69
ENG
“heaterSteam” +0300075EN - rel. 1.2 - 29.09.2015
13.6 User-adjustable max. allowed no. of
evaporation cycles between 2 dilution
drains
The number of evaporation cycles between 2 consecutive drains for
dilution is calculated internally, based on the conductivity of the supply
water. The parameter b8 allows the user to set the maximum number
of evaporation cycles allowed between 2 dilution drains. If the number
calculated is greater than b8, it shall be used the value of this parameter
in place of that calculated internally.
Parameter b8:
Variation range 1…50
Default 0.
Note: if b8=0, when the heaters are powered for the
rst time
b8 shall be automatically set to
2 if conductivity measured in the supply water
is <= 100 µS/cm, or at 5.
Step 1
Tab. 13.k
13.7 Reduced lls to restore water level after
evaporation
When, during the steam production, the upper oater switches because
the water level has decreased, a ll starts for restoring the water level. The
duration of the ll can be decreased through the new user parameter
bA which de nes the new duration as a % of the internally set default
duration: new duration=default duration xbA/100. It should be noted
that, regardless of the value set for bA, the water leve shall always be
restored up to the upper ball cock.
Parameter bA
Variation range 20…100%
Default 100%
Step 10%
Comments bA= 100 % means that the default duration will be
used
bA< 100 % means that the duration is < default du-
ration: less fresh water is introduced into the cylinder,
reducing the negative impact on steam production
(important in applications of high accuracy) but the
lling valve will be opened more frequently
Tab. 13.l
13.8 PWM lls after dilution and high-level/
foam drains
After a dilution or high-level/foam drain, water is lled into to restore the
water level up to the upper ball cock.
The lled fresh water disturbs the steam production because it decreases
the average temperature of the water inside the boiler: in order to reduce
the negative in uence of the fresh water on the steam production, the
user can enable the PWM lls after the dilution and high-level/foam drain.
PWM lls work as follows:
1. the mass of fresh water required to restore the water level is divided
into smaller masses of fresh water;
2. by keeping the partial lls as farther apart as possible from each
other, each partial mass of fresh water is given the maximum possible
time for heating up before the next one arrives, thus reducing the
e ect of the fresh water on the steam production.
The duration of each ll can be de ned in seconds by the new user
parameter bE:
Variation range 1 to 199 days
Default 5 seconds
Step 1 second
Tab. 13.m
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