Boiler Chemical Cleaning Procedure

ADHI KARYA – KARYA – JEPOE JEPOE JOINT OPERATION

COMMISSIONING PROCEDURE Document No.: PLG-100-COM-PR-001

BOILER CHEMICAL CLEANING PROCEDURE

Page Number Page 3 of 13

TABLE OF CONTENT

1.0

TITLE

4

2.0

SCOPE

4

3.0

REFERENCE

4

4.0

GENERAL DESCRIPTION

4

5.0

WATER CONTENT OF THE SYSTEM

5

6.0

MECHANICAL MECHANICAL PREPARATION

5

7.0

OTHER PREPARATION

5

8.0

CHEMICAL TREATMENT AND INSPECTION PROGRAM

6

9.0

DETAIL DESCRIPTION

7

10.0

LIST OF CHEMICAL

12

11.0

PRELIMINARY PRELIMINARY WATER PROGRAM

12

12.0

SAFETY PRECAUTIONS DURING CHEMICAL CLEANING

13



1.0



TITLE

Procedure for boiler chemical cleaning 2.0

SCOPE

This procedure covers the general requirements for boiler acid cleaning based on chemical to be implemented. The purpose of boiler chemical cleaning is to remove oil/grease, rust/scaling, which is formed during boiler pressure parts fabrication. Final step of boiler chemical cleaning is to perform magnetite film layer formation on boiler tube as an indication boiler is ready to operate.

3.0

REFERENCE

3.1 JINAN BOILER OPERATION MANUAL 3.2 CHEMICAL SUPPLIER DOCUMENT

4.0

GENERAL DESCRIPTION OF THE SYSTEM

4.1 4.1 Data of the boiler Boiler manufacturer

: Jinan Boiler

Type of the boiler

: CFB

Max steam capacity

: 420 t/h

Steam outlet temperature

: 540 °C

Steam outlet pressure

: 9.8 MPa

Total water volume

: 250 m3

4.2 4.2 Description of the Cleaning system 4.2.1

Feed water line from the feed water pumps and economizer

4.2.2

Water wall tube

4.2.3

Steam drum ¾ the volume

4.2.4

Super heater area not to be acid cleaning



5.0



WATER CONTENT OF THE SYSTEM

5.1 5.1

Feed water line and economizer banks

5.2 5.2

Front, rear and side walls incl. heavy down comers and cyclone including down comers.

6.0

7.0

5.3 5.3

Steam drum ¾ volume

5.4 5.4

Total cleaning volume approximately 1750m 3

MECHANICAL PREPARATIONS

6.1 6.1

Temporary filling, draining and circulation system (temporary piping)

6.2 6.2

Install the temporary acid solution tank

6.3 6.3

Install the additional chemical dosing pump (additional pump)

6.4 6.4

Install temporary chemical solution circulation pump

6.5 6.5

Install line acid circulation pump to chemical tank

6.6 6.6

Install drain line from chemical tank to sewer

6.7 6.7

Install drain line from collecting drain front and rear side to sewer

6.8 6.8

Remove cyclone separator of the steam drum

6.9 6.9

Install temporary low pressure boiler for heating the chemicals solution

OTHER PREPARATIONS 7.1 7.1

Personnel

7.1.1

Personnel to carry out the chemical cleaning will be under GPOS SUPERVISION.

7.1.2

Boiler operators for handling the feed water pump

7.1.3

Unskilled labor 2-4 peoples per shift for transportation and dosing the chemicals to circulation tank

7.1.4 7.2 7.2

Personnel for analyzing feed water will be under GPOS SUPERVISION

Electric Power

7.2.1

Electrical supply for circulation pump shall be ready, one from PLN, and the other from genset.


COMMISSIONING PROCEDURE Document No.:


PLG-100-COM-PR-001

7.3 7.3


Boiler System

7.3.1

Demin water specification shall be within the specification mentioned in the design specification:

7.3.2

- pH at 25°C 25°C

: 6.5 6.5 – 7.0 7.0

-

conductivity at 25°C

: ≤ 0.02 µm/cm

-

total Silica as SiO2

: 0,015 mg/l

Chemicalsl circulation piping system shall be tested with the demineralized water.

7.4 7.4

7.3.3

Venting and draining system shall be ready.

7.3.4

Chemicals drainage and neutralization pond shall be available.

Demineralized Water

7.4.1

Demineralized water should be available. Demin water requirement during boile boilerr acid acid clean cleaning ing estima estimated ted 1750 1750 m3.

7.4.2

Demineralized water shall be available in demin storage tank during boiler chemical cleaning process.

7.5 7.5

Safety Precaution

Safety precaution during chemical cleaning following the step at point no. 12.0

7.6 7.6

Valve Check List

All valves for chemical cleaning system will be listed in a check list by GPOS.

7.7 7.7

Neutralization Pit and Sewer System

Arrangement must be made for proper disposing of spent acid and caustic solution befo before re sendi sending ng to waste waste water water treatm treatmen entt plant plant..



