Anatomy of a Fire Douglas Nadeau, MSFPE, PE, CFPS, LEED AP President of RAN Fire Protection Engineering, PC Vice President of truvue Inspection Technology Christopher Crivello, MSFPE, PE Fire Protection Project Engineer at RAN Fire Protection Engineering, PC ccrivello@ranfpe.com 518-275-0791 dnadeau@ranfpe.com 518-275-0791
Agenda Introduction Short History of Fire Protection Fire Dynamics Fire Protection Systems Egress Case Study - Blessings Tavern Fire
Today s Goal Provide the basics of fire dynamics Give reason to Fire protection means more than the Code Look at buildings different tomorrow Learn how fire protection can save your life
Goals of Fire Protection The goal of fire protection is: Protection of Life Protection of Property Continuity of Business Operations
Rules of Thumb Rules of Thumb a procedure or rule based on experience of practice An example is: Loss of 5 psi in water pressure per story of a building If it leaves ash behind it may be a Class A fire
Rules of Thumb Rules of Thumb can and do lead to: Myths Misapplications Bad Decisions
Fire Protection Designs Rules of Thumb
The typical FPE answer It depends
Depends Fire Protection Designs depends on: The building The fire The occupants The fire department The fire protection systems Etc..
Depends Rules of Thumb cannot substitute for: Knowledge of the code Scientific facts Good design decisions Knowing the reason for an action We want to avoid we always did it this way.
Depends leads to Communication Building Owner Architect t Engineer Code Enforcement Officials The Public
How Fire Protection is Perceived There are 3 main classifications of thought in relation to fire protection Code Based Statistics Based Performance Based
Agenda Introduction Short History of Fire Protection Fire Dynamics Fire Protection Systems Egress Case Study - Blessings Tavern Fire
Fire Protection Engineering History To understand the practice of fire protection engineering it is essential to understand its history. A condensed d version is presented here
Derivation of FPE Codes, regulations, and fire departments began after major fires: 1835 New York 1861 London 1871 Chicago 1872 Boston 1906 San Francisco Rules initially from experience of fire fighters, builders, architects, & engineers Little understanding of fire dynamics, structural behavior, and human behavior
Brief History of Fire Protection Fire protection is one of the youngest engineering trades Great London Fire of 1666 - first building regulations 1 st professional fire brigade 1824 (London) Patent for an automatic sprinkler was awarded to Henry S. Parmelee in 1874
Fire Protection 1850-1940 Building separation distances conflagrations Compartmentation Egress travel distances Active systems sprinkler systems Passive systems fire resistance ratings
Brief History of Fire Protection 1896 NFPA formed Discipline i of fire engineering i emerged in the early 20th century as a distinct discipline, i in response to new fire problems posed by the Industrial Revolution
Fires of the 1960s Issues with smoke management Issues with material selection Structural t problems Limited FPE knowledge but more complex buildings False sense of security with codes Codes slow progress of innovation
Today s Codes & Standards Construction is advancing much faster than the codes Construction methods, Size and complexity, Technology, ect Innovation advancing faster than educating engineers ability to use codes & standards Performance Based Designs
Agenda Introduction Short History of Fire Protection Fire Dynamics Fire Protection Systems Egress Case Study - Blessings Tavern Fire
Combustion Process FIRE TRIANGLE FIRE TETRAHEDRON http://svfd.net/svfd%20files/articles/foam/1b1_qr_fire_behavior.html. Retrieved November 30, 2015. Fires can be prevented or suppressed by removing any one of these.
