specific optical density
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Natural wood has been used in structural applications for decades. Smoke from wood fires, additives and wood-protective coatings is a cause of death and serious injury in limited ventilation compartment. Ventilation restrictions in modern day designs complicate the combustion process and increase incomplete combustion products due to a reduction in the amount of oxygen available for fuel oxidation. Jordanian hardwood samples have been examined, tested and evaluated according to their mass loss rates, specific optical density, mass optical density, transmittance, and visibility using qualitative research used to realise the dynamics of fire phenomena. Four types of natural wood were tested under different heat fluxes with different Flaming combustion in a Smoke Density Chamber (SDC). The samples studied were Beech, Oak, Rhamnus, and Abies. The samples have been exposed to 25 and 50 kW/m2 heat fluxes in a limited ventilation compartment. Twelve samples were tested, each with dimensions of 75 x 75 mm and 10 mm thickness. An evaluation of the tested parameters, such as mass loss rate (MLR), specific optical density, transmittance, visibility and mass optical density (MOD have been carried out to determine their effectiveness as predictive parameters. Main results shows Beech has the lower values of specific optical density despite it has higher values of MLR% and MOD compared to other samples studied. Also, the mass loss rate (MLR %) increases with the heat flux even with different flaming conditions. In the opposite, there is a strong dependence for the mass optical density (MOD) on the heat flux and flaming conditions. Key conclusions have been drawn up that could be used in wood products and future works. The main objective of this work is to model the fire dynamic behavior in the pre-fire time. The results of this study can provide the bases for ventilation process and considerations of using natural woods in Jordan for different applications.


2019 ◽  
Vol 10 (4) ◽  
pp. 382-390
Author(s):  
A. A. Antoshyn ◽  
V. I. Nikitin

The existing methods for monitoring the performance of multi-criteria fire detectors do not provide for verification of their characteristics in the conditions of transition from smoldering to flame burning. The aim of the work is the development of the research methods of the environmental parameters during the transition from smoldering (pyrolysis) to flame combustion for simulation a test fire while checking the quality of multi-criteria fire detectors.A technique to conduct research of environmental parameters under conditions of heating wood samples of different sizes to a temperature of selfignition and burning crumpled and smooth paper has been developed.Changes in the concentration of carbon monoxide, specific optical density, and scattering ability during the transition from smoldering (pyrolysis) to flame burning of prepared wood and crumpled paper were studied for the first time.It is shown that the controlled environmental parameters during the transition from smoldering pyrolysis to flame burning change together. Conclusion: the speed of growth of the scattering ability of smoke decreases by 2.4 times, the speed of increase in the specific optical density and concentration of carbon monoxide increases by 2 and 5.3 times (respec-tively), during the transition from pyrolysis to flame burning of wood.


2018 ◽  
Vol 45 ◽  
pp. 00107
Author(s):  
Łukasz Zubek

The paper presents the results of tests for smoke optical density conducted on five various elements of car interior design. The tested samples were taken from the dashboard, ceiling lining, floor lining, seats and side door upholstery. A smoke density chamber was used to measure the propensity of the materials to generate smoke after being exposed to a heat source. The specific optical density, as a function of time, was determined for each material. There were two burning conditions simulated: radiant heating in the absence of ignition, and flaming combustion in the presence of supporting radiation. The highest values for specific optical density were measured for the side door upholstery and driver’s dashboard. The tests results were compared with international optical smoke density requirements for the interior design of ships and trains.


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