Acid Cleaning in Commissioning

8/12/2019 Acid Cleaning in Commissioning

1/85

3.3 ................................................................................................... 4

3. ......................................................................................................... 43. ............................................................................ 4

- ........................................................................................................................... 5.4 ................................................................................................. 5

.4.4 ................................................................................................... 5.4. ..................................................................................................... 5

.4.3 ....................................................................................................... 5.4. .............................................................................................................. 5

.4. ................................................................................................. 5.4. ................................................................................................... 5

.4.5 ........................................................................................... 5.4.6 ........................................................................................ 5

. .......................................................................... 6..4 ........................................................................................... 7


2/85

.. ...................................................................................... 10. ................................................................................................................ 10

..4 ................................................................................................... 10.. ............................................................................................................ 10

..3 .............................................................................. 10.. ............................................................................................................ 10

.. ...................................................................................... 10 .......................................................................................................... 11 .......................................................................................................... 11

4.Process ............................................................................................................................ 134.1 Pre-flushing of the boiler system ................................................................................ 13

4.1.1 Objectives of the flush ......................................................................................... 134.1.2 Flow rates ........................................................................................................... 134.1.3 Water management ............................................................................................. 134.1.4 Water temperature .............................................................................................. 134.1.5 chemical monitoring ............................................................................................ 134.1.6 Performance of the flush ..................................................................................... 144 1 7 Demin Water consumption 14


3/85

4.4.2 Water temperature .............................................................................................. 204.4.3 Chemical monitoring ........................................................................................... 204.4.4 water consumption .............................................................................................. 20

4.5 Passivation treatment ................................................................................................ 204.5.1 Flow rate ............................................................................................................. 204.5.2 Water temperature .............................................................................................. 214.5.3 Chemical monitoring ........................................................................................... 214.5.4 Water consumption ............................................................................................. 214.5.5 Brief outline of the process .................................................................................. 21

5.Draining and inspection .................................................................................................... 216. Effluent treatment ............................................................................................................ 22Check Lists ......................................................................................................................... 23Reference drawing No. CKW H004 263 c ......................................................................... 23Chemical Cleaning diagram .............................................................................................. 23Check List No.1 ................................................................................................................... 28Initial valves status for filling of system ................................................................................ 28Check List No.2 ................................................................................................................... 34Pre-flushing of the boiler system ......................................................................................... 34


4/85

7 3.3

-(HP): RL42

.- (MP) :RR09

RR06. 3.

.

. 4.4

RR01 RR01

4.

RR02RR03RR04 RR01


5/85

-.4

.4.4 .

.4.100600 m3/h.

.4.3 3 .

.

(80 m3/h) ) ( . 600 m3/h 2 .

. .4.

50 -7 0C (.)

4


6/85

600 t/h .

) 200 t/h

CC06 RR06.

600 t/h . (side-streaming) .

600 t/hRR07 CC07

. .

CC08CC16CC17CC20 .

.

.


7/85


8/85

300 t/h .

{ . }

.3 .3.4

60C. 4.

.

60C . 300 t/h.

.3.3.4

.


9/85

HFRL40J1 .

4. % NC90 .

) CC05) CC05 8 barCC05. CC03CC04.

CC31 CC05 1000

ppm HF4. %

. . RR06.

CC068 bar. HF CC32

.


10/85

300 t/h50 - 60C.

. ..4

600 m3/h

..5060C

..3 10 S/cm- 2.4-

pH= 6 - 7

.. 3-:500700 m3..

50 - 60C 1 - 3 .

.


11/85

. J2

. pH

3.

... .

4.

.

.

.52 % .


12/85

temp drain line RR15 from the steam condensate lines RA 10 Z 021, RA 10 Z 023, RB 15

Z 023 and RC 10 Z 021.

Temp. drain line RR16 from the steam condensate line RB 20 Z 0213.3 Acid injection points

- HP-System

The injection point for the acid at the feed water line RL42 shall be at the intersection

f th d i li RL 40 Z 012


13/85

Stage 3:

Feed water lineseconomizerdrumsuper heaterlive steam linetemp. connectingline RR09cold reheat linere heaterhot reheat linefinal discharge line RR 07main

drain collector RR01effluent basin.

3.5 pressure testing of temporarily installed piping

Prior to the commencement of the chemical cleaning process, the boiler system will be filled

at low flow (100 t/h).

As soon as the system is full, and the pressure increases at the pressure gage upstream of

the final discharge valve CC07, regulate the valve in order to maintain a pressure of 28 bars.

Then check all temporarily piping thoroughly.

After checking the chemical cleaning process starts with the initial water flushing.

4.Process

4.1 Pre-flushing of the boiler system

4.1.1 Objectives of the flush

The objective of the cleaning operation is to remove small quantities of loosely adherent

sand dust, Welding flux, wood splinters and construction debris.


14/85

Turbidity less than 0.1 units above the incoming water (measured on absorbiometer 425 nm,

50 mm cuvette).

Conductivity of less than 10 S/cm above the incoming water.

4.1.6 Performance of the flush

Status of valves and flow rates according to Framaborgs check-list

4.1.7 Demin. Water consumption

Approx. 3-4 times filling volume = 7501000 m3.

4.1.8 Brief outline of the process

After completion of pressure the system is full of water. With boiler feed pump in operation at

a flow rate of 100 t/h, the entirely system shall be re vented. When venting being performed

and the system pressure increased, regulate valve CC07 at the end of the system to

maintain a pressure of 8 bars.

Then divert flow via drain line RR02 to stage 1.1 outlet with valve CC05.


15/85

When turbidity and conductivity are stable at low level, flush re heater elements at max.

available of 600 t/h. via outlet drain line RR07 and valve CC07.

Flush through re heater spray water lines successively.

When water quality is satisfied flush through all auxiliaries, i.e. CC08, CC16, CC17, and

CC20, then flush all permanent drains shortly.

Then shut down boiler feed pumps and refill water storage facilities.

Then drain evaporator, economizer and drain lines outside of the turbine house.

4.2 degreasing of boiler system and re-flushing

Note:

The HP-Heaters and the feed-water pipe work up to the isolating valve RL 49 S 002 shall be

degreased separately.

Th t ill b i l t d b f th t il i t ll d id d i d


16/85

After completion of the soak, the detergent will be displaced with max flow rates of the feed

water pumps. (600 t/h).

Then the evaporator will be drained.

4.2.1 Flowrates

- The HP heaters will be circulated with a flow of approx. 30 t/h

- The flow during open circuit treatment will be 300 t/h.

4.2.3 Detergent injection point

For the completely filling of the boiler system only the injection point J1 at the feed water line

RL40 will be used.

4.2.4 Chemical monitoring

The degreasing will be considered to have been successfully completed when the effluent

water on the completion of detergent displacement meets the following criteria:

Turbidity less than 0.1 units above the incoming water


17/85

During the soaking period the HP feed heaters and the feed water lines will be degreased.

Before starting the circulating pumps the flow direction will be set up as follows:

Close valve RL 40 S 002, CC01, open valves CC21/22 in the acid injection line RR21, and

valve CC26 in temporary line RR24 from feed water line RL20 to the mixing tank.

Feed water lines and HP Heaters receive a reverse flow.

The degreasing agentstrisodium phosphate and detergentwill be dosed and circulated

for a duration of approx. 3 hours. Then the system will be shut down and the degreasing

agents allowed to soak for 6 hours.

After completion of the soak degreasing solutions will be displaced from feed water and

boiler system by means of the feed water pumps with a flow of 300 t/h.after removal a

high velocity flushing takes place until the turbidity & conductivity is stable at lowest level.

Then drain evaporator completely.


18/85

This process should also provide an ideal surface in service generation of a passive

magnetite film.

