Experimental Study of the Effect of Confining on the Development of Fire in a Closed Compartment

Backdraft is a complex phenomenon which occurs during cases of confined fires. It appears by a fast deflagration which occurs after the introduction of oxygen into a compartment filled with hot gases rich in unburned combustible vapor. Practically, this situation could occur at the time of intervention of firemen who break the door or when a window breaks under the action of thermal stresses. Based on a strong experimental campaign, the present paper aimed to make a quantitative investigation of the effect of confining on a totally closed fire. With this focus, fire tests were carried out in a completely closed room of dimensions 1.20 m × 1.20 m × 1.02 m, with five sources of fire of different heat release rates. The same fire sources were also tested in a free atmosphere in order to get reference data. After a statistical study of data, a comparative analysis between both results has been done. Its outcome is that confining has a major impact on the quality of combustion and on the fire duration. More precisely, it has been noticed comparatively to fire tests in free atmosphere that confining increases the fire duration by 14.85 percent while it decreases the heat release rate by 21.72 percent.

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Reaction to fire tests. Determination of fire parameters of materials, products and assemblies using an intermediate scale heat release calorimeter (ICAL)

10.3403/01956938u ◽

2015 ◽

Keyword(s):

Heat Release ◽

Fire Tests ◽

Fuel ◽

10.1016/j.fuel.2021.120746 ◽

2021 ◽

Vol 297 ◽

pp. 120746

Author(s):

Hao Shi ◽

Kalim Uddeen ◽

Yanzhao An ◽

Yiqiang Pei ◽

Bengt Johansson

Keyword(s):

Heat Release ◽

Statistical Study ◽

Pressure Sensors ◽

Engine Knock

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Reference materials for the study of polymorphism and crystallinity in cellulosics

Powder Diffraction ◽

10.1017/s0885715612000930 ◽

2013 ◽

Vol 28 (1) ◽

pp. 18-31 ◽

Cited By ~ 15

Author(s):

T. G. Fawcett ◽

C. E. Crowder ◽

S. N. Kabekkodu ◽

F. Needham ◽

J. A. Kaduk ◽

...

Keyword(s):

Powder Diffraction ◽

Reference Materials ◽

Reference Data ◽

Powder Diffraction File ◽

Material Identification ◽

Cellulosic Materials ◽

Chemical Substitution

Eighty specimens of cellulosic materials were analyzed over a period of several years to study the diffraction characteristics resulting from polymorphism, crystallinity, and chemical substitution. The aim of the study was to produce and verify the quality of reference data useful for the diffraction analyses of cellulosic materials. These reference data can be used for material identification, polymorphism, and crystallinity measurements. Overall 13 new references have been characterized for publication in the Powder Diffraction File (PDF) and several others are in the process of publication.

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Calculations of the Heat Release Rate by Oxygen Consumption for Various Applications

Journal of Fire Sciences ◽

10.1177/073490418400200505 ◽

1984 ◽

Vol 2 (5) ◽

pp. 380-395 ◽

Cited By ~ 102

Author(s):

W.J. Parker

Keyword(s):

Oxygen Consumption ◽

High Temperature ◽

Heat Release ◽

Heat Release Rate ◽

Release Rate ◽

Fire Tests ◽

Total Heat Release ◽

Exhaust Duct ◽

Closed Systems ◽

Gas Burner

The calculation of heat release rate by oxygen consumption is based on the assumption that all materials release approximately the same amount of heat per unit mass of oxygen consumed. This technique is now being employed to determine the heat release rate of materials in various heat release rate cal orimeters. Other uses include the heat release rate of assemblies in the fire en durance furnaces and the total heat release rate in room fire tests. These dif ferent applications lead to different experimental procedures which require dif ferent formulas. The experimental choices or constraints include open or closed systems, paramagnetic or high temperature oxygen analyzers, CO2 analyzers or CO2 traps, and the use of a gas burner whose heat release rate must be deducted from the total. Various assumptions about CO levels in the exhaust duct and vitiation and humidity in the incoming air are made. General formulas for the heat release rate by oxygen consumption are developed in this paper from which the formulas for specific applications can easily be derived.

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Investigation of Surface Quality of CoCrMo Alloy Used in the Tibial Component of the Knee Prosthesis According to the Methods of Turning and Turning-Grinding

Materials Science ◽

10.5755/j01.ms.26.1.21729 ◽

2019 ◽

Vol 26 (1) ◽

pp. 41-48

Author(s):

Erkan BAHÇE ◽

M. Sami GÜLER ◽

Ender EMİR

Keyword(s):

Surface Quality ◽

Tibial Component ◽

Thermal Stresses ◽

Knee Prosthesis ◽

Cutting Speed ◽

Tool Geometry ◽

Depth Of Cut ◽

Cocrmo Alloy ◽

Grinding Method

CoCrMo alloys, which are well-known Co-based biomedical alloys, have many different types of surface integrity problems reported in literature. Residual stresses, white layer formation and work hardening layers are some those, matters which occur as a microstructural alteration during machining. Therefore, such problems should be solved and surface quality of end products should be improved. In this paper, the surface quality of CoCrMo alloy used in tibial component of the knee prosthesis produced by means of turning was investigated. An improvement was suggested and discussed for the improvement in their machinability with the developed turning-grinding method. Finite element analyses were also carried out to calculate temperature and thermal stresses distribution between the tool and the tibial component. The results showed that many parameters such as cutting speed, feed rate, depth of cut, tool geometry, and tool wear affect the surface quality of workpieces of CoCrMo alloy. In the turning-grinding method, the machining time is reduced by about six times compared to machining only method. The EDX analysis performed on the surface after machining showed that metal diffusion occurred from tool to the tibial component.

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