Calc Mode; Figure 18: The Moisture During Calc Mode - Hydronix Hydro-Control VI Operator's Manual

Using Moisture Control

2 CALC Mode

Mixer
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Moisture
Introduction
2.1
CALC Mode takes an average moisture reading at the end of the dry mix phase and uses that
to calculate a quantity of water to add to reach the target defined in the recipe. The water
addition is then performed as one complete addition.
Advantages:
CALC Mode is less dependent on the quality of the mixing action or the final
•
homogeneity in the mixer and therefore may be faster in certain applications.
The calculated water is dosed in one shot making the main water addition phase quicker
•
than AUTO Mode.
• Different applications will require a different level of homogeneity in the final product.
Running in CALC Mode enables the water/cement ratio to be correctly adjusted for
without a long Wet Mix Time.
• As the water calculation is performed at the end of the Dry Mix and the Main Water
Addition is performed in one shot, the degree of homogeneity at the end of the Wet Mix
can be varied by adjusting the Wet Mix Time. It is important to note that if the Wet Mix
Time is shortened then the alarm tolerances may need to be increased to stop the
controller from alarming at the end of the mix, due to the mix not being completely
homogenous.
Disadvantages:
• The dry reading used for the calculation must be stable which usually requires the dry
mix time to be longer than is necessary for AUTO Mode control.
The water calculation is batch size dependant so if the dry weight of material varies
•
significantly then the recipe must be updated with the current batch weight, either by
manually editing the recipe or sending the value from a remote connection.
• If significant changes are made to the recipe then it will need to be recalibrated.
Configuring the recipe
2.2
When using CALC Mode each recipe must first be calibrated. This is done by using a batch
that has previously been run which is of the correct moisture and quality. The previous chapter
details how to run the first batch. The Hydro-Control will then use the data recorded during the
batch to generate a calibration for the recipe to use with further batches.
42 Hydro-Control VI Operators Guide HD0456 Rev 1.7.1
Main Water
Dry Mix Time
Addition
Average moisture Calculated
reading is taken at water added
the end of the Dry in one dose
Mix and the quantity
of water needed is
calculated

Figure 18: The moisture during CALC Mode

Wet Mix
Discharge
Time
Chapter 8
Time