4.3.2 Flow rate

For the cleaning of the boiler (Eco, evaporator and super-heater) a flow of 100/300 t/h if

required, for the re-heater a flow of 350 t/h is necessary.

4.3.3 Temperature

The temperature of the demin. water will be between 50 and 60C.


During the acid cleaning, the following chemical monitoring takes place:

Measurement of the acid concentration by conductivity, iron content by a photometer.

HF concentration and dissolved Iron will be measured in a two minute interval.

4.3.4 Water consumption

Approx. 3 x volume = 750 m3 demin. water (incl. displacement)


19/85

Monitoring of acid concentration and dissolved iron will be dissolved iron will be carried out

at the sampling point CC31 upstream of the valve CC05, and continue until iron

concentration drops down to approx. 1000 ppm and HF concentration reaches approx. 1%.

Then the flow will be diverted through the second and after that through the third water wall.

Monitoring will be in the same way as for the first water wall.

After completion, the flow will be directed through super heater and dumped via intermediate

discharge line RR06.

A backpressure of 8 bars will be required and maintained with valve CC06.

Iron and HF will be monitored at the sampling point CC32, and continued until the above

mentioned criteria will be reached.

When the effluent meets the criteria, shut down boiler system and allow acid to soak for 1

2 hours.


20/85

Then the HP & LP relief station and the spray water line RL20 to the HP station, will be

opened and filled up with fresh acid.

After completion the feed pump and acid injection pump will be shut down for a soak of

approx. 2 hours.

After completion of the soak the bulk of acid will be displaced at a flow of 300 t/h at 50 -

60C temperature.

4.4 Conductivity flush

4.4.1 Flow rate

600 m3/h

4.4.2 Water temperature

50 - 60C


Conductivity less than 10S/cm above incoming water.


21/85

4.5.2 Water temperature

Approx. 40C


pH monitoring at the inlet and at the final discharge line

redox potential measurement at the inlet and at the final discharge line

Required values:

pH 10.2

redox potential: +20 100 mV.

4.5.4 Water consumption

Approx. 1.25 x volume: 300 m3

4.5.5 Brief outline of the process

At a flow rate of 350 m3/h ammonia solution and hydrogen peroxide will be dosed via the

injection point J1 at the feed water line RL40.


22/85

Tube samples will cut from the boiler and the residual of oxides will be measured together

with the client.

6. Effluent treatmentAll effluent shall be collected in the effluent basin.

The acid will be neutralized with lime. About 70% of the necessary amount of lime will be

dosed in to the basin prior to the acid clean. To avoid a settling of lime compressed air shall

be injected via the air injection equipment.

The rest of the lime shall be dosed during the acid displacement.

For proper mixing of the lime and acid, the lime will be directly dosed in to the discharge line

prior to entry to the effluent basin. The pH of neutralized effluent will be in a range of a pH

from 79 units. The basin will be emptied by neutral evaporation.


23/85

23

Check Lists

Reference drawing No. CKW H004 263 c

Chemical Cleaning diagram


24/85

24

Water management table Page 1

DayNo. Action Time(min) Flowm3/h Storagem3 Consumptionm3 Make upm3 Availablem31 Pre-flushing of the boiler system

- Filling and venting of boiler system 180 100 1600 300 90 1390- Flushing of stage 1/1 15 400 1390 100 7 1297

- Flushing of stage 1/2 30 600 1297 300 15 1012

- Flushing of stage 2 15 600 1012 150 7 869

- Flushing of stage 3 30 600 869 300 15 584

- Flushing of all permanent drains 30 100 584 50 15 548

15 hours to refill water storages up to at least 1000 m3and heated to 60 - 70C for the heating approx. 30 tones of steam (16 bar) are required.


25/85

25


DayNo. Action Time(min) Flowm3/h Storagem3 Consumptionm3 Make upm3 Availablem32 Degreasing of boiler system and re-flushing

- Fill economizer and evaporator with hot wettingagent

75 100 1000 125 37 912

- Detergent injection for super-heater & re-heater 30 300 912 150 15 777

- Soaking phase 480 - 777 - 240 1017

- Displacement of detergent 45 300 1017 225 22 814

- Re-flushing to turbidity 45 600 814 450 22 386

3 & 4 Re-filling and heating of four RFWST

40 hours to refill water storages up to at least 1600 m3 and heated to 60-70C for the heating approx. 130 tones of steam (16 bar) are required.


26/85

26


DayNo. Action Time(min) Flowm3/h Storagem3 Consumptionm3 Make upm3 Availablem35 Acid phase

- Filling and venting 75 100 1600 125 37 1512- Re-circulating and heating 180 300 1512 - 90 1602

- Drain Econ. & Evap. 120 - 1602 - 60 1662

- Fill Econ. & Evap. with hot acid 75 100 1662 125 37 1574

- Once through treatment of Evap. 30 300 1574 150 15 1439- Once through treatment of super-heater 30 300 1439 150 15 1304

- Soaking period of HP-boiler part 60 - 1304 - 30 1334- Once through treatment of re-heater 30 350 1334 175 15 1174- Soaking period of re-heater 120 - 1174 - 60 1234

- Acid displacement 60 300 1234 300 30 964

- Conductivity flushing 60 600 964 600 30 394

- Passivation 60 300 394 300 30 124


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27


DayNo. Action Time(min) Flowm3/h Storagem3 Consumptionm3 Make upm3 Availablem36 - Soaking period of 3 hours for the passivation

solution- Draining of the system

7 InspectionCut tube specimen

Day 618 hour


28/85

Check List No.1

Initial valves status for filling of system

AbbreviationsUCR: Unit Control Room (to operate from UCR)

RFST: Reserve Feed Water Storage Tank

FWT: Feed Water Tank, RL 01 B 010

BFP: Boiler Feed Pump

W/W: Boiler Water Wall

BEDT: Boiler Empty Drain Tank, RT 10 B 010

BDT: Boiler Blow Down Tank, NC 20 B 001


29/85

Procedure: Initial valve status for filling of system Page:

Pre-condition Valve No. LocationFLR/Level

Valveposition Purpose

Temporary drain manifold

CC 01 Stage 1.1 drain Ground Close Isolation

CC 30 Close SamplingCC 02 Stage 1.2 Drain Close LHS w/w Head

CC 03 Close Rear w/w Head

CC 04 Close RHS w/w head isolation

CC 05 Close Control

CC 31 Close Sampling

CC 50 Open P.I.

CC 06 Stage 2 Drain Close Control


CC 51 Open P.I.

CC 07 Stage 3 drain Close Control


CC 52 Open P.I.

CC 08 LP By-pass drain Close Control


CC 09Connecting line RR09 from HP-part to re-heater

Open Isolation

CC 38 Close SamplingCC 10 System warming line Close Control

CC 11 Close Isolation

CC 37 Open Leak detection

CC 53 Open P.I.

CC 12 Temp. filling pump discharge Ground Close Isolation

CC 13 Close Isolation

CC 14 Temp. filling pump suction Close Isolation

CC 15 Main drain line to effluent basin Open Isolation


30/85




RL 20 S 026 No.5 HP-Heater inlet Open Quick closing 3-way valve

RL 20 S 240/241 Feed line before No.5 HP-Heater Open Drain (to BEDT)

RL 20 S 332/356 Close P.I. (RL 20 P 006)RL 20 S 339/340 Feed line after No.5 HP-Heater Close P.I. (RL 20 P 008)

RL 20 S 042 Close Safety valve

RL 20 S 230/231 Close Vent (to BEDT)

RL 20 S 027 No.5 HP-Heater outlet Open Quick Closing Check Valve

RL 20 S 043/044 Balance line around RL 20 S 027 Open

RL 20 F 002/3 Feed line after No.5 HP-Heater Open Do not alter Flow meter

RL 20 S 364/365S 366/367

S 368/369

OpenP.I. (RL 20 P 010)

(RL 20 P 013)

(RL 20 P 014)RL 20 S 370 Close dp-measurement

RL 40 S 301 Close

RL 31 S 001 Feed water Reg. Station UCR Close Isol.

