No description available.

Fluorinated fire fighting foams provide superior performance for extinguishing Class B flammable liquid fires when compared to other types of fire fighting foams. Perfluorocarboxylates and perfluorosulfonates have historically been surfactants used in these foams with a recent shift to fluorotelomer-based foams due to environmental and health concerns surrounding perfluorinated compounds such as PFOA and PFOS. Releases of aqueous film forming foams from training, accidental spills, or fire events where wastewater is not captured have, among other sources, led to detectable concentrations of fluorinated compounds in groundwater, surface water, and drinking water supplies globally. Persistence, toxicity, and bioaccumulation potential of these substances are areas of ongoing research. Biodegradability data for these AFFFs in published studies and manufacturers’ material safety data sheets may be based on a comparison of BOD and COD measures. The present study concludes that COD is an inappropriate measure of organic content for fluorinated compounds due to the carbon-fluorine bond strength, and thus published biodegradability data must be critically evaluated for validity. TOC measured an average of 91% of carbon content for four fluorinated test substances, recommending it for use as an analytical parameter in biodegradability tests when specific compounds’ identities are not required, e.g. in the absence of an LC/MS. Biodegradability of three fluorinated foams (AFFF, AR-AFFF, and FP) purchased from a major U.S. manufacturer measured in the range of 77-96% based on DOC die-away during a 28-day test using activated sludge inoculum. This meets OECD criteria for “ready biodegradability� and NFPA biodegradability recommendations in Standards 18, 18A, and 1150. Defluorination of two foams was measured using ion chromatography and, based on an estimate for total fluorine content developed in part from manufacturer MSDSs, was found to liberate a detectable level of fluorine that was 1 to 2 orders of magnitude less than the estimated value. In this 28-day test, foams underwent significant biodegradation but fluorinated compounds’ biodegradation was likely incomplete.

Diplomová práce se zabývá přestavbou dvoumotorového letounu EV-55 vyvíjeného společností Evektor s.r.o. na požární verzi. Konstrukční úprava odpovídá předpisu CS-23 Amendment 3. Nejprve je provedena studie a porovnání se současnými konkurenčními požárními letouny. Na základě této studie je zhodnocena vhodnost letounu EV-55 pro přestavbu na požární verzi a stanoveny požadavky, které musí požární EV-55 splňovat z hlediska konkurenceschopnosti. Na základě těchto požadavků a certifikačních předpisů je provedena hlavní část práce - konstrukce hasicího zařízení a navrženy nutné konstrukční úpravy trupu letounu. Dle uvedeného předpisu je dále provedena pevnostní kontrola zařízení a trupu s úpravami. Na závěr je zhodnocen vliv hasicího zařízení na letové výkony a stabilitu letounu.

Fire Safety Engineering is required at every stage in the life cycle of modern-day buildings. Fire safety design, detection and suppression, and emergency response are all vital components of Structural Fire Safety but are usually perceived as independent issues. Sensor deployment and exploitation is now common place in modern buildings for means such as temperature, air quality and security management. Despite the potential wealth of information these sensors could afford fire fighters, the design of sensor networks within buildings is entirely detached from procedures associated to emergency management. The experiences of Dalmarnock Fire Test Two showed that streams of raw data emerging from sensors lead to a rapid information overload and do little to improve the understanding of the complex phenomenon and likely future events during a real fire. Despite current sensor technology in other fields being far more advanced than that of fire, there is no justification for more complex and expensive sensors in this context. In isolation therefore, sensors are not sufficient to aid emergency response. Fire modelling follows a similar path. Two studies of Dalmarnock Fire Test One demonstrate clearly the current state of the art of fire modelling. A Priori studies by Rein et al. 2009 showed that blind prediction of the evolution of a compartment fire is currently beyond the state of the art of fire modelling practice. A Posteriori studies by Jahn et al. 2007 demonstrated that even with the provision of large quantities of sensor data, video footage, and prior knowledge of the fire; producing a CFD reconstruction was an incredibly difficult, laborious, intuitive and repetitive task. Fire fighting is therefore left as an isolated activity that does not benefit from sensor data or the potential of modelling the event. In isolation sensors and fire modelling are found lacking. Together though they appear to form the perfect compliment. Sensors provide a plethora of information which lacks interpretation. Models provide a method of interpretation but lack the necessary information to make this output robust. Thus a mechanism to achieve accurate, timely predictions by means of theoretical models steered by continuous calibration against sensor measurements is proposed. Issues of accuracy aside, these models demand heavy resources and computational time periods that are far greater than the time associated with the processes being simulated. To be of use to emergency responders, the output would need to be produced faster than the event itself with lead time to enable planning of an intervention strategy. Therefore in isolation, model output is not robust or fast enough to be implemented in an emergency response scenario. The concept of super-real time predictions steered by measurements is studied in the simple yet meaningful scenario of concurrent flow flame spread. Experiments have been conducted with PMMA slabs to feed sensor data into a simple analytical model. Numerous sensing techniques have been adapted to feed a simple algebraic expression from the literature linking flame spread, flame characteristics and pyrolysis evolution in order to model upward flame spread. The measurements are continuously fed to the computations so that projections of the flame spread velocity and flame characteristics can be established at each instant in time, ahead of the real flame. It was observed that as the input parameters in the analytical models were optimised to the scenario, rapid convergence between the evolving experiment and the predictions was attained.

