Smoke Extinction Area Research Articles

A machine learning tool for future prediction of heat release capacity of in-situ flame retardant hybrid Mg(OH)2-Epoxy nanocomposites

In this work, the fire behavior of a sol-gel in-situ hybrid Mg(OH)2-epoxy nanocomposite was investigated and an artificial neural network-based system built on a fully connected feed-forward artificial neural network was developed to predict its heat release capacity. The nanocomposite containing only ∼5 wt% loading of Mg(OH)2 promoted a remarkable decrease in heat release capacity (∼34%) measured by pyrolysis combustion flow calorimetry and in peak of heat release rate (∼37%), and heat release rate (∼29%), as assessed by cone calorimetry, as well as a significant decrease of total smoke release and smoke extinction area about 22 and 5%, respectively, indicating the suitability of Mg(OH)2 as an effective smoke suppressant. The proposed machine learning approach may be used as a promising alternative for a cost- and time-saving prediction of the fire performances of novel flame retardant polymer-based nanocomposites.

Ramie fabric Elium® composites with flame retardant coating: Flammability, smoke, viscoelastic and mechanical properties

This investigation studied the utilization of intumescent thermal resistive mats to provide surface protection to the core natural fibre-reinforced Elium® composite structural integrity. The intumescent mats contained flame retardant (FR) i.e. expandable graphite (EG) with four different expansion ratios and alumina trihydrate (ATH). All natural fibre thermoplastic composites were fabricated using a resin infusion technique. The impact of char thickness and chemical compositions on the flammability and smoke properties was investigated. It was found that surface protection significantly reduced the peak heat release rate, total smoke release, smoke extinction area and CO2 yield, and substantially enhanced UL-94 rating, time to ignition and residual char network, depending on the EG exfoliation ratio, ATH and mineral wool fibre. The glass transition temperature increased for the FR composites containing EG with lower expansion ratio. Inclusion of intumescent mats increased the strength of the composites while it had a negative effect on the modulus.

Experimental studies on different liquid pool fires inside the compartment

Experimental studies have been carried out using three distinct liquid fuel fires to explore the effect of fuel on fires. The test facility consist of a compartment of dimensions 4 m × 4 m × 4 m with a door opening of size 2 m height and 1 m width. Three fuels - diesel, isopropanol and methanol, used as fire sources, are placed inside a pan of 60 cm diameter and 15 cm height. These fuels have different nature; diesel contains sooty properties while isopropanol and methanol contain the oxygenated properties. The experiments are carried for a duration of 1500 s. Thermal environment development inside the compartment is investigated using thermocouples and heat fluxes located at different locations inside the compartment. The average heat release rate are found 473, 245 and 78 kW in diesel, isopropanol and methanol fires respectively. It is observed that the fuel properties (heat of combustion, burning rate, sootiness etc.) have a most important role in the growth of compartment fire. Soot production and concentration of CO and CO2 depends on nature of fuels. Smoke extinction area is found to be higher in diesel fuel fire compared to methanol and isopropanol fuel fires.

A New Approach to the Assessment of the Reduction in Visibility Caused by Fires of Electrical Cables

Electricity is the most important form of household energy and one of the most important forms of energy for industry and transport. Electrical distribution in construction and transport is almost exclusively implemented using electrical cables. One of the unresolved problems associated with electrical cables is the release of smoke and the resulting reduction of visibility in case of fire in the area. In this study, a new approach was developed to assess the reduction of visibility in an area affected by an electrical cable fire. This approach is based on the determination of the critical ratio of smoke volume (in the smoke layer and exhausted from the fire compartment) to the length of the burning cable, through which the visibility of reflective and illuminated signs was reduced to a lower limit value (a standard of 10 m). The input data for this approach was the extinction area of the smoke released from one meter of burning cable and the length of the cables in the area. This approach was used to test two power cables (CHKE-V J3x1.5 and CHKE-R J3x1.5) and one signal cable J-H(St)H 1 × 2 × 0.8 with the B2ca, s1, d1, a1 fire reaction class. The smoke extinction area of the examined cables was determined using a cone calorimeter at a heat flux of 50 kW/m2. The obtained data showed that in order to maintain a visibility of 10 m for reflective signs, the critical ratio of smoke volume to length of burning cable was 7.5 m3/m. For illuminated signs, the critical ratio was 2.8 m3/m. The relationship between burning length and visibility allows the calculation of visibility in the fire compartment affected by cable fire only from cables length.

