Addressing Boiler Water Problems Before They Startcleaverbrooks.com/reference-center/resource-library/webinars/2016... · • Water hammer can destroy piping ... • Light scale in

Addressing Boiler Water Problems Before They Start

Presented by Cleaver Brooks’ Steve Connor& Bill HookeNovember 30, 2016

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TODAY’S TOPICS

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• A review of the key take-a-ways from last month’s session

• What causes boiler water level fluctuations

• The dangerous side of carryover

• The causes and costs of pressure vessel failure & repair

• The causes and telltale signs of system upsets

• Step by step remedy process

• Choosing a qualified water treatment consultant

• Summary & questions

WHAT NEEDS TO BE REMOVED

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• Dissolved Minerals• Hard Scale Formers

• Calcium• Magnesium

• TDS• Calcium (Scale)• Magnesium (Scale)• Sulfate (Instability)• Iron (Scale)• Silica (Deposition)• Chloride (Instability)• Alkalinity (Foaming)

• Dissolved Gas• Free Oxygen (Corrosion)• Free Carbon Dioxide (Corrosion)

Waterside Scale

Waterside Corrosion

Like what?Carryover• Sink & swell• Foaming & priming

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Sink and Swell

Pump on/off

NormalLow waterHigh water

Carryover

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Foaming & Priming

Steam Outlet

Level Control/Sensor

Lose steam energy efficiencyDamage equipmentIncreases water hammer possibility

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Condensate & Carryover Formation

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Steam Velocity 70 – 100 MPH

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Steam pipe Water Hammer!

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BANG!

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“We thought it was another 9/11 terrorist attack!”

New York CityMidtown ManhattanJuly 18, 2007

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OK, how do I diagnose water hammer?

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Listen Observe

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Waterside Scale

Waterside Corrosion

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PREVENT SCALE FORMATION


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Waterside Scale

Waterside Corrosion

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OXYGEN PITTING ONFIRE TUBE BOILER

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OXYGEN CORROSION

TUBE FAILURE!!

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Stress Relieving

Welding Repair

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Downtime Costs

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Bill Hooke 27

Water TreatmentUnderstanding the Basics

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1. Controlled the hardness and iron entering the boiler

2. Maintained the Plant specific Boiler chemistry:• Conductivity• Alkalinity • Sludge Conditioner

MINIMIZED POTENTIALFOR SCALE

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Inspections tell the story.

MINIMIZED POTENTIALFOR SCALE

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HOW CAN THISHAPPEN?

• Check the softener/ pretreatment• Especially at the end of cycle

• Confirm Testing of:• Feedwater: Hardness, iron• Boiler: Sludge conditioner,

Alkalinity, Conductivity

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Otherwise you can have this….

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Light scale (egg shell depth or less)30 years ago, engineers liked a bit of scale

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1. Minimized the oxygen entering the boiler2. Maintained the oxygen scavenger in the boiler

• ALL THE TIME!

PREVENTED BOILERCORROSION

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Whenever the boiler is opened for inspection, check for oxygen pitting.

INSPECTION:GIVES REPORT CARD

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If there are insufficient residuals of oxygen scavengermaintained in a boiler, this can happen.

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1. Maintain the oxygen scavenger in the boiler ALL THE TIME

2. Testing confirmed scavenger residual when running or idle

PREVENT BOILERCORROSION

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Minimized the carbon dioxide generated in boiler.

Reduced potential for H2CO3 Carbonic acid in the returning condensate water.

OUTSIDE THE BOILERPROTECTED CONDENSATE

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1. Employed proper condensate treatment

2. Tested and confirmed pH, iron, hardness and conductivity limits.

3. Kept logs of test results.

4. Test condensate from different areas of the plant, near and far.

PROTECTINGCONDENSATE

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Morpholine – protection near the steam generators

DEAE – Diethylaminoethanol –protection moderate distance from the boiler plant

Cyclohexyalmine – further protection.

Blends often used; testing several condensate sites help determine the best choice for each plant.

Different \ Amines:

PROTECTINGCONDENSATE

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Carbonic Acid Attack…Inspect

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Condensate corrosion with no corrective action results in…

Condensate loss, greater energy loss, more make up.

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CARRYOVER

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CARRYOVER

Effects of priming, carryover and surging:• Boilers can shut down on low water• Water hammer can destroy piping –

Dangerous• Processes can be shut down• Product can be contaminates• Carryover causes more carryover

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CARRYOVER

Possible causes:• Pressure drop• Water level issues• Contamination• Chemical Feed

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• Drop in Pressure

20 psi Temperature , 259° F

CARRYOVER -PRESSURE DROP

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Drop in Pressure• Sudden demand

259° F

Now, only 10 psi, and water boils at 239°

CARRYOVER -PRESSURE DROP

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Want to peel a lot of potatoes?

CARRYOVER - EXAMPLEPROCESS DEMAND

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Solution to potentially appalling potato peeling problem?

Three element feed/forward level system.

When the peeler is ready to call for steam, feedwaterpumps pre-emptively begin feeding feedwater to boiler prior to water level control signal.


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CARRYOVER FROM CONTAMINATION

Contamination:• Oil• Process Side• CIP Chemicals• Hardness

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Overfeed of Treatment Chemicals High ConductivityHigh alkalinity

Sudden surge of suspended solidsHardness, chlorides

CARRYOVER -CHEMICALLY CAUSED

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Large feed of amine to the boiler Amine(s) vaporize at once

Automate feed.

