Effect of flame pulsating on heat transfer rate and quality of cutting surface for impinging flame jet
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Abstract
The objective of this research is to study the effect of pulsating of flame jet on heat transfer rate on surface with flame jet impingement and quality of cut surface. In the experiment, we used LPG as gas fuel and pure oxygen gas as oxidizer and mixed at different equivalent ratio. The effect of cutting torch nozzle-to-plate distance was also investigated. The experimental results show that the cutting torch nozzle-to-plate distance at h = 5 mm and 6 mm give the maximum heat transfer rate. When decreasing the equivalent ratio or increasing the frequency of pulsating flame jet, the heat transfer rate on impingement surface is enhanced. The condition for maximum heat transfer rate is flame jet with equivalent ratio Ø=1.07, at nozzle-to-plate distance h = 6 mm and frequency of pulsating at f=20 Hz. The heat transfer rate is increased about 30% when compare with case of continuous flame jet. For the quality of cut steel plate with thickness 12 mm, it was found that the optimum condition is found at equivalent ratio Ø=1.29, nozzle-to-plate distance h=2 mm and frequency of pulsating at f=10 Hz. The pulsating flame jet can uniform the surface cut when compare to continuous flame jet.
Article Details
Copyright @2021 Engineering Transactions
Faculty of Engineering and Technology
Mahanakorn University of Technology
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