RL 31 S 004 UCR Close Low-Load Control valve

RL 31 S 005 Open Isol.

RL 32 S 001 UCR Close Isol.

RL 32 S 002 UCR Close By-pass

RL 32 S 004 UCR Close Full load control valve

RL 32 S 005 Close Isolator

RL 32 S 006 Close By-pass

RL 33 S 001 Close Isol.


RL 33 S 004 UCR Close Full load control valve



RL 20 S 245/246 Close Vent


31/85




NA 20 S 338/339S 340/341

Boiler drum CloseRemote water levelindicator

NA 20 S 342/343S 344/345

Close

NA 20 S 346/347S 348/349

Close

NA 20 S 350/351S 352/353

Close

NA 20 S 301/302 Close P.I.(NA 20 P 001)

NA 20 S 303/304 Close P.I. (NA 20 P 002)

*)

NA 20 S 305/306

S 307/308 Blow down line to B.F.V. Close F.I.*)NA 20 S 003 Close NA 20 S 004 Open

NA 20 S 007 Open

NA 20 S 363 Close

NA 20 S 001 Drum over flow to B.D.T. Close

NA 20 S 002 UCR Open

NC 10 S 001/002 L.H.S. w/w Headers CloseDrain (to drainheader evap. part)

NC 17 S 001/002 Close NC 16 S 001/002 Close

NC 15 S 001/002 R.H.S. w/w Headers Close Drain

NC 18 S 001/002 Close

NC 19 S 001/002 Close

NC 11 S 001/002 Rear w/w headers Close

NC 12 S 001/002 Close

NC 13 S 001/002 Close

NC 14 S 001/002 Close


32/85




NA 90 S 305/306 S/H 3 Outlet header Close P.I. (NA 90 P 002)

NA 90 S 308/309 Live steam line RA2 Close Sampling (permanent)

RA 04 S 001 Open Boiler stop valveRA 04 S 002 Open Bypass

RA 10 S 310/314 Close F.I.

RA 10 S 312/316 Close

RA 10 S 311/317 Close

RA 10 S 313/315 Close

RA 20 S 010 UCR Close Hp-Bypass station

RA 10 S 221S 222

UCR

CloseOpen

Drain

RA 10 S 223S 224

UCR

CloseOpen

Drain

RA 10 S 302/305 Live steam line Close P.I. (RA 10 P 001)

RA 10 S 301/304 Close P.I. (RA 10 P 002)

RA 15 S 332/334 Close P.I. (RA 10 P 003)

RA 15 S 001 Warm up line Close

RA 15 S 002 UCR Open

RL 27 S 201/202 S/H attemperator spray water supply Close Drain

RL 27 S 002 UCR Open Isol.

RL 28 S 301/302S 303/304

Spray water to attempt. 1 Close F.I.


RL 28 S 001 UCR Open Control


RL 28 S 307 Bypass Open Isol.


RL 28 S 308 Close Isol


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NC 73 S 301/302 R/H 2 outlet headerClose/Open

Vent

NC 75 S 001S 002

R/H 1 outlet headerUCR

CloseOpen

Drain

NC 76 S 001S 002

R/H 2 inlet headerUCR

CloseClose

Drain

NE 10 S 301/302 R/H 1 inlet header Close P.I. (NE 10 P 001)

NE 40 S 301/302 R/H 2 outlet Close P.I. (NE 40 P 001)

NE 40 S 001 Close Safety valve (gagged)

NE 40 S 002 Close

RB 10 S 331/332 Hot reheat line Close P.I. (RB 10 P 001)

RB 15 S 223S 224

UCR

CloseOpen

Drain

RB 20 S 220S 221

UCR

CloseOpen

Drain

RL 24 S 201/202 R/H Spray water Close Drain

RL 24 S 002 UCR Open Isol.

RL 25 S 301/302S 303/304

Spray water to L.H.S. R/Hattemperator

Close F.I. (RL 25 F 001)




RL 25 S 307 Bypass Open Isol.



RL 26 S 301/302S 303/304

Spray water to R.H.S. R/Hattemperator

Close F.I. (RL 26 F 001)



34/85

Check List No.2

Pre-flushing of the boiler systemNotes on pre-flushing of the boiler

Aim:

The aim of the pre-flushing is to remove loose debris from the system.

This is achieved by flushing the system with water at velocities in the range of 0.3 to 1.4 m/s,

which will require a flow rate of 600t/h (167Kg/sec).

The loose debris being removed, increases the turbidity of the water being discharged. To

arrive an endpoint, chemist stationed at the outlet, monitors continuously the turbidity of the

water being discharge which decrease as the system is being flushed clean.

Turbidity is measured in the form of absorbance using a absorbiometer.

Absorbance can be related back to the suspended debris in the discharge water with the

following assumption: 0.1 absorbance in a 5 cell is equivalent to 1.4 ppm suspended solids.

Our theoretical aim is to achieve an analytical endpoint of 0.1 absorbance above the

incoming water in a 5 cm cell. Our practical end point is to flush till absorbance reading level

out at a low level.

Brief outline of the procedure


35/85

35

Phase Pre-condition Performances

Actual valveattitude

Action

Floor CommentsValvesclosed

Valvesopen

Openvalve

Closevalve

Flushing ofstage 1/1 & 1/2

1. System has beenpressure tested to28 bar

2. Pressure tripswitch set at 23 bars3. Water storagefacilities full.4. Valves set as perchecklist.5. B.F.Ps temp.filling pump anddemin. watertransfer pumpsready.6. All personnel

ready and incommunication.7. Boiler system isfull.

1. Confirm valve CC15 isstill open.

Valve CC15 must remain openduring all operations!

Notify staff on valve CC07on starting B.F.P. on leakoff.

CC07 CC07 Crack CC07 open.

Increase flow steady to

100t/h

.

Regulate CC07 to maintain

pressure of 8 bars.


36/85

36



Action


Valvesopen

Openvalve

Closevalve

NC 86S 001

NC 86S 001

NC 82S 001

NC 82S 001

NC 83S 001

NC 83S 001

NC 84S 001

NC 84S 001

NC 85S 001

NC 85S 001

When air is expelled

NC 81NC 82

NC 83NC 84NC 85S 001

NC 81NC 82

NC 83NC 84NC 85S 001

Vent re-heater elements NC 71S 301

NC 71S 301

NC 72S 301

NC 72S 301

NC 73S 301

NC 73S 301

NC 74S 301

NC 74S 301

When air is expelled NC 71NC 72NC 73NC 74S 301

NC 71NC 72NC 73NC 74S 301


37/85

37



Action


Valvesopen

Openvalve

Closevalve

When venting is completedstart temp. filling pump andfill up feed water tank to

max. available level.

CC12 CC12

Divert flow via stage 1/1drain

CC01CC05

CC01CC05 Crack CC05 open.

CC07 CC07 Regulate CC05 to maintain apressure of 8 bars.

RL 40S 002

RL 40S 002

Increase flow steady to400t/h

Regulate CC05 to maintain 8 bars.

Monitor F.W.T.level Note: during flushing with flow rates

up to 600t/h the temp. filling pumpmust run with max. avail flow rate.When F.W.T. is empty notify staffon the stages drains and run B.F.P.in leak off operation till FWT is filledagain then continue flushing again.

Chemist to be monitoringwater quality at stage 1/1outlet sampling point CC31.

