关键词: 搅拌槽, 宏观不稳定, 功率谱密度, 小波分析, 扭矩, 信号处理

Abstract: Experiments were carried out in a flat-bottom cylindrical stirred tank with 0.476 m in diameter. The digital-signal processing approaches for macro-instability were analyzed and the combined approach of power spectral density and wavelet analysis was proved to be suitable for analyzing one-dimensional low-frequency signal with noise and peak value. The torque of the impeller was measured by torque transducer and analyzed by using the combined approach. The results show that there are macro-instabilities in the stirred vessel. The dimensionless macro-instability frequency (f/N) obtained by the combined approach was in good agreement with those from the literature. The combined approach of power spectral density and wavelet analysis was proved to be a useful tool for the investigation of macro-instability phenomenon.

Key words: stirred vessel, macro-instability, power spectral density, wavelet analysis, torque, signal processing