Bhatia Gummidipoondi Whrsg o&m Manual Final Copy

ENMAS GB POWER SYSTEMS PROJECTS LIMITED Chennai 600 018 INDIA

OPERATION AND MAINTENANCE MANUAL

CUSTOMER: BHATIA COKE & ENERGY LTD PROJECT CODE : IB002A & IB004A

GUMMIDIPOONDI, TAMILNADU 2 x 26.4 TPH/71 kg/cm/4905 C WHR BOILER.

BOILER OPERATION & MAINTENANCE MANUAL Page.No.1

F O R E W O R D T O I N S T R U C T I O N S

These recommendations and instructions have been written as a direction to the starting up

and operation of the 2 X 26.4 TPH Waste Heat Recovery Boiler supplied to M/s. BHATIA

COKE & ENERGY LIMITED, GUMMIDIPOONDI, TAMILNADU.

The recommendations and instructions are for the guidance of competent and responsible

engineers having knowledge of standard operational procedure and routine maintenance of

boiler plant.

It is appreciated that conditions on individual plant may require minor modifications to the

instructions, but major changes should not be made without prior consultation with the

boiler manufacturer.






Important Instruction to End User

The instruction provided in this manual are Standard practices on boiler maintenance as per

manufacturer / consultants years of experience in the field of Pressure and Process

equipment operation and maintenance. It is highly recommended for the end user to ensure

the operation team is familiar & qualified to operate Waste Heat Recovery Steam Generator

as per the instructions of Original Equipment Manufacturer [EGBPSPL] for operations &

maintenance of the system. The Operational parameter will vary drastically, if the

recommended input parameter is not maintained.

Quality of Feed Water and Boiler water should be maintained as per the

recommendation to avoid the failure in pressure parts.

Hot Flue Gas (COFG) Quality & Quantity should be within the Manufacture

recommended range.

Over-Loading of Equipments is not recommended at any point of time.

Utility inputs from End user should be within the recommendation.

EGBPSPL here by confirm that the user is responsible for the cause and failure of boiler

unit due to violation of recommendation given at the Project stage.

ENMAS GB POWER SYSTEMS PROJECTS LIMITED,

CHENNAI INDIA.






VOLUME - I

BOILER OPERATIONS

CONTENTS

CHAPTER

No DESCRIPTION PAGE No

1. INTRODUCTION AND SCOPE 4

2. GENERAL & TECHNICAL INFORMATION 18

3. DESCRIPTION OF BOILER PLANT 22

4. DESIGN DATA FOR BOILER PERFORMANCE 49

5. BOILER PLANT SAFETY AND PROTECTION 54

6. FEED AND BOILER WATER 61

7. BOILER OPERATIONS 96

8. SHUT DOWN, TUBE FAILURES, TROUBLE SHOOTING 184

9. BOILER MAINTENANCE 201

10. ANNEXURE 223






CHAPTER 1

INTRODUCTION AND SCOPE






CHAPTER 1


CONTENTS

SL.NO. DESCRIPTION PAGE NO

a. Radiant Chamber 8

b. Steam Drum 8

c. Water Wall Panel 8

d. Super Heaters 9

e. Supports & Hangers 9

f. Buck Stays 9

g. Economizer 10






CHAPTER 1


The boiler supplied for this contract is of WHRB (Waste Heat Recovery Boiler) which is

located at downstream of Coke Oven to recover waste heat from the Oven exhaust. The

salient features of the boiler are as described below:-

The boiler is of Water tube, natural circulation, bottom supported, single drum, all welded

type pressure part design, negative/suction draft waste heat recovery steam generator

type. The boiler allows unrestricted and uniform upward expansion ensuring better leak

tightness and low thermal stress for pressure parts over prolonged periods.

The boiler has enclosure of radiant chamber surrounded by water cooled walls to ensure

better optimum recovery of heat from the hot flue gas from coke oven exhaust.

The supporting structure consists of the main columns, their foundation, the framework for

the boiler and the built-in auxiliarys supports and the section girders for bracing the

structure. The calculations of the column strength takes into account an earthquake

resistant factor.

The gallery supports outside and over the main structure consisting of a sectional girder

frame properly spaced and braced, for the safe working at different levels as well as to

approach highest elevation in the boiler, for the operation and maintenance of the boiler.

Hot flue gases, from the Coke oven exhaust is supplied normally at 900 to 950 C which is

considered for sizing the boiler pressure parts. The Hot flue gas shall be supplied at

approximately 0.0 m elevation with a flange to connect the hot flue gas duct to the boiler.

The duct cross section considered is approximately 2.875 x 1.555 (ID) m. The flue gas is

routed through refractory lined hot flue duct to the boiler.

1 No. Hydraulic Operated Guillotine water cooled damper of bottom supported

arrangement is placed in the hot flue gas to the boiler and 1 No. Hydraulic






Operated Guillotine water cooled damper of the bottom supported arrangement is

placed in the cold flue gas connecting the ID fan and existing process stack, with the

guillotine operating in vertical direction. Provision for drying chamber with manual

damper/valve is provided in the flue gas duct from ID fan outlet and process stack inlet

before the Hydraulic Operated Guillotine water cooled damper.

The WHRB units have been designed and arranged in 2 vertical passes with the hot flue

gases received in the first pass horizontally into the Screen tubes of the Water

wall radiant chamber, and then flows vertically upwards through the Primary Super

heater, Secondary Super heater and Evaporator coil assemblies; cross over to the second

pass Economizer section and flows vertically downwards.

All the heating surfaces of Primary Super heater, Secondary Super heater, and Economizer

are arranged horizontally; and the Evaporator coils are arranged with a slight slope to the

horizontal.

The Vertical sections are of the self supporting type; and are of bottom supported

design And will be rested on the supporting steel work of boiler, the high temperature

water wall section.; and the Economizer section at a higher level. Ash collection

hoppers are provided below radiant chamber and economiser sections.

The steam drum is located at the front side of boiler, above the top Water wall

headers and is supported on 2 No. Large sized down comer pipes which is mounted on a

slide bearing arrangement on the structure for thermal movement of down comer when

boiler is heated up with waste heat gases.

The boiler is provider with proper circulation system consisting of bottom water wall

headers, top water wall headers, relief and supply tubes. Circulation system of boiler

provides appropriately sized system with unheated down comers, which avoids formation of

De-nucleate boiling at all operating conditions.






All required structural steel, platforms & stairs, piping & duct supports; Weather

Rain protection roof covering arrangement over each boiler are provided. Flue gas from

Economizer outlet will be drawn by an ID fan and delivered to Process stack.

