Modeling of Pulse Combustion Drying

Zbicinski, L, EquipmenL technology, perspectives and modeling of pulse combustion drying. Journal of Chemical Engineering, 2002, 86, 33 6. 

I. Zbicinski, Equipment, Technology, Perspectives and Modeling of Pulse Combustion Drying, Chemical Engineering Journal, 86 33-46 (2002). 

Wu, Z., 2007. Mathematical modeling of pulse combustion and its applications to innovative thermal drying techniques. Diss., National University of Singapore, Singapore. 

A third example of the role of kinetic modelling in the analysis of practical combustion systems at high temperatures is in simulations of pulse combustion. Pulse combustors have been used for many years in propulsion, industrial processes such as drying, and in home furnaces, where they are valued for their thermal efficiency and low NOx production rates. However, until kinetic modelling was used to analyze the role of thermal ignition in these systems, it had been impossible to understand the principles of pulse combustion and the real reasons for their good performance. 

The only validated CFD model of a pulse combustion spray-drying process has been presented by Zbicinski et al (1999) and Smucerowicz (2000). The two-dimensional axi-symmetric CFD calculations of water evaporation and drying of salt solutions in the oscillating flow of a continuous phase were carried out for a valved pulse combustor. Extensive experiments (PDA, LDA, temperature, noise, pressure measurements) to determine the inlet conditions and also to validate the model were performed for a horizontal pulse combustion dryer (Smucerowicz, 2000). Sinusoidal axial velocity oscillations have been defined as follows ... 

Wu and Liu (2002) analyzed the mechanism of the pulse combustion spray drying of salt solution in an oscillating flow field produced by a Helmholtz-type pulse combustor with an external flapper valve. The solution was atomized directly by the pulsating flow in the combustor tailpipe, which reduced the average droplet diameter by about 50% in relation to conventional nozzle atomization. An optical analyzer was applied to measure the droplet size distribution in the spray in order to determine the initial conditions for the CFD model of the process. The results of CFD simulations enabled the average residence time of droplets in the drying chamber (ca. 0.1 s) and the... 

Kuts, P. S., Akulich, P. V., Grinchik, N. N., Strumillo, C., Zbicinski, I., Nogotov, E. F., 2002. Modeling of gas dynamics in a pulse combustion chamber to predict initial drying process parameters./. Chem. Eng. 86 25-31. 

Data generated using the experimental techniques described above are used to formulate hydrodynamic models that may be used to predict reactor performance. In this section, studies that employ chemical reactions to evaluate mass transfer and contacting efficiency are described. Selected references are shown in Table 7. Dry et al. have applied hot air pulses as a reacting tracer [87]. Chemical reactions used to probe gas phase hydrodynamics include thermal decomposition of sodium bicarbonate, ozone decomposition, coal combustion, and FCC coke combustion. 

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