SEM-9486E Boiler Feed Water Chemical Treatment

CONTENTS

Page

11OBJECTIVES & MAKING

11.1Objectives

11.2Complementary Point

11.3Making

12COMPONENT OF CHEMICAL INJECTION

12.1Scale Control

42.2Corrosion Control

52.3Condensate Return Line Corrosion Control

62.4Chemical Agent Injection Place

73SELECTION OF CHEMICALS & INJECTION POINT

74INJECTION LIQUID

74.1Dilution

74.2 Vapor Press

74.3 Viscosity

85INJECTION PUMP

85.1 No Req'd

85.2 Capacity (L/hr)

135.3Capacity Control

136SOLUTION TANK

136.1Capacity

136.2 Material

146.3 Accessories

157AGITATOR

158ACCESSORIES

159REVISION HISTORY

1OBJECTIVES & MAKING1.1Objectives

This Guide explains technical specification that need in Boiler feed Water Chemical Treatment's Data Sheets creation by Data Sheet Format, and can filled-up correctly through standardization at data sheets and save time.1.2Complementary PointThis Guide is applied chemical agent to present immediately by producing. But in most cases, chemical agents vendors make complexes of several same kinds of materials according to their light. Therefore, we need preliminary consultations with vendors in choice of final chemical agent. Moreover, because medicines processing is marching by tending to minimize waste water regarding the final pollution problem, it will make up for processing by using newest tendency and Vendor Data.

1.3Making

Write position of Data Sheet Format on left side and find easily explaining on right side.

- Example: [1-2]: second row in first data sheet

: left side of 12th row in second data sheet

- Description: start to right of line no.

Data Sheet of Boiler Feed Water's chemical treatment can divide by

Scale Control, Corrosion Control, and Condensate Treatment greatly.2COMPONENT OF CHEMICAL INJECTION2.1Scale Control

2.1.1Phosphate Control (Fig. 1.1)

Ca, Mg in Boiler evaporation surface is not baking and these salt as insolubility sludge settlement derive, and can remove by Blow-Down keeping in melting state.

Because phosphate settlement does not get up well in pH 9.5 low, constant alkalinity is required.Conventional Phosphate Control (Caustic Based Control) By keeping Free Caustic of constant concentration, make sludge, liquefy Silica and protect Carry-Over. PO4's remaining concentration is 10 - 40 mg/ls, alkalinity is 100 - 350 mg/l NaOH (PH 11.4 - 12).It is applied to Boiler lower than 600 psig, and is used widely because processing is simple.- Coordinated Phosphate-PH Control (Fig. 1.2)

Phosphate concentration is keeping 3Na/PO4 ratio by method to control PH with phosphate sodium without using caustic soda. It is applied that operating pressure is 1000 - 1500 psig low.

- Congruent Phosphate Control (Fig. 1.3)

Because Hide-Out phenomenon occurs and picks up 'Gouging Attack' of glass caustic soda as for 3Na/PO4 ratio over 1500 psig, PO4 concentration keeps by 2.6 Na/PO4s ratio in 2 - 20 mg/l extent.

2.1.2Chelating ControlBecause Chelating Agent (Chelant) occurs soluble reaction product by chemical reaction with metal ion, it be not deposited on the Boiler evaporation surface and increased Boiler efficiency and Reliability. EDTA and NTA are used representatively.

1) Use extent- Low hardness (below 1 ppm) of make-up water applies and high hardness (over 2 ppm) is not economical.

- Usually, NTA below 900 psig, EDTA below 1200 psig is applied. (Table 2-1)

The following table shows the reaction ratio in parts per million for technical grades of EDTA and NTA.

FOR. 1 PPM IT TAKES METAL ION PPM 100% EDTA 38% EDTA* 100% PPM NTATotal Hardness (10) 2.75 Calcium 9.5 (25) 6.9

Magnesium 15.8 (41.6) 11.45 Iron 6.8 (17.9) 4.9

Copper 6.0 (15.8) 4.3

Aluminum 14.1 (37.1) 10.0

*Commercial grade EDTA is marketed as 38% solution, but some suppliers may have different strengths.

2.1.3Organic Agents

If Ca, Mg salts is made sludge by phosphate process, it be can removed by blow-down without sticking on metal surface as keeping by fluid form using organic matter. Organic matter is Tannin, Lignin, starch, seaweeds etc.2.2Corrosion Control

2.2.1PH ControlCaustic soda (NaOH) and soda ash (NaCO3) are used by counteragent.

2.2.2Removal of Dissolved OxygenAfter it is removed to 0.005 mg/l by De-aerator, remained O2 is removed by chemical agents.1)Sodium Sulfite (Na2 SO3)

It is used below 900 psig and Hydrazine is used over 900 psig. It is not used in case Sulfur picks up Catalyst fouling.

- Reaction

1/2O2 + Na2SO3 -----> Na2SO4.

3Fe2O3 + Na2SO3 -----> 2Fe3O4 + Na2SO4- Reaction rate

It can decreased reaction time using recently developed Cobalt catalyst.

