scholarly journals Flammability parameters of sprayed and foam aerosols selected for studies

2018 ◽  
Vol 247 ◽  
pp. 00029
Author(s):  
Bozena Kukfisz

The paper presents classification criteria for flammability parameters of sprayed and foamed aerosols [1-3]. Tests were carried out to determine such flammability criteria, as combustion heat of a substance, distance of sprayed aerosol from the ignition source at which ignition takes place, time equivalent necessary for ignition to take place and the density of deflagration for sprayed aerosols. For foamed aerosols the determined parameters comprised combustion heat parameters for a substance, the maximum flame height and the flame retention time. Based on the obtained flammability it may be unequivocally stated that aerosol products pose a serious fire hazard. Aerosols selected for testing pose a serious explosion hazard within a confined space. It seems that from among all the tested aerosols the most hazardous products in this respect comprise solvent and stain remover and DW 40. Within a space of 200 dm3 those products required 3 and 4 seconds of aerosol spraying respectively until the moment of initiating an explosion. Aerosol products in which use was made of propane-butane a carrier gas characterise by very similar flammability and explosivitiy parameters within a closed or confined space.

2017 ◽  
Vol 23 (4) ◽  
pp. 455-463 ◽  
Author(s):  
Weigang YAN ◽  
Lin JIANG ◽  
Weiguang AN ◽  
Yang ZHOU ◽  
Jinhua SUN

Buildings have U-shape façade designs for certain purposes such as lighting. However, such designs may lead to a higher fire hazard. In this paper, large scale experiments of upward flame spread over XPS insulation material were conducted to investigate the fire hazard of building’s U-shape façade wall geometry. Comparison to previous labora­tory scale experiments were also presented. Theoretical analysis was performed to reveal the mechanism of the U-shape geometry’s influences. It is found that such geometry design would increase the fire hazard of buildings: flame spread rate and flame height increased with U-shape’s geometrical factor. The results agreed with theoretical analysis. It is ex­pected that the buildings’ U-shape façade wall geometry would greatly benefit flame spread for full scale applications and increase the fire hazard. Thus engineers should be careful with such façade wall designs, especially for residential building designs.


2011 ◽  
Vol 2011 ◽  
pp. 1-11 ◽  
Author(s):  
M'Hamed Hachmi ◽  
Abdessadek Sesbou ◽  
Hassan Benjelloun ◽  
Nesrine El Handouz ◽  
Fadoua Bouanane

A formula to estimate forest fuel flammability index (FI) is proposed, integrating three species flammability parameters: time to ignition, time of combustion, and flame height. Thirty-one (31) Moroccan tree and shrub species were tested within a wide range of fuel moisture contents. Six species flammability classes were identified. An ANOVA of the FI-values was performed and analyzed using four different sample sizes of 12, 24, 36, and 50 flammability tests. Fuel humidity content is inversely correlated to the FI-value, and the linear model appears to be the most adequate equation that may predict the hypothetical threshold-point of humidity of extinction. Most of the Moroccan forest fuels studied are classified as moderately flammable to flammable species based on their average humidity content, calculated for the summer period from July to September.


2017 ◽  
Vol 6 (2) ◽  
pp. 142
Author(s):  
Putri Sahara Harahap ◽  
Irwandi Rachman ◽  
Firdaus Simanjuntak