When water quality issatisfactory, flush via HPheaters bypass line

RL 20S 008RL 20

S 026

RL 20S 008RL 20

S 026After 2 mins. flushing viabypass lines

RL 20S 008RL 20S 026

RL 20S 008RL 20S 026


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38



Action


Valvesopen

Openvalve

Closevalve

When water quality issatisfactory, divert flow viaeconomizer and water walls

to stage 1/2 drain.

CC02

CC03CC04

CC02

CC03CC04

CC01 CC01


Regulate CC05 to maintainpressure of 8 bars.

When pressure is stableflush through water wallsseparately

CC03CC04

CC03CC04

Chemist to be monitoringwater quality at outletsampling CC31

When water quality issatisfactory, flush via 2ndwater wall

CC03CC02

CC03CC02

Divert flow through 3rdwater wall

CC04CC03

CC04CC03

When water quality issatisfactory, decrease flowrate to 150t/h

CC05 CC05 Close CC05 in

Flushing of

stage 2

Divert flow via super-heater

elements and stage 2 drain CC06 CC06 Crack CC06 openCC05CC04

CC05CC04 Regulate CC06 to maintain

pressure at 8 bars.

When pressure is stable,flush through super-heaterspray-water lines

RL 28S 306RL 28S 308

RL 28S 306RL 28S 308


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39



Action


Valvesopen

Openvalve

Closevalve

After 5 mins. RL 29S 306RL 29

S 308

RL 29S 306RL 29

S 308RL 28S 306RL 28S 308

RL 28S 306RL 28S 308

After 3 mins. RL 29S 306RL 29S 308

RL 29S 306RL 29S 308

When flushing of super-heater spray-water lines iscompleted, increase flowsteady to 600t/h


Monitor FWT level

Chemist to be monitoringwater quality at stage 2outlet sampling point CC32

When water quality at outletand/or water storage

facilities are depleted, notifystaff at CC06 valve ofintention to decrease flowsteady to 150 t/h

CC06 CC06 Close CC06 in


40/85

40



Action


Valvesopen

Openvalve

Closevalve

Flushing ofStage 3

When 150 t/h is achieved CC07 CC07

CC06 CC06 Regulate CC07 to maintainbackpressure of 8 bars.

When backpressure isstable, increase flow steadyto 400 t/h


Flush re-heater spray-waterlines RL 25

S 306RL 25S 308

RL 25S 306RL 25S 308

After 5 mins. RL 26

S 306RL 26S 308

RL 26

S 306RL 26S 308

RL 25S 306RL 25S 308

RL 25S 306RL 25S 308

After 3 mins. RL 26S 306RL 26S 308

RL 26S 306RL 26S 308

When flushing of re-heaterspray-water lines iscompleted, increase flowsteady to 600 t/h.


Monitor FWT level


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41



Action


Valvesopen

Openvalve

Closevalve

Chemist to be monitoringwater quality at the stage 3outlet sampling point CC33.

When water quality isapproaching our endpoint,flush through HP-Bypassstation and back-flush HP-bypass station spray-waterlines

RA 20S 010

RL 20S 302

RL 20

S 304

CC20

RA 20S 010

RL 20S 302

RL 20

S 304

CC20

Check water quality atsampling point CC36

When quality is satisfactoryCC 20

RL 20S 302

RL 20S 304

RA 20A 010

CC 20

RL 20S 302

RL 20S 304

RA 20A 010

Flush through LP-bypassstation CC08 CC08 Regulate CC07 to maintain

pressure of 8 bars.


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42



Action


Valvesopen

Openvalve

Closevalve

When water quality atsampling point CC34upstream of CC08 is

satisfactory CC08 CC08When water quality at stage3 sampling point CC33 issatisfactory, decrease flowto 100 t/h CC07 CC07 Close CC07 in

Temp. emptying pump onboiler blow down tankready for use.

Confirm temp. water walldrain valves CC02, CC03,CC04, closed CC05

CC25CC05CC25

Emptying pump discharge

Monitor water level at blowdown tank, and startemptying tank if necessary.

During flushing of system drains,listen for steady flow then close.

Drains in the feed line RL 20S 222/S 223

RL 20S 222/S 223

RL 20S 240/S 241

RL 20S 240/S 241

RL 24S 201/S 202

RL 24S 201/S 202

In re-heater spray-water supply

RL 27S 201/S 202

RL 27S 201/S 202

In super-heater spray-water supply


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43



Action


Valvesopen

Openvalve

Closevalve

Economizer NC 09S 001/S002

NC 09S 001/S 002

Drain header for evaporation part

Lower water wall headers,permanent drains NC 15

NC 18NC !9S 001/S 002

NC 15NC 18NC !9S 001/S 002

RHS w/w headers

NC 11NC 12NC 13NC 14S 001/

S 002

NC 11NC 12NC 13NC 14S 001/

S 002

Rear w/w headers

NC 10NC 16NC 17S 001/S 002

NC 10NC 16NC 17S 001/S 002

LHS w/w headers

Super-heater NC 61NC 62NC 63NC 64NC 65

S 001/S 002

NC 61NC 62NC 63NC 64NC 65

S 001/S 002

Super-heater drains on drainheader HP part

Re-heater NC 75NC 76S 001/S 002

NC 75NC 76S 001/S 002

Drain header for re-heater part


44/85

44



Action


Valvesopen

Openvalve

Closevalve

Live steam, cold & hot re-heat lines CC16 CC16 Temp. drain manifold

RA 10

S 221

RA 10

S 221

RA 10S 223

RA 10S 223

RC 10S 229

RC 10S 229

RB 15S 223

RB 15S 223

CC16 CC16

Hot re-heat line drain CC17 CC17 Temp. drain manifold

RB 20S 220 RB 20S 220

When steady flow RB 20S 220

RB 20S 220

CC17 CC17

Notify staff on CC07 ofintention to shut down,decrease flow steady CC07 Close CC07 in

Shut down B.F.P. andtemp. filling pump CC07 CC07

Empty blow down tankcompletely.

Refill water storagefacilities.

Heat one feed waterreserve storage tank up60C


45/85

45



Action


Valvesopen

Openvalve

Closevalve

Open drum venting valve,then drain economizer andevaporator completely.

NC 81S 001/002

CC02CC03CC04CC05NC 09-88?S001-002

NC 81S 001/002

CC02CC03CC04CC05NC09-88?S 001-002

CC15 CC15 Drain external lines.


46/85

Check list No. 3

Degreasing and re-flushing of the boiler systemNotes on degreasing and re-flushing of boiler system

Aim:

Degreasing by means of 0.050.1% nonionic detergent at 60 - 70C for the boiler system, with

subsequent period of approx. 8 hours.

Degreasing by means of 2 -3 % trisodium phosphate and 0.05% ionic detergent for HP-feed water

lines and HP-heaters 4 & 5 tube-nest, at a temperature of 60 - 70C.

Brief outline of procedure

Prior to the commencement of detergent injection economizer and evaporator will be drained.

At a flow of 100 t/h the boiler will be filled subsequently with hot detergent solution. Overflowing the

boiler drum , the super-heater and re-heater elements will be flushed with an increased flow rate of 300

t/h till the boiler system is full of detergent solution. Then the feed water pumps will be shut down for a

soaking period.

During the soaking period of boiler system feed water lines and HP-heaters tube-nests shall be

degreased.

On completion of the soaking period the degreasing solution will be displaced from feed water line via


47/85

47



Action


Valvesopen

Openvalve

Closevalve

Degreasing andre-flushing ofthe boilersystem

1.Initial waterflushing completed

- confirm CC09, CC15,CC05, CC02, CC03, CC04is open.

2. water storagefacilities full i.e. allRFSTs full at 60-70C

-confirm CC01 is closed

-confirm pressure tripswitch is still activated.

3. FWT full at 60C

4.BFP, S-F-injectionpumps and temp.filling pump ready.

