c. If the improper amount of polyelectrolyte is pumped through the
system, the formation of floc particles will not be controlled. A mid-range
concentration (optimization) of polyelectrolyte is required for operation.
The optimum setting is determined as follows:
(1) If the turbidity decreases with increased stroke setting, but
then stops changing for 3 successive stroke increases, set the stroke at 5
less than the last setting.
If the turbidity increases after a stroke
change, set the stroke back to the setting which first resulted in the
lowest turbidity.
(2) If the speed is at a setting of 16 or 32.5 and the stroke reaches
100 with the turbidity still decreasing with each stroke increase, set the
stroke back to 50 and double the speed. Continue optimization by increasing
stroke from 50.
(3) If the speed is at 65 and the stroke reaches 100 with the
turbidity still decreasing with each stroke increase, leave the stroke at
100 for the final setting.
(4) If the increased stroke settings from the initial setting do not
result in a decreasing turbidity and the speed is 32.5 or 65, decrease the
speed by 1/2 and repeat.
(5) If the increased stroke settings from the initial setting does
not result in a decreasing turbidity and the speed is 16, set the stroke at
10 for the final setting. If allowed by mission demands, backwash the media
filter after optimization.
d. During a typical filter run (such as, the time between backwashes)
the turbidity will usually continue to decrease with time. On occasion it
will increase after some time, indicating that the filter is so loaded with
dirt that it can no longer remove dirt efficiently and it requires
19. Once the polyelectrolyte level in the feed water and the chlorine
level in the product water are correctly set, the ROWPU is fully
operational.
It will keep on working with very little attention.
Only
routine tasks, and special jobs indicated by warning lights and the alarm
horn, will need to be done.
20. Have an operator enter the data from start-up procedures on the Water
Production Log.
Ensure the crew understands the importance of keeping an
accurate log.
The information from all the logs maintained on your
operation can be used to improve your operation and prevent maintenance
shortcomings.
21. Now is a good time to have the crew perform the operational set
points/pressure points testing. This is only performed at
1-15
QM4911
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