Firefighters often arrive at structures in which the state of fire progression can be described as ventilation-controlled or under-ventilated. This means that inside the enclosure the pyrolyzed fuel has consumed most, if not all of the available oxygen, resulting in incomplete combustion. Under-ventilated (fuel rich) combustion is particularly dangerous to occupants because of the high yield of toxins such as carbon monoxide and to firefighters because once firefighters enter the structure and introduce oxidizer, the environment can rapidly change into a very dangerous, fast burning condition. The fuel load in many compartment fires would support a several megawatt fire if the fire were not ventilation controlled. In the process of making entrance to the fire compartment, firefighters will likely provide additional ventilation paths for the fire and may initiate firefighting tactics like positive pressure ventilation to push the hot flammable combustion products out of the attack pathway. Forced ventilation creates a strongly mixed flow within the fire compartment. Ventilation creates a complex fluid mechanics and combustion environment that is generally not analyzed on the scale of compartment fires. To better understand the complex coupling of these phenomena, compartment scale non-reacting and reacting experiments were conducted. The experiments, which were conducted at The University of Texas at Austin’s fire research facility, were designed to gain insight into the effects of ventilation on compartment thermal characteristics. Computational models (low and high order) were used to augment the non-reacting and reacting experimental results. Though computationally expensive, computational fluid dynamics models provided significant detail into the coupling of buoyantly driven fire products with externally applied wind or fan flow. A partially stirred reactor model was used to describe strongly driven fire compartment combustion processes because previously there was not an appropriate low dimensional computational tool applicable to this type of problem. This dissertation will focus on the experimental and computational characterization of strong vent flows on single room enclosure fires. / text

Protective helmets used by fire-fighters must be designed to minimize the amount of heat transferred to the users head while providing durability, comfort, and affordable costs. This thesis highlights the evaluation of new helmet technology specifically tailored to high radiant heat environments to advance the state-of-the-art in head protection for this application. The research focused on the assessment of the outer shells of helmets and the properties of the surfaces. The development included the evaluation of radiation heat transfer, in a laboratory environment, to various helmet shell surface constructions. Industry standards were considered, and critiqued. Experiments were designed to isolate critical design variables for measurement and evaluation. Custom, purpose-built laboratory apparatus for testing helmets were designed, explained and utilized in the testing of specimens. Additionally, market demands for firefighting helmets were explored. Helmet durability was specifically addressed with abrasion criteria established and the reflectivity effects of the abraded surfaces evaluated. Resulting from this study, new surface technologies were identified for possible development in future helmet designs. Various surface materials, finishes, and coatings were compared and contrasted to current industry state-of-the-art equipment. The knowledge discovered further advanced modern head protection science in aim of increased safety and performance of fire-fighting personnel.

No description available.

As the nature of coal mInmg changes, to higher production associated with higher mechanization, the way in which mine safety is approached must also change. This situation was clearly shown in a very devastating coal mine fire in late 1984. In the absence of effective fire-fighting procedures and equipment the affected mine was quickly rendered helpless. Of particular concern with coal mine fires is the possibility of entering a fuel-rich state. In this state current practices have proven to be of little use in gaining control over the conflagration. Recent experiences with the application of water mist to industrial fires has shown that use of fog can be an efficacious agent in controlling large scale fires. The postulations of this phenomenon concern the ability of the water, as a fog, to get deeply within the fire structure. In this manner it works to remove the three legs of the fire triangle~ heat, oxygen, and fuel. The research contained in this thesis dwells in three associated areas. These are: the general theory of water mist application relative to current practices~ the design and construction of a fire tunnel for experimental work; and the results obtained from experiments with fuel-rich fires in the simulated coal mine entry. The results of this research are most encouraging, not only for the more devastating fuelrich fires, but also for application from the onset of fire fighting activities in the coal mine environment. / Master of Science

Thesis (M.B.A.)--University of Hong Kong, 1993.

Despite advancements in the development of synthetic fibers and materials that provide better insulation, fire ground burn injuries remain a significant issue. The current test methods for fire fighting clothing were investigated to determine their adequacy in evaluating the actual performance of clothing materials. This investigation uncovered several potential problems with the current test methods. A series of new, small scale, tests were used to evaluate the shortcomings of the current test methods and develop possible improvements. A small test apparatus, designed and donated by Ktech Corporation, was used to measure the thermal properties (thermal conductivity and volumetric heat capacity) of a series of fire fighting clothing materials. The thermal properties were estimated for single fabric layers, as well as ensembles, with various levels of moisture added to simulate actual end use conditions. In addition, a skin simulant sensor was used to assess the time to 2nd degree burn for exposures similar to those required in current standards for fire fighting clothing. A one dimensional heat conduction model was developed to predict the time to 2nd degree burn for the skin simulant sensor protected with outer shell materials that may be used as wildland fire fighting clothing, using the thermal property data obtained from earlier tests. An alternative method was developed to calculate the time to 2nd degree burn for ensembles evaluated with the new skin simulant sensor. The predictions for the time to 2nd degree burn obtained from the new skin simulant sensor were compared against results obtained using the sensor specified in the current test methods. The predictions for the skin simulant sensor were consistently shorter than those from the current test sensor. The current test sensor predictions for the time to 2nd degree burn were nominally 40% to 50% higher than the predictions from the skin simulant sensor during the evaluations of outer shell materials.