8.0



CHEMICAL TREATMENT AND INSPECTION PROGRAM

8.1 8.1

Pre rinsing of the system.

8.2 8.2

Grease removing treatment.

8.3 8.3

Rinsing of the system.

8.4 8.4

Hydrofluoric acid treatment.

8.5 8.5

Flushing to low conductivity.

8.6 8.6

Final citric acid treatment, neutralization and passivation.

8.7 8.7

Final flushing with ammonia dosed demineralized water pH > 10, 2 if cold water available.

8.8 8.8

Inspection of steam drum and if necessary headers.

8.9 8.9

Final installation of the steam drum internal. Leak test of the boiler.

8.10 Magnetite formation treatment at min 2,7 MPa (part of steam blowing)

9.0

DETAILED DESCRIPTION 9.1

Pre Rinsing of the System

9.1. 9.1.1 1

Fill water to boiler through feedwater line until level in the steam drum is below manhole .While filling the water to steam drum, open air vent on the steam drum, and closed after there is no air comes out from the air vent. Stop the circulation pump, and drain the water necessary through bottom header until the water is clean

9.1. 9.1.2 2

Fill the water again until until level in the steam drum drum is below manhole. During water filling to boiler, charging the steam from low pressure boiler for heating the water in chemical tank (50°C – (50°C – 60°C) 60°C)

9.1. 9.1.3 3

Continue for circulating the water, open three (3) valve at bottom header, and maintain drum level below normal level. During this circulation maintain chemical tank level at 75%.

9.1. 9.1.4 4

Stop circulation pump pump and add hydrazine (75 kg), start again circulation pump, and continue filling water until main steam line (hydrazine blanket). Crack open drain valve 2” on main steam line check valve





blank, if water already comes out, stop circulation pump, and close cl ose main steam line air vent.

9.2

Grease Removing Treatment

9.2.1

Maintain level in steam drum on normal water level and start circulation pump. While continue circulating ensure water temperature is 60°C. Stop steam supply from the boiler if temperature already a lready reach 60°C.

9.2.2

Add chemicals to tank alternatively: - TSP 90% 75 kg (3 sack) - Detergent 38 kg (2 pails) - Defoamer 13 kg (1 jerigen)

9.3

9.4

Rinsing of the System

9.3.1

After circulating the chemicals solution for four (4) hours, stop circulation pump.

9.3.2

Drain the boiler until empty.

9.3.3

Fill water to boiler until normal level water, stop the pump and and drain the boiler directly (boiler flushing process).

Hydrofluoric Acid Treatment

9.4.1

After boiler boiler flushing is finish, fill demin water to chemical tank. tank.

9.4.2

After the level is sufficient start circulation pump, and and continue filling water to boiler until level in the steam drum is below manhole.

9.4.3

Stop the pump and and heating the water by using steam from temporary low pressure boiler until water temperature reaching 50°C. Stop steam supply from the boiler if temperature already reach 50°C.

9.4.4

Add chemicals to tank alternatively: - HCl 30% 4500 kg (4 kemps) - Armohib 28 (2 pail)





9.4.5

Circulate the chemicals solution for five (5) hours.

9.4.6

Chemical analysis shall be performed every one (1) hour. hour.

9.4.7

Drain the boiler after circulation process.

9.4.8

Add chemicals to pond alternatively, for neutralizing the chemicals pH: pH:

- PAC 100 kg - NaOH (48%) 2500 kg

9.5

9.6

Flushing to Low Conductivity

9.5.1

After draining boiler is finish and chemical tank is empty, fill demin water to chemical tank. After the level is sufficient, start circulation pump and continue filling water to boiler until level in the steam drum is at normal level water.

9.5.2

Circulate the water for two (2) hours, and drain the boiler (1st flushing)

9.5.3

Repeat the process process until conductivity of the the water is below 20µS/m.

Final Citric Acid treatment, treatment, Neutralization and Passivation

9.6.1

After flushing to low conductivity is complete, fill the boiler again again until level in the steam drum is below manhole.

9.6.2

While continue circulating, circulating, heating the water by using steam from from temporary low pressure boiler until water temperature reaching 50°C. Stop steam supply from the boiler if temperature already a lready reach 60°C.

9.6.3

Add chemicals to tank alternatively for neutralization phase, and circulate for four (4) hours : - Citric acid 50% 500 kg (20 sacks) - Ammonia 1000 kg (7 drum)

9.6.4

Ensure chemical solution pH is 9.6

9.6.5

Add chemicals chemicals to tank for passivation phase, and circulate for two (2) hours : - Sodium nitrite 388 kg (15 sacks)



9.6.6

9.7

9.8

9.9



After chemical circulation is complete, stop the pump and drain the boiler.

Final Rinsing with Ammonia Water

9.7.1

After draining the boiler is complete, fill the water water again until level in the steam drum is below manhole, and stop the circulati on pump.

