气动射流除泡器参数仿真分析及优化

Simulation and Optimization on Parameters of Pneumatic Jet Bioreactor Defoamer

为解决发酵中大量泡沫导致的工作体积减小、环境污染等问题,研制出一种环保生物发酵除泡器,用纯机械的拉瓦尔结构达到无污染、高除泡效率的目的.通过三维共轭有限体积模拟,比较了传统螺旋式和拉瓦尔式除泡器结构在同等工作条件下的进口流速和负压性能.针对拉瓦尔结构进行了参数分析,利用ANSYS Workbench进行了响应面和敏感度分析,并进行了优化.结果表明:相较于螺旋式除泡器,以拉瓦尔结构为核心的除泡器泡沫进口处平均气体流速提高了2~4倍,入口平均负压提高了57~599 Pa;拉瓦尔结构的最佳喉部半径为5 mm,压缩段长度50 mm,扩张段长度85 mm.采用拉瓦尔结构除泡器有望推动生物发酵行业低能耗、零排放,助力"双碳"目标的实现.

To resolve the problem of working volume reduction and environmental pollution caused by a large number of foams in fermentation,a type of environmentally friendly fermentation defoamer was proposed in this study.For the aim of pollution-free and high defoaming efficiency,a purely mechanical Laval structure was used for defoamer.Under the same working conditions,the inlet flow rate and negative pressure performance of the traditional spiral and Laval defoamer structures were compared through a three-dimensional conjugate finite volume simulation.The effects of the Laval structure parameter on the inlet flow rate and negative pressure performance of the Laval defoamer were investigated.Besides,ANSYS Workbench was used to analyze response surface(RS)and sensitivity to perform optimization.Results show that compared with the spiral deaerator,the average airflow velocity at the foam inlet of the defoamer with Laval as the core structure increases by 2-4 times.The inlet negative pressure increase by 57-599 Pa.The optimal throat radius of the Laval structure is 5 mm,the length of the compression section is 50 mm,and the length of the expansion section is 85 mm.The Laval defoamer is expected to promote low energy consumption and zero emissions in the bio-fermentation industry,and help achieve the“dual carbon”goal.