A brief pressure part description of boiler is as follows:

a. Radiant Chamber

The primary purpose of the radiant chamber is to provide a gas tight enclosure for complete

absorption of heat source from coke oven flue gas to the water walls.

b. Steam Drum

The boiler is provided with sufficiently sized steam drum which houses baffles, cyclones and

scrubbers to remove water particles from saturated steam before it enters super heater

coils. Steam drum is also provided with necessary nozzles for mountings, feed water and

chemical injection. Steam drum is also provided with manhole entries on either side with

door and bull dog clamp arrangement for its closure. Necessary air vent and pressure

tapings were provided as per the requirements.

c. Water Wall Panel

The Water wall section provided essentially covers all 4 sides of the Inlet Radiant

chamber to enclose Primary and Secondary Super heater sections and the Evaporator

section. All four sides of water wall is membrane wall construction having bottom and top

headers, which are connected by supply pipes and risers tubes respectively. The entire

water walls are robust in construction with gas tight conditions. The water wall is also

provided with dilution duct arrangement along with necessary damper to control the gas

temperature entering the radiant chamber.






d. Super Heaters

The Super heater consists of Primary and Secondary Super heater sections located in the

radiant chamber. The secondary super heater is located just above the primary super heater

coil arrangement.

The Primary SH and Secondary SH had been arranged as counter and parallel flow type

and fully drainable type. The Primary super heater coil assemblies; and the Secondary

super heater coil assemblies are horizontal, in-line tube arrangement, with the main

inlet and outlet headers located outside the Water wall enclosure.

The PSH & SSH heat recovery surfaces are placed inside welded water wall

enclosures; suspended through Evaporative hanger tubes from the top side of Water wall

section; and is free to expand upwards, along with the hanger tubes.

e. Supports & Hangers

The boiler is bottom supported construction with free upward movement. The entire boiler

is supported from external steel work. The heaviest girders are formed as a support

framework below the bottom side wall headers and down comer. All the pressure parts of

the boiler and integral piping are supported from this frame work with sling rod

construction.

f. Buck Stays

The buck stays are provided around the radiant chamber wall to ensure the structural

rigidity when there is a pressure increase or decrease inside the radiant chamber due to

mal-operation of draft system. The buck stays are acting likes a stiffener to the boiler

enclosure. Buck stay also guides the boiler thermal expansion.






g. Economizer

Boiler is provided with huge economizer sections in the 2nd pass of the gas to recover the

heat from hot flue gas coming out of evaporator section. Bottom side of the economizer is

also provided with hopper and slide gate arrangement to remove fly ash coming out of

boiler.

The following are the components of major equipments for the boiler:

1. Steam Drum

Steam drum with nozzles and manholes.

Steam drums internals with cyclones, baffles, Primary & Secondary separators.

Feed distribution sparge flange pipe with thermal sleeve.

Chemical distribution pipe.

Continuous Blow down Line.

2. Water Walls

Tubes with attachments / fins / Membrane wall.

Openings for access doors, inspection doors, Temperature & Pressure instrument tapping

Top headers along with stubs and attachments.

Bottom headers with stubs and attachments.

Structural attachments.

3. Evaporative Boiler Bank System

Evaporative Bank tubes.

Bottom Headers.

Top Headers.






4. Primary Super Heater

Inlet header along with stubs and attachments.

Outlet header along with stubs and attachments.

Lugs and spacers for Coils.

5. Attemperator

Complete Attemperator with spray nozzles,

Thermal Sleeve and Venturi.

6. Final Super Heater

Super heater elements.



Lugs and spacers for the same.

7. Economizer

Economizer Elements.



Lugs and spacers & spectacle plates for the same.

Erosion shields.

Cassette baffles.

Hoppers






8. Integral Piping

Large bore down-comers with stubbed ends.

Supply pipes.

Riser pipes.

Saturated steam pipe to Primary Super Heater.

Link between Primary Super heaters to Attemperator.

Link pipe between Attemperator to Secondary Super heater.

Main steam flow nozzle.

Link pipe between Attemperator tap off point to Attemperator control station inlet.

Link pipe between Attemperator control station outlets to inter stage Attemperator.

Attemperator water flow orifice.

Link pipe between battery limit and feed control station.

Link pipe from outlet of Feed Control Station to economizer inlet header.

Feed water flow orifice.

Link pipe between economizer outlet and steam drum.

Start -up vent piping.

Link between drum to Blow down Tank.

Super heater and boiler drains to drain header.

Drain header to Blow down Tank.

Intermediate blow down piping.

Piping to sample coolers.

9. Low Pressure vessels and piping

Safety Valve exhausts piping.

Blow Down tank with drains.

Blow Down tank escape / vent piping.

Cooling water piping to sample coolers.

Temporary piping for steam blowing.

HP chemical dosing system.

Piping from HP chemical system to drum.






10. Piping supports

Supports for Main Steam piping.

Supports for Feed Water control station to Economizer inlet.

Supports for Economizer to Drum Piping

Supports for risers piping

Supports for Saturated Steam Line piping

Supports for Supply Line piping

Supports for Down comer

Supports for start-up vent piping.

Supports for safety valve escape piping.

Supports for BD tank escape piping.

Supports for Primary Super Heater to Attemperator piping.

Supports for Attemperator to Secondary Super Heater piping.

Supports for Attemperator spray water line piping.

Supports for all drain piping.

Supports for risers.

Supports for supply pipes.

11. Casing, Flue Gas Ducting System

1. Refractory lined hot flue gas duct from coke oven exhaust to inlet radiant chamber.

2. Flue gas from boiler exit to economizer.

3. Economizer casing.

4. Flue gas duct from economizer to existing common flue gas duct.

5. Duct from common flue gas duct to ID inlet.

6. ID discharge duct to stack.

7. All expansion joints.

8. Necessary supports.

9. Measurement tapping on ducts.

10. Necessary fasteners.






12. Structural

Total boiler structure along with main columns, bracing, tie beams, & ceiling structure.

13. Galleries and Ladders

Galleries, platform, stairs.

Hand rails and guard plats.

14. Hot Structures

Buck Stays and Tie Bars.

Stand Off Plates.

Corner connections.

Earthquake restrains.

Boiler thermal anchors and ties.

Arch support beams, channels and structures.

Economizers hot support beams.

15. Supports and hangers.

Necessary guide for steam drum along with saddles.

Necessary slide bearings for water wall along with saddles.

Necessary supports for final / primary super heaters along with saddles / lugs.

16. Miscellaneous Structures

Structures for handling equipment.

Run way beams.






17. Castings

Access door with mounting plate.

Inspection door with mounting plate.

18. Dampers and expansion bellows

All Manual dampers as per the P & I drawings.

Hot flue gas duct bellows as required.

19. Insulation and Cladding

Complete boiler insulation and cladding.

Insulation and cladding for flues and ducts.

Insulation and cladding for air integral piping.

20. Refractory

Refractory at radiant hopper region.

Refractory at the inlet of flue gas duct.

Refractory on doors / openings

21. Pumps

Boiler Feed Pumps.

HP Chemical dosing pump.






22. Valves

Manual and motorized valves as per P & ID.

Super heater safety valve.

Drum safety valves.

Motorized main steam stop valve.

All air release valves.

All header drain valves.

Chemical line valves.

Necessary root valves.

All control valves as per P & I.

1 x 100% Pneumatic Feed Control Valve.

1 x 30% Pneumatic Feed Control Valve

1 x 100 % manual feed bypass valve.

23. Silencers

Silencer for startup vent.

Silencer for main steam line safety valve.

24. Electrical

Local Isolators (only for LT, MOV and dampers).

Local Push button stations.

Junction Boxes.

Inter connecting power and control cabling.






25. Motors

Motors for ID fans.

Motors for Feed pump.

