TITLE:
Integrity Assessment of Pipe System in a Full-Scale Membrane Water Treatment Plant
AUTHORS:
H. K. Oh, J. Y. Eom, S. H. Kang, H. C. Yoo, Y. J. Kim, D. M. Yoon, J. H. Lim
KEYWORDS:
Fatigue; Integrity; Lifetime; Membrane; Pipe System; Vibration
JOURNAL NAME:
Journal of Water Resource and Protection,
Vol.6 No.4,
March
28,
2014
ABSTRACT: The pipe
system roles as a main bridge between membrane modules and pumps in membrane
water treatment plants. Membrane operation modes generally consist of
filtration and backwash processes in a normal mode, a pressure decay test as an
integrity test and a chemical circulation through pipe system in a cleaning
mode. Thus factors effecting on membrane performance should be sufficiently
considered before design and operation. This study evaluated flow analysis for
vibration diagnostic and evaluation of the fatigue lifetime in the
microfiltration system applied for a drinking water treatment plant. Vibration
of main membrane pipelines was measured to identify the source of vibration.
Also natural frequency and fluid dynamics was calculated by computational fluid
dynamics. It showed that maximum magnitude frequencies were at 12 Hz and 22 Hz,
respectively at water and air pipeline during filtration and backwash. Backwash
process caused mainly vibration on the backwash water pipe. The calculated
frequency from analysis of frequency response and CFD was in a good agreement
with the measured frequency. Fatigue analysis showed that pipelines were
getting little damage caused by vibration. Fatigue lifetime was predicted more
than 15 years under the operation condition of daily filtration, and more than
27 years under the operation condition of a daily backwash mode, resulting in
minor damage on the pipe lifetime.