Fire Protection Engineering
Permanent URI for this communityhttp://hdl.handle.net/1903/2241
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Item Investigation of the Effect of Oxygen Concentration on the Pyrolytic Decomposition of Polypropylene(2018) Turner, Brent Allen; Stoliarov, Stanislav; Fire Protection Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Limited research exists on the effect of oxygen on the species production during the controlled surface area pyrolytic decomposition of polypropylene. In this study, the pyrolytic decomposition of polypropylene was conducted in 0% O2, 5% O2, and 15% O2. The pyrolyzate produced during the experiments was analyzed using three methods. First, a custom tube-furnace reactor, auto-sampling system, and unique sample boat were developed to pyrolyze, collect, and deliver pyrolyzate to a GC-BID/MS for species identification and quantification. Data collected were converted to rates of production and mass evolved for individual species identified. Second, using the same tube-furnace reactor pyrolyzate was sent directly to a stack of IR and FID analyzers to measure O2, CO, CO2, and total hydrocarbon production. This data was converted and used to compare with and verify the data from the GC-BID analysis. Thermogravimetric analysis was used as a third technique to measure the mass loss of the polypropylene under the three O2 scenarios. For all three analytical methods, the effect of O2 was studied and was found to have a profound effect on species evolution and the temperature at which the reactions initiated.Item A Generalized Model for Wall Flame Heat Flux During Upward Flame Spread on Polymers(2015) Korver, Kevin; Stoliarov, Stanislav; Fire Protection Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)A current model accurately predicts flame to surface heat flux during upward flame spread on PMMA based on a single input parameter, the mass loss rate. In this study, the model was generalized to predict the heat flux for a broad range of polymers by adding the heat of combustion as a second input parameter. Experimental measurements were conducted to determine mass loss rate during upward flame spread and heat of combustion for seven different polymers. Four types of heat of combustion values were compared to determine which generated the most accurate model predictions. The complete heat of combustion yielded the most accurate predictions (± 4 kW/m2 on average) in the generalized model when compared to experimental heat flux measurements collected in this study. Flame heat flux predictions from FDS direct numerical simulations were also compared to the generalized model predictions in an exploratory manner and found to be similar.Item A Non-Intrusive Method for Temperature Measurements in Flames Produced by Milligram-Sized Solid Samples(2014) Frances, Colleen; Stoliarov, Stanislav I; Fire Protection Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Fires are responsible for the loss of thousands of lives and billions of dollars in property damage each year in the United States. Flame retardants can assist in the prevention of fires through mechanisms which either prevent or greatly inhibit flame spread and development. In this study samples of both brominated and non-brominated polystyrene were tested in the Milligram-scale Flaming Calorimeter and images captured with two DSL-R cameras were analyzed to determine flame temperatures through use of a non-intrusive method. Based on the flame temperature measurement results, a better understanding of the gas phase mechanisms of flame retardants may result, as temperature is an important diagnostic in the study of fire and combustion. Measurements taken at 70% of the total flame height resulted in average maximum temperatures of about 1656 K for polystyrene and about 1614 K for brominated polystyrene, suggesting that the polymer flame retardant may reduce flame temperatures.Item EVOLUTION OF FLAME TO SURFACE HEAT FLUX DURING UPWARD FLAME SPREAD ON POLYMETHYL METHACRYLATE (PMMA)(2011) Leventon, Isaac Tibor; Stoliarov, Stanislav I; Fire Protection Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)The heat feedback profile across 5cm wide, 15cm tall samples of PMMA is measured as a flame spreads vertically across its surface. Incident heat flux to a water cooled gauge is determined with peak values averaging to 36kW/m^2 across the height of the sample. This heat flux has been separated into its convective and radiative components and, at this scale, radiative heat transfer is shown to account for between 5 and 15% of total flame to surface heat flux. Based on these measurements, net heat flux into the pyrolyzing material can be determined. Correlations, expressed solely as a function of sample burning rate, predicting net heat feedback to the material's surface are developed.Item An Investigation of the UL-94V Plastics Flammability Test(2009) Downey, Brian Patrick; Quintiere, James G.; Fire Protection Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)The UL-94 Vertical Burning Flammability Test (UL-94V) is used to measure flammability characteristics of plastic materials. The results of the test allow for plastic materials to be separated into classification categories. These categories will be discussed and related to fire phenomena. Simulations of the test have allowed for the development of general flame height and heat flux correlations. We believe these are independent of the actual solid fuels. In addition, the heat flux from the ignition burner, a specified premixed flame, has been measured. These data provide the basis for assessing fire behavior of materials using their fire properties such as heat of combustion, heat of gasification, ignition temperature, and thermal properties. Criteria for ignition, sustained burning, and flame spread are determined. These outcomes are then related to the UL-94V classification categories. An analysis of melting is also considered in order to assess the flaming drip aspect of the test.