Motors for chemical dosing systems / agitators.

Motors for all motorized dampers and Valves

26. Instrumentation

Field mounted instruments as shown in P & ID.

Local gauge instruments as shown in P & ID.

Instrument Cables.

Local junction boxes and instrument racks.

Instrument cable trays.

Instrumentation piping.

Instrument air piping.

27. Major Mountings

Drum safety valves

Drum level Direct Water Level gauge.

Drum Level Remote Water Level Indicator with 4 20 mA DC Output.

Drum Level level Transmitter & indicator.

Pressure and temperature gauge.






CHAPTER 2

GENERAL AND TECHNICAL INFORMATION






CHAPTER 2


CONTENTS


1. General Information 20

2. Technical Information 20

2.1 Boiler 20

2.2 Electrical & Instrumentation 21

2.3 Process Steam 21

2.4 Instrument Air 21






CHAPTER 2


1. GENERAL INFORMATION

SL.No Description Information

1. Plant 2 X 26.4 TPH Waste Heat Recovery

Steam Generator in M/s. BHATIA COKE

& ENERGY LTD,Gummidipoondi,Tamilnadu

2. Elevation Above Sea Level About 15 M (approx) above MSL

3. Road Link NH 5

4. Air Port Chennai about 65 KM

5. Rail Link Gummidipoondi

6. Seismic Zone & Co efficient Seismic Zone III (Light to Moderate)

9. Relative humidity - Design 90 %

10. Ambient Temperature 50C

2. TECHNICAL INFORMATION

2.1 Boiler

SL. No Description

1. Numbers and type of Boiler 2 off Single drum, Natural circulation, Bottom

supported Fully drainable Waste heat recovery Boiler.

SL. No DESCRIPTION UNITS VALUES

APPROXIMATE

2. Final Super Heater Flow at 100 % BMCR TPH 26.4

3. Steam Pressure at Main Steam Stop Valve Outlet

(MSSV) kg/cm2(g) 71

4. Boiler Steam Drum Design Pressure kg/cm2(g) 85

5. Main Steam Temperature at Super Heater Outlet C 4905

6. Boiler Feed Water Inlet Temperature C 140

7. Maximum Flue Gas Temperature at Boiler Outlet C 160






2.2 Electrical & Instrumentation

For all drive motors : 415V; 50 Hz, 3 Phase

For Controls : 220 V

Instrumentation Interlocks and Annunciation : 24V (2 Wire) DC

Voltage Variation : 10%

Frequency Variation : 5%

Combined Variation : 10%

2.3 Instrument Air

Quality : Oil and Moisture Free

Pressure : 7.0 Kg/cm2 (g)

Dew Point : -40C

Temperature : Ambient

2.4 Cooling Water

Water inlet Temperature : 32C

Pressure : 5 Kg/cm2 (g)






CHAPTER 3

DESCRIPTION OF BOILER PLANT






CHAPTER 3 DESCRIPTION OF BOILER PLANT

CONTENTS

SL.NO. DESCRIPTION PAGE NO.

a. Feed control Station 24

b. Circulation System & Steam Drum 25

c. Boiler Water Wall Systems 27

d. Evaporator Section 29

e. Super Heater Section 30

f. Attemperator Unit 34

g. Economizer Section 35

h. Boiler Inter Connecting Piping 36

i. Boiler Internal / Trim Piping 37

J. Valves & Fittings 38

k. Non-Pressure Parts 40

l. Boiler Supporting Structural, Platforms & Stairs 41

m. Economizer Casing & Supporting Steel 42

n. Flue Gas Ducting 42

o. Hot Flue Gas I/L Duct to WHRB 42

p. Slide Bearings Supports 43

q. Ash Hoppers 43

r. Buckstays 43

s. Refractory Materials, Insulation & Outer Casing 44

t. Induced Draft Fan 45

u. Guillotine Dampers 45

v. Dosing System 46

w. De-aerator, Feed Storage Tank 47

x. Boiler Feed Pumps & Drives 47

y. Soot Blower 48






CHAPTER 3

DESCRIPTION OF BOILER PLANT

PRESSURE PARTS BRIEF DESCRIPTION AND DETAILS

The High Pressure Boiler primarily consists of the following Pressure Parts:

1. Feed Control Station

2. Circulation System & Steam Drum (with internals)

3. Water walls system (including the inlet radiant section)

4. Super heaters consisting of Primary and Secondary Sections

5. Attemperator unit

6. Evaporator Sections

7. Economizer Sections

8. All the Boiler Connecting Piping (between Economizer Drum Evaporator; and

between Super heater sections etc.): Feed control station to Economizer feed piping;

Main Steam piping up to MS stop valve.

9. All the Boiler integral / Trim piping

10. One number BD Tank

11. Valves and Fittings (Steam & Water System)

The Pressure parts design materials and thickness has been conservatively chosen, with

required margins over the code requirements for trouble free unit operation. The Access

doors are provided on both side of the boiler, to which required access platforms are

provided.

The Brief Description and Details of the various Pressure parts are as follows:

a. Feed Control Station

Feed control station is meant for controlling feed water to boiler. The feed water line

comprises of following:

- 100 % Pneumatic feed control valve.

- 30 % Pneumatic feed control valve.






- 100 % manual by-pass valve.

- Manual isolation Valves for Control Valve.

- Drain Valve located before Feed water Regulator valve.

- Feed check valve and Shut-off Valve.

- Pressure Gauge Isolation valves.

- Thermo well box with Thermo well.

- Feed water sampling valves.

- Initial filling line valve.

- Root & Isolation valve for all HP tappings.

b. Circulation System & Steam Drum

The heated feed water from outlet

of Economizer is discharged into

the drum, below the Normal Water

level, where it gets mixed with hot

water in the steam drum. From the

drum, the water flows down

through the unheated down comer

pipes to the bottom headers of

water wall section. The water flows

through the heat absorbing walls

and gets partly evaporated into

steam. The steam water mixture

flows to the drum through riser

pipes. The internals provided in the

steam drum separates steam from

the water. The water particles fall

down and enter the circulation

system again, while the saturated

steam leaves the drum for super

heaters.

Figure 1: Circulation System






Boiler is provided with two main down comer which supply water to water wall, evaporator

and hanger tubes. Evaporator circuit is provided with four supplies and six risers. Hanger

tube is provided with two supplies and two risers. Water wall is provided with bottom and

top headers along with down comer and raisers.

Steam Drum

The Boilers are of the single drum type. The steam drum of each WHRB unit is placed

horizontally on the RHS side of the boiler, at an elevation of approx. 33.0 m above

ground level. The drum is supported on 2 Nos. Large size vertical down comer pipes.

FIGURE 2: ELEVATION (Steam Drum)

(View looking from Rear of Boiler)

The steam drum will be of fusion welded construction, with semi ellipsoidal dished

ends with a manhole doors. Cyclone separator type drum internals are provided, for

this high pressure duty to achieve assured steam purity over wide operating conditions.

The steam drum is sized sufficiently large to have sufficient water holding between the NWL

and Trip level for full load operation.






