58194986 Boiler Construction Ppt
-
Upload
ranvir-raj -
Category
Documents
-
view
222 -
download
0
Transcript of 58194986 Boiler Construction Ppt
-
7/31/2019 58194986 Boiler Construction Ppt
1/56
Boiler
Construction
62b - 203
-
7/31/2019 58194986 Boiler Construction Ppt
2/56
IntroductionObjectives
Know function, purpose and
location of boiler components
Describe path of a drop of
water/steam through boilerDescribe the flow path of
combustion gases
-
7/31/2019 58194986 Boiler Construction Ppt
3/56
Boiler Types
Main propulsion
Supply steam to propulsionturbines and auxiliary equipment
Auxiliary
Supply steam to auxiliary services
only
-
7/31/2019 58194986 Boiler Construction Ppt
4/56
600 PSI D Type Lighter and smaller than M type
Both 600 and 1200 psi steam
Superheater protection required during light-off and securing
Uncontrollable superheat
Superheater temperature is directly
proportional to firing rate and steam demand
-
7/31/2019 58194986 Boiler Construction Ppt
5/56
Navy Boiler DesignReliability
Flexibility
Wide range of steam loads Rapid changes
Responsive to automatic controls
Relatively compact
-
7/31/2019 58194986 Boiler Construction Ppt
6/56
Navy Boiler Design
Efficient operation
5 different heat exchangers
Combustion air Economizer
Furnace
Superheater Desuperheater
Accessability for cleaning and repair
-
7/31/2019 58194986 Boiler Construction Ppt
7/56
Boiler Construction
Watersides
Firesides
Casings
-
7/31/2019 58194986 Boiler Construction Ppt
8/56
Watersides
-
7/31/2019 58194986 Boiler Construction Ppt
9/56
Watersides
Economizer
Steam drum
Water drum
Headers
Downcomers Blowdown piping
Tubes
Generating
Screen
Furnace circuit
Superheater Desuperheater
-
7/31/2019 58194986 Boiler Construction Ppt
10/56
Economizer
Multi-pass heat exchanger
Top of boiler at uptake (stack)
Combustion gases pass through
-
7/31/2019 58194986 Boiler Construction Ppt
11/56
Economizer
Feedwater in tubes heated
Inlet temp 246 F
Outlet temp 440 F
Vents
-
7/31/2019 58194986 Boiler Construction Ppt
12/56
Economizer
2 inch tubes with fins or ringsattached
Attached to the inner casing
Element ends between casings
Check valve between outlet andfeed piping to steam drum
-
7/31/2019 58194986 Boiler Construction Ppt
13/56
Steam Drum
Collects steam
Separates moisture
Receives feedwater and distributes
boiler water
Provides a water reservoir
-
7/31/2019 58194986 Boiler Construction Ppt
14/56
Steam Drum
Steel cylinder at top of boiler
Four piece construction
Upper half called WRAPPER PLATE
Lower half called TUBE SHEET
Tubes penetrate tube sheet
Disc surfaces welded on each end;manway doors for access
-
7/31/2019 58194986 Boiler Construction Ppt
15/56
Steam DrumDrum penetrations
Feed inlet
Saturated steam pipe(outlet)
downcomers & tubes Three safety valve flanges
Surface blow pipe
Two drum level transmitter lines
Two gage glass lines
Drum vents(air cock)
Injection flange(blanked)
-
7/31/2019 58194986 Boiler Construction Ppt
16/56
Steam Drum
Baffle plates / apron plates
Attachment framing supports drum
internals
Separate steam/water mixture from
feedwater in the drum
Direct steam mixture to moisture
separators
-
7/31/2019 58194986 Boiler Construction Ppt
17/56
Steam Drum Moisture separators
Primary separators
Cyclone separators impart swirling motion to
steam/waterHeavy water flung to sides and back down
Secondary separators
Chevron separators / corrugated scrubbers
change direction of steam rapidly
Moisture hits scrubber & drains down
-
7/31/2019 58194986 Boiler Construction Ppt
18/56
Steam Drum
Dry pipe / dry box
Collects steam as it exits scrubbers
