Scale-up of vortex based hydrodynamic cavitation devices: A case of degradation of di-chloro aniline in water

• Published in: Ultrasonics sonochemistry 2021-01, Vol.70, p.105295, Article 105295
• Main Authors: Ranade, Vivek V., Prasad Sarvothaman, Varaha, Simpson, Alister, Nagarajan, Sanjay
• Format: Article
• Language: English
• Subjects: Hydrodynamic cavitation; Original; Per-pass degradation; Scale-up; Vortex-based devices
• ISSN: 1350-4177; 1873-2828; 1873-2828
• DOI: 10.1016/j.ultsonch.2020.105295

•Vortex based hydrodynamic cavitation devices degrade complex pollutants in water.•It is essential to use per-pass degradation model for evaluating efficacy of cavitation devices.•For the first time, experimental data for nearly 200 times scale-up is presented.•Degradation performance first decreases with increase in scale and then plateaus. Hydrodynamic cavitation (HC) is being increasingly used in a wide range of applications. Unlike ultrasonic cavitation, HC is scalable and has been used at large scale industrial applications. However, no information about influence of scale on performance of HC is available in the open literature. In this work, we present for the first time, experimental data on use of HC for degradation of complex organic pollutants in water on four different scales (~200 times scale-up in terms of capacity). Vortex based HC devices offer various advantages like early inception, high cavitational yield and significantly lower propensity to clogging and erosion. We have used vortex based HC devices in this work. 2,4 dichloroaniline (DCA) – an aromatic compound with multiple functional groups was considered as a model pollutant. Degradation of DCA in water was performed using vortex-based HC devices with characteristic throat dimension, dt as 3, 6, 12 and 38 mm with scale-up of almost 200 time based on the flow rates (1.3 to 247 LPM). Considering the experimental constraints on operating the largest scale HC device, the experimental data is presented here at only one value of pressure drop across HC device (280 kPa). A previously used per-pass degradation model was extended to describe the experimental data for the pollutant used in this study and a generalised form is presented. The degradation performance was found to decrease with increase in the scale and then plateaus. Appropriate correlation was developed based on the experimental data. The developed approach and presented results provide a sound basis and a data set for further development of comprehensive multi-scale modelling of HC devices.