Notify staff at drain valveCC05 on starting BFP onleak off.

5. Detergent ready

Increase flow steady to 100t/h6. All personnelready and incommunication Commence detergent

injection7. Economizer andevaporator empty,super-heaters andre-heaters full ofclean demin. water

Chemist to be monitoringdetergent at stage 1 outletsampling point.

When detergent is detectedat sampling CC31 CC 05 CC05

Vent boiler NC 81S 001

NC 81S 001

Drum vent

NC 86S 001

NC 86S 001


48/85

48



Action


Valvesopen

Openvalve

Closevalve

When economizer andevaporator is full i.e. openstage 1 drain CC05 CC05 Regulate CC05 to maintain

pressure of 8 bars.

When detergent is detectedat the boiler vents NC 81

S 001NC 81S 001


Keep pressure with CC05

Divert flow through 1stwater wall

CC 03CC 04

CC 03CC 04

When the bulk of debris isdisplaced, divert flow via2ndwater wall. CC 03

CC02CC03

CC02When the bulk of debris isdisplaced, divert flow via 3rdwater wall.

CC 04CC 03

CC 04CC 03

When the bulk of debris isdisplaced, divert flow viasuper-heaters and re-heaters to stage 3 drain. CC 07

CC 05CC04

CC 07CC 05CC 04


Vent super-heaters and re-heaters

NC 82NC 83NC 84NC 85S 001

NC 82NC 83NC 84NC 85S 001

Close vent when detergent isdetected.


49/85

49



Action


Valvesopen

Openvalve

Closevalve

5 mins after flow has beendiverted to super-heaters,open stage 2 drain line. CC 06

CC07CC 06

CC 07Regulate CC 06 to maintainpressure of 8 bars.

Chemist to be monitoringdetergent at stage 2 outletsampling CC 32.

When the bulk of debris isdisplaced, divert flow to re-heater elements. CC 07

CC 06CC 07

CC 06Regulate CC 07 to maintainpressure of 8 bars.

Chemist to be monitoringdetergent at stage 3 outletsampling point CC 32.

5 mins after the flow has

been diverted to re-heaterelements, flush throughHP-Bypass station andback-flush HP-Bypassstation on spray water lines

RA 20S 010

RA 20A 010

RL 20S 302

RL 20S 302

RL 20S 304

RL 20S 304

CC 20 CC 20When detergent is detectedat sampling point CC 33upstream of the valveCC20

CC 20 CC 20


50/85

50



Action


Valvesopen

Openvalve

Closevalve

RL 20S302

RL 20S302

RL 20

S 304

RL 20

S 304RA 20S 010

RA 20S 010

When detergent is detectedat stage 3 outlet samplingpoint CC 33, flush line toLP-Bypass station CC 08 CC 08

When detergent is detectedat sampling point CC 34,upstream of the drain valveCC 08 CC 08 CC08

When the bulk of debris isremoved from re-heaterelements, notify staff onCC07 of intention to shutdown.

Shut down BFP CC 07 CC 07

Shut down detergentinjection pump CC 21

CC 22CC 15

CC 21CC 22CC 15

Allow detergent solution tosoak for at least 8 hours orovernight.


51/85

51



Action


Valvesopen

Openvalve

Closevalve

Degreasing ofHP-Heaterstube-nests andfeed-water line.

Prior to thecommence of thedegreasing, thefeed-water line up to

valve RL 40 S 002and HP-Heatertube-nests must bedrained.

The following valvestatus is required: RL 40

S 002RL 40S 002

(draining is onlynecessary, if thetemperature in thefeed-water piping is

less 60C !)

RL 31S 001

RL 31

S 004

RL 31S 001

RL 31

S 004RL 31S 005

RL 31S 005

RL 32S 001

RL 32S 001

RL 32S 004

RL 32S 004

RL 32S 005

RL 32S 005

RL 33S 001 RL 33S 001

RL 33S 004

RL 33S 004

RL 33S 005

RL 33S 005


52/85

52



Action


Valvesopen

Openvalve

Closevalve

Check status of BFPsdischarge valves

RL 11S 009

RL 12

S 009RL 13S 009

Confirm setting of HP-Heaters in- and outletvalves

RL 20S 008

RL 20S 025

RL 20S 026

RL 20

S 027Spray-water line to super-heater RL 27

S 001RL 27S 001

Spray-water line to re-heater RL 24

S 001RL 24S 001

Open vents RL 20S 214/S 215

RL 20S 214/S 215

RL 20S 212/S 213

RL 20S 212/S 213

RL 20S 230/S 231

RL 20S 230/S 231


53/85

53



Action


Valvesopen

Openvalve

Closevalve

RL 20S 245/S 246

RL 20S 245/S 246

Start draining feed-watersystem

RL 20S 222/S 223

RL 20S 222/S 223

RL 20S 240/S 241

RL 20S 240/S 241

CC 21CC 22CC 40CC 41


When system is drainedcompletely RL 20S 222/S 223

RL 20S 222/S 223

RL 20S 240/S 241

RL 20S 240/S 241

CC 40CC 41

CC 40CC 41

Fill system with hot water(60 - 70C) from FWT bygravity.

RL 11S 009

RL 11S 009

When air is expelled andhot water detected at vents

RL 20S 241/S 215

RL 20S 241/S 215

RL 20S 212/S 213

RL 20S 212/S 213


54/85

54



Action


Valvesopen

Openvalve

Closevalve

RL 20S 230/S 231

RL 20S 230/S 231

RL 20S 245/S 246

RL 20S 245/S 246

When system is full RL 11S 009

RL 11S 009

Start S-F-pumps andcommence circulation CC 26

CC26ACC 26CC26A

Regulate CC26 and CC26A tomaintain a backpressure of 2 bars.

When backpressure isstable, dose trisodiumphosphate and detergent.

Chemist to be monitoringP2O5- content in thedegreasing solution.

When P2O5is stable, stoppump circulation and allowdetergent to soak forapprox. 6 hours.On completion of the soak. CC 21

CC 22CC 21CC 22

Drain feed water linepartially by means of thecirculating pump. Thenprepare system (disconnectsuction piping from feedwater line) for re-flushingwith the boiler feed-waterpumps.


55/85

55



Action


Valvesopen

Openvalve

Closevalve

Re-flushing ofthe boilersystem

1. Water storagefacilities full.

Prior to re-flushing confirmCC 09 is still open. CC 09

2. BFPs and temp

filling pump ready

Furthermore open CC 15

and CC 01

CC 15

CC 01

CC 15

CC 01Confirm pressure tripswitch is still activated.

Notify personnel on CC 05on starting BFP on leak off.

CC 05 CC 05 Crack CC05 open

Monitor FWT level

Chemist to be monitoringpH and turbidity at stage 1sampling point CC 31



Vent feed water system RL 20S 214/S 215

RL 20S 214/S 215

RL 20S 212/S 213

RL 20S 212/S 213

RL 20S 230/S 231

RL 20S 230/S 231

When air has beenexpelled, divert flow via

HP-heaters bypass forapprox. 3 mins.

RL 20

S 008

RL 20S 025

RL 20

S 008

RL 20S 025

RL 20S 026

RL 20S 026


56/85

56



Action


Valvesopen

Openvalve

Closevalve

RL 20S 027

RL 20S 027

Divert flow via HP-heatertube-nests RL 20

S 008

RL 20

S 008

RL 20S 025

RL 20S 025

RL 20S 026

RL 20S 026

RL 20S 027

RL 20S 027

When the bulk ofdegreasing solution isdisplaced, increase flow to300t/h

When the pH value atsampling point CC31 isapproaching 6, divert flowto economizer and waterwalls to stage 1/2 drain.