2)Hydrazine

It does not increase Boiler Water's Solid than Sulfite and need not to Boiler Blow-down.- Reaction

N2H4 + O2 --------------> 2H2O + N2 It is very slow reaction than Sulfite.

2.3Condensate Return Line Corrosion Control

Soluble O2, CO2 in steam condensation cause corrosion. Among them, CO2 create carbonate in water and increase corrosion under PH 5.9.2.3.1PH Control

1)Neutralizing Amine

As acting directly with coal mine and it is volatility alkali material that raise PH. Morpholine (C4H9NO), Cyclo Hexylamine (C6H13N), DEAE (Di-Ethyl-Amino Ethanol, C6H15NO) etc. are used.

- Distribution Ratio (DR)

As CO2 is carried with steam, neutralizing amine be must distilled steam. Also, it must be able to neutralize carbonic acid by CO2 of team condensation because is melted at steam condensation. Distilled tendency is described separation ratio when steam is condensed.Amine concentration in vapor amine concentration in steam DR = ---------------------------------------- = ------------------------------------------- Amine concentrationin liquid amine concentration in condensate (Table 4-1)2.3.2Ammonia

When there is not damage in ammonia steam process with condensate water polishing unit, it is decreased to use them than to use volatile amine. But it is economical to use condensate water for PH control.

2.3.3Film Protection

1)Filming Amine

- By chemical agent to keep corrosion prevention over coating, systems to leak amount of air or included much CO2 is used filming amine or inhibitor.

- Must not use in system to happen Catalyst Coat.

- There are Octadecylamine (C18 H37 NH2), Hexadecylamine (C16 H33 NH2), and Dioctadecylamine (C36 H73 NH2) etc.- Injection agent is injected slowly by small quantity and is not proportional in CO2 concentration.

Because it is formed very thin film, it does not disturb electric heat and improve electric heat to cause drop wise condensation.

2.4Chemical Agent Injection PlaceMost chemical or organic matter is continuously fed into pump, it does not make a problem, but phosphate processing can make a problem in supply line.- Phosphate Soda: Directly injected boiler drum. Only, Hexametaphosphate can be injected in supply line.- Caustic soda, soda ash: Supply line. Only, injected in Boiler drum if BFW is high hardness, temperature, pH.- Organic sludge controller: Supply line. or Boiler drum- Chelants: Use Sus Quill between BFW Pump and Boiler Drum but avoid to inject in Boiler Drum

- Amine & Ammonia Steam header/BFW Line (Boiler input)3SELECTION OF CHEMICALS & INJECTION POINTRecord decision in [1 - 12] [1 - 25] by Item.4INJECTION LIQUID4.1Dilution

Used dilution (Wt %) is as following. Chemical Injected dilution Agent specification

Phosphate soda 1.0 - 3.0 % KS

Caustic soda 1.0 - 3.0 % KS

Hydrazine 0.5 - 3.0 % 35-60% solution,

over 99.9% Ammonia 1.0 - 3.0 % 5-25% solution, over 99.9%

Neutralizing Amine 40% solution

Sodium sulfite KS

4.2 Vapor Press

Usually, because dilution by water is high, steam pressure at operating temperature (1030) almost ignore. Specially, neutralization amine with low flash point and hydrazine are used solution without Flash Point, (each under 40%, 35%)4.3 Viscosity

5INJECTION PUMP5.1 Required No.Establish supply Unit (tank, pump, connection pipe laying, chief) by each chemical agent, and establish supply pump by each boiler in case of phosphate soda. And establish a Common Stand-By pump per a Unit.5.2 Capacity (L/hr)The following is Nor. Capacity. Explain and decide to take into account extra margin 200%.5.2.1Scale Control 1) Injection of Sodium Phosphate (tri-Phosphate)The injected amount is sum of phosphate soda amount and phosphate amount in Blow.- Molecular formula: Na3 PO4 12H2O [MW=380]

380- W (g/HR) = P B + 2.28 H F

95

380 1

PPM req'd = P + 2.28 H

95 N

W = Injected amount, P = PO4 concentration in boiler [ppm]

B = Blow amount [T/H], N = F/B. Concentration Cycle

F = Feed Water [T/H]*1. Actual used amount becomes different according to crystal water of phosphate.*2. Form of settlement is Ca3 (PO4) Ca (OH) 2, ratio of phosphate for hardness ingredient

380 2

1.2 = 2.28

100 (3+1)

2) Injection of Sodium Phosphate (di-Sodium Phosphate)

- Molecular formula: Na3 HPO4 12H2O [MW=380]

358

- W (g/HR) = P B + 2.15 H F 95

3) Injection of poly Sodium Phosphate (hexa-meta-Phosphate)

- Molecular formula: (NaPO3)6, MW = 612

612 612

- W (g/HR) = P B + H F

570 N 1000

612/6 2 612

*3. 1.2 =

100 4 1000

4)Chelant-The injection amount is decided concentration, ph, temperature, used Chelant's reactivity.- EDTA of 1mol reacts with metal of 1mol and inject to 1 - 2 ppm excess amount to necessary Chelant (table 2 - 1) by Feed Water. Over dosing brings Boiler Metal's loss.

