Evaluation of the Thermal Conditions and Smoke Obscuration of Live Fire Training Fuel Packages

2019 ◽  
Author(s):  
Jack Regan ◽  
◽  
Robin Zevotek
Keyword(s):  
Thermal Conditions ◽  
Wood Products ◽  
Fuel Load ◽  
Fire Dynamics ◽  
Synthetic Fuel ◽  
Engineered Wood Products ◽  
Series Of Experiments ◽  
Effective Heat Of Combustion ◽  
Load Weight

Firefighters routinely conduct live fire training in an effort to prepare themselves for the challenges of the fire ground. While conducting realistic live fire training is important, it also carries inherent risks. This is highlighted by several live fire training incidents in which an inappropriate fuel load contributed to the death of participants. NFPA 1403: Standard on Live Fire Training Evolutions was first established in response to a live fire training incident in which several firefighters died. Among the stipulations in NFPA 1403 is that the fuel load shall be composed of wood-based fuels. The challenge of balancing safety with fidelity has led instructors to explore a variety of different methods to create more realistic training conditions. A series of experiments was conducted in order to characterize common training fuels, compare these training fuels to furnishings, and examine the performance of these training fuels in a metal container prop. Heat release rate (HRR) characterization of training fuels indicated that wood-based training fuels had a constant effective heat of combustion. Depending on the method used, this value was between 13.6 and 13.9 MJ/kg. This indicates that, even in engineered wood products, wood is the primary material responsible for combustion. In order to further explore the conclusions from the HRR testing, additional experiments were conducted in an L-shaped metal training prop. The results of these experiments highlighted a number of considerations for firefighter training. Thermal conditions consistent with “realistic fires” could be produced using NFPA 1403 compliant fuels, and in fact the thermal conditions produced by larger wood-based fuel packages were more severe than those produced by fuel packages with a small amount of synthetic fuel. The fuel package used in training evolutions should reflect the training prop or building being used, the available ventilation, and the intended lesson. Fuel load weight and orientation are both important considerations when designing a fuel package. The training considerations drawn from this report will help to increase firefighters’ understanding of fire dynamics, and help instructors better understand fuel packages and the fire dynamics that they produce.

Evaluation of Ventilation-Controlled Fires in L-Shaped Training Props

2016 ◽  
Author(s):  
Joseph Willi ◽  
◽  
Keith Stakes ◽  
Jack Regan ◽  
Robin Zevotek
Keyword(s):  
Field Experiments ◽  
Oriented Strand Board ◽  
Thermal Environment ◽  
Thermal Conditions ◽  
Mineral Wool ◽  
Fuel Load ◽  
Gypsum Board ◽  
Fire Dynamics ◽  
Fire Environment ◽  
Shipping Containers

Investigations of recent firefighter line of duty deaths caused by rapid fire progression have highlighted a deficiency in firefighters’ understanding of how certain tactics affect the fire dynamics of ventilation-controlled fires. Many fires are in a ventilation-limited, decay state by the time firefighters arrive at the scene, meaning that introducing additional ventilation to the environment has the potential to cause rapid and intense fire growth. To more effectively teach firefighters about the potential effects of ventilation on a compartment fire, ventilation-controlled fires should be gener- ated during training. Safely creating such fires while maintaining compliance with NFPA 1403: Standard on Live-Fire Training Evolutions allows instructors to educate students on this important principle of fire dynamics in the training environment. Structures utilized for live-fire training have evolved from typical concrete burn buildings to now include smaller purpose-built props, like those constructed from steel shipping containers or wood and gypsum board. Such props have been embraced by organizations due to their cost-effectiveness and potential to improve fire behavior training. Obtaining a thorough understanding of the capa- bilities and limitations of such props is critical for instructors to convey accurate messages during training and properly prepare firefighters for scenarios they’ll encounter in the field. Experiments were conducted to quantify the fire environment in L-shaped props with different wall constructions. One prop had an interior wall lining of gypsum board over wood studs and fiberglass insulation. The two other props were constructed from metal shipping containers with corrugated steel walls; one had ceilings and walls comprised solely of the corrugated steel, while the other had ceilings and walls comprised of rolled steel sheeting over mineral wool insulation with the corrugated steel wall as its backing. Three fuel packages were compared between the props: one contained furnishings mainly composed of synthetic materials and foam plastics; another contained wooden pallets and straw; and the third contained wooden pallets, straw, and oriented strand board (OSB). A stochastic approach was used to compare data between replicate tests and quantify the repeatability of the different props and fuel packages, all of which were deemed sufficiently repeatable. Comparisons of data between the three props revealed that thermal conditions between experiments in the two metal props were indistinguishable, suggesting that the additional layer of insulation did not significantly alter the fire environment. Additionally, thermal conditions in the gypsum-lined prop were more severe than those in the metal props. The effects of ventilation changes on fire conditions were also analyzed across various prop and fuel load combinations. Lastly, the response of the thermal environment in each prop during interior suppression was evaluated, and the results implied that the thermal exposure to the firefighter was more severe in the metal props than the gypsum prop for a brief period following the start of suppression.