CC 02CC 03CC 04

CC 02CC 03CC 04

RL 40S 002

RL 40S 002

CC 01 CC 01 Regulate CC05 to maintainpressure of 8 bars.

Vent evaporator NC 81S 001

NC 81S 001

NC 86S 001

NC 86S 001


57/85

57



Action


Valvesopen

Openvalve

Closevalve

When air is expelled NC 81S 001

NC 81S 001

NC 86S 001

NC 86S 001



When the bulk of detergentis displaced fromevaporator water walls,divert flow through eachwater wall separately.

CC 03CC 04

CC 03CC04

When turbidity issatisfactory, divert flow to

2nd

, water wall.CC 03

CC 02CC 03

CC 02When turbidity issatisfactory, divert flow to3rdwater wall.

CC 04CC 03

CC 04CC03

When turbidity issatisfactory, open waterwalls together.

CC 02

CC 03

CC 02

CC 03


58/85

58



Action


Valvesopen

Openvalve

Closevalve

Decrease flow steady to100t/hDivert flow via super-heaterand re-heater to stage 3

outlet drainCC 07

CC 05CC 07

CC 05Regulate CC07 to maintainpressure of 8 bars.

Vent super-heater and re-heater elements

NC 82NC 83NC 84NC 85S 001

NC 82NC 83NC 84NC 85S 001

Close vents when air is

expelled

NC 71

NC 72NC 73

NC 71

NC 72NC 73


NC 74S 001

NC 74S 001 Regulate CC07 to maintain

pressure of 8 bars.Chemist to be monitoringturbidity at stage 3sampling point CC33

When the bulk of detergentis displaced from super-heater and re-heaterelements, flush super-heater and re-heater spray-water lines.

RL 28S 306

RL 28S 306

RL 28S 306

RL 28S 306

?


59/85

59



Action


Valvesopen

Openvalve

Closevalve

After 3 mins. RL 29S 306

RL 29S 306

RL 29S 308

RL 29S 308

RL 28S 306

RL 28S 306

RL 28S 308

RL 28S 308


RL 29S 306

RL 29S 308

RL 29S 308

RL 25S 306

RL 25S 306

RL 25S 308

RL 25S 308

After 3 min. RL 26S 306

RL 26S 306

RL 26S 308

RL 26S 308

RL 25S 306

RL 25S 306

RL 25S 308

RL 25S 308

After 2 mins. RL 26

S 306

RL 26

S 306RL 26S 308

RL 26S 308

When flushing of re-heaterspray-water lines iscompleted, increase flowsteady to 600t/h



60/85

60



Action


Valvesopen

Openvalve

Closevalve

When turbidity at stage 3outlet is nearing ourendpoint flush HP-Bypassstation and back-flush HP-

Bypass station spray-waterlines.

RA 20S 010

RA 20S 010

RL 20S 302

RL 20S 302

RL 20S 304

RL 20S 304

CC 20 CC 20When water quality atsampling point CC36 is

satisfactoryCC 20 CC 20

RL 20S 302

RL 20S 302

RL 20S 304

RL 20S 304

RA 20S 010

RA 20S 010

Flush LP-Bypass station CC 08 CC 08

When water quality atsampling point CC34 is

satisfactory CC 08 CC 08Flush stage 2 drain line CC 06 CC 06 Crack CC06 open

Regulate CC07 to maintainpressure at 8 bars.


61/85

61



Action


Valvesopen

Openvalve

Closevalve

When water at stage 3outlet drain meets theircriteria, decrease flowsteady shut system down.

CC 07CC 15CC 02CC 03CC 04


Drain evaporator !


62/85

Check list No.4

Heating up boiler systemNotes: on heating up boiler system

Aim:

Heating of the iron masses of the boiler system by means of circulating hot water across the system till

a metal temperature of approx. 60C is achieved.


With the feed water tank full of hot water, the system will be circulated by means of a boiler feed pump

at a flow rate of 300t/h. the flow will be directed as follows:

BPF - feed water lineeconomizer or evaporator water wallsdrumsuper-heaterlive steam line

temp. piping RR09cold re-heat linere-heaterhot re-heat linetemp. piping RR07 and RR10

main condensate piping RM 20feed water tank.

During circulation, auxiliary steam from unit 1/2 or from auxiliary boiler will be injected into feed water

tank continuously.

As soon as the desired temperature is achieved, the steam injection will be stopped and the pump shut

down.

Prior to the subsequent acid treatment the economizer and evaporator shall be drained completely.


63/85

63



Action


Valvesopen

Openvalve

Closevalve

Circulation andheating of boilersystem 1. Boiler is filled with

clean water- Confirm CC 09 is stillopen.

2.FWT is full at60C

- Confirm pressure tripswitch is still activated

3. RFST are full at60C

Prior of staring the BFP setvalves as follows: CC 15 CC 15

4. Auxiliary steamready

5. BFPs ready

6. All personnelready and in

communicationNotify staff on valve CC07of intention to start BFP onleak off CC 07 CC 07 Crack CC07 open


Regulate CC07 to maintain apressure of 8 bars.

Vent boiler system NC 81NC 86S 001

NC 81NC 86S 001

NC 82NC 83NC 84NC 85S 001

NC 82NC 83NC 84NC 85S 001

Super-heater vents


64/85

64



Action


Valvesopen

Openvalve

Closevalve

NC 71NC 72NC 73NC 74

S 001


S 001

Re-heater vents

When air is expelled closethe vents.

Change flow from oncethrough to re-circulationmethod CC 11

CC 10CC 11CC 10 Crack CC01 open

CC 07 CC 07 Regulate CC10 to maintain apressure of 8 bars.

When system pressure is

stable, increase flow steadyto 300t/h

After 1 hour of circulatingvia economizer, drum,super-heaters and re-heater divert flow via lowerevaporator water wallheaders

CC 01RL 42S 002

CC 01RL 42S 002

Check wall temperature offeed water line, live steamline, cold & hot re-heat line.

When wall temperatureapproaching 60C, divertflow via economizer again

RL 40S 002

CC 01

RL 40S 002

CC 01


65/85

65



Action


Valvesopen

Openvalve

Closevalve

When wall temperature ofapprox. 60C, is achieved,shut down circulation.

CC 37

CC10CC 11

CC 37

CC10CC 11 Leak detection between CC10 and

CC 11

Drain economizer andevaporator.Open boiler vent NC 81

NC 86S 001

NC 81NC 86S 001

CC 01CC 05

CC 01CC 05 Crack CC05 open

When draining hasstopped, open allpermanent evaporator w/wdrains.

NC 10NC 11

NC 10NC 11

Monitor water level on blowdown tank and start drainpump if necessary

NC 12NC 13NC 14NC 15NC 16NC 17NC 18NC 19S 001/

S 002

NC 12NC 13NC 14NC 15NC 16NC 17NC 18NC 19S 001/

S 002

NA 20S 003

NA 20S 003

Boiler drum blow down lineisolation.


66/85

66



Action


Valvesopen

Openvalve

Closevalve

When evaporator is drainedcompletely

NC 10NC 19

S 001

NC 10NC 19

S 001

NA 20S 003

NA 20S 003

CC 05CC 01

CC 05CC 01


67/85

Check No.5

Acid cleaning phase

Notes on HF acid phase

Aim:

To provide chemically cleaned surfaces free of any loose or adherent mill scale or material.

Briefly outline of the procedure

Economizer and evaporator empty, super-heater, re-heater and steam lines full of clean demin. water.

At a flow rate of 100t/h at 60C, inhibited acid will be dosed via injection point J1 in the feed water line

RL 40 till the economizer and evaporator is filled with acid at a strength of approx. 1%.

After filling, the flow shall be increased to 300t/h and directed via each water wall to the stage 1 outlet

drain.

