Effect of Thermal Radiation From a Hot Gas Layer on Heat of Ablation

1961 ◽  
Vol 28 (7) ◽  
pp. 582-583 ◽  
Author(s):  
Robert T. Swann
Keyword(s):  
Hot Gas ◽  
1995 ◽  
Vol 13 (4) ◽  
pp. 257-260 ◽  
Author(s):  
J.C. Jones
Keyword(s):  
Hot Gas ◽  

The Forum is intended to provide for dialogue and discussion among fire experts, scientists and consultants. Contributions to The Forum will not be refereed in the conventional sense, but will be subject to review by the Journal's Editorial Board relative to appropriateness, clarity, timeliness, and scope of interest. The Editorial Board will be the sole judge of those contributions to be published. Opinions expressed, however, are those of the authors and not of the Editors or Technomic Publishing Com pany, Incorporated.


Author(s):  
Rodolfo Prediger Helfenstein ◽  
Calisa Katiuscia Lemmertz ◽  
Felipe Roman Centeno

2014 ◽  
Vol 610 ◽  
pp. 993-997 ◽  
Author(s):  
Jun Bo Huang ◽  
Jiin Yuh Jang ◽  
Chien Nan Lin ◽  
Chao Hua Wang

A two-dimensional mathematical heat transfer model for the prediction of temperature distribution within the slab has been developed by considering the thermal radiation in the walking-beam-type reheating furnace chamber and transient heat conduction in the slab, respectively. The steel slabs are heated up through the preheating, heating, and soaking zones in the furnace. Heat transfer characteristics and temperature uniformity of the slab is investigated by changing hot gas temperature. Comparison with the in-situ experimental data show that the present heat transfer model works well for the prediction of thermal behavior of the slab in the reheating furnace. The skid mark severity decreases with an increase in hot gas temperature. Keywords: Reheating Furnace, Thermal Radiation, Transient heat conduction


2004 ◽  
Vol 137 (1-2) ◽  
pp. 222-229 ◽  
Author(s):  
Jongmook Lim ◽  
Yudaya Sivathanu ◽  
Jun Ji ◽  
Jay Gore

2014 ◽  
Vol 521 ◽  
pp. 76-80
Author(s):  
Si Ke Wu ◽  
Bo Lou ◽  
Xiao Cong Wang ◽  
Kuo Ma

The flashover phenomenon in biomass boiler causes serious damages to the equipments performance as well as security of people due to people are not clear about biomass boiler running, and thus preventing flashover from happening has a positive significance on boiler running. The characteristics of biomass fuel particles have been analyzed at first, and then simplifying the structure of boiler in order to model conveniently. This essay focus on justifying the stability of combustion system of biomass boiler with catastrophe theory in combination with the measured and calculated data, it demonstrates that swallowtail catastrophe conforms to the flashover mechanism. By building energy equation, conducting dimensionless treatment and carrying out the swallowtail catastrophe research method, the instability point is obtained. The gained critical flashover temperature of hot smoke layer is 686.71°C which is similar to predecessors studies, Then changing the parameters values for the sake of calculating different hot gas layer temperatures. The higher the hot gas layer temperature is, more hazardous the flashover tends to be. The research reveals that increasing the initial temperature of air or aggrandizing area of fire grate (larger than 3.36m2) contribute to increase flashover temperatures. However, augment of vapor heat and heat transfer area have the opposite effects.


Author(s):  
K. Fukushima ◽  
N. Kohyama ◽  
A. Fukami

A film-sealed high resolution environmental cell(E.C) for observing hydrated materials had been developed by us(l). Main specification of the E.C. is as follows: 1) Accelerated voltage; 100 kV. 2) Gas in the E.C.; saturated water vapour with carrier gas of 50 Torr. 3) Thickness of gas layer; 50 μm. 4) Sealing film; evaporated carbon film(20 nm thick) with plastic microgrid. 5) Resolving power; 1 nm. 6) Transmittance of electron beam; 60% at 100 kV. The E.C. had been successfully applied to the study of hydrated halloysite(2) (3). Kaolin minerals have no interlayer water and are basically non-expandable but form intercalation compounds with some specific chemicals such as hydrazine, formamide and etc. Because of these compounds being mostly changed in vacuum, we tried to reveal the structure changes between in wet air and in vacuum of kaolin minerals intercalated with hydrazine and of hydrated state of montmori1lonite using the E.C. developed by us.


Author(s):  
Ahmed M Abdel-Ghanya ◽  
Ibrahim M Al-Helal

Plastic nets are extensively used for shading purposes in arid regions such as in the Arabian Peninsula. Quantifying the convection exchange with shading net and understanding the mechanisms (free, mixed and forced) of convection are essential for analyzing energy exchange with shading nets. Unlike solar and thermal radiation, the convective energy, convective heat transfer coefficient and the nature of convection have never been theoretically estimated or experimentally measured for plastic nets under arid conditions. In this study, the convected heat exchanges with different plastic nets were quantified based on an energy balance applied to the nets under outdoor natural conditions. Therefore, each net was tacked onto a wooden frame, fixed horizontally at 1.5-m height over the floor. The downward and upward solar and thermal radiation fluxes were measured below and above each net on sunny days; also the wind speed over the net, and the net and air temperatures were measured, simultaneously. Nets with different porosities, colors and texture structures were used for the study. The short and long wave’s radiative properties of the nets were pre-determined in previous studies to be used. Re and Gr numbers were determined and used to characterize the convection mechanism over each net. The results showed that forced and mixed convection are the dominant modes existing over the nets during most of the day and night times. The nature of convection over nets depends mainly on the wind speed, net-air temperature difference and texture shape of the net rather than its color and its porosity.


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