A wide variety of both raw materials and components, besides auxiliary plant and equipment, are required to construct a boiler plant. Materials employed in boiler making can be broadly classified as shown in Table 5.1.
Depending on the type of boiler and its scope, each of the three items in Table 5.1 contributes to —30 to 40% of the cost of the boiler plant. In a typical industrial plant, the common bought-outs (BOs) are often included in the scope of boilers, whereas in larger boilers, item 3c is excluded.
If the BOs are taken out, the boiler is primarily steel and BRIL, with steel divided into boiler steels and structural steels for items 1 and 2, respectively. With the exception of aluminum sheets required for cladding the boiler, there is no requirement for nonferrous materials.
Parts of a Boiler
S. No
|
Item
|
Description
|
Consisting Mainly
|
1
|
Pressure parts
|
Pressure-holding parts, mainly FW,
|
Drums, tubes, pipes, headers, tanks, forgings,
|
|
(PPs)
|
Drum water, and steam
|
And castings
|
2
|
Nonpressure parts (NPPs)
|
Fabricated items
|
Structure, flues and ducts, casing and hopper, tubular air heater (AH), cyclones, BRIL
|
3a
|
Bought-outs (BOs)
|
Equipments procured from others
|
Valves, mountings and fittings, soot blowers, attemperators, fans, electrostatic precipitator (ESP), rotary AH
|
3b
|
Firing equipment
|
|
Mills, burners, burner management system (BMS), stoker, feeders, air nozzles for fluidized bed combustion (FBC), hot gas generators
|
3c
|
Common BOs
|
Common for the total plant with one or more boilers
|
Feed pumps, deaerator, ash handling plant, coal handling plant, oil storage, P&H units, gas conditioning skid
|
Note:
|
BRIL stands for bricks, refractory, insulation, and lagging.
|
|
|
Комментирование и размещение ссылок запрещено.