Influence of particle size on the heat release rate and smoke opacity during the burning of dead Cistus leaves and twigs

This experimental study is a contribution to the understanding of the phenomena of the wildfire. This work was realized on the dead twigs of Cistus monspeliensis exposed to the heat flux at 50 kW m2 using a cone calorimeter. The experiments were realized on the shrub particles with different thicknesses (range of leaves and twigs: 1–20 mm) in function of the stage of combustion (pre-ignition, flaming, and glowing phases). For this, heat release rate, smoke production rate, smoke extinction area, the aerosol yield ( Ya) via the light extinction measurements, and modified combustion efficiency were measured. The results show that there is a size limit for which the heat release rate had a different combustion behavior. The smoke production rate was also measured, and it showed that smoke was mainly emitted during the pre-heating phase. Aerosol yield ( Ya) was calculated depending on these combustion phases (pre-ignition and flaming stage) and for the range of thickness of the samples.

Thermal degradation behavior and flame retardant mechanism of poly(vinyl chloride) plasticized with a soybean-oil-based plasticizer containing phosphaphenanthrene groups

This represents the first description of a flame retardant plasticizer based on soybean oil containing phosphaphenanthrene groups (PSPE). This additive has been prepared and applied in the generation of flame retardant PVC materials. The molecular structure of PSPE was characterized using FT-IR, 1H NMR and 31P NMR spectroscopy. The thermal degradation behavior and flame retardant performance of PVC blends plasticized with different amounts of DOP and PSPE has been examined based on mass loss, LOI values, morphologies of residues, smoke production rate (SPR), smoke extinction area (SEA), mass loss rate (MLR) and heat release rate (HRR), thermal degradation processes and modes of flame retardant action has been proposed. The results showed that the addition of PSPE promotes the formation of high quality char residue. Replacement of DOP with PSPE provided PVC blends which exhibited high thermal stability; Td, T50, Tp1 and Tp1 of 291.3 °C, 325.8 °C, 283.0 °C and 461.8 °C, respectively, were observed. The degradation of PSPE released PO2 and HPO2 radicals and a series of long chain fatty acid, which provided abundant carbon sources and acid sources for PVC blends. The flame retardant effect was mainly in the condensed phase.

Scale effects on the heat release rate, smoke production rate, and species yields for a vegetation bed

The burning of a vegetation bed was investigated employing the cone calorimeter and the furniture calorimeter for testing on a small and a large scale. Heat release rate, smoke production rate, and species yields were measured at both scales and with two different setups at the full scale. The results show a clear influence of the scale on: the peak of heat release rate, the smoke extinction area, the soot yield, and the rate of smoke release. The species yields appear to depend not only on the burning scale but also on the experimental setup. This study clearly shows that even for litter with high packing ratio, the results obtained at bench scale cannot be extended directly to the full scale.