The dimensions of the Steam Drum are as below:

Number of Drum / Boiler - One

Drum ID / Raw Plate Thickness mm 1220 X 55

Minimum Shell Length mm 3400

Dished Ends Type - Semi Ellipsoidal

Material of Drum Plates - SA 515/516 Gr 70 or

Equal: Carbon Steel

Drum Internals 2 Stage - Turbo Separators and

Screen dryers.

Water Holding Capacity (NWL Trip Level) Max

at 100% BMCR. minute One

Number of Down Comer Pipes - 2 (Two)

Drum Supporting Arrangement - On 2 Nos. Down Comer

pipes

Drum Design Pressure kg/cm (g) 85

Key Drawing:

Steam Drum : ICAA0200-1-F-03-01-0352

c. Boiler Water Wall Systems (Including the inlet Radiant Section)

The Water wall section provided essentially covers all 4 sides of the Inlet Radiant

chamber, the Primary and Secondary Super heater sections and the Evaporator section

as shown in the figure-3. All required bottom and top headers are provided.

The water wall system will be designed for a pressure of 400 mm WC, and

required Buck stays and tie bars are provided. Required access doors and soot blower

openings etc. are provided in the water wall panels. The entire Water wall will be supported

at about ~ 7.0 m level over structural support steel work and is free to expand upwards.






The dimensions of the Water wall systems

are as below:

Description Design Values

Boiler

Width W 3657.6 mm

Depth D 2349.8 mm

CL of WW Top Header

[Height] 30700 mm

WW Tubes [OD X T]

Front & Rear (50.8 X 4.0) mm

WW Tubes [OD X T]

LHS & RHS (50.8 X 4.0) mm

WW Tubes [OD X T]

Roof Tubes (50.8 X 4.0) mm

Material Tubes SA 210 Gr A1

WW Tubes [OD X T]

Front & Rear 76.2 mm

WW Tubes [OD X T]

LHS & RHS 76.2 mm

WW Tubes [OD X T]

Roof Tubes 76.2 mm

WW Fins [W X T] (25.4 X 6) mm

Material Fins IS 2062 Gr C

WW Header OD

[Top/Bottom]

(219.1/219.1)

mm

Hanger Tube Header

OD [Inlet/Outlet]

(219.1/219.1)

mm

Material Header

[WW/Hanger]

SA 106 Gr B/ SA

106 Gr B

WW Heating Surface

Area 440 m

FIGURE 3: ELEVATION






Key Drawing:

Arrangement of Water Wall Panel : ICAA0200-1-F-04-01-0939

d. Evaporator Section

The Evaporator heating surfaces consist

of a number of Evaporator coil

assemblies, in-line tubes; each element

arranged at 9 to the horizontal.

The coil assemblies are connected at

the inlet and outlet end by large size

headers. The Evaporator heating surfaces

are arranged inside the welded wall

enclosure. The Evaporator coils are

suspended through Evaporator hanger

tubes from the top side of the Water

wall section; and is free to expand

downwards along with the hanger tubes.

FIGURE 4: ELEVATION (Arrangement of

Evaporator Coils with Sling Tubes)

(View looking from R.H.S of Boiler)






The dimensions of the Evaporator Section are as below:

Description Units Design Values

Number of V Tube Section = One

Type of Flow =

Parallel Flow (With

Saturated water flowing

upwards)

Tube OD X Thk mm = 60.3 X 4.0

Materials - Tube = SA 106 Gr. B/

SA 210 Gr. A1

Materials Header [Inlet & Outlet] = SA 106 Gr. B/C

On load cleaning System = Steam soot blower

(Rotary Type)

Total Bed Evaporator Coil Heating Surface

Provided m = 868

Key Drawing

Evaporator Coil Assembly : ICAA0200-1-F-04-35-0001

e. Super Heater Section

The waste heat recovery boilers is provided with two stage super heater (primary and

secondary) and inter stage attemperator to have better control to the final steam

temperature. The Primary super heater coil assemblies; and the Secondary super heater

coil assemblies are horizontal, in-line tube arrangement, with the main inlet and

outlet headers located outside the Water wall enclosure. The Primary SH and Secondary SH

have been designed as counter and parallel flow type and fully drainable type.






FIGURE 5: ELEVATION (Arrangement of PSH with Sling Tubes)

(View looking from RHS of Boiler)

FIGURE 6: ELEVATION (Arrangement of SSH With Sling Tubes)







The PSH & SSH heating surfaces are placed inside welded water wall enclosures;

suspended through Evaporative hanger tubes from the top side of Water wall section; and is

free to expand down wards, along with the hanger tubes.

FIGURE 7: STEAM FLOW DIAGRAM






The dimensions of the Super Heater Section are as below:

Sl.No Description Units Primary Super Heater Secondary Super Heater

1.

Number of

Sections/WHRB

-

One One

2.

Location in the gas path

(In the direction of gas

flow)

-

Rear Side Front Side

3. Type of flow - Counter & Parallel

Flow Counter & Parallel Flow

3. SH tubes OD X Thick mm 50.8 X 4.0 50.8 X 4.0 & 5.0

4. Material of SH Tubes (all

as required per IBR)

- SA 210Gr.A1

&

SA 213Gr.T11

SA 213 T11 & T22

5.

SH Headers materials

(all as required per IBR)

- SA 106Gr. B /

SA 335 P11

SA 335 P11 /

SA 335 P22

6.

Size / Material of SH

Inter connecting pipes

(PSH -SSH)

-

100 NB / SA 335 P11

7.

Enclosure Side Water

wall tubes & Screen

tubes [OD X T]

-

50.8 X 4.0 50.8 X 4.0

8. WW Headers Material - SA 106 Gr. B/C

9.

Total heating surface of

the Super heaters

sections (approx.)

m2 126 103

Key Drawing:

Arrangement of PSH : ICAA0200-1-F-05-01-0149

Arrangement of SSH : ICAA0200-1-F-05-06-0052






f. Attemperator Unit

To have a wide range of controlling from 50% to 100 % of MCR steam flow for the final

steam temperature an attemperator is located in the connecting piping, between PSH outlet

and the SSH inlet connecting pipe.

FIGURE 8: ATTEMPERATOR ASSEMBELY

The dimensions of the De-Super Heater Section are as below:

Number of DSH - One

Type - Spray Type (Variable Orifice)

Control of Spray - By Spray Control Valve

DSH OD mm 114.3

Material - SA 335 P11

Control Range - 50% to 100% of Boiler MCR

Key Drawing:

De Super Heater Assembly : ICAA0200-2-F-06-03-0064






g. Economizer System

The Economizer heating surfaces are arranged in the

second pass of gas flow. The Economizer coil

assemblies consist of horizontally arranged inline

tubes, with the inlet and outlet headers located

outside the gas path. The Economizer coil assemblies

are supported / suspended over support beams and

the coils are free to expand.

The Economizer heating surfaces are enclosed in a

steel casing, suitably stiffened and arranged with a

structural steel system. Economizer section as a whole

is of the self supporting type, and of bottom supported

design.

The Economizer is the last stage of heat recovery, placed

in the gas path, on the downstream side of the

Evaporator surfaces. Each bank height of the

economizer will be approximately 3000 mm and

interbank gap will be 700 mm. Necessary soot blowers

for periodically cleaning the soot at the economizer

sections are provided.