Collected steam comes into contact with
safety valves and vents
Directs steam to saturated outlet piping
-
7/31/2019 58194986 Boiler Construction Ppt
19/56
Steam Drum Internal feed pipe
Pipe runs length of drum with holes at equal
intervals
Distributes incoming feedwater evenly
Surface blow pipe
Pipe runs length of drum with holes at equal
intervals
Removes contaminates from water surface
-
7/31/2019 58194986 Boiler Construction Ppt
20/56
Steam Drum
Receives water from economizer
Distributed through internal feedpipe
-
7/31/2019 58194986 Boiler Construction Ppt
21/56
Steam Drum
Water flows to ends & into
downcomers
To water drum and headers
-
7/31/2019 58194986 Boiler Construction Ppt
22/56
Downcomers
Large diameter piping (4- 8)
Send water from steam drum to
water drum/ headers
-
7/31/2019 58194986 Boiler Construction Ppt
23/56
Downcomers
Located between inner and outer
casings
Path for cool, dense water to flow
down
-
7/31/2019 58194986 Boiler Construction Ppt
24/56
Water Drum
Receives water from the steam drum
Distributes water to the generating
tubes
Collects sludge and solid matter
Has bottom blow connections toremove sludge
-
7/31/2019 58194986 Boiler Construction Ppt
25/56
Water Drum
Upper half is TUBE SHEET
Bottom half is WRAPPERPLATE
Drum heads welded with one
manway for access
-
7/31/2019 58194986 Boiler Construction Ppt
26/56
Headers
Similar purpose, but smaller than
water drum
Distribute water to side wall, rear
wall, and screen tubes
-
7/31/2019 58194986 Boiler Construction Ppt
27/56
Headers
Handhole plugs for access
Bottom blow connections to remove
sludge
-
7/31/2019 58194986 Boiler Construction Ppt
28/56
Boiler Tubes
Generating tubes (1" diameter)
Connect water and steam drumMost numerous tubes in boiler
Generate the majority of steamSonic baffles
-
7/31/2019 58194986 Boiler Construction Ppt
29/56
Boiler Tubes Furnace circuit tubes (1. 5 -2")
Connect rear wall & side wall headers to steamdrum
Protect furnace refractory Generate some steam
Water screen tubes
Connect water and steam drum Protect s/h tubes from direct radiant heat
-
7/31/2019 58194986 Boiler Construction Ppt
30/56
SuperheaterReceives all steam from steam drum
Raises steam temp above saturation
Vertically or horizontallyconfigured
Multi-pass heat exchanger
Two headers support tubes
Backfill valves
-
7/31/2019 58194986 Boiler Construction Ppt
31/56
Superheater
Tubes (1.5" dia) connected to
headers at each end
Tubes bent in u shape
-
7/31/2019 58194986 Boiler Construction Ppt
32/56
Superheater
Headers have handhole plugs
Steam flow required to protect s/h
from heat during start up &
shutdown
-
7/31/2019 58194986 Boiler Construction Ppt
33/56
Desuperheater
Heat exchanger in either water drum or
steam drum
Reduces superheated temperature forlower energy applications (auxiliaries)
Reduces material cost and QA
requirements
Multi-pass tube loop
-
7/31/2019 58194986 Boiler Construction Ppt
34/56
Desuperheater
Must verify desuperheater inlet
valve locked open prior to
operating or hydrostatic test of
boiler
If valve is shut, pressure differentialwill crush the desuperheater
-
7/31/2019 58194986 Boiler Construction Ppt
35/56
Blowdown Piping
Surface blow - steam drum Control water chemistry
Surface blow while steaming boiler
Bottom blow - water drum andheaders Removes sludge
Only when boiler secured
-
7/31/2019 58194986 Boiler Construction Ppt
36/56
Firesides
-
7/31/2019 58194986 Boiler Construction Ppt
37/56
Furnace
Steel inner casing
Space for combustion
225 cubic ft of air to 1 lb of fuel Lined with refractory
Insulates inner casing from high temperature(3000o F)