CARRYOVER -OVERFEED OF AMINE

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Review: When does carryover occur?• Drop in Pressure

• Sudden demand?• What is happening?

• Check condensate for source• When equipment is cleaned• After ‘break’, early morning• Was chemistry in system

out of range?

Look for boiler chemistryin condensate, normally not far from the boiler room.

CARRYOVER SOLUTIONS

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Conductivity = 3500

Conductivity = 100

Contamination• Carryover from any cause will

contribute to more carryover

35 Cycles

CARRYOVER

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Conductivity = 3500

Conductivity = 700

Contamination• Carryover from any cause will

contribute to more carryover

5 Cycles

CARRYOVER

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Dump feedwater and/or contaminated condensate to slow carryover and replace tainted water with fresh make up.

• If oil is contaminant, maintain high OH alkalinity to tie up oil.

CARRYOVER -SOLUTIONS

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TESTINGIMPORTANCE OF LOG KEEPING

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Make up water-pretreated

• Hardness• Conductivity• Water meter Track

Feedwater • Hardness 0• Conductivity Record• Alkalinity • Water meter Track • Iron 0


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Be on lookout for changes and upsetsThink “Cause & Effect”


Monitor and record boiler (minimum):• Conductivity (neutralized)• Alkalinity• Sludge conditioner (residual & inventory)• Oxygen Scavenger (residual & inventory)

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• Identify Control limits• Maintain Limits

• Make small adjustments to feed and bleed• Record adjustments• Record water use


The program manual by WT provider directs you to what to do.

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Logs help:• Show other operators

actions taken• Track chemical use, prevent

inventory mistakes• Document program

administration/protection


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Define Limits


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Logging plant chemistry provides Better control.

NOTE: Insight into operating changes will Predict & Prevent greater problems


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Notice changes in boiler • Oil in sight glass• Milky look to boiler

• Hardness overwhelms Polymer• OH alkalinity drops

• Make up use change• Condensate / feedwater change

Notice Changes – Confirm, Retest, Explore


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1. Tests are done2. Trending is moving outside

of prescribed limits3. Notice this and…

MAKE AN ADJUSTMENT!!

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BOILERLAY UP

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WET OR DRYBOILER LAY UP

Wet Dry

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Wet Lay Up


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Wet Lay Up

Maintain:• Sulfite – 100 ppm• P Alkalinity – 400 ppm


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Wet Lay Up

Maintain:• Sulfite – 100 ppm• P Alkalinity – 400 ppm

Warm boiler to circulate chemicals and insure protection.

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Dry Lay Up

Desiccant Tray


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Dry Lay Up


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Which is better, wet or dry?

BOILERLAY UP

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Wet• Quick Turnaround• Need to warm

regularly• Cascading bd• Circ. pump

• Maintain water level• Leaky header

Dry• Longer turn around to

fire• Header must be closed!!• Long term lay up• Seasonal lay up


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CHOOSING A WATERTREATMENT SUPPLIER

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What are your needs?

Inspections?


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How you will evaluate the supplier? Experience –

Do they have depth?How many years does the individual or company have in the field?Can they respond in timely fashion?Is the rep worthy of your business?


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How will you evaluate the supplier?Education –

Does rep have significant education in related field? Do they have experience and aptitude? Certified Water Technologist (CWT)?


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How will you evaluate the supplier?Expertise –

Does rep have knowledge of your system or problem?Can they share a similar application they’ve encountered?


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How will you evaluate the supplier?Costs –

Does the rep understand the cost for a barrel of chemical is unrelated to cost for competitor’s barrel of the ‘same’ stuff?

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Inspections


How will you evaluate the supplier?Costs –

Does the rep realize that cost of chemicals represents a small percentage of operating utility?

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How will you evaluate the supplier?Product Handling –

• Options for product handling?• Hands free?• Powder/liquid?• Solid?

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TODAY’S TAKE-A-WAYS

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• A sound water treatment program is one which uses both mechanical and chemicalmeans.

• Bouncing water line in the boiler can be both system and water composition induced.• Most often it is system related involving sudden pressure drops. • A three element feedwater system can help solve sink/swell problems in the boiler.• Sink/swell, foaming and priming can lead to carryover which can lead to water hammer.• Water hammer is NOT NORMAL! It MUST be remedied!!• Important to check for corrosion and scale and if evidence, check your log against that

of the water treatment professional you have engaged.• Regularly documenting The Chemical Log Book is essential for a reliable program.• Light scale in or on boiler tubes is no longer considered wise for boiler protection. • Look for evidence of boiler chemicals in the condensate. Could be sign of Carryover• Laying a boiler up Wet or Dry is largely dependent on the amount of time the boiler will

be off line.• The key factors to consider when choosing a reputable water treatment expert are

Education, Expertise and Cost.

Steve ConnorConsultant: Marketing & [email protected] 377- 6347

QUESTIONS?

Bill HookeWater Treatment ConsultantChemtex [email protected]

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mailto:[email protected]

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Documents

Addressing Boiler Water Problems Before They Startcleaverbrooks.com/reference-center/resource-library/webinars/2016... · • Water hammer can destroy piping ... • Light scale in