AQUADYN® FZ50 Series Hollow Fiber Module | OPERATION MANUAL
MICRODYN-NADIR | REVISION: B | DATE: 01/08/2020
8
4
Operation
To ensure proper operation of AQUADYN
®
FZ50 hollow fiber modules, please refer to the operating limits specified on the
product data sheet.
4.1
START-UP
A trial run is recommended prior to actual operation. This eases the membranes into operation and allows purging of any
remaining air from the system.
At start-up, gradually increase the pressure and flow rate. Then, adjust the flow of the module to approximately 60% of the
actual operating flow. Allow the system to operate under this condition for at least half a day (approximately 8 hours) or 1 to
2 days.
TABLE 1. RECOMMENDED START-UP FLOWS & FILTRATION TIMES.
Filtration Time (intervals between backwashes)
30 to 90 minutes
Backwashing Time
> 50 seconds
Backwashing Water Volume
> 200 L
4.1.1
Preservative & Air Purge
1.
After start-up, set the permeate flow to 0.5 m
3
/h (2.2 gpm) per module and discharge excess water. This will flush
out any residual preservative and air from the system.
2.
Be sure to purge the air from the piping and backwash pump. Failure to purge air from the system can result in
hollow fiber breakages during backwash.
4.2
STANDARD OPERATING CONDITIONS
TABLE 2. STANDARD OPERATION CONDITIONS FOR VARYING FEED WATER TURBIDITIES.
Type of Feed Water
Water at Low Turbidity Level (
≤
0.5
NTU)
Water at Middle Turbidity Level (0.5 to
5 NTU)
Water at High Turbidity Level (
≥
5 NTU)
Pretreatment
None
100-150 µm filter or screen
100-150 µm filter or screen
Flow Rate
a
10 m
3
/hr
(44 gpm)
3.1 to 5.2 m
3
/hr
(13.6 to 22.9 gpm)
≤
3.1 m
3
/hr
(
≤
13.6 gpm)
Circulation Flow Rate (outlet port)
0 to 7.4 m
3
/hr
(0 to 32.6 gpm)
3.7 to 7.4 m
3
/hr
(16.3 to 32.6 gpm)
7.4 m
3
/hr
(32.6 gpm)
Backwash Flow Rate
b
15 m
3
/hr (66 gpm)
15 m
3
/hr (66 gpm)
15 m
3
/hr (66 gpm)
NaClO Concentration in Backwash
Water
3 to 5 mg/L
3 to 5 mg/L
3 to 5 mg/L
Water Temperature
≤
35°C (95°F)
c
≤
35°C (95°F)
c
≤
35°C (95°F)
c
pH Range
4 to 8
4 to 8
4 to 8
Chemical Cleaning
1)
Periodical cleaning
2)
Implemented when the
transmembrane pressure increases
to 0.07 MPa (10.2 psi)
d
1)
Periodical cleaning
2)
Implemented when the
transmembrane pressure
increases to 0.07 MPa (10.2 psi)
d
1)
Periodical cleaning
2)
Implemented when the
transmembrane pressure increases
to 0.07 MPa (10.2 psi)
d
a
Value based on 20°C (68°F) water temperature.
b
To be set according to the recovery ratio.
c
While the data sheet lists a maximum temperature of 40°C, this is for short time periods only. The maximum recommended
temperature for long periods of operation is 35°C.
d
The supply pressure at the general start of operation is approximately 0.01 to 0.03 MPa.
Note:
The values above are the standard conditions and they vary depending on the quality of feed water.
4.3
OPERATION
The operating flux largely depends on the quality of the feed water and is usually determined based on test or pilot results.
Pilot tests typically last about 6 months and include periods at various temperatures. The feed flow rate, just like the flux, is
based on the feed water quality. For standard filtration, set the recovery ratio to 90%. The valves switch and the pump
starts and stops automatically in the following order during operation:
1.
Filtration for 45 minutes
2.
30-second backwashing is implemented twice
