9
3.2
Function
From the reversing osmosis system (RO system) the fully demineralized
water (also called permeate) is fed to the booster pump (9) via a shut-off
valve (7) and a filter (8). Depending on the current output re quirements
the booster pump increases the water pressure to the required operating
pressure of approximately 7 bars (yield load).
From the booster pump the fully demineralized water is fed to the connec-
tor box (16), either directly (on systems for exhaust air cooling) or via the
silver ionization unit (12) which degerminates the water.
If humidification is required, one or both spray valves (18) of the connector
box are opened, depending on the current humidification requirements (if
the optional third spray valve is available, the system opens one, two or all
three valves at a time).
The fully demineralized water is now fed to the respective spray nozzles
(21) producing fine aerosol fog. The air passing by the nozzles absorbs
the aerosol fog thus getting humidified. Aerosol fog not absorbed by the
air is retained in the post-evaporation elements (20) thus humidifying the
air passing through the postevaporation elements. Excess water is flow
-
ing down to the bottom of the post-evaporation elements and is led to the
siphon trap (19), via the drain in the water tub.
Control
The system is controlled by an external controller or by the PI controller
built into the control unit.
The standard system with a 2-valve connector box provides a 3-step con-
trol corresponding to 1/3, 2/3 and 3/3 of maximum output. The first valve
opens at approximately 20% and the second one at approximately 50%.
If the humidification requirements reach approximately 80% both valves
are open.
Note: systems equipped with the optional third valve provide 7-step control
with respective humidification power.
Monitoring
The system continuously monitors the minimum and maximum pressure,
the conductance of the fully demineralized water, and the temperature of the
booster pump. If the conductance of the fully demineralized water exceeds
the admissible range (max.
15 µS/cm
), the drain valve (14) of the connector
box opens and the water system is flushed until the conductance meets the
preset value. A
fault
message is displayed if the conductance value does
not reach the admissible range within a certain period.
0
0
1
0
0
1
1
1
0
1
2
3
100
0
0
20
50
80
100
0
0
0
1
0
0
0
1
100
0
0
15 27
100
39 51 63 75 87
0
1
0
2
0
0
1
3
1
1
0
4
1
0
1
5
0
1
1
6
1
1
1
7
Steps 1 to 3
Spray valve Y6
Spray valve Y7
Capacity [%]
Control signal [%]
Steps 1 to 7
Spray valve Y6
Spray valve Y7
Spray valve Y8
Capacity [%]
Control signal [%]