Abstrak   Latar Belakang : Hasil observasi ditemukan bahwa 8 dari 10 tenaga kerja  hanya menggunakan kacamata biasa namun dalam jangka waktu 3 tahun bekerja mereka merasakan keluhan pada mata dan gangguan penglihatan. Pekerja rata-rata bekerja selama 8 jam  dalam sehari. Risiko bahaya yang ada pada pekerjaan las adalah debu, gas, sengatan listrik, cahaya dan sinar, radiasi panas, bahaya ledakan, bahaya kebakaran, dan bahaya percikan las. Pada mata, sinar tersebut dapat mengakibatkan iritasi dan penyakit mata Metode : analitik dengan pendekatan cross sectional yaitu suatu penelitian untuk mempelajari dinamika korelasi antara faktor-faktor penelitian observasi atau pengumpulan data dilakukan sekaligus pada suatu saat secara bersamaan/point time aprroach. Tujuan : Penelitian ini merupakan analitik dengan pendekatan cross sectional  yang bertujuan untuk mengetahui faktor-faktor yang berhubungan dengan keluhan mata pada pekerja. Populasi dalam penelitian ini adalah seluruh pekerja las yang berjumlah 106 orang.  Proses penelitian dilakukan pada tanggal 4-23 Agustus Tahun 2017  di Kecamatan Tungkal Ilir Kabupaten Tanjab Barat. Data dianalisis secara univariat dan bivariat Hasil : Hasil penelitian secara univariat diperoleh bahwa sebagian besar (56,6%) lingkungan kerja baik, (84,0%) responden dalam masa kerja bersisiko, (68,9%) responden menggunakan kaca mata standar APD dan (74,5%) responden mengalami keluhan mata. Hasil analisis bivariat menggunakan uji chi-square menunjukkan bahwa terdapat hubungan antara lingkungan kerja dengan p-value= 0,019,  masa kerja dengan p-value= 0,000 dan pemakaian APD dengan p-value= 0,022 terhadap keluhan mata pada pekerja las. Saran : Diharapkan pemilik usaha bengkel las menerapkan lingkungan kerja yang baik diantaranya adanya aturan dan SOP dalam bekerja maupun kelengkapan dan fasilitas APD yang sesuai dengan standar.   Kata Kunci    : Lingkungan Kerja, Masa Kerja, Pemakaian APD, Keluhan Mata   Abstract   Background : Observations found that 8 out of 10 laborers only used regular glasses but within 3 years of working they felt complaints on the eyes and impaired vision. Workers work on average for 8 hours a day. The hazards present in welding work are dust, gas, electric shock, light and light, heat radiation, explosion hazard, fire hazard, and the dangers of weld splashes. In the eyes, these rays can cause irritation and eye disease Method : This research is an analytic with cross sectional approach which is aimed to know the factors related to eye complaints to the workers. Population in this research is all welder worker which amounted to 106 people. The research process was conducted on August 4-23 Year 2017 in District Tungkal Ilir West Tanjab Regency. Data were analyzed univariat and bivariate Results : The result of univariate research showed that most (56,6%) good work environment, (84,0%) respondent in working period at risk, (68,9%) respondents using standard APD eye glass and (74,5%) respondent have eye complaints. The result of bivariate analysis using chi-square test shows that there is a relation between work environment with p-value = 0,019, working period with p-value = 0,000 and APD usage with p-value = 0,022 to eye complaints on welding workers. Conclusion : It is expected that the owner of the welding workshop to implement a good working environment such as the rules and SOPs in the work and completeness and facilities of PPE in accordance with the standards.   Key words: Work Environment, Work Period, Use of PPE, Eye Complaint


2021 ◽  
pp. 40-43
Author(s):  
V. I. Moiseev ◽  
◽  
A. V. Zhebanov ◽  
T. A. Komarova ◽  
◽  
...  

The method of unloading and reloading solidified oil fuels, with the use of pipelines made according to temporary technological schemes, produced in winter, is considered. Cooling of solidified fuels is accompanied by a sharp increase in their viscosity, which makes pipeline transmission impossible. In fire hazard, it is proposed to produce continuous heating of the pumped fuel using devices based on low-temperature combustion of propane-butane mixture on the surface of the catalyst carried out at fire-safe temperatures. It is also proposed to install a temporary heat-insulating shell on the pipeline that meets the operating modes of the heaters.


Author(s):  
James Carter ◽  
Timothy Harrigan ◽  
S. K. Punwani

Flammable materials such as gasoline, ethanol, and diesel fuel are commonly transported in bulk via rail. In many cases, pockets of vapor can be generated inside the tank that can present a hazard if spilled during a collision or other catastrophic accident. Vapor conditions above the Lower Explosive Limit (LEL) if exposed to an external ignition source can result in an explosion or fire. Alternately, residual vapors within a tank present an explosion hazard if not properly vented or inerted prior to maintenance activities. This paper summarizes a generalized study of hazards associated with flammable liquids using computation fluid dynamics (CFD) to predict vapor conditions within a tank or following a spill. The analysis was verified in laboratory testing using scaled tank geometries. A demonstration case was developed using diesel fuel in a locomotive fuel tank. Typical road locomotives carry 3000–5000 gal of diesel fuel during normal operation. As the locomotive consumes fuel, large volumes are available for vapor generation within the tank. In a post-collision scenario, under ambient temperatures over the flash point of the fuel, the vapor that vents to the atmosphere presents a significant fire hazard. Further, flammable mists can be generated by the sprays that develop due to fuel leaks from a moving train. Studies of accident cases over a 10 year period indicated that a fire occurred in 80% of the accidents in which fuel was spilled. A CFD analysis was applied to the geometry associated with a locomotive fuel tank. The analysis models the two phase flow using the “volume of fluid” formalism in Fluent, and using a user defined diesel fuel evaporation algorithm. The tank and environmental parameters included fuel volume, fuel temperature, and air flow within the tank, and critical values of vapor content, temperature and velocity were plotted. The analysis predicted ignition of the external vapor cloud at temperatures relevant to a spill in a summer environment in the southwest, and propagation of the flame into the fuel tank. Laboratory testing confirmed the analysis: Once ignited, a flame propagated into the tank, causing an explosion and fire. The analysis methods developed can be applied to a variety of geometries and fluids, providing a basis for full scale testing. The overall intent of the analysis is to aid in the development of fire mitigation approaches for fuel and flammable material transport that would be practical for railroad use.


