Instruction Manual

INTERLOCKS
Mixer interlocks are additions to the feed pumping system
interlocks and alarms and vary mill by mill. Typically,
they depend upon what instruments are available.
The following are the basic guidelines for interlocks.
Steady pulp flow must be maintained before adding
any chemicals or steam.
·
Installation of flow and consistency measurement
in the feed line is recommended.
·
Chemicals or steam can be added only when the
minimum flow and consistency levels are satisfied.
The levels depend on the size of the mixer and
pumping system.
The mixer must be running when steam or chemicals
are added.
·
It is possible, but not recommended, to pump
through the mixer when it is not running, since
mixing will not be effective and chemical usage
will be high.
The mixer runs only when the feed pump is running.
·
If the feed pump is down for more than five (5)
minutes, the mixer will shut down.
Seal water is required to operate the mixer.
·
The mixer has a cartridge mechanical seal with
flush meter and alarm and cannot be operated with
-
out seal water.
NOTE: Some mixers have a single mechanical seal
instead of the double seal.
·
A low seal water flow alarm is recommended
should the seal water flow fall below 50% of the set
flow rate.
In C/D stage, dry chlorine cannot be added alone.
$
CAUTION
In C/D stage, the mixer material is titanium and dry
chlorine will destroy this material!
·
Chlorine has to be mixed with chlorine dioxide or
water before it enters into the chemical addition
pipe of the mixer.
24
3501 IOM 11/10