9.7.2

Add ammonia ammonia (260 kg or or 2 drum) to chemical tank and circulate for four (4) hours. Ensure chemical solution pH is 10.2

9.7.3

After the circulation is complete, drain the boiler

Inspection

9.8.1

Inspect steam drum, compare the result by picture (by comparing comparing the result before and after acid cleaning)

9.8.2

Install the dismounted drum internal parts.

9.8.3

Cut three (3) bottom header cap, and compare compare the result before and after acid cleaning (others three bottom header cap already cut off for temporary pipe connection)

Hydrostatic (Pressure) Leak Test

9.9.1

Leak test at operating pressure (9.8 MPa).

9.9.2

After leak inspection is complete, temporary piping installation shall to be removed, and boiler is ready for normal operation. operation.

9.10 Magnetite Formation Treatment (Part of Steam Blowing)

9.10.1 Fill the system with chemical for the start of magnetite film formation, using ordinary chemical dosing system to the drum. 9.10.2 Considering the service length and the operative capability of the boiler the presence of homogeneous and pure film of magnetite is a matter of the greatest importance. After the cleaning part of the pickling is




PLG-100-COM-PR-001


finished, the boiler is to be operated under low load. min 2,7 MPa for about 10 – 10 – 24 24 hour with a dosage in the feed water. During treatment the boiler is being blown off powerfully. After this time when the boiler water will be show satisfactory values of chemical analysis, the boiler is to be set in operation. the purpose of this so called “Protecting Film Operation” are : are :

a) Build up a protecting film of magnetite on almost uniform thickness. b) Blowing off of finely powdered slug residual During this magnetite formation the following analysis to be carried out by the laboratory personnel under GPOS SUPERVISION:

Parameter pH at 25°C

Units

Feedwater

Boiler water

Steam/Condensate Steam/Cond ensate

-

8.8 – 8.8 – 9.3 9.3

9 – 10.5 – 10.5

-

9.0 – 9.0 – 9.3 9.3

Without Cu system

mg/L

10 – 10 – 30 30

Volatile treatment

mg/L

10 – 10 – 50 50

mg/L

≤ 0.3

With Cu system

N2H4

Oil Hardness

µmol/ L

Remarks

≤2

Dissolved oxygen

mg/L

≤7

Fe

mg/L

≤ 30

≤ 20

Cu

mg/L

≤5

≤3

Na

mg/L

SiO2

mg/L

≤2

Chloride

mg/L

-

PO4

mg/L

≤ 50

Salinity

mg/L

≤ 100

Conductivity

µS/m

< 150

≤ 10 ≤ 20




PLG-100-COM-PR-001

10.

Page 12 of 13

LIST OF CHEMICALS

Sequence

Degreasing

Acid Cleaning

No.

Chemicals

Dosage

Quantity (kg)

Quantity (kg) for

(%)

for 2 boiler

1 boiler

1

TSP 90%

0,0286

143

71,5

2

Detergent Liquid

0,01435

72

36

3

Defoamer

0,0036

18

9

4

HCl 30%

1,8572

2286

1143

5

Armohib 28

0,1

500

250

6

Citric Acid 50%

0,2

1000

500

0,5429

2715

1358

Ammonium

Passivation

7

Neutralization

8

Sodium Nitrite

0,1572

786

393

Preservation

9

Hydrazine 35%

0,1286

643

321.5

10

Cyclohexilamine

0,0428

128

64

11

NaOH

1,1428

5714

2857

12

PAC

0,0428

214

107

Waste handling

11.

Page Number

Hydroxide

PRELIMINARY PRELIMINARY WATER PROGRAM

Activity Activity Day no. 1 Flushing the boiler Day no. 2 Fill and flush the boiler Day no. 3 Flush/fill the boiler. flush to low conductivity

m of Water

Temperature Temperature

Quality

30 °C

Demin water

30°C

Demin water

30°C

Demin water

30 °C

Demin water

Day no. 4 Flushing to low conductivity. Final flushing




Day no. 5 Final Flushing Day no. 6 Final flushing Day no. 7 Filling for Hydrostatic pressure test. Day no. 8 – 8 – 10 10 Magnetite formation Total

12.


30 °C

Demin Water

30 °C

Demin water

3°C 0

Demin water

30 °C

Demin water

± 1750

SAFETY PRECAUTIONS DURING CHEMICAL CLEANING

12.1 The area where chemicals will be handled handled to be be roped off off 12.2 Sign “ Danger” chemical cleaning in progress”, similar warning should be posted in area where spillage of solution may occur. 12.3 Fire hose should be available available at chemical cleaning pump suction level in the event of solution leak or spillage. 12.4 Rubber gloves, aprons, gas mask and glasses should be provided for the personnel handling chemical cleaning solution 12.5 Good ventilation should be provided in the steam drum prior to entering the drum for inspection. 12.6 Safety water shower shall be provided near chemicals tank

Boiler Chemical Cleaning Procedure

Recommend Documents