5) Organic Agents

5.2.2Corrosion Control

1) NaOH

Because NaOH is not evaporated by Steam, amount which NaOH is lost by Blow-Down. W [g/H] = 0.91 [CO2] F

[CO2]: ppm concentration, F: Feed Water [T/H]

2)PH control agent

Can find from NaOH suitableness amount (Equivalent NaOH Quantity).( table 3-1 )

Na2 CO3 1/4.5, SO3 1/2.85

Na2 SO3 1/4.5, CO3 1/2.55

Na3PO4 12H2O 1/15, PO4 1/3.75

3)De-oxidant, Na2 SO38 - 10 ppm per oxygen 1 ppm is required and the injection amount originates to Blow-Down by request remaining excess concentration. W = B [SO3] 1.6 W: used Amount (g/H)

B: Blow-Down (T/H)

Boiler pressure concentration limit SO3

0-600 psig 30-50 ppm SO32-

600-900 psig 10-20

900 psig 4-6

4)De-oxidant, Hydrazine

1ppm per O2 1 ppm requires theoretically but 1.5 - 2 ppm is applied actually. BFW's remaining concentration limit is 0.05- 0.1 ppm. 50

W = [O2] 2 F (g/H) or

32

50

W = ([O2] + [N2H4] F

32

Pure material can not use because of low flash point, use 35% solution without flash point.5)Neutralizing Amine

Volatility amine makes neutralization product by reacting with CO2 and later CO2 is recovered in circulation cycle because drop in Deaerator if is heated, but recovery rate is different by distribution ratio of used amine and operating condition of deaerator. That is, recovery rate of Morpholine (DR = 0.4) is high and that of Cyclohexylamine (DR = 2.0) is low because of loss in apparatus for excluding air. The inject amount is decided according to necessity density (picture - reference) and the recovery rate in boiler drum. The inject amount is calculated by amount to neutralize CO2 of condensate water and keep fixed request pH in a boiler drum.

- Used concentrationBecause of danger of fire, used 40 % solution.

EMBED hunmin.doc Fig 5.1 pH vs., Amine/CO2 Concentration Fig 5.2 pH vs., Amine Concentration6)Ammonia

When reclaim and reuse condensate water, ammonia of about 70% is lost in De-Aerator.

7)Filming Amine

Injection is slowly by small amount and is not proportional in CO2 concentration.

5.3Capacity Control

5.3.1Stroke Adjustment

It is used most usually by method to control flux controlling Stroke's length.5.3.2Speed Control

It is used when wish to control correct flux in all range(0 ~ 100%) adjusting Motor's rotations by VVVF using Inverter. 120 F

rpm = , F : frequency (ex : 60HZ)

P P: pole (ex: 4 poles)5.3.3Capacity Control RangeDo 0100 % to principle but promise accuracy in 10100 % ordinarily in case of Stroke control.6SOLUTION TANK6.1Capacity

Chemical agent tank establishes one by one per chemical kind and makes capacity can possess during about 3 days.6.2 Material

Material is Stainless Steel ordinarily.

6.3 Accessories

6.3.1Level Gauge & Alarm

Attach seeing through or reflection surface (Level Gauge) on each tank, and low level alarm must ring to central panel.6.3.2Floating Cover

Do to minimize evaporation of volatility material with Hydrazine, Ammonia and Amine, and intercept surface with air always as establish to keep away air contact of deoxidizer (hydrazine, Sodium Sulfite).6.3.3Steam Heater

Establish for keeping proper temperature of chemical agent.6.3.4Measuring Cup

It is small size tank having making scale that installed on top of main tank and used to add measured amount of chemicals to main tank.6.3.5Inner Basket

Establish into tank upper part side to elutriate Over-Size's lump when chemical agent is injected on main frame, and attach Opening Cover.6.3.6Steam Bubbling Pipe

Establish Agitator in phosphate and sulfuric acid tank for powder solid to melt easily.7AGITATOR

It is used to liquefy Phosphates and Na2 SO3.8ACCESSORIES9REVISION HISTORYRevDatePageRevision Status

006.08.23All- Team : Process Eng'g Team

- Made by : J.W. Lee- Checked by : J.C. Ro, E.D. Lee, Henry Sung, B.S. Son

- Approved by : C.S. Jung

APPENDIX 1

DATA SHEET FORMATAPPENDIX 2

SIMPLE DATA SHEET

SAMSUNG ENGINEERING CO., LTD.

SAMSUNG ENGINEERING CO., LTD

SAMSUNG SEI TOWER, 467-14 Dogok 2 Dong,

Kangnam-Ku, Seoul, KOREA 135-280

DESIGN MANUAL

SEM-9486E

PROCESS DESIGN MANUAL

Preparation of Datasheet

for Boiler Feed Water Chemical Treatment

REV. : 0

DATE : 2006.8.23

PAGE

_1218350688.bin

_1224938552.bin

_1218350674.bin