Types of Concentrates (Water Additives)

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Transcript Types of Concentrates (Water Additives)

Types of Concentrates (Water Additives)

Foam Concentrate - Water Additives

Wetting agents Not to be mistaken for Class A concentrate

Class A foam concentrate

– Class A Foam •

Class B foam concentrate

– Protein & Film Forming Fluoroprotein (FFFP) – – Aqueous Film Forming Foams (AFFF) Alcohol Resistant-AFFF (AR-AFFF) •

Emulsifiers / Spill response agents

Gels

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• • • •

Concentrate Usage Class A foam

(Proportioned 0.1-1.0%) – Wood, paper, tires, any Class A combustible – Effective in initial attack, overhaul, mop-up and exposure protection – Does NOT affect application rates or manpower requirements

Class B foam

(Proportioned 1.0-6.0%) – Hydrocarbons and polar solvents

Emulsifier/Spill response agent

(Various rates) – “Fuel neutralizer” and hydrocarbon recovery

Gel

(Various rates) – Exposure protection 14

Class A Foam

Class A Foam Characteristics Finished foam

adjusted by concentrate percentage

using the proportioner

Wet 0.2% Fluid 0.5% Dry 1.0% Overhaul Initial Attack Exposure 16

Wet Foam At 0.2% - Overhaul

Small bubble structure and quick drain time 17

Fluid Foam At 0.5% - Initial Attack

Medium bubble structure and slower drain time 18

Dry Foam At 1.0% Exposure Protection - Long Lasting

Produces a dry foam blanket with a very slow drain time 19

Foam Properties

Expansion ratio

– Volume of

finished foam solution

to volume of

foam

– Hose-end appliance dictates expansion ratio –

Based on amount of air introduced

– – – Low Expansion Medium Expansion High Expansion 1:1 - 20:1 20:1 - 200:1 200:1 + 20

Exterior Low Expansion Application

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Medium Expansion Foam

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High Expansion Foam

High expansion generator Flowing down a hillside 23

The Value Of Using Class A Foam Improves Fire Fighting Effectiveness By 2 To 4 Times

Salem Tests Fire Engineering, February 1993 Temperature drop from 1,000 ° F to 212 ° F, at a four foot level

250 200 150 100 50 0

Water Water:

223 Seconds

Foam:

103 Seconds

CAFS:

39 Seconds

Foam CAFS

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Dr. Holger de Vries (Germany) Fire Chief Magazine, August 1999

Crib burn - controlled test conditions

– Class A foam vs. plain water – 40% less solution than plain water – 43% less

extinguishing effort

than with plain water (extinguishing agent volume x time to extinguish) •

Conclusion

– Reduced exposure to hostile environments and

improved fire fighter safety

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Palmdale Study Fire Chief Magazine, August 2001

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Palmdale Study

L.A. County Fire Dept. scientifically conducted tests to compare effectiveness of:

– – – Plain water Foam solution Compressed air foam •

Temperature readings obtained via wall and ceiling mounted thermocouples at one foot increments

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Palmdale Study

Three identical 1100 sq./ft. homes and contents

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Critical Application Rate

The IOWA formula was used to calculate flow rate

Cubic Feet Involved 100 = GPM 9,075 100 = 91 30

0:57 0:50 0:43 0:36 0:28 0:21 0:14 0:07 0:00

Knockdown Time Results Water Foam CAFS Extinguishment Medium

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Water:

50 seconds

Foam:

25 seconds 50% better than water

CAFS:

11 seconds 78% better than water 66% better than foam

Gallons Required To Knockdown

40 30 20 10 80 70 60 50 0

Water Foam Water:

73 gallons

Foam:

44 gallons 40% better than water

CAFS:

16 gallons 79% better than water 64% better than foam

CAFS Extinguishment Medium

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350 300 250 200 150 100 50 0

Total Gallons Used Water

After 225 gallons, IC ordered foam to aid overhaul

Water:

320 gallons

Foam:

95 gallons 71% better than water

CAFS:

45 gallons 86% better than water 53% better than foam

Foam CAFS Extinguishment Medium

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Time To Cool: 600°F To 200°F

7:12 6:00 4:48 3:36 2:24 1:12 0:00

Water Water:

6:03 min

Foam:

1:45 min 71% better than water

CAFS:

1:28 min 76% better than water 17% better than foam

Foam CAFS Extinguishment Medium

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Total Foam Concentrate Used

35 30 25 20 15 10 5 0

Foam CAFS Concentrate Cost:

$15/gal

Foam Solution:

31 oz = $3.63

CAFS:

5.8 oz = $0.68

Extinguishment Medium

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What These Tests Prove

• •

Naturally aspirated foam (NAF) beats water

– – – – Time to knockdown Gallons to knockdown Total water used Cooling

Compressed Air Foam beats NAF - in all categories

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Why Does Foam Work?

Smaller droplets – faster heat absorbtion

Reduces surface tension – penetrates and wets fuel

Foam blanket – provides protection

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Water And Class A Concentrate

Surface tension causes water to bead up on fuel…

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Water And Class A Concentrate

Add Class A foam to plain water… solution spreads and penetrates the fuel…

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Water And Class A Concentrate

Chance of rekindle lessens with Class A solution

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Give It A Try

• • •

Place a small drop of plain water on piece of corrugated cardboard (Note: it maintains beaded shape, caused by surface tension) Place a small drop of soapy water next to it (soap is a surfactant similar to Class A) Which would provide better extinguishment and have less runoff?

