2.8.4.2
Guillotine Dampers
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NOTE: Guillotine dampers shall be used for
open-shut service where tight shutoff is required
for example, for air pollution control equipment
bypass dampers.
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Provide factory fabricated guillotine dampers with heavy structural frame
rigid enough to support the extended blade and external loads through the
breeching flange. Damper shall be capable of operating without precleaning
or manual assistance under normal operating conditions. Provide enclosed
bonnets [where indicated]. Provide 80 mm 3 inch diameter cleanout ports on
both sides for cleaning bottom sections.
a.
Guillotine Damper Blade: A stress-relieved flat plate. Damper
blade shall be nonwarping; intermediate blade supports are
acceptable to limit blade deflection. Leading edge of damper
blade shall be beveled and capable of guiding damper blade into
frame seat. Blade guides shall be continuous and self-cleaning
and capable of preventing binding from deposits and damage from
misalignment. Bonnet guides shall be removable and damper shall
be designed so that a damper blade can be replaced without opening
the frame.
b.
Guillotine Damper Bonnet Seal: Provide bonnet seal to effectively
seal against atmospheric leakage under normal operating conditions.
c.
Double-bladed Guillotine Dampers: Provide where indicated.
Damper frame, blades, and bonnet seals shall be as specified for
single-bladed guillotine dampers, except frame shall be thicker
and two blades shall be provided instead of one. Double-bladed
guillotine damper shall provide absolute zero leakage across
damper blades. This shall be accomplished by utilizing a blower
to introduce air into the space between the damper blades. Blower
shall be mounted on damper frame complete with isolation valve.
Blower shall have sufficient capacity to maintain a pressure of at
least 498 Pa 2 inch water column over breeching pressure.
d.
Guillotine Damper Drive: A positive dual endless chain drive
capable of driving damper in both directions. Chain-drive head
shaft shall have sufficient torsional rigidity to prevent binding
of blade when the blade is stalled. Damper shall be motor-operated
with manual override. Design drive mechanism to prevent back
driving of motor. Entire drive mechanism shall be of a simple
design and require no routine maintenance other than inspection.
Chain shall be capable of operating up to the stall torque of the
damper drive motor.
e.
Electric Motor: Motor shall be [totally enclosed fan cooled]
[open drip-proof], [_____] kW hp, [_____] volt, [_____] phase, 60
Hz, as specified under paragraph entitled "Motors and Drives" in
this section. Provide removable, totally enclosed chain guard.
SECTION 15502N
Page 93
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