Study of the Fire Service Training Environment: Safety and Fidelity in Concrete Live Fire Training Buildings

2018 ◽  
Author(s):  
Jack Regan ◽  
◽  
Robin Zevotek
Keyword(s):  
Oriented Strand Board ◽  
Fire Behavior ◽  
Fire Service ◽  
Fuel Load ◽  
Living Room ◽  
Synthetic Fuels ◽  
Fire Dynamics ◽  
Training Environment ◽  
Service Training ◽  
Series Of Experiments

The goal of fire service training is to prepare students for the conditions and challenges that they face on the fireground. Among the challenges that firefighters routinely face on the fireground are ventilation-controlled fires. The hazard of these fires has been highlighted by several line-of-duty deaths and injuries in which a failure to understand the fire dynamics produced by these fires has been a contributing factor. The synthetic fuels that commonly fill contemporary homes tend to result in ventilation-controlled conditions. While synthetic fuels are common on the residential fireground, the fuels that firefighters use for fire training are more often representative of natural, wood-based fuels. In order to better understand the fire dynamics of these training fires, a series of experiments was conducted in a concrete live fire training building in an effort to evaluate the fidelity and safety of two training fuels, pallets and OSB, and compare the fire dynamics created by these fuels to those created by a fuel load representative of a living room set with furniture items with a synthetic components. Additionally, the effects of the concrete live fire training building on the fire dynamics were examined. The two training fuel loads were composed of wooden pallets and straw, and pallets, straw, and oriented strand board (OSB). The results indicated that the high leakage area of the concrete live fire training building relative to the fuel load prevented the training fuel packages from becoming ventilation-controlled and prevented the furniture package from entering a state of oxygen-depleted decay. The furniture experiments progressed to flashover once ventilation was provided. Under the conditions tested, the wood based fuels, combined with the construction features of this concrete live fire training building, limited the ability to teach ventilation-controlled fire behavior and the associated firefighting techniques. Additionally, it was shown that the potential for thermal injury to firefighters participating in a training evolution existed well below thresholds where firefighter PPE would be damaged.

scholarly journals Development of a Field Deployable Firebrand Flux and Condition Measurement System

2020 ◽  
Author(s):  
Simone Zen ◽  
Jan C. Thomas ◽  
Eric V. Mueller ◽  
Bhisham Dhurandher ◽  
Michael Gallagher ◽  
...  
Keyword(s):  
Imaging Techniques ◽  
Time History ◽  
Infrared Camera ◽  
Thermal Conditions ◽  
Particle Characterization ◽  
Fire Dynamics ◽  
Rate Of Spread ◽  
New Instrument ◽  
History Of

AbstractA new instrument to quantify firebrand dynamics during fires with particular focus on those associated with the Wildland-Urban Interface (WUI) has been developed. During WUI fires, firebrands can ignite spot fires, which can rapidly increase the rate of spread (ROS) of the fire, provide a mechanism by which the fire can pass over firebreaks and are the leading cause of structure ignitions. Despite this key role in driving wildfire dynamics and hazards, difficulties in collecting firebrands in the field and preserving their physical condition (e.g. dimensions and temperature) have limited the development of knowledge of firebrand dynamics. In this work we present a new, field-deployable diagnostic tool, an emberometer, designed to provide measurement of firebrand fluxes and information on both the geometry and the thermal conditions of firebrands immediately before deposition by combining a visual and infrared camera. A series of laboratory experiments were conducted to calibrate and validate the developed imaging techniques. The emberometer was then deployed in the field to explore firebrand fluxes and particle conditions for a range of fire intensities in natural pine forest environments. In addition to firebrand particle characterization, field observations with the emberometer enabled detailed time history of deposition (i.e. firebrand flux) relative to concurrent in situ fire behaviour observations. We highlight that deposition was characterised by intense, short duration “showers” that can be reasonably associated to spikes in the average fire line intensity. The results presented illustrate the potential use of an emberometer in studying firebrand and spot fire dynamics.

scholarly journals B-1 cell: the precursor of a novel mononuclear phagocyte with immuno-regulatory properties

2009 ◽  
Vol 81 (3) ◽  
pp. 489-496 ◽  
Author(s):  
José Daniel Lopes ◽  
Mario Mariano
Keyword(s):  
Mammalian Cells ◽  
Giant Cells ◽  
Mononuclear Phagocyte ◽  
Different Types ◽  
Series Of Experiments ◽  
B1 Cells ◽  
Regulatory Properties

