wear bars shall be provided for the empty run of the conveyor. Liners and
wear bars shall be attached to the casing using countersunk stainless steel
bolts with stainless steel nuts and washers. Drive sprocket shall be heat
treated, induction hardened to a minimum depth of 6.4 mm 1/4 inch. Drive
shaft shall be heat treated, designed, and sized based on AGMA 6009
requirements. Bearings shall be spherical double roller bearings. A dust
seal shall be provided where the drive shaft ends go through the casing.
The conveyor shall have inlet and outlet spouts, inspection doors giving
access to the drive sprocket, cleaner, and wear surfaces. Chain tension is
achieved by a screw take-up. Each discharge opening shall be provided with
rack-and-pinion-operated gates with [hand wheels] [motor operated] [air
operated]. Motor shall drive conveyor through a speed reduction unit which
is either direct connected or roller chain connected to the drive shaft.
Motor shall be [totally enclosed, nonventilated type] [totally enclosed,
fan cooled type] [totally enclosed, fan-cooled type suitable for
installation in a Class II, Division 1, Group F hazardous location in
accordance with NFPA 70]. [Motor starter shall be [manual] [[magnetic]
[across-the-line] [reduced voltage start]] type with [general-purpose]
[weather resistant] [water-tight] [dust-tight] [explosion-proof]
enclosure.] Conveyor frame shall be constructed essentially as indicated,
with support and additional bracing as required for rigidity.
2.30
ASH HANDLING SYSTEM
2.30.1
Boiler Room Ash Handling System
**************************************************************************
NOTE: When specifying boilers with capacity of 4.1
MW (14,000,000 Btuh) per boiler or less, this
paragraph and subsequent paragraphs will be deleted,
except applicable portions.
**************************************************************************
The ash handling system shall be the dry pneumatic type in stoker fired
boilers. This system shall gather ash from the boiler forward ash
discharge grate hopper and from [economizer] [air preheater] ash discharge
hopper and other filtration systems and shall discharge to the ash storage
silo located outside of the building. The entire system shall be
coordinated to fit the equipment supplied. Ash dust control conditioners
shall be used to reduce fugitive dust emissions during discharge of ash
from the storage silo.
2.30.1.1
Ash Hopper
Ash removal hopper for each boiler shall be constructed of 6.4 mm 1/4 inch
thick steel plate, minimum, with suitable external structural steel
supports for connection to boiler ash hopper and necessary internal anchors
for holding refractory lining in place. Refractory lining shall be 225 mm
9 inches thick on vertical walls and 150 mm 6 inches thick on feed plates.
Each hopper shall be furnished with a sliding ash gate. Each boiler
sliding gate unit shall be provided with an access compartment to allow
gathering and cooling of ash. A cast-iron grate shall be provided along
with a manually-operated air-tight inlet valve for feeding ash into the
pneumatic gathering line. A hinged, steel access gate shall be provided at
each compartment. Spring loaded air intakes shall be provided at the end
of each header. The structural integrity of the hopper shall be based on
the ash weight of 1120 kg/cubic meter 70 pcf.
SECTION 15559A
Page 90
Previous Page