FIGURE 9: ELEVATION







The dimensions of the Economizer Section are as below:

Number of Economizer Sections - One

Type -

Counter flow (With FW flow

upwards and gas flow

downwards

Tube Outer Diameter x Thickness (38.1 x 3.6) mm

Material of Tubes - SA 210 Gr A1

Header Outer Diameter - 141.3 mm

Header Material and Connecting Pipes - SA 106 Gr B

Enclosure of Economizer Coil Assembly - 6 mm Carbon steel plates

Total Heating Surface Area Economizer (approx) - 1969 m

Key Drawing:

Arrangement of Economizer : ICAA0200-1-F-02-01-0043

h. Boiler Inter connecting piping

1. Economizer Sections & System Feed Pipe

Sl.No Description Pipe Size Material

1. Feed Control station to Economizer inlet 80 NB SA 106 Gr B

2. Economizer outlet to drum 80 NB SA 106 Gr B

2. Evaporator Sections / Circulating System


1. Down comer Pipes -From Drum 200 NB SA 106 Gr B

2. Supply Pipes DC Pipes to Evaporator & Water Wall 125 NB SA 106 Gr B

3. Riser Pipes - From Evaporator & WW Top Outlet 125 NB SA 106 Gr B

4. Connecting Pipes to Drum (Risers) Distribution at

Drum end 125 NB SA 106 Gr B






3. Super Heater section (Saturated Steam Pipes)


1. Saturated Steam Pipe - Drum to PSH Inlet 100 NB SA 106 Gr B

2. SH Inter Connecting Pipe & DSH Connecting PSH &

SSH 100 NB SA 335 P11

3. Main Steam Piping up to MS Stop Valve 100 NB SA 335 P11

i. Boiler Internal / Trim Piping

a) The complete requirements of boiler integral trim piping will be supplied for each

boiler. This will include the following.

Drain piping

Vent piping

Drum emergency drains / Intermittent Blow down piping

Exhaust piping for Safety valves and starting vent

Drain header for HP drains

Steam / water piping connections for instrument connection

De-Super Heater spray water piping

Chemical feed piping

De SH spray water Pipings

Sampling piping to Sample coolers

b) A Blow down tank (Common for both intermittent blow down and Continuous Blow

Down) will be provided for each WHRB unit. All the drain of super heater and boiler drain

lines, IBD, CBD are terminated at a common header collecting water / condensate from the

mentioned sources are connected to the BD tank. The BD tank is provided with a vent

piping to atmosphere at safe elevation. The condensate drain is passing through a siphon

into the blow down pit. The condensate drain is passing through a siphon into the blow

down pit.






j. Valves and fittings (Steam & Water System)

The Steam Generator are equipped with all required Valves and fittings for safe and efficient

unit operation as part of the Boiler Integral pressure part system. The details, arrangement

and location of Valves and fittings are shown in the P&IDs enclosed in Volume II

(Mechanical Drawings).

For the ready reference, we had enclosed herewith the list of major valves and fittings.

LIST OF MAJOR LARGE SIZE VALVES AND FITTINGS

(Refer P&ID Steam and Water system also for details)

Sl.No Service / Description NB No.

provided

Operation Remarks

A BOILER FEED WATER

SYSTEM

1

Feed Control valve(100%

capacity)

NB 50

(On NB 80

feed line)

1 Pneumatic At feed control

station

2

Feed Control valve(30%

capacity) for low load

operation

NB 25/32

(On NB 40

feed line)

1 Pneumatic At feed control

station

3

Bypass Feed Control valve

(100% capacity) NB 80 1 Hand

At feed control

station

4

Isolation valves for the

100% capacity valve NB 80 2 Hand

At feed control

station

5

Isolating valves for the 30%

capacity valve NB 40 2 Hand

At feed control

station

6 Feed stop valve NB 80 1 Hand Eco inlet

7 Feed check valve NB 100 1 Auto Eco inlet






8 Flow Nozzle NB 80 1 - Inlet of feed

control station

Sl.No Service / Description NB No.

provided

Operation Remarks

B DRUM EVAPORATION

SYSTEM

1

Drum Safety valves (Without

silencers) NB 25 2

Auto spring

loaded Steam Drum

2 Direct water level gauges NB 25 2 - Steam Drum

3

Electronic water level

indicator unit (with local &

remote indication)

NB 25 1 - Steam Drum

4

Blow down valve

CBD

NB 25

1

Hand

(Angle

Type)

In CBD Line

5 Blow down valve isolation NB 25 1 Hand In CBD Line

6.

Drum emergency drain

valve NB 25 1 Hand In IBD Line

7.

Drum emergency drain

isolation valve NB 25 1 Hand In IBD Line

C SUPERHEATED STEAM

SYSTEM

1 Super heater safety valve

with silencer NB 25 1

Auto spring

loaded

MS Line at FSH

outlet

2 Start up vent valves (30%

capacity) with silencer NB 50 1 Hand






3 Isolating valve to start up

vent valve NB 50 1 Hand

4 Main steam stop valve (with

integral MO bypass) NB 100 1 Motor

5 Main steam check valve NB 100 1 Auto

6 Main steam flow nozzle NB 100 1 -

D DESH SPRAY WATER

1 Flow orifice NB 15 1 - Spray water line

2 Spray water control valve NB 15 1 Pneumatic

Spray water

control station

3 Standby Spray water Motor

Operated valve NB 15 1 Hand

4 Isolating valves for Spray

Control valve and Regulating

valve

NB 15 2 Hand

k. Non-Pressure parts

The main Non Pressure parts of the each WHRB units, essentially consist of the following:

Boiler supporting structurals and connected steel work; Platforms; Stairways; Supports

for Boiler Connecting Piping and Ducting, etc.

Economizer Casing and Supporting steel work.

Hoppers (below the vertical gas passes).

Flue ducting from outlet of Evaporator and inlet of Economizer; Flue ducting at

Eco outlet side, from the outlet of Economizer to inlet of ID fan; and ID fan to

stack (with the required supporting steel)

Hot flue gas inlet duct (at inlet of Radiant Boiler section) with supporting steel, as

required.






Structural support steel for Boiler roof and sides covering (weather protection).

Buck stays (for the Water wall enclosure section).

Other miscellaneous supports; Structural steel for ID fan and motor handling

arrangement.

The Structural steel supporting steel system will include all the main and auxiliary

columns, beams and bracings, Duct and piping supports, equipments, support

structures, etc. as required.

The brief description and details of the various non pressure parts will be as

follows:

The brief description and details of the various non pressure parts are as follows:

l. Boiler Supporting Structural, Platforms & Stairs

The complete Boiler Pressure parts in 2 vertical sections, and the Drum & Piping etc.

will be supported from bottom side, on the structural steel work (at approx. 7.0

m elevation).

The complete structural system will be of the Welded Construction.

The Steam drum is provided with flooring all around, for access to the manhole

doors, various valves and fittings etc.

The Platforms and stairs have been provided on one side of the boiler (giving

approach to the Access doors, valves and fittings, etc.).

Slope of stairways will be between 40-45: Ladders are provided only wherever

required. The Slope of the stairways will be preferably 41.

