A theoretical investigation of the ignition of a combustible gas by a heated vertical surface is described. Laminar, natural convection conditions were treated by numerical solution of the nonsimilar boundary layer equations, assuming an ideal gas and a one-step reaction and neglecting radiation. Th
Ignition of combustible fluids by heated surfaces
β Scribed by J. Michael Bennett
- Book ID
- 105358986
- Publisher
- American Institute of Chemical Engineers
- Year
- 2001
- Tongue
- English
- Weight
- 1010 KB
- Volume
- 20
- Category
- Article
- ISSN
- 1066-8527
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β¦ Synopsis
Abstract
Industrial machinery fires are commonly caused by flammable operating fluids leaking onto hot machinery surfaces. This paper discusses doctoral research currently underway to identify the dominant fundamental mechanisms controlling the overall ignition process of combustible liquid streamβfed pools impinging on heated surfaces. Experiments are now underway to characterize these processes, via modeling and the use of dimensional analysis, to be able to predict the minimum surface ignition temperature for a given set of fluid and surface properties, more accurately define safe operating boundaries of equipment to mitigate fire events, and suggest optimal designs to widen the safe operating envelope. As a result of recent analyses, a surface modification technique has been proposed to use a pattern of microβcavities, sized to prevent fluid seepage, on the exterior of the heated surface to reduce the heat transfer from surface to liquid (due to reduced direct contact), and inhibit the formation of superheated vapor films. This behavior could increase the temperatures necessary for ignition, permitβting a wider range of safe operating conditions.
π SIMILAR VOLUMES
The ignition of a stoichiometrie methane-nitric oxide mixture by stationary pilot flames has been investigated. These pilot flames can be burned indefinitely in the surrounding explosive mixture without causing ignition if the temperature or mass flow of the pilot is insufficient. For very small pil