Contact
    Start Publications Experimental investigation on characteristics of venturi ...
    ←  Publication Finder
    Attension

    Experimental investigation on characteristics of venturi cavitating flow and Rhodamine B degradation in methanol solution

    Year: 2022

    Journal: Flow Meas. Instrum., Volume 85, JUN

    Authors: Zhang, Jiahui; Luo, Jingquan; Wang, Yiwei; Dong, Bo; Xu, Zhen; Wang, Lin; Liu, Aixian; Guo, Xuqiang

    Organizations: Technology Innovation Program of Karamay [2020CGZH0001]; Xinjiang Uygur Autonomous Region Natu-ral Science Foundation [2020D01B64]; Chinese National Natural Sci-ence Foundation [22008257]; Youth Foundation of the University Research Program of Xinjiang Uygur Autonomous Region [XJE-DU2020Y044]; Research Foundation of China University of Petro-leum-Beijing at Karamay [XQZX20190043]

    Keywords: Hydrodynamic cavitation; Venturi reactor; Bubble dynamics; Pressure pulsation; Vibration; Degradation

    Hydrodynamic cavitation (HC) commonly occurs within industrial pipelines and its unsteady flow characteristics are of great significance for energy conservation and efficiency improvement. This study investigates the effects of methanol concentration (0-20 wt%) on the cavitating flow characteristics and the degradation of Rhodamine B (RhB) under operating conditions of a 0.7 MPa pressure drop, temperature of 30 degrees C, 200 passes through a venturi reactor, and an initial RhB concentration of 40 mu mol/L. The transient cavitation behavior was monitored using a high-speed camera. The cavitation images show that the presence of methanol generates more stable bubbles, which results in less violent bubble collapse. The pressure pulsation and vibration induced by cavitation flow were synchronously measured using high-frequency pressure and acceleration sensors. The spectral analyses of the pressure pulsation indicate that methanol has no effect on the dominant frequency (~5.5 Hz) at different positions, and the amplitude initially increases with increasing methanol concentration and then stabilizes. The pressure pulsation intensity increases due to the increased vapor pressure of the solution. The vibration spectral analyses show that methanol has little effect on the peak frequencies, which occur near 4.0 kHz and 14.3 kHz of the low and high-frequency bands, respectively, whereas the peak amplitude decreases with increasing methanol concentration. The per-pass degradation model of RhB in methanol solution considering pyrolysis of methanol was verified for the first time and show to adequately describe the experimental data. The degradation percentage and per-pass degradation factor decrease with increasing methanol concentration. The reduced surface tension of the solution prolongs the bubble lifespan and prevents bubble coalescence, thus weakening the vibration and degradation performance. The results provide important insight for cavitation applications and degradation modeling of mixed solutions.
    View publication