알킬렌디아미노알킬-비스-포스폰산 유도체에 의해 처리된 중밀도섬유판의 연소성

이 연구에서는 피페라지노메틸-비스-포스폰산(PIPEABP), 메틸피페라지노메틸-비스-포스폰산(MPIPEABP), N,N-디메틸 렌디아미노메틸-비스-포스폰산(MDEDAP), 비스-디알킬아미노알킬 포스폰산(DMDAP)으로 처리된 중밀도섬유판(MDF)의 연소성을 시험하였다. 15 wt%의 알킬렌디아미노알킬-비스-포스폰산 수용액으로 MDF에 3회 붓칠하여 실온에서 건조시킨 후, 콘칼로리미터(ISO 5660-1)를 이용하여 그의 연소성을 시험하였다. 그 결과, 알킬렌디아미노알킬-비스-포스폰산 및 비스-디메틸아미노메틸 포스피닉산(DMDAP)로 처리한 시험편은 연소속도 감소에 의하여 무처리한 시험편에 비해 최대질량감소율 도달시간(<TEX>$TMLR_{peak}$</TEX>) = (340475) s을 지연시켰다. 게다가 <TEX>$CO_{mean}$</TEX>은 (0.0883~0.0963) kg/kg으로서 무처리한 시험편(0.0612 kg/kg)보다 높게 측정되었다. 특별히 화학 첨가제 수용액으로 처리한 시험편의 비소화면적(<TEX>$SEA_{mean}=5m^2/kg{\sim}21.5m^2/kg$</TEX>)은 무처리한 시험편의 비소화면적(<TEX>$-426.8m^2/kg$</TEX>) 보다 높았다. 따라서 알킬렌디아미노알킬-비스-포스폰산 및 비스-디알킬아미노알킬 포스폰산으로 처리된 MDF의 시험편은 무처리한 MDF 시험편의 난연성을 향상시킨 것으로 판단된다. 그러나 연기발생량 감소에는 부정적인 영향을 주었다. This study was performed to test the combustive properties of Medium Density Fibreboard (MDF) specimens treated with piperazinomethyl-bis-phosphonic acid (PIPEABP), methylpiperazinomethyl-bis-phosphonic acid (MPIPEABP), and N,N-dimethylethylenediaminomethyl-bis-phosphonic acid (MDEDAP). MDF Plates were painted in three times with 15 wt% solution of the alkylenediaminoalkyl-bis-phosphonic acids at the room temperature, respectively. After drying specimen treated with chemicals, combustive properties were examined by the cone calorimeter (ISO 5660-1). It was indicated that the specimens treated with chemicals showed the later time to peak mass loss rate (<TEX>$TMLR_{peak}$</TEX>) = (340475) s than that of virgin plate by reducing the burning rate. In adition, the specimens treated with chemicals showed the higher <TEX>$CO_{mean}$</TEX> production (0.0883~0.0963) kg/kg than that of virgin plate. Especially, the specimens treated with chemicals showed the higher mean smoke extinction area (<TEX>$SEA_{mean}$</TEX>) (<TEX>$5m^2/kg{\sim}21.5m^2/kg$</TEX>) than that of virgin plate. Thus, It is supposed that the combustion-retardation properties were improved by the partial due to the treated alkylenediaminoalkyl-bis-phosphonic acids in the virgin MDF Plate. However, It gave a negative effect on smoke reduction.

The Impact of Metal Oxides on the Combustion Behavior of Ethylene–Vinyl Acetate Coploymers Containing an Intumenscent Flame Retardant

The objective of this work was to compare the flame retardancy of intumescent flame retardant ethylene–vinyl acetate (EVA/IFR) composites containing different metal oxides including lanthanide oxide, iron oxide, the mixture of iron oxide and lanthanide oxide, and lanthanum ferrite nanocrystalline (LaFeO3). A novel compound containing iron and lanthanum, LaFeO3 was successfully prepared. The EVA/IFR composites with these different coadditives were then fabricated through a melt blending process. Thermogravimetric analysis data showed that these different coadditives could increase the char residue formation. Cone calorimeter results revealed that these different coadditives and IFR could clearly change the decomposition behavior of EVA and form a char layer on the surface of the composites, consequently resulting in efficient reduction of the flammability parameters, such as heat release rate, total heat release, average mass loss rate, average smoke extinction area, and so on. Moreover, significant improv...

Research on the Capability and Application of Flame Retardant Cable

This paper, analyzes some parameters with the help of Cone Calorimeter (CONE) for the time to ignition, smoke extinction area, heat release rate, carbon monoxide yield and mass loss rate. The results show that the fire retardant agents affect KVV’s flame retardant property. Such as TTI ( time to ignition ) is prolonged to nearly two times, and the average HRR ( heat release rate ) reduces about 18% compared with the ordinary one and the maximum HRR down about 33%of its counterpart.

Fire Behaviour Enhancement of Epoxy Polymer Mortars Modified with Flame Retardant Systems

In the present study, fire reaction improvement of an epoxy polymer mortar (PM) formulation, induced by polymer modification with three different flame retardant (FR) systems, was analyzed and quantified. For this purpose, several epoxy PM formulations, modified with different contents and/or types of phosphate, metal hydroxide and brominated based FR systems, were manufactured and tested for both, fire reaction and flexural strength. The results were compared with those of plain epoxy PMs. Fire reaction of PM formulations was assessed by means of the Oxygen Consumption Calorimeter test, also known as Cone Calorimeter test. This test allows the determination of the main parameters that assess fire reaction behaviour of combustible materials: heat release rate, smoke extinction area, carbon dioxide and monoxide release rates, and ignitability. Test results revealed that all FR systems, in particular the phosphate based one, are effective in improving fire reaction performance of epoxy PMs. Moreover, this improvement is attained without significant losses of bearing carrying capacity of PM materials.

