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对气-固流化床特别是气-固加压流化床压力脉动信号进行深入分析有助于更好地了解该类反应器内的流动行为。为了研究压力脉动信号与加压气-固流化床内流动行为的关系,以FCC催化剂为实验物料,采用密相段内径300 mm、高度3800 mm、扩大段内径600mm、高度800mm的加压流化床,对其压力脉动信号进行快速傅里叶变换(FFT)和小波分析,获得了代表气泡行为的特征频率(D5-D7);分析此频段能量特征值随表观气速的变化规律,得出了流型转变速度u_c,并考察压力对u_c的影响。结果表明:压力波动能量集中在低频,随着气速的增加能量特征值先增加后减小,压力升高u_c减小。
In-depth analysis of gas-solid fluidized bed, especially gas-solid pressurized fluidized bed pressure pulsation signals helps to better understand the flow behavior in such reactors. In order to study the relationship between the pressure pulsation signal and the flow behavior in pressurized gas-solid fluidized bed, FCC catalyst was used as the experimental material. The dense phase with an inner diameter of 300 mm and a height of 3800 mm was used to expand the pressurized flow with an inner diameter of 600 mm and a height of 800 mm (D5-D7), which is representative of bubble behavior, was obtained by fast Fourier transform (FFT) and wavelet analysis of the pressure-pulsation signals. The variation of the energy eigenvalues in this band with the apparent air velocity was analyzed. The velocity of flow pattern u_c was obtained and the effect of pressure on u_c was investigated. The results show that the energy of pressure fluctuation concentrates at low frequency. With the increase of gas velocity, the energy eigenvalue firstly increases and then decreases, and the pressure increase u_c decreases.