When iron levels being monitored at the outlet have past their peak and fresh acid being detected, the

acid will be diverted via boiler drum and saturated steam off takes to the super-heaters and dumpedvia stage 2 outlet drain.

When iron and acid meets their above mentioned criteria shut down carefully.

Allow acid to soak for approx. 1 hour to dissolve suspended matters.

On completion of the soak, start B.F.P. and increase flow steady to 350t/h. The flow is directed in such

way that the fresh acid from economizer and evaporator will be pushed through re-heater elements


68/85

68



Action


Valvesopen

Openvalve

Closevalve

Acid cleaningphase

1. RFST full at 60C - Confirm CC09 is still open CC092. FWT full at 60C - Confirm pressure trip

switch is still activated MSV

3. acid ready

4. BFPs ready

- prior to thecommencement of acidphase, confirm thefollowing valve attitudes:

5. All personnelready and incommunication


CC01 economizer "

6. Lime dosingstation ready

CC 05CC 06CC 07

Drain stage 1.2Drain stage 2 3

7. Economizer and

evaporatorcompletely drained.

CC 08

CC 10CC 11

HP-bypass drain

8. Super-heater, re-heaters and steamlines full of cleandemin. water

CC 16CC 17CC 21

CC 37CC 15

CC10CC11 Soak away pit

pumpRFWT

CC 22CC22A

J1 CC 23

CC 24CC 20

CC 40CC 41

J2 J2

RR14 CC36

NC 81NC 86S 001

"

A t l l


69/85

69



Action


Valvesopen

Openvalve

Closevalve

Notify staff at valve CC05of intention to start BFP inleak off CC 05

CC 05 Crack CC05

Increase flow steady to100t/hCommence injection of1.4t/h inhibited hydrofluoricacid.

CC 21

CC21

Chemist to be monitoringHF-inlet strength atsampling point NC 09

Eco-inlet drain on boiler basement.When acid strength isregulated to 1%, monitor

acid at stage 1 outletsampling point CC31When strong acid isdetected

CC 05 CC 05When pressure increase atstage 1 outlet CC 05 CC 05 Regulate CC05 to maintain a

pressure of 8 bars.Close drum vents when airis expelled NC 81

NC 86

S 001

NC 81NC 86

S 001Commence line dosing toeffluent pit.

Commence re-filling ofFWT with temp. fillingpump.Increase flow steady to Regulate CC05 to maintain

A t l l


70/85

70



Action


Valvesopen

Openvalve

Closevalve

300t/h pressure of 8 bars.

When backpressure isstable, divert acid to 1stwater wall.

CC 03CC 04

CC 03CC 04

Chemist to be monitoringacid and iron at stage 1outlet sampling valve CC31When iron levels havepassed their peaks, divertacid via 2ndwater wall. CC 03

CC 02CC 03

CC 02When iron levels havepassed their peaks, divertacid via 3rdwater wall. CC 04

CC 03CC 04

CC 03

When iron levels havepassed their peaks, divertacid to super-heaterelements and stage 2 outlet CC 06

CC 05CC 04

CC 06CC 05CC 04


Vent super-heaterelements

NC 82NC 83NC 84NC 85S 301

NC 82NC 83NC 84NC 85S 301

When air is expelled NC 82NC 83NC 84NC 85S 301

NC 82NC 83NC 84NC 85S 301

A t l l


71/85

71



Action


Valvesopen

Openvalve

Closevalve

Chemist to be monitoringiron and acid at stage 2outlet sampling point CC 32

When iron levels have

passed their peak,decrease flow carefully toleak off operation CC 06 CC 06 Close CC 06 in

Shut down BFPShut down acid injectionpumpShut down lime dosing

Allow acid to soak for atleast 1 hour

CC 15CC 21CC 22CC22A

CC 15CC 21CC 22CC22A

To avoid penetration ofacid into feed water system RL40S 002

RL40S 002

During soaking timefor the HP-Boilerpart confirm:1- Fill FWT withwater at 60C2- Before startingthe re-heater acidphase=1000 m3water at 60C must

be available3- acid ready

RL 31/32/ 33S 005

RL 31/32/ 33S 005

Isolation downstream feed watercontrol valves.

Actual valve


72/85

72



Action


Valvesopen

Openvalve

Closevalve

Prior to the commencementof re-heater acid clean setvalves as follows:

CC 02CC 03CC 04

CC 24CC 15RL 33S 005

CC 02CC 03CC 04

CC 24CC 15RL 33S 005

Confirm CC 09 is still open

Confirm pressure switchtrip is still activated.

Notify staff at valve CC 07of intention to start BFP onleak off

RL 40S 002CC 07

RL 40S 002CC 07

Crack CC 07 open.


Commence lime dosing toeffluent basinVent re-heater elements NC 71

NC 72NC 73NC 74S 301

NC 71NC 72NC 73NC 74S 301

When air is expelled NC 71NC 72NC 73

NC 74S 301

NC 71NC 72NC 73

NC 74S 301

After 3 mins. Of steady flowof 350t/h CC 01

RL 40S 002

CC 01RL 40S 002

Actual valve


73/85

73



Action


Valvesopen

Openvalve

Closevalve

Chemist to be monitoringacid strength at samplingpoint CC 38 before cold re-heat line

When acid strength dropdown, start acid injectionpump and dose via J2 CC 23 CC 23

Chemist to be monitoringacid and iron at stage 3outlet sampling point CC33When acid is detected treatHP-Bypass line and HP-Bypass spray-water linewith acid.

RA 20S 010

RL 20S 002

RL 20S 004

CC 20

RA 20S 010

RL 20S 002

RL 20S 004

CC 20When acid is detected assampling point CC 36upstream of the valveCC20

CC 20

RL 20S 002

RL 20

S 004

RA 20S 010

CC 20

RL 20S 002

RL 20

S 004

RA 20S 010

Actual valve


74/85

74



Action


Valvesopen

Openvalve

Closevalve

When iron levels have pasttheir peak at stage 3sampling point, treat LP-Bypass line CC 08 CC 08

When acid is detected atsampling point CC34upstream of the valveCC08 CC 08 CC 08

Notify staff at CC 07 ofintention to shut down.

Decrease flow steady toleak off operation CC 07 CC 07

Shut down BFP

Shut down acid injectionpump

CC 23CC 24

CC 23CC 24

Shut down lime dosingAllow acid to soak for atleast 2 hours in the re-heater elements CC 15 CC 15


75/85

Check list No.6

Displacement of acid and flushing to conductivityNotes on displacement of acid and flushing to conductivity

Aim:

To displace acid from boiler system completely and to achieve a final conductivity of less than 10

S/cm above the incoming water.


The HP-boiler part is full of slightly acidic water: the re-heater is full of acid at a strength of 1%.

After starting the BFPs the acid will be displaced at a flow of 300t/h. during displacement all system

vents, drain, dead legs etc. must be rinsed thoroughly, then conductivity flushing with up to max. load

of two feed pumps takes place.

Actual valve


76/85

76



Action


Valvesopen

Openvalve

Closevalve

Displacementof acid andflushing toconductivity

1. Two RFST arefull at ambienttemperature.

- Confirm CC09 is still open CC09

2. FWT full at amb.

Temperature

- Confirm pressure trip

switch is still activated

MSV 3. BFPs ready Prior to the commencement

of the flush

4. Temp.filling pumpready

Confirm the following valveattitudes:

RL 40S 002

5. Lime dosingstation ready


CC 05Notify staff at CC 07 ofintention to start BFP on

leak off. CC 07 CC 07 Crack CC 07 openIncrease flow steady to300t/h

Regulate CC 07 to maintainpressure of 8 bars.

Vent boiler and super-heaters

NC 81NC 86S 001

NC 81NC 86S 001

Check pH at venting through, closevent when pH= 5-6 units.