A Stairways arrangement up to drum level has been provided, as per the GA drawings.

The Width of Stairways and platform is 750 mm and will be as per ENMAS

standards. Hand railing design and arrangement will be as per ENMAS standards.

Handrails made out of 34.2 and 27.3 OD pipes.

Floor grating and stair (step) treads will be about 25 mm thickness open type, as per

ENMAS standards.






The supporting steel for boiler roof covering materials.

Please refer to GA drawings of boiler for general details of

the arrangement of the supporting structurals, platform and

stairs, etc.

m. Economizer Casing & Supporting Steel

Complete Structural steel for the Economizer section, with platforms is provided.

Economizer casing are fabricated of 6 mm thick Carbon steel plates, suitably stiffened.

The Economizer sections are provided in separate gas passes, with separate ash hoppers.

The Structural supporting steel materials and manufacture will be as that of main

Boiler supporting steel. This arrangement is to facilitate O & M even under adverse

operating conditions.

n. Flue Gas Ducting

Flue gas duct work connecting Evaporator and Economizer section (min. 6 mm thick.)

will be supplied including required expansion joint.

The complete flue gas ducting from Eco outlet, up to stack will be fabricated

with min. 5 mm thick Carbon steel plates and suitably stiffened. Flue ducting will be

of rectangular cross section, with suitable stiffeners. This duct will be laid out as

shown in the GA drawing enclosed in Volume II (Mechanical Drawing).

All required metallic / non-metallic type expansion joints and dampers as

required per design, will be provided for the gas ducting. Required steel supports

for this flue ducting are provided.

The supporting steel materials and manufacture will be as that of main boiler

steel work.

Notes






o. Hot Flue Gas Inlet Duct to WHRB

A small length of Hot flue gas duct is provided at inlet to the SH section and the

same will be fabricated with 5 mm thickness, carbon steel, suitably stiffened. This duct

will be lined with suitable 2 layer high temperature refractory materials on the inside,

applied over SS anchors; This duct will be supported over the boiler structural steel work.

The flue gases from stacks is to be tapped off at 0.0 m elevation through the

T off connection from the existing hot flue gas duct to stack. At the inlet of hot flue gas

duct to boiler 100 % leak proof guillotine damper is provided.

p. Slide Bearings Supports

The Water wall enclosure and Down Comer pipes are supported at the bottom side

on structural base at approx. 7.0 m elevation. To ensure free thermal expansion at

each of the support locations special slide bearings were provided and mounted over

the supporting structural frame.

q. Ash Hoppers

In order to collect fly ash from the hot flue gas from the coke oven a hopper is provided

both below radiant section and economiser section which is made out of 6 mm thick Carbon

steel plates. The outlet of the hoppers will be of approx. size 400 x 400; and will

be kept closed by slide gates. The slide gates shall be opened to remove fly ash as and

when required.

r. Buckstays

The hot inlet flue gas passes water wall enclosure section will be provided with a system

of Buckstays and Tie bars, at various levels, to withstand any unusual variations in gas

pressure in the boiler. Buck stays are designed for a internal gas pressure of 400 mmWC

and are allowing free thermal Expansion of pressure parts.






Key Drawing:

Arrangement of Buck stay : ICAA0200-0-F-04-28-0035

s. Refractory Materials, Insulation & Outer Casing

1. Refractory

The hot flue gas inlet duct will be lined with suitable high temperature refractory

material: SS anchors will be welded to the inlet duct for holding the refractory in its

position.

The ash hoppers of (the Water wall section) below Radiant section will be also

refractory lined over SS anchors welded to the hoppers, as required.

All access doors, peep hole doors provided on the radiant chamber will be refractory

lined to with stand the high temperature.

The refractory materials which are to be used in the hot flue inlet gas duct are as given

below:

SL.NO. Location Refractory Material

1.

a) Hot Flue Gas inlet duct from existing coke

oven exhaust to radiant chamber.

Hot face will be ACC:WHYT HEAT

C = 200 mm (thick)

And

Cold face will be calcium silicate

block = 50 mm (thick)

b) Anchors

Stainless steel SS 310

Stud / Anchors will be welded to

carbon steel duct.

2. Insulation

Boiler is provided with lightly bonded insulating mattress and cladding over all hot surfaces

to prevent heat burn to personnel as well as to reduce the radiation losses while boiler is in

operation.






Similarly all integral and process pipes are provided with required thickness of insulation

and cladding material.

t. Induced Draft Fan

The boiler is having 2 x 85 % MCR capacity Induced Draft Fans to suck hot flue gas from the

coke oven exhaust duct which passes through all pressure parts located in the downstream

of inlet guillotine damper located at inlet hot flue gas duct. ID fan also discharges the low

temperature flue gas to stack after heat is recovered by various section of WHR boiler. The

ID fans were designed in such a way that at MCR flow the suction pressure will be

maintained at -33mmWC at the inlet to the WHR Boiler.

1. No. of Fans / WHRB - 2 (Two) both in operation.

2. Type - Backward curved, Over hung; Plate

bladed design, Variable speed operation

3. Drive - Motor driven

4. Control of Fan - Multi Loure dampers in suction ducts, of

the fan; with pneumatic actuator / VFD

Sl.No Particulars/Fans Units 100% MCR Load (2 Fan Operation)

1. Flow m/Sec 14.99

2. Temperature C 160

3. Suction Pressure mmWC -420

u. Guillotine Dampers

Two Number water cooled guillotine dampers one at the hot flue gas inlet and another at ID

discharge duct to stack were provided for each WHR boiler to ensure 100 % sealing.

1. Number provided/WHRB = 2 No. (one in each hot flue gas






duct,

connected from tap of point to boiler

and the other in the cold flue gas

duct to process stack )

2. Type =

Water cooled disc - Refractory lined

on casing and on Disc, at the gas

flow section

3. Duty / Service =

Gas side isolation of Coke oven flue

gases at WHR Boiler inlet - 100%

open/close

4. Arrangement / damper blade opening

/ location =

Vertical shaft with horizontal Gas

Flow - Damper supported at the

bottom (on structural base)

5. Gas flow to damper - Normal

(100%MCR) =

63000 Nm3/hr at 950C Hot

Flue Gas duct to boiler inlet

6. Design temperature = 1000C

7. Operating pressure = -33 mmWC

8. Dust loading in COFG mg/Nm3 = 150 (max)

9. Sealing efficiency (on cross sectional

area basis) = 98%

10. Method of operation = Hydraulic

v. Dosing Systems

HP Dosing Units

Boiler is provided with a High pressure chemical dosing unit which consists of SS tank for

mixing motorized agitator and 2X100% capacity Hydrazine Dosing pumps simplex,

reciprocating plunger type positive displacement pump along with necessary valves and

fittings.






w. De-aerator, Feed Storage Tank (Common for Two WHRB Unit)

1. De-aerator

The boiler is provided with common De-aerator along with Feed Storage Tank to scavenge

oxygen from the DM water before feed water is fed into the boiler. The Deaerator is spray

cum tray type with SS trays located in the Deaerator tower which is mounted on the feed

storage tank. The Deaerator is complete with all the connected piping (Auxiliary steam,

Condensate & DM Water) Valves and Fittings as required. Spray nozzles and Trays of

Deaerator are of Stainless steel. The De-aerator has been sized considering boiler operation

2 X 26.4 TPH.

2. Feed Storage Tank

Number of Unit - One

Type / Orientation - Horizontal, Cylindrical

Supports arrangement & Location - 2 No. Saddle supports;

Size approx.: ID x Shell Length - 2400 mm x 5000 mm

Capacity of water holding (as - 12 min

specified) (between NWL and Trip)

Operating pressure and temperature - 2.7 kg/cm (g); 140 C

The Feed Water Storage Tank is complete, with all the connected piping, valves and fittings.

x. Boiler Feed Pumps & Drives

The High pressure feed pump located below the Deaerator supplies water to WHR Boiler.