Influence of Cu2+‐organic montmorillonites on thermal decomposition and smoke emission of poly(vinyl chloride) by cone calorimetric study

AbstractCu2+‐Organic montmorillonites were prepared by modifying Na+ montmorillonite (Na+‐MMT) with silane coupling agents and cupric sulfate. PVC/organic montmorillonite composites were prepared by the melt intercalation method. Morphological structure of modified MMT and PVC/MMT was obtained by using XRD and SEM. The XRD results showed that silanes and Cu2+ were intercalated among interlayers and that modified MMT may have exfoliated dispersion in PVC. Effects of Cu2+‐organic montmorillonites on decomposition and smoke emission of poly(vinyl chloride) (PVC) in the flaming mode were investigated by using a cone calorimeter at an incident heat flux of 25 kW·m−2. Cone experimental data demonstrated that the Cu2+‐organic montmorillonites prepared were new effective smoke suppressants. They clearly promoted an early HCl elimination, crosslinking reactions, and char residue formation, based upon the decomposition parameters of mass loss, mass loss rate, and time of initial decomposition (tinitial). Cu2+‐Organic montmorillonites decreased peak heat release rate, total heat release, peak smoke production rate, total smoke production, and smoke extinction area during the flaming process. The smoke‐reducing efficiency of Cu2+‐organic montmorillonites (Cu2+‐OMMTs) was the best. However, the content of cupric ion was only 0.6–0.8% in Cu2+‐OMMTs and 0.03–0.04% in PVC composites. They may make the smoke‐reducing efficiency reach 45–50%. This result further demonstrates that Cu2+ ion is a very effective smoke suppressant for PVC. J. VINYL ADDIT. TECHNOL., 13:31–39, 2007. © 2007 Society of Plastics Engineers.

Calculating FED and LC 50 for testing toxicity of materials in bench-scale tests with a cone calorimeter

Thermal properties and smoke toxicity upon burning combustibles, especially polymers, are two key aspects to be considered in fire hazard assessment. The cone calorimeter is demonstrated to be a useful bench-scale apparatus to evaluate the thermal properties. Even some key parameters on smoke, such as the smoke extinction area, the carbon dioxide and carbon monoxide concentrations can be measured. As most cone tests are conducted under well-ventilated conditions, there are arguments on whether the cone calorimeter is suitable for assessing the smoke toxicity. In this paper, the calculation procedure for the ‘lethal concentration of the fire effluent emitted to produce death in 50% of test animals for a specified exposure time’ LC 50 and the fractional effective dose FED based on the cone data will be clarified. The objective is to inspect how the concentrations of toxic gases upon burning polymers can be derived from such bench-scale tests. Cone data on polycarbonate sheets are taken as examples to illustrate the procedure. The values of LC 50 deduced from measuring only the carbon monoxide will be discussed. From the study, there might be misinterpretation in using the gas concentration measured in the duct of the cone calorimeter. An appropriate control volume should be taken to ensure that all toxic products are collected.

Effect of copper chelate of pyridineanilide modified montmorillonite on the flammability and thermal stability of polypropylene

Polypropylene (PP) compositions with montmorillonite (MMT) modified with either pyridineanilide (PyA) or its copper chelate (CuPyA) were the subjects of our study. The effects of PyA/MMT and CuPyA/MMT on the following properties of PP compositions were studied using cone calorimetry: time to ignition (TTI), combustion time, heat release rate (HRR), heat of combustion, CO and CO2 evolution and specific smoke extinction area (SEA). It has been found that the composition PyA/MMT:PP (5:95, MH2) showed the best flame retardant properties. Thermal stability of the compositions investigated has been determined by thermogravimetric analysis. Introduction of PyA/MMT as well as of CuPyA/MMT significantly improves thermal stability of PP, although what concerns an increase in onset temperature slightly better effect has been observed in case of the samples containing copper.

