Stefan-Boltzmann

Spectral bandwidth of excita- Stefan-Boltzmann constant a... 

Blackbody Radiation Engineering calculations of thermal radiation from surfaces are best keyed to the radiation characteristics of the blackbody, or ideal radiator. The characteristic properties of a blackbody are that it absorbs all the radiation incident on its surface and that the quality and intensity of the radiation it emits are completely determined by its temperature. The total radiative fliix throughout a hemisphere from a black surface of area A and absolute temperature T is given by the Stefan-Boltzmann law ... 

Design Methods for Calciners In indirect-heated calciners, heat transfer is primarily by radiation from the cyhnder wall to the solids bed. The thermal efficiency ranges from 30 to 65 percent. By utilization of the furnace exhaust gases for preheated combustion air, steam produc tion, or heat for other process steps, the thermal efficiency can be increased considerably. The limiting factors in heat transmission he in the conductivity and radiation constants of the shell metal and solids bed. If the characteristics of these are known, equipment may be accurately sized by employing the Stefan-Boltzmann radiation equation. Apparent heat-transfer coefficients will range from 17 J/(m s K) in low-temperature operations to 8.5 J/(m s K) in high-temperature processes. 

I By Radiation (Wr) This heat loss is related to the difference of the fourth power of the absolute temperatures and the emissivity of the enclosure, and is represented by the Stefan-Boltzmann law expressed by (see Dwight ci al.. 1940)... 

Tj is the surface temperature of the panel, Tj, the thermometer bulb temperature, Tj the air temperature, and T the temperature of the walls of the building. F is the view factor from the bulb to the heating panel, e is the emissivity of the thermometer bulb at temperature T cr is the Stefan-Boltzmann constant (5.67 X 10 W m K " ), and is the convective heat transfer coefficient from bulb to air. 

The use of Stefan-Boltzmann s law to calculate radiation requires the knowledge of the fire s temperature and emissivity. Turbulent mixing causes fire temperature to vary. Therefore, it can be more useful to calculate radiation from data on the... 

The radiation from a black body is proportional to the fourth power of the adiabatic flame temperature, according to the Stefan-Boltzmann s law ... 

The following Stefan-Boltzmann formula applies to both plane and cylindrical surfaces ... 

Stefan-Boltzmann law and is usually written The name Stefan-Boltzmann law... 

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