Nalco 3D TRASAR Series, Инструкция по установке и эксплуатации

Страница: 147 / 243

521-OM0108.88
Copyright

2009 Nalco Company
6-26
Technical Help
(630) 305-CHEM
3D TRASAR

5500 - Installation & Operation Manual
17. How does 3D TRASAR Bio-Control apply Oxidizing biocide? (con’t)
Control Band (3D TRASAR Bio-Control):The ratio is maintained within a control band by applying
oxidizing biocide. The decision on whether to apply oxidizing biocide and how long to turn on the
pump is a complex function of the biocide being used, how far the ratio is from the control set point,
the slope of the ratio trajectory, and the historical response of the system.
Control Band (3D TRASAR Bio-Shock): When the ratio reaches a set point, bio-reporter feed into
the system is suspended. The system slugs oxidant into the tower. The duration of the slug feed is
set by the user. During the Ox-slug the oxidizing biocide is maintained under ORP control with a
preset setpoint and range. The oxidant slug can also be simple timer based. After the slug is com-
pleted the system waits for the ORP readings to dissipate to preslug values. Bio-Reporter is then
again added to the system and the ratio is monitored.
Control Loop: After 20min, the response of the system is again evaluated by processing the ratio
and a decision is made again on whether or not to feed oxidant and for how long.
Non-Oxidizer Feed: 3D TRASAR feeds non-oxidizer based on a timer. Feed of a biodispersant is
slaved to the feed of the non-oxidizer.
Ox Slugs: Oxidizing biocide slugs may be applied to the system when it is under normal 3D
TRASAR Bio-Control. These slugs may be scheduled or be manually triggered from the controller.
During the Ox slug bio-reporter feed is suspended. The duration of the slug feed is set by the user.
During the Ox-slug the oxidizing biocide is maintained under ORP control with a preset setpoint and
range. The oxidant slug can also be simple timer based. After the slug is completed the system
waits for the ORP readings to dissipate to preslug values. Bio-Reporter is then again added to the
system and normal 3D TRASAR Bio-Control resumes. We recommend using the slug feed feature
once a week in order to vary the system stresses for good microbial control
18. What is 3D TRASAR Bio-Shock Mode?
3D TRASAR Bio-Shock mode is an alternate oxidant feed strategy to normal 3D TRASAR Bio-
Control. This is an all shock method of applying oxidizing biocide. The bio-reporter monitors micro-
biological activity and when it reaches a preset value oxidizing biocide is slugged into the system.
The duration of the slug can be user set from 10 minutes to 35 hours and the ORP setpoint for the
slug is also user set. This mode allows the user to actively control the dosage of the oxidizing
biocide. Thus under 3D TRASAR Bio-Shock mode the bio-reporter determines the timing of the
biocide feed but the user determines the amount of biocide to be applied.
3D TRASAR Bio-Shock mode is recommended in certain situations:
•
System has recirculation problems (with zones which have stagnant or slow-moving water)
•
Systems is struggling with algae control
•
Positive
Legionella
counts require regular slug dose of Oxidizing biocide into the system
•
System needs to respond to a process leak
•
Bio-Reporter is being used to control feed of Towerbrom 991