Hydronix Hydro-Control VI, Operator'S Manual

Page: 25 / 88

Hydro-Control VI Operators Guide HD0456 Rev 1.7.1 25
Chapter 5 Water Addition Modes
The Hydro-Control has been designed with three modes of water addition, Preset Mode, AUTO Mode
and CALC Mode. In all installations, the initial setup of each mix design should be done with the water
addition set to Preset Mode.
1 Preset Mode
No sensor signal is required to operate in this mode, which simply adds the fixed amount of water
in litres, gallons, kilograms, pounds or seconds as defined by the recipe.
Preset Mode is used when setting up a recipe to add a fixed quantity of water to the mixer. The
amount of water that is added can be adjusted on subsequent batches to optimise the amount of
water added to the mix. After a good batch has been made, that batch can then be selected in the
mix log and a recipe calibration can be obtained automatically.
As the Preset Mode does not require a signal from the sensor, it may be used in the event of a
sensor problem to keep a system running. To enable an easier changeover from CALC Mode or
AUTO Mode to Preset Mode, when batches are completed, the system will update the preset water
parameter with the amount of water dosed.
2 CALC Mode
This mode takes a reading at the end of the dry mix, and then calculates the exact quantity of water
required to reach the moisture target in the recipe using calibration data and the dry weight of the
materials in the mixer.
Moisture
Time
Mixer
Loading
Dry Mix Time
Main Water
Addition
Wet Mix
Time
Discharge
Calculated
water added
in one dose
Average moisture
reading is taken at
the end of the Dry
Mix and the quantity
of water needed is
calculated
Figure 9: The moisture during CALC Mode
Figure 9 shows a typical moisture trace during a batch run in CALC Mode. The boxes show the
point at which an average moisture reading is taken at the end of the Dry Mix and Wet Mix Times.
The length of time that the system uses for averaging is defined using the Averaging Time
parameter in the System Parameters.
As the moisture calculation relies in part on the dry weight of the materials in the mixer, it is
necessary that the dry weight parameter in the recipe is accurate. If there is a possibility of this
changing, for example if the raw material moisture is not being compensated for, then it is
preferable to use AUTO Mode.
For best results, it is important to have a stable moisture reading (homogenous mix) at the end of
the Dry Mix Phase to give accurate data for the water calculation. However it is not necessary to
have complete homogeneity at the end of the final mix stage. If the final product homogeneity is
not important, for example if there is further processing after the mixer, then the Wet Mix Time can
be decreased.