Analysis on a vibration character of hollow fiber membrane bundle in MBR

Prattakorn Sittisom Prattakorn Sittisom,Yoonjae I Yoonjae I,Tomoaki Itayama Tomoaki Itayama

doi:10.54279/mijeec.v1i3.244930

Abstract

We have focused on membrane vibration in MBR to find an effective design for the reduction of membrane fouling. In the previous study, we developed a direct measurement method for membrane vibration of a hollow fiber membrane (HFM) using an accelerometer (ACM). In this study, we studied on vibration characters on an HFM bundle in a practical membrane module in MBR using the ACMs in a large transparent water tank. Three ACMs were attached at the middle (P1), top (P2) and bottom (P3) position along a center line in the HFM bundle in which air was supplied from a diffuser below the membrane module with different aeration rates from 0 to 250 L/min. The acceleration of membrane vibration time series for the X-axis direction (left-right displacement) and Z-axis direction (back-front displacement) was recorded at three positions. The average vibration amplitudes of the acceleration along both directions at each position were increased as the aeration rate was increased. The HFM bundle showed a collective vibration with a frequency peak between 0 and 50 Hz. The Z-axis motion character of HFM bundle is regarded as a sheet vibration. The obtained vibration character was useful for the new design of a membrane module in MBR against the membrane fouling.

Highlights

Membrane bioreactors (MBRs) using microfiltration membrane (MF) such as hollow fiber membrane (HFM) have been used widely in wastewater treatment as an application because MBRs can produce high water quality with minimized space and sludge production
The vibration was measured using ACMs attached on the different positions on a string of a membrane to analyze the vibration character in each position in the membrane module, the effect of the bubbling strength for the vibration character was measured because there has been no research to clarify these characters though the basic vibration characters must be essential to design the new membrane module and MBR system
As hollow fiber membranes of 102 cm in length were set in the module, the looseness of the fiber was defined as 2% looseness

Summary

Introduction

Membrane bioreactors (MBRs) using microfiltration membrane (MF) such as hollow fiber membrane (HFM) have been used widely in wastewater treatment as an application because MBRs can produce high water quality with minimized space and sludge production. In the experiment to clarify the effect on the vibration of a single string HFM with the different looseness, the comparison between ACM measurement and HSC measurement was performed. Practical MBRs use several membrane modules in which many HFM strings were bundled with high density. To fill the knowledge gap on the vibration character of HFM bundles, we conducted the experiment using a practical scale membrane module in a test chamber. The vibration was measured using ACMs attached on the different positions on a string of a membrane to analyze the vibration character in each position in the membrane module, the effect of the bubbling strength (air sparge rate) for the vibration character was measured because there has been no research to clarify these characters though the basic vibration characters must be essential to design the new membrane module and MBR system

Experimental set-up

Data Processing

Measurement of membrane vibration using ACM

Conclusion