521-OM0108.88
Copyright
2009 Nalco Company
6-20
Technical Help
(630) 305-CHEM
3D TRASAR
5500 - Installation & Operation Manual
7.Where is 3D TRASAR Bio-Control not a good fit?
3D TRASAR Bio-Control is not a fit where any one of the following conditions apply:
• The system is NOT an open recirculating cooling water system (e.g. once through, closed
loop, etc.).
• System HTI < 6 hours.
• The system volume divided by the recirculation rate exceeds 20 minutes.
• The system has highly halogenated make-up water which is added to the tower in incre-
ments greater than 5% of the system volume.
• Bleach (as opposed to bromine) is used with frequent or persistent ammonia contamina-
tion.
• The customer requires a fixed halogen residual.
• Near sterile control is desired.
• Oxidizing biocides other than bleach, ACTI-BROM, ST-AB-REX, Chlorine gas, BCDMH
and TowerBrom 991 is being used (
Note
: Check with 630-305-CHEM regarding ongoing
work to include new oxidizing biocides that are compatible with 3D TRASAR Bio-Control.)
• System has high background fluorescence (often associated with yellow tower water).
Before bio-reporter is added to the system, check diagnostic screen and see if Rz or Rf
reading (background) is greater then 8 ppb. To check the diagnostic data press
Informa-
tion
key, select
Diagnostic Data
, select
Fluorometer Data,
read
Rz
and
Rf
(number is in
ppb).
• The amount/timing of oxidizing biocide fed to the system is constrained to be below the
amount necessary for adequate control. An example: power plants where the time of
oxidizing biocide feed is limited by regulatory constraints. Another example: the amount of
halogen fed is limited by how much money is allocated towards microbial control.