Feed pumps are motor driven and provided with minimum circulation mechanical valve

(ARC) to ensure that minimum quantity of water is always circulated through the feed pump

to prevent over heating of pump internals and thereby failure of internal components.

No. of Feed pumps provided

(2 operating + 2 stand-by) - 4 x 100% Both Motor driven

Type - Multistage, Centrifugal, Horizontal axis,

Constant speed, direct motor driven






Parameters of pump (Each)

4 X 100 %

MCR TB

1. Volume of Flow TPH 27.19 29.9

2. Feed Water Temperature C 140 140

3. Density of Water kg/m 926.13 926.13

4. Delivery Pressure kg/cm (g) 91.5 95.97

5. Feed Pump Suction Pressure kg/cm (g) 2.7 2.7

6. Speed RPM 2980

7. Power required at Pump Shaft KW 160

y. Soot Blower

Boiler is provided with soot blower to remove soot deposition on the pressure parts during

running of the WHRB unit. Two long retractable soot blowers one each to clean primary and

secondary super heaters. Similarly 6 Nos. of rotary type soot blowers were located at the

economizer zone. Necessary PRV station for reducing the steam pressure to require steam

blowing pressure through soot blower along with Program logic controller to take care of

sequential logic control for soot blower operation is provided. Soot blowing shall be always

carried out only above 60% of MCR load of the boiler to avoid metal temperature increase

during steam blowing operation from the soot blower.






CHAPTER 4

DESIGN DATA FOR BOILER PERFORMANCE






CHAPTER 4


CONTENTS


4.1 Design Data 51

4.2 Waste Gas 51

4.2.1 Predicted Hot Flue Gas (approx. values) 51

4.2.2 Ambient Conditions 51

4.2.3 Properties of COFG 52

4.3 Predicted Performance Details 52






CHAPTER 4


4.1 Design Data

SL.No Description Remarks

1. Number and type of

boiler

2off Single drum, Natural circulation, Balanced

draft Waste Heat Recovery Steam Generator Unit.

SL.No Desciption Units Values

2. Final Super Heater Flow at 100 % BMCR per

WHRB Unit TPH 26.4

3. Steam Pressure at Main Steam Stop Valve

Outlet (MSSV) kg/cm (g) 71 kg/cm (g)

4. Boiler Steam Drum Design Pressure kg/cm (g) 85

5. Main Steam Temperature at Super Heater

Outlet C 490+5

6. Main Steam Temperature Control Range. % BMCR 50 to 100

7. Feed Water Temperature at Economizer I/L C 140

8. Maximum Flue Gas Temperature leaving

economizer to ID Fan and to stack C 160

9. Quantity of COFG & temperature required

at inlet of each WHRB

Nm/hr &

C

63,000

950

10. Dust Concentration in Hot Flue Gas mg/Nm 150

4.2 Waste gas

4.2.1 The predicted approximate hot flue gas requirement are given below

Sl.No Description Unit Values

1. 100% MCR Load Condition Nm/hr 63,000

2. 50% MCR Load Condition Nm/hr 31,500

4.2.2 Ambient Conditions (For Performance Design of Boiler) are given below

Sl.No Description Unit Values

1. Temperature C 50

2. Relative Humidity % 90






The Proposed Waste gas analysis for the boiler are given below

4.2.3 Properties of COFG

Sl.No Constituents Symbols Unit Values

1. Nitrogen N2 % Vol. 68.65

2. Sulphur Di-Oxide SO2 % Vol. 00.05

3. Carbon Di-Oxide CO2 % Vol. 04.10

4. Oxygen O2 % Vol. 13.70

5. Water Vapour H2O % Vol. 13.50

6. Total - % Vol. 100.00

7. COFG Flow rate per WHRB Unit - Nm/hr 63,000

8. Inlet temperature of COFG per WHRB - C 950

4.3 Predicted Performance Details as per Technical Specification

The following is the Predicted Performance of the each WHRB unit and Auxiliaries, based on

the Basic Design Parameters and Data, detailed in the specification as follows:

Boiler Parameters Units

100% MCR-

Maxi. Flue Gas

Flow

Proportionate steam generation TPH 26.4

SH steam pressure at outlet of MS stop valve kg/cm2(g) 71

SH steam temperature at outlet of MS stop valve C 4905C

Feed water temperature entering Economizer C 140

Temp of Hot inlet flue gases at entry to each WHB C 950

Hot inlet flue gases at entry to each WHB Nm/hr 63000

Gas Temperature

COFG entering Inlet screen tubes of Radiant section C 950

Entering Primary Super heater C 834

Entering Secondary Super heater C 716

Entering Evaporator section C 644

Entering Economizer section C 349

Entering ID Fan Entering Stack C 160






Water & Steam Temperature

Feed inlet of Economizer C 140

Feed outlet of Economizer C 277

Drum operating (Saturated - Entering Pry. SH section) C 289

Steam leaving Pry. SH C 415

Steam entering Sec. SH C 402

Steam leaving Sec. SH C 490 5

Spray water quantity kg/hr 363

Flue Gas Pressure

Radiant Chamber mmWC -59

Super Heater O/L mmWC -76

Evaporator O/L mmWC -112

Economizer O/L mmWC -312

ID Fan I/L mmWC -337

ID Fan O/L mmWC +25

These are all the above values for information purpose only.

Notes






CHAPTER 5

BOILER PLANT SAFETY AND PROTECTION






CHAPTER - 5

BOILER PLANT SAFETY AND PROTECTION

CONTENTS

SL.NO DESCRIPTION PAGE NO

a. General Requirements 56

b. Safety Precautions 56

c. Radiant Chamber Inspection 56

d. Maintenance Work 56

e. Steam & Water Source Isolation 57

f. Residual Pressure (or) Vacuum 57

g. Safety Measures for Internal Inspection and during Start-Up

57

h. Residual Heat 57

i. Hot dust and/or Noxious / inflammable gas 58

j. Flue Gas Leakage and Firefighting equipment 58

k. Burning / welding within Boiler interior 58

l. Deviation from Recommended Procedures 58

m. Maintenance Equipment 59

n. Work Permits 59

o. Dampness 59

p. Steam & Water at Elevated Pressure & Temperature 59

q. Mechanical Equipments 60

r. Flue Gases 60

s. HP and LP dosing Chemicals 60

t. Noise 60

u. Protective Materials and Clothing 60






CHAPTER 5

BOILER PLANT SAFETY

a. General Requirements

In the interest of safety of all personnel who are operating the unit, the compliance with the

instructions on the boiler plant safety should be effected by or under the supervision of

responsible, competent and properly trained personnel familiar with the operating and

maintenance procedures relevant to this type of plant.

