3. 1,220 mm 48 inch (steam flow of 45,450 to 68,180 kg/hr 100,000
to 150,000 pounds/hr).
4. 1,370 mm 54 inch (steam flow of 68,180 to 81,800 kg/hr 150,000
to 180,000 pounds/hr).
b.
Lower drum shall not be less than 610 mm 24 inches in diameter.
c.
Drum shall be provided with two 300 by 400 mm 12 by 16 inch
elliptical manholes with double clamps, studs and gaskets.
d.
Boiler shall be provided with connections as shown.
2.3.5.2
Tubes
a.
Furnace and Boiler
Furnace and boiler tubes shall not be less than 50 mm 2 inches in
diameter and the thickness shall conform to that given in ASME
BPVC SEC I for the pressure specified. Tubes shall be bent to a
true radius. Tubes that are distorted in bending, flattened or
ridged are not acceptable. Tube holes in the drum shall be
drilled, reamed and serrated. Design of the tubes shall permit
drums and tubes to drain by gravity.
b.
Furnace Waterwall
Furnace waterwall shall extend the entire length of furnace
setting and shall consist of 50 mm 2 inch tangential electric
resistance welded steel tubes or welded furnace membrane wall.
Tubes connected to the drums and/or lower headers shall be
expanded into bored tube seats. If headers are provided,lower
headers of sidewalls shall be round or square design. Lower
header shall be provided with gasketed handhole covers for easy
access to each wall tube. Tube bend radii shall be sized for
standard turbine type cleaners for easy pass through for cleaning
of the full length of the tubes.
c.
Convection Tubes
Convection tubes shall be electric resistance welded construction
in accordance with ASME BPVC SEC I. Convection tubes shall be
arranged to ensure proper and effective soot blowing. Convection
tubes in the boiler section shall be expanded into the upper and
lower drums.
2.3.5.3
Baffles
Baffles shall be arranged to direct products of combustion into contact
with heating surfaces without short circuit of flue gas at the outlet or
excessive loss of draft. Baffles shall be either a refractory material,
tangent tubes or a metal suitable for the temperature encountered.
2.3.5.4
Supports
Boiler and firing equipment shall be supported from the foundation with
structural steel independent of brickwork. Boiler supports shall permit
free expansion and contraction of each portion of the boiler without
SECTION 15561A
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