English (GB)
33
Fig. 47
Proportional control
Setpoint control
The purpose is e.g. to keep the excess chlorine in
the swimming pool at a constant value, the setpoint.
To do this, constantly measure the excess chlorine in
the water. The chlorination of the supplied water is
influenced accordingly.
Fig. 48
Setpoint control
Proportional control with disturbance variable
feedforward
The purpose is to chlorinate a flow of water
uniformly. A purely proportional control is not
possible if the water quality varies greatly since the
same dosing quantities do not necessarily result in a
uniform excess of chlorine.
Therefore the
concentration of chlorine is also measured.
A controller processes the two signals into the
manipulated variable:
•
The flowing quantity of water which results in a
specific quantity of dosed chlorine.
•
The measured concentration of chlorine with
which the quantity of dosed chlorine proportional
to the flow is varied upwards or downwards.
Fig. 49
Proportional control with disturbance
Dual setpoint control with acid and leach
The purpose is to retain the pH value in the water at
a specific value. If the pH value increases or
decreases as a result of the disturbance variables,
acid or leach must be dosed depending on the
situation. Therefore you must be able to control the
two dosing pumps alternately.
Fig. 50
Dual setpoint control
TM0
3
710
3
1
6
1
3
TM0
3
710
4
1
6
1
3
M
CODE
SP 1
SP 2
XP
TN (s)
s
CONEX DIS-2Q
IDM
TV (s)
Open-loop
controller
Dosing unit with
servomotor
Flowmeter
Conex
DIA-1
Ma
n
Ca
l
O
K
Es
c
Alar
m
Measuring amplifier
and closed-loop
controller
Dosing unit with
servomotor
Swimming pool
Measuring
cell
TM
0
3
7
105
1
613
TM
03
71
06
16
13
Conex
DIA-1
Ma
n
Ca
l
O
K
Es
c
Alar
m
M
CODE
SP 1
SP 2
XP
TN (s)
s
CONEX DIS-2Q
TV (s)
IDM
Flowmeter
Dosing unit with
servomotor
Measuring
cell
Closed-loop
controller
Measuring amplifier
pH
Conex
DIA-1
Man
Cal
OK
Esc
Alarm
pH
Water to be neutralised.
pH electrode and
temperature
sensor
Measuring amplifier
and controller
Dosing pump for
leach
Dosing pump for
acid
