Hydro-Control VI Operators Guide HD0456 Rev 1.7.1 23
2.4
The Mix Cycle when using Pre-wet Water
The mix cycle when using Pre-wet Water is shown, along with a typical moisture trace, in Figure
Load
mixer
Dry Mix Time
Main Water
Addition
Wet Mix Time Discharge Mixer
Mix Phase
From PLC
To PLC
START
PRE-WET*
DONE
Signal
increases
from mixer
empty
reading.
As materials mix
the signal
continues to
stabilise. A
stable signal
indicates that all
the materials are
mixed thoroughly
and the mix is
homogeneous.
As more
water is
added the
signal
increases
again.
As the water
gets mixed
the signal
begins to
stabilise. A
stable signal
indicates that
all of the
water is
mixed to
homogeneity.
As the mixer is
discharged the
signal reduces
back to the mixer
empty reading.
Moisture
Time
Signals
Pre-wet Water
Addition
As water is
added the
signal
increases
further.
CEMENT IN*
MIX
COMPLETE
*Optional Signals
Optional
Cement Dosing
Pre-wet
Mix Time
As the
materials
mix with
the water
the signal
starts to
stabilise.
Figure 8: The mix cycle with pre-wet
The Hydro-Control VI starts its cycle when the “Start” signal is received. The first phase is the
addition of the Pre-wet Water followed by the mix time defined in the parameter “Pre-wet Mix
Time”. The “Pre-Wet Done” output then goes high and, if enabled, the Hydro-Control pauses
until the “Cement In” input is activated (the Cement Timeout parameter in the recipe must be
set to enable the “Cement In” input).
The next phase is the dry mix time, set in the recipe. After this period, water is added, after
which the wet mixing time commences, also set in the recipe. At the end of the wet mix time
the cycle is finished and the “Mix Complete” signal is set, which signals the batch control PLC
to unload the mixer.
2.5
The Mix Cycle when using Initial and Pre-wet mix phases
In some mix designs it may not be possible, or take an undesirable amount of time, to obtain a
stable reading in the dry or wet mix once certain materials or chemicals are added. Reasons
may include:
•
Using metal fibres
Summary of Contents for Hydro-Control VI
Page 4: ...4 Hydro Control VI Operators Guide HD0456 Rev 1 7 1 ...
Page 6: ...6 Hydro Control VI Operators Guide HD0456 Rev 1 7 1 ...
Page 8: ...8 Hydro Control VI Operators Guide HD0456 Rev 1 7 1 ...
Page 10: ...10 Hydro Control VI Operators Guide HD0456 Rev 1 7 1 ...
Page 18: ...Navigation Chapter 2 18 Hydro Control VI Operators Guide HD0456 Rev 1 7 1 ...
Page 20: ...Plant Operator Controls Chapter 3 20 Hydro Control VI Operators Guide HD0456 Rev 1 7 1 ...
Page 34: ...Editing Recipes Chapter 6 34 Hydro Control VI Operators Guide HD0456 Rev 1 7 1 ...
Page 40: ...Running the First Mix Chapter 7 40 Hydro Control VI Operators Guide HD0456 Rev 1 7 1 ...
Page 56: ...Using Moisture Control Chapter 8 56 Hydro Control VI Operators Guide HD0456 Rev 1 7 1 ...
Page 70: ...Setting Up User Accounts Chapter 11 70 Hydro Control VI Operators Guide HD0456 Rev 1 7 1 ...
Page 72: ...Remote Support Chapter 12 72 Hydro Control VI Operators Guide HD0456 Rev 1 7 1 ...
Page 86: ...Document Cross Reference Appendix C 86 Hydro Control VI Operators Guide HD0456 Rev 1 7 1 ...