Chemist to be monitoringiron and acid at stage 3outlet sampling point CC33

NC 82NC 83

NC 84NC 85NC 86S 001

NC 82NC 83

NC 84NC 85NC 86S 001

Commence lime dosing toeffluent basin.Rinse permanent drains

Actual valveA ti


77/85

77



Action


Valvesopen

Openvalve

Closevalve

Open drains for ca. 1 min.,check steady flow acrossthe valve then close.Monitor water level at blow

down tank.Start tank emptying pump ifnecessary

RL 40S 205/S 206

RL 40S 205/S 206

NC 09S 001/S 002

NC 09S 001/S 002

ECO drain

NC 15NC 18NC 19S 001/S 002

NC 15NC 18NC 19S 001/S 002

NC 11NC 12NC 13NC 14S 001/S 002

NC 11NC 12NC 13NC 14S 001/S 002

NC 10

NC 16NC 17S 001/S 002

NC 10

NC 16NC 17S 001/S 002

Actual valveA ti


78/85

78



Action


Valvesopen

Openvalve

Closevalve


NC 65S 001/S 002


NC 65S 001/S 002

Flush super-heater spray-water lines RL 28

S 306RL 28S 306

RL 28S 308

RL 28S 308

RL 29S 306

RL 29S 306

RL 29

S 308

RL 29

S 308After 3 mins. RL 28

S 306RL 28S 306

RL 28S 308

RL 28S 308

RL 29S 306

RL 29S 306

RL 29S 308

RL 29S 308

When bulk of acid is

removed from re-heaterelements, flush re-heaterspray-water lines

RL 25S 306

RL 25S 306

RL 25S 308

RL 25S 308

RL 26S 306

RL 26S 306

Actual valveAction


79/85

79

Phase Pre-condition Performancesattitude

Action


Valvesopen

Openvalve

Closevalve

RL 26S 308

RL 26S 308


RL 25S 306

RL 25S 308

RL 25S 308

RL 26S 306

RL 26S 306

RL 26S 308

RL 26S 308

Flush re-heater vents NC 71NC 72NC 73NC 74NC 75

S 301

NC 71NC 72NC 73NC 74NC 75

S 301

Check pH at venting trough closevent when pH= 5-6 units

Increase flow steady to 600t/h

Regulate CC 07 to maintainpressure of 8 bars

After 5 mins. of steady flowof 600 t/h decrease flow to300 t/hDivert flow to lower waterwall headers CC 02

CC 03CC 04CC 01


RL 40S 002

RL 40S 002

When pressure is stable atCC 07, divert flow via 1st.water wall.

CC 03CC 04

CC 03CC 04



Actual valveAction


80/85

80


Action


Valvesopen

Openvalve

Closevalve

After 3 min. at max. load,divert flow via 2ndwaterwall.

CC 03CC 02

CC 03CC 02

After 3 min. at max. load,

divert flow via 3rd. waterwall.

CC 04CC 03

CC 04CC 03

Decrease flow to 300 t/h Regulate CC 07 to maintainpressure at 8 bars.

When backpressure isstable, divert flow via stage2 outlet CC 06

CC 07CC 06

CC 07Regulate CC 06 to maintainpressure at 8 bars.

Chemist to be monitoringconductivity at stage 2outlet sampling point CC 32



When conductivity is lessthan 20 S/cm divert flowvia stage 3 outlet

CC 07CC 06

CC 07CC 06

Chemist to be monitoringconductivity at stage 3outlet sampling point CC 33

When turbidity isapproaching its endpoint,flush via HP-bypass lineand back-flush HP-Bypassspray-water lines

RA 20S 010

RL 20S 302

RA 20S 010

RL 20S 302

RL 20S 304

RL 20S 304

CC 20 CC 20

Actual valveAction


81/85

81


Action


Valvesopen

Openvalve

Closevalve

After 3 mins. RA 20S 010

RA 20S 010

RL 20S 302

RL 20S 302

RL 20S 304

RL 20S 304

CC 20 CC 20

Open LP-Bypass line CC 08 CC 08

After 3 mins. CC 08 CC 08

When conductivity is lessthan 10S/cm aboveincoming water, decreaseflow steady to 150 t/h

Regulate CC 07 to maintainpressure at 8 bars.

Flush drains in steam lines CC 16 CC 16

Flush drains for app. 1 min.check flow across thevalves

RA 10S 221

RA 10S 221

RA 10S 223

RA 10S 223

RC 10S 229

RC 10S 229

RB 15S 223

RB 15S 223

CC 17 CC 17

RB 20

S 220

RB 20

S 220Notify staff on CC 07 ofintention to shut down

Decrease flow steady shutdown BFPs

CC 07CC 15

CC 07CC 15


82/85

Check list No.7

Passivating treatmentNotes on passivation treatment

Aim:

To passivate the strongly activated metal surfaces and to form by means of Hydrogen Peroxide dosing

an extremely thin coating of iron oxide to prevent post-rusting.


With the boiler system full of clean demin. water, Ammonia and Hydrogen Peroxide will be dosed at a

BFP flow rate of 300 t/h. the passivation chemicals shall be dosed via injection point J1 in the feed

water line RL40. The water temperature must not exceed 40C.

The whole boiler system will be filled with passivation solution at a pH of greater than 10.2 and a

positive redox potential reading at a range of +20 +100 mV.

As soon as the reading will be monitored at stage 3 outlet drain, the system will be shut down. A

subsequent soaking period of at least 3 hours is necessary before draining the system. After draining

the system will be prepared for blow-through.

Actual valveAction


83/85

83


Action


Valvesopen

Openvalve

Closevalve

Passivationtreatment

1. one RFST full at40C.

- Confirm CC09 is still open

2. FWT full at 40Ctemperature

- Confirm pressure tripswitch is still activated

3. Ammonia andperoxide ready

4. BFP ready Confirm the following valveattitudes:



RL 40S 002

RL 40S 002

Notify staff at valve CC 07

of intention to start BFP onleak off CC 07 CC 07 Crack CC07 openIncrease flow steady to 100t/h Regulate CC07 to maintain

pressure of 8 barsVent boiler systemcompletely

NC 81NC 86S 001

NC 81NC 86S 001

NC 82NC 83NC 84NC 85NC 86S 001

NC 82NC 83NC 84NC 85NC 86S 001

Actual valvei d

Action


84/85

84


Action


Valvesopen

Openvalve

Closevalve


NC 75S 301


NC 75S 301

When air is expelled. Closevents


Regulate CC 07 to maintainpressure at 8 bars.

Commence injection ofammonia and hydrogenperoxide.

Chemist to be monitoringpH and redox potential atinlet sampling point NC09(?)

After 5 mins. of steady flowat 350 t/h, divert flow to thelower evap. water wallheaders, one wall afterother.

CC 01CC 02

CC 01CC 02

After 5 mins. divert flow via2nd. water wall. CC 03

CC 02CC 03

CC 02

After 5 mins. divert flowthrough 3rd. water wall. CC 04CC 03

CC 04CC 03

Chemist to be monitoringpH and redox potential atstage 3 outlet samplingpoint CC33

Actual valvettit d

Action


85/85


Action


Valvesopen

Openvalve

Closevalve

When ammonia andperoxide is detected at thesampling point, flush viaHP-Bypass station and

back-flush HP-Bypassspray-water lines.

RA 20S 010

RL 20S 302

RA 20S 010

RL 20S 302

RL 20S 304

RL 20S 304

CC 20 CC 20When ammonia andperoxide is detected atsampling point CC 36upstream of the valveCC20

CC 20

RL 20S 302

RL 20S 302

RL 20S 304

RL 20S 304

.

Date post:	03-Jun-2018
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Acid Cleaning in Commissioning

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