It should be clearly under stood that for plant of this complexity; it is not practicable to

anticipate all the possible circumstances, which may arise during the operating life of the

plant.

b. Safety Precautions

To ensure that the boiler and its auxiliaries operated efficiently and reliably as possible, the

periodic maintenance of all Equipments and auxiliaries should be done. Procedures

recommended by the various manufacturers for preventive and corrective maintenance

should be implemented to obtain the maximum plant utilization and safety.

c. Radiant Chamber Inspection

When opening the radiant chamber inspection door to view hot flue gas, dark glasses should

be worn and care should be taken to stand to one side to guard against a chamber

disturbance. Never open a radiant chamber inspection door to view the flue gas without the

prior knowledge of the boiler operator.

d. Maintenance work

Before commencing any maintenance work on the boiler unit or auxiliaries particularly

those items connected to an electrical power supply the Equipment must be completely






isolated, both mechanically and electrically, in accordance with current Safety Regulations

laid down for the plant.

e. Steam and Water Source Isolation

Prior to opening up a boiler for inspection, cleaning, or maintenance, the boiler must be

cool, and extreme care must be taken to prevent steam or hot water entering the unit from

systems that may be under pressure from other sources. This includes steam and feed

piping, drains and blow down lines, which can be connected to systems in use, and it is

imperative therefore to avoid serious accidents that the boiler is completely isolated

from any steam and water sources by locked shut off valves and blanking if required.

f. Residual Pressure or Vacuum

In necessity demands, opening up any pressure part on a hot boiler, a check must be made

to ensure that there is no residual pressure, or a vacuum, by means of the releasing the air

by opening the vent provided on the pressure parts, pressure gauge readings are not to be

taken for granted under these circumstances.

g. Safety Measures For Internal Inspection & During Start Up

When inspecting the boiler unit internally, protective clothing goggles and gloves, footwear,

and helmet must be worn before entering any enclosed internal space. A hand held

inspection lamp of the twenty four volt (24 volt) type or a torch should be taken inside for

checking. Before going for internal inspection of radiant chamber or other enclosed space,

there must be another person posted outside at the inspection / access door monitoring the

movements of the operator inside so that, if necessary, external assistance may be sought

for due to any emergency situation.

h. Residual Heat

Before entering the radiant chamber or gas passages to carry out an inspection,

maintenance, or water washing, the amount of residual heat must be carefully considered.






i. Hot Dust and / or Noxious / Inflammable gas

Accumulations of dust / flue gas contaminant particles can retain high temperatures inside

for extended periods and on contact with water can generate sufficient steam to injure any

unprotected person in the immediate vicinity.

The effect is accentuated in a confined space. Precautions must therefore be taken to avoid

scalding of operators and adequate ventilation must be ensured to guard against the

possible presence of noxious or inflammable gas.

j. Flue Gas Leakage and Fire Fighting Equipment

Firing galleries should be kept clean. Any flue gas leaks should be immediately arrested. All

precautions should be taken to avoid boiler front fires and the firefighting equipment must

be maintained in good order as prescribed by the manufacturer. The Fire Extinguisher

should be appropriate for Class of Fire.

k. Burning / Welding within Boiler Interior

Any burning or welding work to be carried out within the boiler interior, the space must be

adequately ventilated, and suitable firefighting equipment must be available, together with

a bucket of water for cooling any dismantled part. Staging complying with the Factory Acts

must also be used in those places inaccessible to the radiant chamber assess equipment.

Skill Worker has to attend the work, to avoid damage of pressure parts.

l. Deviation from Recommended Procedure

The maintenance instructions must be followed as closely as possible, although

circumstances can arise which may necessitate a deviation from the recommended

procedure. In any instance where doubt can exist that will involve risk to personnel, the

decision must rest with a responsible engineer who must examine every aspect of the

particular case before giving a decision whether or not to proceed with the work in question.






m. Maintenance Equipment

Generally however, full use must be made of the maintenance equipment provided access

doors, walkways, and ladders, runway beams hoists, and cable reeling drums rather than

improvising for the sake of expediency.

n. Work Permits

Where doubt exists concerning the safety of mechanical or electrical plant, then the station

Safety Regulations are to be followed, complete isolation of all mechanical and electrical

equipment in accordance with the Permit to work system - must be obtained by

the responsible Engineer before the work is commenced. Guards on rotating machinery, belt

drives etc., must be refitted before plant is re- commissioned after maintenance.

o. Dampness

Certain equipment, although located within the plant building, can be subject to dampness

or condensation. Cubicles housing electrical or other control equipment, if located in a cold

draft position, are particularly vulnerable to this condition. Therefore, precautions must be

taken against dampness occurring. Cubicle doors must be closed and locked to prevent

them being inadvertently left open. Electric heaters can be installed or, if in short supply,

carbon filament lamps may be used.

p. Steam and Water at Elevated Pressures & Temperatures

Saturated steam is generated in the boilers. This is visible. However, extreme care should

be taken when trying to locate it. Sampling of steam and water must be carried out with

care, Gloves and face masks must be worn.






q. Mechanical Equipment

Moving machinery can always be dangerous, should be treated with respect. It should be

ensured that guards are in place on all operating machinery.

r. Flue Gases

Flue gases have very low oxygen content and will cause asphyxiation if breathed even for a

short time. Usually flue gas will at a temperature of above 100 C, so it is dangerous for the

persons who working near to the flue gas leakages or passing from the radiant chamber

zone.

s. H P & L P Dosing Chemicals

Water treatment chemicals used in H. P. and L. P. dosing are both irritants and toxic if

ingested. Gloves and eye protection must be worn when handling these chemicals.

t. Noise

Noise can permanently damage the hearing ability. Hence, care should be taken for ear

protection at all times when in the plant.

u. Protective Materials and Clothing

Table below indicates the name of the protective materials and clothing that may be used

for protection of the operating and maintenance personnel.

SL. No. Description Protection

1 Safety Boots Foot Protection

2 Overalls Body Protection

3 Hard Hat Head Protection

4 Goggles or Face mask Face and Eye Protection

5 Dust Mask Lung Protection

6 Safety Gloves (leather and PVC) Hand Protection

7 Ear Plugs Hearing Protection






CHAPTER 6

FEED AND BOILER WATER






CHAPTER - 6

FEED AND BOILER WATER

CONTENTS

SL.NO. DESCRIPTION PAGE

NO.

6.1 WATER CONDITIONING 63

6.2 DE AERATION 71

6.3 ALKALINITY CAUSTIC SODA, AMMONIA, AMINES 76

6.4 SUPPLEMENTARY WATER TREATMENT 80

6.5 SIGNIFICANT SALT SOLUTIONS PROPERTIES 90






6.1 - WATER CONDITIONING



CUSTOMER: BHATIA COKE & ENERGY LTD PROJECT CODE : IB002A

Bhatia Gummidipoondi Whrsg o&m Manual Final Copy

Documents

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description of boiler

maintenance manual customer

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