2019 ◽  
Vol 59 (7) ◽  
pp. 43-49
Author(s):  
Igor S. Borisevich ◽  
◽  
Yury K. Kryshchenko ◽  
Evgeny N. Ofitserov ◽  
Viktor M. Pozhidaev ◽  
...  

Before scientists in science there was always a problem in predicting the physicochemical parameters of substances, in particular, members of homologous series. It often happens that data for a number of compounds of the homologous series may simply be absent. One of the most important characteristics of homologues is the boiling point. This value is directly related in gas chromatography to the retention time, however, it is impossible to create the same temperature conditions for chromatography of all compounds. On the other hand, according to some properties, for example, according to the melting temperature, the members of the series are divided into two contracts – even and odd. Phase transitions are associated with the loss or acquisition of one of the degrees of freedom. Analysis of chromatograms showed that by the retention time there is no division of the series into even and odd, which indicates the absence of adsorption of the adsorbate with the loss of the rotational degree of freedom. Based on this, the possibility of predicting these parameters using the moment of inertia of rotational motion and recurrence relations introduced into the chromatography by I. Zenkevich was investigated.


2015 ◽  
Vol 24 (4) ◽  
pp. 573 ◽  
Author(s):  
Jesse K. Kreye ◽  
Leda N. Kobziar

Mastication of understorey shrubs and small trees to reduce fire hazard has become a widespread forest management practice, but few empirical studies have quantified the effects of this mechanical treatment on actual fire behaviour and fire effects at the stand scale. We conducted experimental burns in masticated pine flatwoods with palmetto/gallberry understories, a common ecosystem of the Southern US Coastal Plain. Fire behaviour (flame height, rate of spread) and fire effects were compared between treated and untreated sites burned in the typical winter prescribed burning season. Mastication effectively reduced flame heights by 66%, but recovering shrubs (cover, height) influenced fire behaviour within six months following treatment, suggesting time-limited effectiveness. Trees had less crown scorch and bole char in masticated sites, but tree mortality was minimal on both treated and untreated sites. Consumption of masticated fuel was substantial across both treatments, but little duff was consumed under the moist soil conditions. When burning is conducted soon after treatment, mastication may effectively reduce fire behaviour in pine flatwoods sites, but the duration of treatment efficacy remains unclear.


2020 ◽  
Vol 65 (6) ◽  
pp. 461
Author(s):  
M. Yu. Trofimenko ◽  
S. K. Aslanov ◽  
G. S. Dragan ◽  
V. P. Smolyar

We perform the analysis of a prepared propane-butane flame structure, by using the computer processing of the radiation from the chemical reaction zone. We mark out the stoichiometric reaction along with the zones of the external oxidant inflow into the flame for different burner diameters. We suggest a method of determining the normal flame speed based on catching the moment of the complete fuel combustion in the upper part of a flame. We show a role of the external oxidant inflow in the kinetic processes within the burning zone. The absolute value of the normal component of the flame speed and its dependence on the burner diameter and on the excess oxidant ratio for a prepared propane-butane flame are determined experimentally.


2007 ◽  
Vol 16 (5) ◽  
pp. 511 ◽  
Author(s):  
Dominique Morvan

The efficiency of fuel breaks installed in wildland–urban interfaces to reduce fire hazard depends strongly on the conditions of spread (rate of spread, flame height) of a surface fire through the shrub on the ground and also on the possibility of a transition for this fire from the understorey vegetation to the canopy. The aim of the present paper was to study (using numerical simulation with a physics-based model) the behaviour of surface fires propagating through Mediterranean shrub and to evaluate, from the characteristic dimensions of the flame, the onset of transition from a surface fire to a crown fire. The geometry of the flame was defined from the energy loss in the gas resulting from the radiation emission of soot particles, the flame contour was reconstructed from a threshold level fixed at 60 kW m–3. The numerical results were compared with experimental correlations of the geometry of the flame obtained for static and spreading fires. Extensive calculations were performed through a shrubland (Quercus coccifera and Brachypodium ramosum) for various fuel depths Hfuel ranging from 0.25 to 1.5 m and for wind speeds UH ranging from 1 to 10 m s–1. Then this study was extended to situations including a supplementary fuel layer representing the canopy of small trees (Pinus halepensis). The numerical results were analysed, introducing a dimensionless physical parameter, the Froude number, defined as the ratio between the inertial force due to the wind flow and the buoyancy. The results obtained with an upper fuel layer highlighted the role played by radiation heat transfer for the transition of surface fire to the crown. Some calculations were also carried out to study how a reduction of surface fuel on the ground can affect the vertical transition of the fire.


Sign in / Sign up

Export Citation Format

Share Document