Section 5: 3D Trasar Scale Control; Nalco Scale Index (Nsi) Measurement; Trasar Scale Blowdown Control - Uses Nsi To Adjust The Blowdown Setpoint; Trasar Scale Tagged Polymer Control - Uses Nsi To Adjust The Tagged Polymer Setpoint - Nalco 3D TRASAR Series Installation And Operation Manual

Section 5: 3D TRASAR Scale Control

3D TRASAR Scale Control is a revolutionary way to manage scale stress in cooling systems. The
3D TRASAR 5500 coupled with an innovative "tagged" high stress polymer (essentially a barcode
attached to the polymer molecule) monitors the actual performance of the polymer as system scale
stress changes. 3D TRASAR Scale Control then takes corrective action through blowdown or
chemical inhibitor feed adjustments. For 3D TRASAR Starter controllers, 3D TRASAR Scale
Control is available through the 3D TRASAR Fluorometer upgrade P/N 060-TR3200.88.
WARNING: DO NOT use 3D TRASAR Scale Control if the TRASAR Background is > 15%
! or TAG Background is > 30%. DO NOT use T agged Polymer Control if TAG Background is
> 75%. Refer to Section 4.4.1 for more details.
5.1

Nalco Scale Index (NSI) Measurement

The Nalco Scale Index (NSI) is a calculated variable that compares the current rate of polymer
consumption against the learned average rate of polymer consumption. The NSI number has a
direct correlation to cooling system stress level as shown in the table below .
3D TRASAR Scale Control uses NSI to make setpoint adjustments in response to both high and
low stress conditions. There are two different control methods to choose from, either 3D TRASAR
Scale Blowdown Control, or 3D TRASAR Scale T agged Polymer Control.
Nalco Scale Index (NSI)
5.1.1 3D TRASAR Scale Blowdown Control – Uses NSI to Adjust the Blowdown
Setpoint
• If NSI < 0: the blowdown setpoint is increased.
(e.g. NSI = – 20; blowdown setpoint adjusted by + 2.0%)
• If NSI = 0: no blowdown setpoint adjustment is made.
• If NSI > 0: the blowdown setpoint is decreased.
(e.g. NSI = + 20; blowdown setpoint adjusted by - 2.0%)
5.1.2 3D TRASAR Scale Tagged Polymer Control – Uses NSI to Adjust the Tagged
Polymer Setpoint
• If NSI < 0: the Tagged Polymer setpoint is decreased.
(e.g. NSI = – 20; T agged Polymer setpoint adjusted by - 2.0%)
• If NSI = 0: no Tagged Polymer setpoint adjustment is made.
• If NSI > 0: the Tagged Polymer setpoint is increased.
(e.g. NSI = + 20; T agged Polymer setpoint adjusted by + 2.0%)
Technical Help
(630) 305-CHEM
3D TRASAR
<10
10 – 30
>30
521-OM0108.88
Copyright © 2009 Nalco Company
®
5500 - Installation & Operation Manual
Performance Level
Low Stress
Moderate Stress
High Stress
5-1