Characterization of the origin, properties, functions and fate of cells is a fundamental task for the understanding of physiological and pathological phenomena. Despite the bulk of knowledge concerning the diverse characteristics of mammalian cells, some of them, such as B-1 cells, are still poorly understood. Here we report the results obtained in our laboratory on these cells in the last 10 years. After showing that B-1 cells could be cultured and amplified in vitro, a series of experiments were performed with these cells. They showed that B1 cells reside mostly in the peritoneal and pleural cavities, migrate to distant inflammatory foci, coalesce to form giant cells and participate in granuloma formation, both in vitro and in vivo. They are also able to present antigens to immunologically responsive cells and are endowed with regulatory properties. Further, we have also shown that these cells facilitate different types of infection as well as tumor growth and spreading. These data are presently reviewed pointing to a pivotal role that these cells may play in innate and acquired immunity.

Characterization of Carbon Nanotube Growth via CVD Synthesis from a Liquid Precursor

2014 ◽  
Vol 23 (01n02) ◽  
pp. 1420001 ◽  
Author(s):  
Carol Jenkins ◽  
Melissa Cruz ◽  
Jen Depalma ◽  
Michael Conroy ◽  
Barbara Benardo ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Thermal Conditions ◽  
Outer Diameter ◽  
Carrier Gas ◽  
Phase Precursor ◽  
Multi Walled Carbon Nanotubes ◽  
Carbon Nanotube Growth ◽  
Nanotube Growth ◽  
Walled Carbon Nanotubes

As novel theories and uses of carbon nanotubes (CNT) advance, it becomes increasingly important to characterize the methods of production. One such method of CNT production uses a liquid phase precursor (hydrocarbon with nanoparticle catalyst mix) that is injected into a tube furnace with a flowing carrier gas. The CNTs are grown in high purity and are collected on the surface of the quartz tube. The system allows for a number of variables to be tested such as growth temperatures, flow rate of the carrier gas, precursor injection rates and variations of precursor mix however, here only thermal effects are considered. Under thermal conditions ranging from 500 to 850°C, multi-walled carbon nanotubes (MWCNTs) are synthesized and characterized to determine inner and outer diameter as well as tube thickness.

Surface and Subsurface Quality Evaluation of Engineered Wood Products by Ultrasonic Means

2014 ◽  
pp. 182-220
Author(s):  
Frank C. Beall ◽  
Henrique Reis
Keyword(s):  
Product Development ◽  
Material Properties ◽  
Rapid Evolution ◽  
Solid Wood ◽  
Wood Products ◽  
Assessment And Evaluation ◽  
Engineered Wood Products ◽  
Engineered Wood ◽  
History Of ◽  
Ultrasonic Techniques

The use of ultrasonic techniques to evaluate the properties of engineered wood-based materials is discussed with respect to research to date and the use of more advanced techniques. The latter is critical because of the rapid evolution from solid wood to reconstituted structural materials. In addition, although considerable research has been done, there have been few introductions into manufacturing. This chapter traces the history of the use and latest developments of ultrasonics in several key areas, particularly the measurement of adhesive curing and quality in composites and laminates, and detection of flaws in solid wood materials. The techniques reviewed apply to product development, material properties, process control, product quality assessment, and evaluation of products in service.

Timber-Concrete Composite Structural Elements

2021 ◽  
Author(s):  
Anita Ogrin ◽  
Tomaž Hozjan
Keyword(s):  
Tensile Strength ◽  
Composite Structures ◽  
Wood Products ◽  
Structural Elements ◽  
Long Span Bridges ◽  
Long Span ◽  
Bending Load ◽  
Engineered Wood Products ◽  
Floor Systems ◽  
Connection Type

Timber-concrete composites are interesting engineered wood products usually used for structural elements, which are mainly subjected to bending load; from simple floor systems to long-span bridges. This way, the advantage can be taken of timber tensile strength and concrete compression strength. The chapter begins with an introduction of various types of timber-concrete composite structural elements regarding type of the element, connection type and types of timber and concrete. Next, specific characteristics and advantages of timber-concrete composite structural elements are thoroughly discussed from viewpoints of engineering, architecture, builders and ecology. Furthermore, basic mechanical principles of timber-concrete composite structural elements are presented and some design methods are briefly described. Finally, worldwide inclusion of timber-concrete composite structures in currently applicable standards is discussed.

Water Mobility and Mold Susceptibility in Engineered Wood Products-a Magnetic Resonance Aspect

2005 ◽  
Author(s):  
X. Philip Ye ◽  
Alvin Womac ◽  
Doug Hayes ◽  
Siqun Wang ◽  
Roger Ruan ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Wood Products ◽  
Water Mobility ◽  
Engineered Wood Products ◽  
Engineered Wood
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