 4.1, steps 1 through 3, and 4.3, steps 1 through 4,
after installing new filter bags in the unit.
5.0 Principles of Operation
An understanding of the design and operating principle of the
Millennium is essential for effective operation and maintenance.
Knowledge of the collector nomenclature is necessary so that parts
may be easily identified and located.
The Millennium is a modular, continuous, automatic, self-cleaning,
cloth pulse-jet dust collector. The dirty air enters the collector through
one or more circular inlets. A baffle is located at the inlet to deflect the
dust into the hopper, provide uniform air stream distribution, and to
protect the bags from direct impingement. After the dust laden air
leaves the baffle area, it passes through the filter media, depositing