Vertical humidifier for installation in AHU-VEH Rel. 13v01.UK pag. 7
Elsteam S.r.l - via E.fermi, 496 - 21042 Caronno Pertusella (va) - Tel.+39 02 9659890 - Fax +39 02 96457007
E-mail: [email protected]/[email protected] - Web: http://www.elsteam.com
p.iva 01463940120 - c.f.05046150156 - trib.di busto a. 16415-c.c.i.a.a. varese 174164 - cap.soc.i.v. euro 10400,00
On one side of the kettle (the easiest to access once installed) you have the body of hydraulic manage-
ment of the system:
-
Sensor for maximum water level in the boiler
-
Tank draining system
This special draining system has been specially designed to empty the tank
from water and limestone pieces without having to block and having to be able
to work without pressure.
It is essentially constituted by a valve having a free passage of 32 mm in diame-
ter, closed by a damper operated by an electric motor and a cam. Grafted rig-
idly on the pivot motor is an electronics rotation sensor, which, communicating
with the microprocessor control is able to manage the correct operation of the
system and communicate any faults that appear in the display.
6
Working Principle
At switch on the humidifier performs a complete draining of tank to ensure a functioning with water hy-
gienically perfect. When the humidistat requires steam production, the power control system (based on
TRIACS) is activated and the humidifier begins to fill with water until reaching a minimum value of current
passage. If the time taken to reach this minimum value of power is greater than a predetermined value,
the humidifiers stops and indicates alarm (possible causes are lack of water supply or not connecting the
system to TRIAC). When the minimum value of production is reached, the humidifier stays in idle state for
about 2 minutes. The conductivity of the water varies greatly, not only depending on the hardness of the
water itself, but also on temperature: cold water is little conductive and its conductivity increases with
temperature up to a maximum at around 95 °C before falling back slightly when boiling. For this reason
the control system wait to manages currents values when the water is close to boiling to compare actual
values of steam production.
At this point, the humidifier will begin filling water at short intervals until reaching a production equal to
the required one.
Following, the control system will keep production at set values with programmed fill or drain of water.
If the production exceeds the required value or the maximum supplied by the set of TRIAC, the control
system will start to choke the power, taking care, however, that the average value of the output current
is always zero, to avoid excessive corrosion of the electrodes.
If the choking electronic proceeds for too long, the electronics will drain water, to avoid thermal overload
of the TRIAC.
At regular intervals, the humidifier makes also small purges, so as to ensure that the salt content in the
water is not too high and thus avoiding an excessive deposit of limestone.
At much longer intervals the control system will make complete draining of the boiler to remove lime-
stone deposits.
If the humidistat request is low for long periods, the micro unloads all the water in order to avoid health
problems due to water rot in storage.
Figura 2 - Cover with slits for steam outlet
