830 likes | 841 Views
Ethanol… The New Hazard In Town. Part II: Foam Delivery Bill Ballantyne. What Municipal Fire Departments Typically Prepare For…. Our Logic…. 97% of the fires we encounter are Class A fuels – so carry Class A foam For the occasional Class B fire:
E N D
Ethanol…The New Hazard In Town Part II: Foam Delivery Bill Ballantyne
Our Logic… • 97% of the fires we encounter are Class A fuels – so carry Class A foam • For the occasional Class B fire: • Use Class A at 1% - BUT know there is no sealing capabilityor… • Call in the local ARFF truck for mutual aidor… • Let it burn
With Ethanol That Logic No Longer Applies • Use Class A at 1% - BUT know there is no sealing capability • Class A foam does not work on Ethanol • Call in the local ARFF truck for mutual aid • The ARFF truck only carries AFFF, which also does not work on Ethanol • Let it burn • Dept of Homeland Security has stated the need to protect critical infrastructure…highways, bridges, railways, ports, etc.
So What We Really Need Is… • Class A capability for the majority (97%) of the fires we encounterAND… • AR-AFFF capability for Ethanol fires
The only concentrate effective on Ethanol fires Foam Concentrates - Water Additives • Wetting Agents • Class A Foam • Class B Foam Concentrates • Protein & Film Forming Fluoroprotein (FFFP) • Aqueous Film Forming Foams (AFFF) • Alcohol Resistant-AFFF (AR-AFFF) • Emulsifiers / Spill Response Agents • Gels
Proportioning Rates • Ratio of concentrate to water • Expressed as a percentage • 1.0% = 1 unit of concentrate to 99 units of water • 3.0% = 3 units of concentrate to 97 units of water • 0.5% = 0.5 unit of concentrate to 99.5 units of water
Common Proportioning Rates • Class A • 0.1% - 1.0% • Class B • 1%, 3%, 6% • (1% x 3%), (3% x 6%), (3% x 3%)(Hydrocarbons x Polar Solvent fuels) • Emulsifiers / Gels • Varies by manufacturer / usage
Do Not Mix Class A & B Concentrates • Result of mixed concentrates (in strainer)
6% Allowable Range: 6%: 6.0 – 7.0% 3%: 3.0 - 3.9% 1%: 1.0 – 1.3% 0.5%: 0.5 – 0.70% 0.2%: 0.2 – 0.28% 3% Lean Rich 1% + - 40% 30% 30% 20% 10% 10% 20% NFPA 1901 Now Requires… • For proportioning rates equal or greater than 1%: • - 0% to + 30% or 1 percentagepoint, whichever is less (21.10.2) • For proportioning rates less than 1%: • - 0% to + 40% (21.10.1)
Why Is Accuracy So Important? • Performance • Ability to make wet, fluid or dry foam (Class A foam) • Ability to richen for heavy rain (Class B foam) • Ability to seal (Class B foam) • Logistics • Cost • Environmental Concerns (Class B)
What Is The Cost Of Inaccuracy? • Let’s assume: • $20 per gallon for concentrate • 5,000 gallons per minute flow rate • 3% proportioning rate • 10% inaccuracy rate
The Cost Of Inaccuracy Becomes: • The logistics of wasted foam: • 15 extra gallons per minute • 900 extra gallons per hour • 9,000 extra gallons per 10 hours • The cost of wasted foam: • $300 per minute • $18,000 per hour • $180,000 per 10 hours
Let’s Look At BIG WATER • Now assume: • $20 per gallon for concentrate • 20,000 gallons per minute flow rate • 3% proportioning rate • 30% inaccuracy rate
Now, The Cost Of Inaccuracy Becomes… • The logistics of wasted foam: • 180 extra gallons per minute • 10,800 extra gallons per hour • 108,000 extra gallons per 10 hours • The cost of wasted foam: • $3,600 per minute • $216,000 per hour • $2,160,000 per 10 hours
What Is The True Cost Of Your System? $ Initial Cost+ $ Ongoing Operational Costs$ True Total Cost
For Your Consideration • Different Initial and Ongoing Operational Costs • Different performance capabilities and limitations • Equipped to consider the total picture
Application Rates • A measure of foam solution, applied per unit of time, per unit of total area • Typically expressed as GPM/Sq Ft • Or, LPM/Sq Meter • Not to be confused with proportioning rate • Expressed as % concentration
Tank Fires – Fixed Roof (Full Surface)NFPA 11 – 2005 (5.2.5.2.2)
Tank Fires – Full Surface (Type III)NFPA 11 – 2005 (5.2.4.2.2)
Tank Fires – Full Surface (Type III)Over 60 foot diameter - Recommended
Tank Fires – Seal Area (Floating Type)NFPA 11 – 2005 (5.2.4.2.2)
NFPA 11 Standards Are MinimumsDesign To Succeed • Flow Rates • At least times 2 or more (especially with Ethanol) • Flow Durations • Enough water and concentrate to flow at least 50% longer than the time specified • Bigger Is Better • One large nozzle generally is more effective than several smaller ones of equal combined flow
Required For Ethanol Fires Example Pre-Plan (Spill Area)Foam Requirements
What IsRealistic Example Pre-Plan (Spill Area)Foam Usage Rate
Foam Pick-up Tubes Or Stingers Foam Supply – 300 Gallon Totes
Note: Portable Pumps Foam Supply – 300 Gallon Totes
Note: Pre Plumbed Foam Concentrate Discharge Manifold Foam Supply – 300 Gallon Totes
Tips For Sizing Equipment • Something is not always better than nothing • The size of the hazard determines the requirements • Size the system to the hazard and size the apparatus to the system • Not the other way around! • NFPA standards are MINIMUM requirements • Design to succeed
Jet Ratio Controllers (JRC’s) • In-line Super Eductors • 60:40 Mix • 60 parts water • 40 parts concentrate • 1-1/2” In / 2-1/2” Out
Foam Mix Injected Here 2-1/2” 60:40 Water/Foam Mix Supply Line From JRC Hot Tip! When setting up – lay water supply first, then foam supply. 2 – 1,500 GPM 5” Water Supply Lines Jet Ratio Controller Layout Note: To make 3,000 GPM foam solution with 3% or 6% concentrate you may need 2 JRC’s feeding this nozzle!
Jet Ratio Controllers (JRC’) • Capabilities: • Can be fairly accurate at a single point • Inexpensive to purchase • Limitations: • Labor intensive to operate • Narrow sweet spot
Foam Tank Concentrate Pump or Metering Valve Pilot-Operated Balance Valve Check Valve Modified Venturi or Ratio Controller (one per discharge) Water Pump Balanced Pressure Pump Proportioners Check Valve