Chemical Reaction A little more on the chemical reaction: To have combustion a chemical reaction between heat, fuel and oxygen Foundation of how fires begin Link
Suppressing the Fire Tetrahedron Fuel remove or shut off a supply Oxygen lower the amount within a compartment Heat cool by applying a suppression agent Chemical Reaction use chemical suppressants or salts
What is a fire? Uncontrolled exothermic reaction C b ti h i l ti Combustion a chemical reaction involving fuel, heat, and an oxidizer
Types of Flames Diffusion flames Premixed flames Link
Diffusion Flames Fick s Law combustion where fuel gas and oxygen are transported to a reaction zone Natural flaming fires are diffusion flames Link
Premixed Flames Mixing of fuel gas and oxygen prior to ignition Controlled example - Bunsen burner Uncontrolled example confined space methane leak Link
Fire Growth A fire grows in a self-sustaining sustaining manner Heat released from a fire is transferred to other nearby fuel packages Fire growth can be predicted within reason
Heat Transfer Combustion gives off heat which can ignite nearby fuels Heat energy always flows from hotter to colder 3 methods of heat transfer Conduction Convection Radiation
Conduction Heat transfer from direct contact
Convection Heat transfer through a fluid such as air or Heat transfer through a fluid such as air or liquid
Radiation Transfer of heat in the form of an invisible energy wave Becomes highly significant at higher temperaturest
Stages of Fire Growth Ignition Established Burning Growth Flashover Full Room Involvement (FRI) Post FRI
Stages of Fire Growth Ignition incipient phase, does not heat up the room Growth (Established Burning) Waste basket type fire that is self sustaining Demarcation between prevention and building fire design Fully Developed enough fuel and oxygen available Decay occurs when all fuel is consumed
Fire Growth Curves Q= t 2
Fire Growth Curve C 1000 Beginbrand Groeifase Volontwikkeld Doven FULL ROOM INVOLVEMENT 800 ESTABLISHED BURNING FIRE GROWTH Flashover POST FULL ROOM INVOLVEMENT 600 400 200 TIME
Terminology 1. Smoke airborne products of combustion in the air 2. Plume column of hot gases, flames, and smoke rising above a fire 3. Ceiling Jet -a flow of smoke under the ceiling
Compartment Fire
Compartment Fire Growth Stage room heats up and ceiling layer development
Compartment Fire Ceiling Layer Development smoke increases, room heats up, negative pressure in room, two layers
Flashover Temperature is about 600 C (1100 F) All materials spontaneously combust Only lasts a few seconds for the transition
Flashover
Rollover (Flameover) Similar to Flashover Usually in large rooms Fire growth between fuel package usually is not because of the upper gas layer development Also known as Spreadover
Full Room Involvement All combustible material in room burns Fire becomes ventilation controlled
Ventilation Fires can be controlled by amount of ventilation As a fire grows, needs more oxygen
Influence of Ventilation Closed compartment might oxygen starve the fire Openings between compartments allows for fresh oxygen New openings can restart a fire
Ventilation Controlled Fire TEMP VENT OPENING TIME
Post Full Room Involvement (FRI) Fuel controlled fire Considered d the decay stage Fire burns itself out
Backdraft Oxygen regulates the fire Fire slows the burning process (produce large amounts of CO) If a vent opens then fire will combust rapidly (CO combines explosively l with O 2 ) Windows blow out Can be confused with an explosion
Backdraft TEMP TIME
Fire Modeling Learn Theory vs. Learning Software Better to learn theory Knowing the theory allows you to use any model Knowing the software gives a false sense of modeling
Computer Modeling Main types of computer models 1. Zone Models 2. Computational Fluid Dynamics Models (CFD) Field Models 3. Evacuation Models 4. Probabilistic Models Know the limitations
The Results Do the results make sense? Is the modeler able to compare the results to empirical correlations? There is no One Answer What is the range of likely answers? Was there a sensitivity analysis run?
Modeling Reality Models supplement engineering judgment, they cannot replace it People assume that CFD and zone models are easy to use Reality is it takes a significant amount of work to use such models properly They are easy to misuse
Agenda Introduction Short History of Fire Protection Fire Dynamics Fire Protection Systems Egress Case Study - Blessings Tavern Fire
Types of Fire Protection Systems There are two main types: Active Passive
Active Fire Protection A device or action that receives a stimulus before acting on a fire condition Fire Department Fire Alarm Sprinkler System Standpipe System Clean Agent System Link
Passive Fire Protection A building component that remains fixed in the building whether or not a fire condition exists Compartment Enclosure Structural Fire Resistance Fire Attack Route Egress System Link
Agenda Introduction Short History of Fire Protection Fire Dynamics Fire Protection Systems Egress Case Study - Blessings Tavern Fire
Can you believe real life? This takes place in less than 3 minutes.
Egress System A passive fire protection system Interconnected t with: Occupant characteristics Type of occupancy Construction Size of the building Active fire protection systems
Egress Computer Models Predict egress time Time = distance/walking speed Could include occupant behavior Should include fire scenario comparison
Egress Computer Models People real life reactions are complicated Sight of smoke can change movement Exposure to smoke/heat affect moving Example Models Pathfinder EXITT Evacnet SIMULEX EXODUS
Agenda Introduction Short History of Fire Protection Fire Dynamics Fire Protection Systems Egress Case Study - Blessings Tavern Fire
Blessings Tavern Fire
Blessings Tavern Fire
Blessing s Tavern
Night Of The Fire
Night Of The Fire
Night Of The Fire
Night Of The Fire
Night Of The Fire
A Few Days Later
A Few Days Later
A Few Days Later
A Few Days Later
A Few Days Later
A Few Days Later
Conclusion Facts of the Inaccuracy - With age comes experience: Code have been reactionary Fire is not an exact science In a perfect world active and passive fire protection installations would all work as intended Preconceived ideas based on common sense is NOT science
Conclusion Fire protection is an evolving science. Hi t h h th t t bl History has shown that acceptable practices change over time
Conclusion The decisions we make impact lives.
Anatomy of a Fire Douglas Nadeau, MSFPE, PE, CFPS, LEED AP President of RAN Fire Protection Engineering, PC Vice President of truvue Inspection Technology Christopher Crivello, MSFPE, PE Fire Protection Project Engineer at RAN Fire Protection Engineering, PC ccrivello@ranfpe.com 518-275-0791 dnadeau@ranfpe.com 518-275-0791