HygroMatik SteamKit E, Manual

Page: 11 / 44

Page 11
4.3 Operating sequence
The operating sequence is determined by the
electrical wiring and control of the kit. Follow-
ing hereafter is the description of a typical
operating sequence when a HygroMatik con-
trol „Standard“ is used:
By pressing the control switch („Pos. I”) the
humidifier is turned on. When the controller
specifies an increase in humidity, the main
contactor is switched on and the electrodes
(48)
*) are supplied with power. The water inlet
solenoid valve (25)
*)
feeds water into the
steam cylinder (19) *) .
As soon as the electrodes are immersed, the
current begins to flow. The water is now
heated. When the pre-selected output is
reached, the control turns off the solenoid
valve and interrupts the water supply.
After a short period of heating up, the water
between the electrodes starts boiling and
then vaporizes. The vaporization lowers the
water level in the steam cylinder, reducing
the output provided. To compensate for that,
fresh water is fed into the steam cylinder
every now and then by opening the intake
solenoid valve.
Humidifier power usage is continuously mon-
itored. With a cold start-up, the nominal cur-
rent increases to 113 % in order to achieve
quick-start output parameters. This activates
the electronic overflow limiter which causes a
partial draining of the cylinder. This reduces
the immersed surface area of the electrodes,
lowering power usage.
The concentration of dissolved salts
increases over time, which can lead to a rise
in the conductivity of the water.This could
damage the unit, but in any case would sig-
nificantly reduce the life span of the elec-
trodes.
For this reason, regular, periodic blow-downs
of some of the concentrated water are very
important. Following this procedure as re-
commended provides stable cylinder water
conductivity as well as minimal water loss for
the expected service life of the cylinder.
Water blow-down is performed by a blow-
down pump 32)
*) . The functioning of the
blow-down pump is continuously monitored
during operation. If the pump is damaged, the
kit shuts down.
With normal water quality the blow-down loss
rate lies between 7 and 15 % of the amount
of steam produced. Depending on water
quality, a full steam cylinder blow-down is run
every 3 to 8 days.
Mineral deposits settle in the open area
below the electrodes and are removed
through periodic maintenance. The blow-
down pump itself has wide openings and can
flush out smaller pieces of mineral deposit.
This extends the service life of the unit and
reduces the required maintenance interval.
On blow-down, water flows from the pump
into the drainage system.
For maintainence purposes, the cylinder
water may be pumped out by pressing and
holding the control switch in the „II“ position.
Monitoring max. level
A sensor electrode (38)
*) monitors the maxi-
mum water capacity of the cylinder. When the
water level reaches the sensor electrode, the
water supply is interrupted. This can occur
when the water has low conductivity or when
the electrodes are worn out. In the case of
low water conductivity, however, this state
usually lasts only a short time. The built-in
control and the large area electrodes com-
bine to produce a rapid rise in conductivity by
increasing the concentration of the water.
*)
numbers indicated correspond with those
in the exploded view in the „Exploded view“
chapter.