Directs gases over the tubes
Protect headers from flame and radiant heat
-
7/31/2019 58194986 Boiler Construction Ppt
38/56
Refractory Types Firebrick
Inner furnace wall
Fire/temp resistant to 3000 F
1/10 insulation cap. Of insulating block Insulating brick
Insulate to 2500 F
Cannot withstand flame
Intermediate insulation
-
7/31/2019 58194986 Boiler Construction Ppt
39/56
Refractory Insulating block
Insulate to 1500o F
Cannot withstand flame; Good insulator
1" layer next to inner casing Silicon baffle tiles
High strength heat conductor
Between screen tubes
Directs gas flow through the superheater
-
7/31/2019 58194986 Boiler Construction Ppt
40/56
Refractory
Refractory mortar
Seals joints; Cushions against stress
Two types (both air dry)Class 1: dry - for firebrick & tile
Class 2: ready mixed - for insulating brick
Burner tile
Shaped to fit specific burner
Protect burner assembly/casing
-
7/31/2019 58194986 Boiler Construction Ppt
41/56
Refractory Anchors
Anchor bolts
Secure firebrick and burner tile
Bolt clips welded to inner casing
Anchor clips
Hold insulating brick to inner casing
Anchor strips
Hold castable in place
-
7/31/2019 58194986 Boiler Construction Ppt
42/56
Refractory Installation
Depot level work
S/f repair only
Anchor bolts a must
Paint metal surfaces
Expansion joints 1/4" Styrofoam between every 4th rowof brick; Then burn away
-
7/31/2019 58194986 Boiler Construction Ppt
43/56
Refractory Life
Aging factors
Rapid temperature changesShock and vibration
Boiler panting
-
7/31/2019 58194986 Boiler Construction Ppt
44/56
Fuel Oil Burners
Atomizer assemblies
Burner barrel
SSD
Air registers
Bladed cone Diffuser
-
7/31/2019 58194986 Boiler Construction Ppt
45/56
Soot Blowers
Location
Fixed elementsRotary elements
-
7/31/2019 58194986 Boiler Construction Ppt
46/56
Casings
-
7/31/2019 58194986 Boiler Construction Ppt
47/56
Boiler Casings Two steel casings
Inner casing holds furnace/tubes
Outer casing holds accessories
Space between is combustion air path Advantages
Reduces heat loss
Preheats combustion air
Reduces fireroom temperatures
-
7/31/2019 58194986 Boiler Construction Ppt
48/56
Boiler Casings
Inner casing leaks Lower furnace temp- combustion/fuel
increase
Thermal stress in refractory
Forced draft blowers speed up Fuel inefficient
-
7/31/2019 58194986 Boiler Construction Ppt
49/56
Boiler Casings
Outer casing leaks
Increase fireroom temperature
Combustion gases may enterfireroom
Forced draft blowers speed upFuel inefficient
-
7/31/2019 58194986 Boiler Construction Ppt
50/56
Boiler Casings
Steam smothering system
Boiler air casing fires
Fuel on furnace deck
-
7/31/2019 58194986 Boiler Construction Ppt
51/56
Combustion Air Path
Intake plenum
Forced draft blower supply
Inner and outer casing
Air register
Gas path
Exit through economizer and out stack
-
7/31/2019 58194986 Boiler Construction Ppt
52/56
Monitoring Exhaust Gases
Periscope
Smoke indicators / stack gasanalyzers
-
7/31/2019 58194986 Boiler Construction Ppt
53/56
Boiler Foundations
Fixed saddles or feet
One end of drums & headersBolted fast to hull girder
-
7/31/2019 58194986 Boiler Construction Ppt
54/56
Boiler Foundations
Sliding feet
Other end of drums & headers
Oblong bolt holes for movementLubrication points for grease
AO 177 feet do not require lube
Movement indicator attached
Should move 1/4" to 1/2" cold to hot
-
7/31/2019 58194986 Boiler Construction Ppt
55/56
Boiler Foundations
Frozen sliding foot
do not steam boilersoak with a solvent to free
last resort-jack boiler up
-
7/31/2019 58194986 Boiler Construction Ppt
56/56
Summary
Watersides
FiresidesCasings