Chemical Engineering & Technology, Vol.34, No.7, 1109-1115, 2011
Optimizing the Benefits of Pulse Combustion Impingement for Paper Drying
Numerical simulation results, quantifying the effects of impingement zone geometry on pulse-combustion-driven and steady-impingement heat transfer, are used to investigate the design tradeoffs between heat transfer rate (i.e., drying rate), heat transfer (jet thermal energy) effectiveness, and heat transfer enhancement due to the pulsating jet. At equal area-average heat flux, it was found that nozzle spacing and, thus, jet thermal energy effectiveness may be as much as three times greater for pulsating impingement jets as for steady-flow jets having the same temperature and mean velocity. Alternatively, at equal jet thermal energy effectiveness, the average heat flux (drying rate) with pulsating impingement may be around 2.4 times greater than with steady impingement.