Alternatively permutated conic baffles generate vortex flow field to improve microalgal productivity in a raceway pond

Jun Cheng; Wangbiao Guo; Chengyi Cai; Qing Ye; Junhu Zhou

doi:10.1016/j.biortech.2017.10.031

Alternatively permutated conic baffles generate vortex flow field to improve microalgal productivity in a raceway pond

Bioresour Technol. 2018 Feb:249:212-218. doi: 10.1016/j.biortech.2017.10.031. Epub 2017 Oct 10.

Authors

Jun Cheng¹, Wangbiao Guo², Chengyi Cai², Qing Ye², Junhu Zhou²

Affiliations

¹ State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China. Electronic address: juncheng@zju.edu.cn.
² State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China.

PMID: 29045924
DOI: 10.1016/j.biortech.2017.10.031

Abstract

Alternatively permutated conic (APC) baffles were proposed to generate vertical and horizontal vortex flow to intensify mixing and mass transfer in a raceway pond. Both clockwise vortexes were generated before and after conic baffles in the main stream to increase perpendicular velocity by 40.3% and vorticity magnitude by 1.7 times on vertical cross section. Self-rotary flow around conic baffles and vortex flow among conic baffles were generated to increase perpendicular velocity by 80.4% and vorticity magnitude by 4.2 times on horizontal cross section. The bubble generation time and diameter decreased by 25.5% and 38.7%, respectively, while bubble residence time increased by 84.3%. The solution mixing time decreased by 48.1% and mass transfer coefficient increased by 34.0% with optimized relative spacing (ε) and height (ω) of conic baffles. The biomass productivity of Spirulina increased by 39.6% under pure CO₂ with APC baffles in a raceway pond.

Keywords: Bubble generation; Conic baffles; Mass transfer; Microalgae; Vortex flow.

MeSH terms

Biomass
Microalgae*
Photobioreactors*
Ponds