electric motor actuated by [automatic sequence from boiler control panel]
[manual switch from boiler control panel]. Soot blower elements shall be
of such length, diameter and total nozzle area that for the operating
pressure involved there will be no significant difference in the cleaning
effect between the nozzle nearest the inlet and those farthest from the
inlet of the element. Soot blower shall be made of a material that will
satisfactorily withstand the temperature in the zone where it is installed.
2.3.5.9
Economizer
a.
Boiler shall be furnished with a rectangular, package extended
surface economizer. Economizer shall be shop assembled and
shipped complete with structural steel frame, inner casing, shop
applied insulation and [_____] mm gauge box ribbed metal lagging.
Economizer shall be designed and fabricated in accordance with
ASME BPVC SEC I. Flue gas flow through economizer shall be
vertical with orientation of economizer as shown.
b.
Economizer shall be of continuous tube, loop tube design and shall
be completely drainable by gravity after installation. Design and
arrangement of economizer shall be such that there will be no
steaming in the economizer under any load or operating condition.
Minimum design temperature of the economizer shall be 370 degrees
C 700 degrees F. Economizer shall be hydrostatically factory
tested at 1.5 times the tube side design pressure or at least 2.07
MPa 300 psi in the presence of a Code Inspector. The unit shall
be ASME code stamped and shall include nameplate and code
documentation.
c.
Extended surface shall be of solid continuous, resistance welded
carbon steel fins. Maximum fin spacing shall be [_____] fins per
meter foot. Fins shall be not less than 1.9 mm 0.075 inches thick.
d.
Headers shall be SA-106-B with minimum Schedule 40 wall thickness
and equipped with minimum ANSI Class [_____] raised face weld neck
flanged connections. Header wall thickness and flange rating
shall be dependent on tube side design pressure in accordance with
ASME BPVC SEC I requirements. Tube arrangement shall be of the
open lattice design. Drilled tube sheets are not acceptable.
e.
Hot structure design shall be gastight and designed for a minimum
of 250 mm 10 inches wc gas side pressure.
f.
Pressure parts shall not be in contact with tube sheets.
g.
Inner casing shall be a minimum of 3.4 mm 10 gauge carbon steel.
h.
The economizer shall be designed for the maximum operating
conditions of the boiler and shall be capable of reducing boiler
stack exit flue gas temperature to 148 degrees C 300 degrees F
when the boiler is being fired with natural gas or oil and being
supplied with feedwater at [107] [_____]degrees C [225] [_____]
degrees F at all boiler loads.
i.
The boiler feedwater head loss through the economizer shall not
exceed 103 Pa 15 psi at maximum boiler load.
j.
The economizer shall be insulated with a minimum 50 mm 2 inch
thick blanket type mineral wool or approved equal.
SECTION 15561A
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