Numerical and experimental investigation of ultrasound effects on filtration process in wire-wrapped filter tube

Abstract

Refinery filtration processes often face challenges related to rapidly increasing permeate pressure differentials and the consequent need for frequent back-flushing. This study investigates the impact of high-intensity immersed sonotrode ultrasound device on flow patterns to address these issues, both numerically and experimentally. Numerical simulations reveal that ultrasound promotes axial circular mixing of the bulk fluid, increasing average flow velocities around the filter tube from 5.11 × 10-5 m/s to 8.76 × 10-3-6.09 × 10-2 m/s, thereby facilitating cleansing of filter tube surfaces. Additionally, high-frequency pressure fluctuations contribute to enhancing the filtration process during positive pressure phases, while robust online back-flushing effects are generated during negative pressure phases. Although the wire-wrapped filter tube attenuates ultrasound energy as it penetrates the tube gaps, ultrasound still induces turbulent mixing inside and outside the filter tubes, aiding in the removal of impurities from the gaps. The utilization of ultrasound is demonstrated to not inflict harm on upstream and downstream facilities. Experimental results demonstrate that ultrasound-assisted filtration with 600 W and 1000 W power inputs reduces filtration pressure differences by 18 % and 73 %, respectively, affirming ultrasound’s effectiveness in mitigating and preventing blockages, highlighting its significance for industrial applicability.

Keywords

• Ultrasound
• Filtration enhancement
• Fast fourier transfer
• Back-flushing
• Turbulent mixing