Two-Dimensional CFD Simulation of Reducing Operating Pressure Effect on the System Hydrodynamics in a Downer Reactor

  • Pilaiwan Chaiwang Chulalongkorn University
  • Benjapon Chalermsinsuwan Chulalongkorn University
  • Pornpote Piumsomboon Chulalongkorn University

Abstract

The effect of the system hydrodynamics in a circulating fluidized bed downer (CFBD) reactor with a reducing operating pressure and solid mass flux on the hydrodynamics in a downer reactor were evaluated using a two-dimensional computational fluid dynamics simulation. Five low operating pressure conditions (0.90 to 0.99 atm) and four different solid mass fluxes (250 to 1,000 kg/m2 s) were explored. The simulation results demonstrated that the CFBD reactor had a higher mean free path when operated with a low solid mass flux than with a high solid mass flux. Moreover, a large difference between the operating and atmospheric pressures induced a high system turbulence or oscillation. The CFBD reactor with hydrodynamic fluctuation showed a good solid circulation between the gas and solid particles, as reflected by the solid volume fraction and velocities and granular temperature. These phenomena will be suitable for the chemical reaction systems. Therefore, a suitable solid mass flux was in the range of 500 to 750 kg/m2 s for all operating pressures

Author Biographies

Pilaiwan Chaiwang, Chulalongkorn University

Fuels Research Center, Department of Chemical Technology, Faculty of Science, Chulalongkorn University, 254 Phayathai Road, Pathumwan, Bangkok 10330, Thailand

Benjapon Chalermsinsuwan, Chulalongkorn University

Fuels Research Center, Department of Chemical Technology, Faculty of Science, Chulalongkorn University, 254 Phayathai Road, Pathumwan, Bangkok 10330, Thailand

Center of Excellence on Petrochemical and Materials Technology, Chulalongkorn University, 254 Phayathai Road, Pathumwan, Bangkok 10330, Thailand

Pornpote Piumsomboon, Chulalongkorn University

Fuels Research Center, Department of Chemical Technology, Faculty of Science, Chulalongkorn University, 254 Phayathai Road, Pathumwan, Bangkok 10330, Thailand

Center of Excellence on Petrochemical and Materials Technology, Chulalongkorn University, 254 Phayathai Road, Pathumwan, Bangkok 10330, Thailand

Published
2017-03-31
How to Cite
CHAIWANG, Pilaiwan; CHALERMSINSUWAN, Benjapon; PIUMSOMBOON, Pornpote. Two-Dimensional CFD Simulation of Reducing Operating Pressure Effect on the System Hydrodynamics in a Downer Reactor. Engineering Journal, [S.l.], v. 21, n. 2, p. 133-149, mar. 2017. ISSN 0125-8281. Available at: <http://engj.org/index.php/ej/article/view/1152>. Date accessed: 24 may 2017. doi: https://doi.org/10.4186/ej.2017.21.2.133.
Section
Modern Engineering Technology

Keywords

Computational fluid dynamics, Circulating fluidized bed downer reactor, Hydrodynamics, Reduced pressure, Simulation


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