in paragraph entitled "Ductwork System" and shall be designed for staged
closing. Minimum reversing air flow shall be 10 L/s per sq m 2 acfm per sf
of net cloth area in a single compartment. Fan shall be V-belt driven by a
constant speed motor through an adjustable speed sheave, rated for flow,
pressure, power, speed of rotation, and efficiency as in AMCA 210, AMCA 201,
and AMCA 99. Mount the motor, Section 16, Electrical, on a slide motor
base designed to allow belt tension adjustment from a screw mechanism.
Provide motor with a belt guard. Provide a heat slinger for temperatures
above 177 degrees C 350 degrees F.
2.7.2.2
Reverse Air Dampers
**************************************************************************
NOTE: Specify air pressure available for pneumatic
installation and location. Include control wiring
installation as part of this section or as part of
Division 16, Electrical. If included in this
section, it must comply with Division 16,
Electrical. A duplicate control timer may be
specified if increased reliability is desired.
**************************************************************************
Provide each compartment with dampers for the dirty gas inlet, the clean
gas outlet, and the reverse air inlet, as specified in paragraph entitled
"Ductwork System." The dirty gas inlet damper shall be a manually operated
poppet or butterfly damper with the operator located within access for
maintenance. The clean gas outlet damper and the reverse air inlet damper
shall be [air cylinder] [electrical motor] operated, adjustable speed
poppet or butterfly dampers arranged for manual lockout capability with
position indicating switches at both ends of travel. The clean gas outlet
damper shall fail-safe in the open position and the reverse air damper
shall fail-safe in the closed position.
Pulse Jet Cleaning System
Provide each compartment with a pulse jet cleaning system including
compressed air dryer and filter system, isolation valves, pulse valves, and
piping. Provide tube sheet arrangement and bag clearance to limit gas
velocity between bags to a maximum 1.27 m/s 250 fpm at design conditions.
Bag to bag clearance and bag to wall clearance shall be minimum 50 mm 2
inches. Provide additional space between rows of bags, if necessary, to
clear access door supports crossing the tube sheet. Arrange tube sheet for
individual top bag and cage removal, and reinforce for minimum 488 kg/m2
100 psf pedestrian traffic.
Dryer and Filter System
Provide a dryer and filter system to remove moisture and particulate from
compressed air for pulse jet cleaning. Size dryer and filter system for
maximum 2 degrees C 35 degrees F dewpoint temperature at 690 kPa (gage) 100
psig, 120 percent of design air flow, and for 90 days of operation without
service under normal operating conditions. Locate filters to be easily
accessible for inspection and service.
Valves and Piping
Provide each compartment with an isolation valve to isolate the
compartments for offline cleaning. When offline, individually pulse each
row of bags with 483 to 690 kPa (gage) 70 to 100 psig dry, filtered
SECTION 15863N
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