DAYLIFF BUF 4, Installation & Operating Manual

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9
4. MAINTENANCE
The key to getting good service from a UF module is maintenance. The main maintenance
procedure required is cleaning/flushing. The flushing cycle is automated to ensure it's not
forgotten or skipped which can be detrimental to the life of the UF membrane. The
filtration cycle (about 30mins) will automatically alternate with the flushing operation that
removes particulates from the UF membrane.
4.1 CIP
A clean in place (CIP) operation includes flushing operation and chemical recycle to clean
the UF membrane. The CIP is an on demand operation. The frequency of CIP is dependent
on the feed water quality but can range from 1 to 5 months. Prior to a CIP operation, the
routine flushing operation is performed. After completing the flushing operation, CIP
chemicals are recycled/re-circulated from the CIP chemical tank to UF membrane while
monitoring the pH until there is no change in pH.
The process operating parameters for the cleaning steps are provided in table below.
Summary of Cleaning Process
Flushing Frequency
Once every 20 to 60 minutes (water source
or pilot test reaults)
Flushing Duration
30 to 120 seconds
2
150 to 250 Lm h
When TMP* exceeds 1.0 bar above starting
/ initioal TMP* (at same temperature)
120 minutes (recycle and soak) or longer
(until no change in pH)
Check with Dayliff retailer for approved
chemicals
2
50L/m h
0
5-45 C
Flushing Flux
Clean in
Place
Frequency
Duration
Cleaning Solutions
Cleaning Flux per
Module
Temperature Range
An Alkali CIP chemical is first used followed by an acid CIP chemical. During the CIP
operation, the flushing timer setting are adjusted to say 2hours to allow use of the Flushing
tanks as the CIP tank using the feed pump. A small chemical filtrate stream will also be
collected and must be recycled to the chemical cleaning tank. Note that the CIP solution
can be heated up to 40ºC to improve its effectiveness at removing contaminants from the
UF membrane.
**TMP =Trans-Membrane Pressure (filtrate pressure minus feed pressure)