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3D TRASAR
5500 - Installation & Operation Manual
6.2.2 3D TRASAR Bio-Shock Mode
In 3D TRASAR Bio-Shock mode the timing of the Oxidant slug is determined by the bio-reporter
ratio (and therefore cannot be scheduled). The four segments of an Ox Slug (Prebleed, Feed,
Post-Feed and Recovery) are used and the parameters determining them must be set by the user.
If Towerbrom 960 is the oxidizing biocide, standard 3D TRASAR Bio-Control cannot be used, and
3D TRASAR Bio-Shock mode is the only option for bio-reporter based Oxidizing biocide control.
3D TRASAR Bio-Shock Mode can be used with any 3D TRASAR Bio-Control approved oxidant.
Under 3D TRASAR Bio-Shock Mode, the Nalco Bio-Index will give an indication of how close the
system is to an oxidant slug. When the bio-reporter dye is first dosed, the Nalco Bio-Index will be
very negative (-100 to -70). As the bio-reporter reacts with microbes, the Nalco Bio-Index number
will slowly (dependent on the overall microbial activity within the system) increase. As the Nalco
Bio-Index approaches 0, this is an indication that the system will soon be slugged.
6.2.3 Ox-slug/shock control settings
Using the 3D TRASAR Configurator, set up the four sequential segments of the ox-slug/shock
event: Pre-Bleed, Feed, Post-Feed, Recovery.
PreBleed:
User may choose to blowdown the system prior to an oxidant slug. This option is
typically used if the blowdown is locked out during the time of the oxidant slug to compen
sate for increasing conductivity. The blowdown is controlled by conductivity set point with a
time limit for the process.
Slug Feed:
Oxidant is fed into the system. A user-set time limit determines the duration of
this segment. The user may choose between ORP control or timer control of the oxidizing
biocide pump. Under ORP control, the time limit determines the duration of ORP control at
an ORP set point, whereas under timer control, this time limit determines the oxidizing
pump on time. The user may choose to lockout the blowdown during oxidizing biocide feed.
Post-Feed:
User may choose to lockout the blowdown following an oxidizing biocide slug.
The post feed blowdown lockout time is determined by a user set time limit or by a user set
ORP set point with an over-riding time limit.
Recovery:
The ORP is monitored until it returns to values close to those measured immedi
ately before the oxidant slug. This is the recovery period. At the end of this time period the
bio-reporter feed and normal 3D TRASAR Bio-Control is resumed. If the ORP does not
achieve values close to pre-slug values within a specified time limit (typically 24-48 hours)
the system will go into failsafe operation of the oxidizing biocide pump.
The 3D TRASAR Configurator program must be used to set these parameters governing the
oxidant slug/shock.