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Why Use Water Additives?

CAFS Foam Water Typical Fire Curve Time

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Class A Foam Applications

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Fire Reported!

• •

1890’s brick schoolhouse

– 4 miles outside of town – No hydrants

First pumper on scene

– 6 minute response – 750 gallons of water – FoamPro 2001 44

Fire Knocked Down!

• •

Initial attack

– – – 2 1/2” line 328 gpm 0.5% Class A foam

Knockdown

– – 6 seconds 33 gallons of water – 0.17 gallons of Class A foam concentrate 45

Effectiveness On Tire Fires Tire Fire Plain Water

Class A foam: – 60 gpm @ 0.5% – Medium expansion – 20 minute knockdown

Tire Fire Class A Foam

Water: – 750 gpm supplied by: – Two 2 1/2” – Two 1 3/4” – No effect 46

Fully Involved Garage!

Class A foam attack - 125 gpm at 0.5% 47

Garage After 35 Second Attack

NOTE: Lack of smoke; ability of Class A foam to bond with carbon 48

• • •

Structural – Exterior Attack

200

'

x 24

'

x 35

'

wood frame structure Attack with single 1 ½

"

CAFS line with 1

"

Approximately 50 gpm, 20 cfm at 0.5% tip

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Structural – Exterior Attack

Exposure on left protected with foam CAFS attack begins 50

Structural – Exterior Attack

CAFS attack continues 51

Exterior Structure Attack with Low Expansion CAFS stream

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Benefits Of Class A Foam To The Department

• • • • •

Improves firefighter safety Increases efficiency of plain water 2 to 4 times Faster fire knockdown Reduces heat rapidly Reduces property damage

• • • • • •

Reduces overhaul Fewer rekindles Exposure protection Preserves evidence Faster cleanup Reduces on scene time

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Points To Ponder

Immediately reduce your fire losses by 50 to 75% … just by implementing Class A foam or CAFS.

What other initiative would have as significant an impact for your department?

If this is not a top priority for your department, why not?

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Class B Foam & Emulsifiers

Class B Foam

• • • •

Designed to form a film and seal vapors Applied at 1%, 3%, or 6% per foam manufacturer Polar solvents require alcohol resistant (AR) foam Multi-use foam can be used on both

– Concentration ratios are 1%x3%, 3%x3%, and 3%x6% (second percentage for polar solvents) 56

Class B Foam

Fuel must be contained to form film 57

Containment Challenges

Training

Real life

– If no containment: – No film forming seal – Then alternatives are: – Class A foam – Emulsifiers 58

Types Of Class B Concentrate

• • •

Film Forming FluoroProtein (FFFP) Aqueous Film Forming Foam (AFFF) Alcohol Resistant-Aqueous Film Forming Foam (AR-AFFF)

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Film Forming FluoroProtein (FFFP)

• •

Capabilities:

– Biodegradable – Excellent fuel shedding – Long lasting foam blanket and high burn-back resistance

Limitations:

– Requires aspiration – Used at ratios 3% or 6% – Poor at flowing and wetting (messy and smelly) 60

Aqueous Film Forming Foam (AFFF)

• •

Capabilities:

– Does not require specialized delivery equipment – Fluid foam that spreads across the fuel surface – – Quick knockdown Long shelf life in original sealed container (unopened)

Limitations

: – Fast drain time – – – – Limited burn-back resistance May be hazardous Storage and shelf-life once original container is opened Use only on hydrocarbons at 1%, 3% or 6% ratios 61

• •

Alcohol Resistant-Aqueous Film Forming Foam (AR-AFFF) Capabilities:

– Multi-use fuels (Hydrocarbons/Polar Solvents) – – Excellent burn-back resistance and stable foam blanket Long shelf life in original sealed container (unopened)

Limitations:

– – – – – Does not require aeration delivery equipment Viscous liquid difficult to premix May be hazardous Storage and shelf-life once original container is opened Used at 3% and 6% ratios (Multi-use 1%x3%, 3%x3% or 3%x6%) 62

What To Consider -“B” Concentrates

• • • •

Cost of solution vs. concentrate

– Your application – hydrocarbon or polar solvent

Shipping, storage and handling

– – Significant logistics improvement with lower ratios Given storage capacity - added protection

Mutual aid Proportioning system

– Higher concentration ratios require larger systems – Lower concentration ratios require high accuracy 63

Do Not Mix Class A & B Foam

Result of mixed foam (in strainer)

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Emulsifiers / Spill Response Agents

• •

Capabilities:

– – – Non-toxic and biodegradable Long term vapor suppression Aids in hydrocarbon recovery

Limitations:

– – Limited extinguishing potential Application rates vary with products-high cost – – – Application by volume not by percentage Not compatible with Polar Solvents No approval process or recognized performance standard 65

Gel

• •

Capabilities

– – Excellent insulator Long term exposure protection

Limitations

– Limited extinguishing potential – – – High cost May cause slippery work areas Solution viscosity very high-most products require hose end eductor – No approval process or recognized performance standard 66

Extinguishing Agent Synopsis Extinguishing Agent Water Wet Water Class A Foam AFFF AR-AFFF FFFP & AR-FFFP Emulsifier Gel CHARACTERISTICS Fuel Class Usage A A A B B B A A Ability to Wet Ability to Foam Ability to Insulate Affinity to Carbon Indifferent to Carbon Reacts with Fuel

Poor Average Excellent 67