SCI和EI收录∣中国化工学会会刊

›› 2015, Vol. 23 ›› Issue (3): 482-489.DOI: 10.1016/j.cjche.2014.11.028

• Fluid Dynamics and Transport Phenomena • Previous Articles     Next Articles

Effects of bubbly flow on bending moment acting on the shaft of a gas sparged vessel stirred by a Rushton turbine

Dai'en Shi1, Ziqi Cai1, Archie Eaglesham2, Zhengming Gao1   

  1. 1 School of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China;
    2 Huntsman Polyurethane, Everslaan 45, B-3078 Everberg, Brussels, Belgium
  • Received:2013-10-11 Revised:2014-05-04 Online:2015-04-03 Published:2015-03-28
  • Supported by:
    Supported by Huntsman Europe (21376016).

Effects of bubbly flow on bending moment acting on the shaft of a gas sparged vessel stirred by a Rushton turbine

Dai'en Shi1, Ziqi Cai1, Archie Eaglesham2, Zhengming Gao1   

  1. 1 School of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China;
    2 Huntsman Polyurethane, Everslaan 45, B-3078 Everberg, Brussels, Belgium
  • 通讯作者: Zhengming Gao
  • 基金资助:
    Supported by Huntsman Europe (21376016).

Abstract: The bending moment acting on the overhung shaft of a gas-sparged vessel stirred by a Rushton turbine, as one of the results of fluid and structure interactions in stirred vessels, was measured using a moment sensor equipped with digital telemetry. An analysis of the shaft bending momentamplitude shows that the amplitude distribution of the bending moment, which indicates the elasticity nature of shaftmaterial against bending deformation, follows the Weibull distribution. The trends of amplitude mean, standard deviation and peak deviation characteristics manifest an “S” shape versus gas flow. The “S” trend of the relative mean bending moment over gas flow rate, depending on the flow regime in gas-liquid stirred vessels, resulted from the competition among the nonuniformity of bubbly flow around the impeller, the formation of gas cavities behind the blades, and the gas direct impact on the impellerwhen gas is introduced. A further analysis of the bendingmoment power spectral density shows that the rather low frequency and speed frequency are evident. The low-frequency contribution to bending moment fluctuation peaks in the complete dispersion regime.

Key words: Bending moment, Bubbly flow, Stirred vessel, Fluid structure interaction, Amplitude distribution

摘要: The bending moment acting on the overhung shaft of a gas-sparged vessel stirred by a Rushton turbine, as one of the results of fluid and structure interactions in stirred vessels, was measured using a moment sensor equipped with digital telemetry. An analysis of the shaft bending momentamplitude shows that the amplitude distribution of the bending moment, which indicates the elasticity nature of shaftmaterial against bending deformation, follows the Weibull distribution. The trends of amplitude mean, standard deviation and peak deviation characteristics manifest an “S” shape versus gas flow. The “S” trend of the relative mean bending moment over gas flow rate, depending on the flow regime in gas-liquid stirred vessels, resulted from the competition among the nonuniformity of bubbly flow around the impeller, the formation of gas cavities behind the blades, and the gas direct impact on the impellerwhen gas is introduced. A further analysis of the bendingmoment power spectral density shows that the rather low frequency and speed frequency are evident. The low-frequency contribution to bending moment fluctuation peaks in the complete dispersion regime.

关键词: Bending moment, Bubbly flow, Stirred vessel, Fluid structure interaction, Amplitude distribution