Synthesis, characterization and flame retardancy of methacrylated phosphate/diphosphate

AbstractMethacrylated phosphate (MAP) and diphosphate (MADP) and were synthesized using diethylphosphoric acid and glycidyl methacrylate, and were characterized by FTIR, NMR and elemental analysis. The thermostability and combustion behaviours of UV‐cured MAP, MADP and their blend films were investigated by thermogravimetric analysis, limiting oxygen index (LOI) and cone calorimeter tests. The results obtained have shown that the samples containing a higher percentage of MAP exhibit relatively lower thermostability at lower temperatures while higher thermostability at elevated temperatures and more char was formed compared with those containing lower percentage of MAP. The average heat release rate (HRR), the smoke extinction area (SEA) and the total smoke production (TSP) during combustion decreased by increasing the MPA content in the films. The LOI values increased from 26.8 to 28.5 by increasing the content of MADP, which depended on the increasing gel content of the UV‐cured films. Compared with MADP, MAP was better in a real fire as it displayed lower HRR, SEA and TSP values, although the LOI was lower than that of MADP. These new compounds can effectively improve flame retardancy if used as components in UV‐curing formulations. Copyright © 2004 Society of Chemical Industry

Effect of scale and fuel type on the characteristics of pool fires for fire fighting training

This paper examines the effects of pool size and fuel type on the characteristics of pool fires. The fuels studied include hydrocarbon solvents, alcohol and their blends. The large-scale experiments were conducted on 0.445 and 1 m diameter pools in two enclosures: 41 m long×5.4 m wide×2.4 m high and 25 m long×2.7 m wide×2.4 m high, under a ventilation rate of 1–1.2 m/s. In these tests, measurements of the fuel pyrolysis mass loss rate, heat release rate (from CO 2 and CO concentrations as well as oxygen depletion), smoke extinction area (from laser attenuation), total heat flux emanating from the flame, and the yields of CO 2 and CO were made. Bench-scale tests were conducted using the same fuels and fuel blends on 100 mm× 100 mm pool fires in a Cone Calorimeter—a well-known fire test method. The hydrocarbon+alcohol fuel blends are used to create large pool fires for fire fighting training. The aim of this study was to: (1) Formulate a fuel blend which will produce a “hot” fire for realistic fire fighting training while generating a minimal quantity of smoke to comply with the pollution regulations. (2) Investigate the effect of fuel type and scale on the properties of the pool fires. (3) Make comprehensive measurements on pool fires in tunnels which can be used for validating mathematical fire models. This study has resulted in the formulation of a fuel blend which satisfies the requirements of fire fighting training as well as Environment Protection Authority of New South Wales. The bench and the large-scale results correlate well showing good agreement between the heat of combustion, smoke extinction area (SEA) and the yields of CO 2 and CO. The SEA increases with the CO and CO 2 yields which in turn increase with the carbon fraction and the aromatic content of the fuel/fuel blend. The SEA correlates strongly with the CO and CO 2 yields and in both the correlations, the entire data collapse on a single curve. These correlations indicate that the SEA and the CO 2 and CO yields vary mainly with the fuel type, and not so much with the pool size. The flame heat flux increases with the carbon content in the fuel.

Assessment Of Smoke Production From Building Products

By use of test data from the Cone Calorimeter bench scale test and two full scale fire tests (IS0 Room Comer Test and CSTB Room Fire Test), relationships between smoke test data for the two scales were investigated. The study was based on test results for 38 products. Bench scale and full scale smoke production were normalized to either area burnt, mass loss or heat release and then compared. The most interesting parameter was smoke production per heat release, and for the products tested in the CSTB Room Fire Test there was found good correlation and a correlation coefficient of 0.99. It was shown that smoke production in full scale was only about 45-60% of what was found in bench scale, and this is probably due to secondary combustion which occurs in the hot smoke layer. Before a secondary combustion occurs, the room fire is ventilation controlled and can produce more smoke than is found in bench scale. Thus the full scale fire influences smoke production in a way that may hinder relationship between bench scale and full scale smoke parameters. Full scale smoke test data from the IS0 Room Corner Test were difficult to calculate, due to problems with finding the net heat release from the burnt products and the estimated burnt area. A one-to-one relationship between bench scale and full scale for the average effective heat of combustion (hhWg) was found and the plot obtained a correlation coefficient of 0.99. Since direct mass loss measurements are not done in these full scale tests the smoke extinction area (SEA) is actually identical to smoke produced per heat release (TSP/THR).