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15.2.6 Dual two-position pulse frequency controller
Application
•
Setpoint control of pH value using acid and
leach.
•
Control of dosing pumps via contact input.
Description
•
Set a pH value of 7.00.
•
Set switching point 1 slightly above this value.
•
Set switching point 2 slightly below this value.
Never set the two switching points to the same
value; in this case acid and leach are constantly and
alternately dosed. This does not improve the result, it
merely leads to an unnecessarily high consumption
of chemicals.
•
The actual value of switching point 1 exceeds the
setpoint:
– Dosing pump for acid carries out individually
controlled dosing strokes.
•
The actual value of switching point 2 falls below
the setpoint:
– Dosing pump for leach carries out individually
controlled dosing strokes.
•
The measured value deviates from the respective
switching point:
– Frequency of dosing strokes of the respective
pump increases
– If the deviation is large, the respective pump
runs continuously with maximum frequency of
dosing strokes.
Fig. 61
Dual two-position pulse frequency controller
TM
03
71
1
4
1
6
1
3
Off
On
Off
On
Off
On
Off
On
Off
On
Off
On
Off
On
Off
On
Off
On
Off
On
SP 1
SP 2
pH value
Deviation from
setpoint
Switching status of
the acid pump
(individual dosing
strokes).
Switching status of
the leach pump
(individual dosing
strokes).
