22
ENG
“optiMist” +0300065EN- rel. 1.1 - 29/01/2013
4. PUMPING
UNITS
4.1 Pumping unit with fl ow control confi guration
optiMist controls the humidifi cation and/or cooling capacity by
continuously controlling the atomised water fl ow-rate across a wide
range of modulation.
This confi guration is used in the following applications:
•
humidifi cation and/or evaporative cooling (direct) in an AHU;
•
humidifi cation and indirect evaporative cooling in an AHU equipped
with a heat recovery unit (a single atomisation system atomises the
water).
optiMist is equipped with an inverter to continuously and precisely
control the speed of the pump and, consequently, the fl ow-rate.
The outlet pressure is kept within the optimum water atomisation limits
by the range of modulation of the pump speed and control of the
number of nozzles that atomise the water.
Based on the fl ow-rate of water to be atomised, optiMist will activate the
number of nozzles that ensures the pressure is within the range indicated
above.
If the fl ow-rate required for humidifi cation or evaporative cooling is small
then a few nozzles will be enough to atomise the water; if the request
increases, the increase in fl ow-rate will cause an increase in pressure that,
if it exceeds 15 bar, will activate other atomising nozzles (from the second
modulation step) with a subsequent decrease in the pressure, bringing it
within the optimum range.
Similarly, if the humidifi cation request decreases, the fl ow-rate and thus
the pressure will decrease and, if the latter approaches 4 bars, some
nozzles will be closed so that the pressure returns within the optimum
atomisation range.
This is possible because the nozzles are assembled into groups of up to
four, with diff erent capacities; when suitably activated, these guarantee
continuous modulation of the fl ow-rate across a wide range, nominally
from 40 or 20 at 100% (40% for pump 50, 100 and 200 l/h, 20% for 400,
800, 1000 l/h) the maximum fl ow-rate.
Questo è possibile perchè gli ugelli sono raggruppati in gruppi, fi no a
2, di capacita diversa che, opportunamente attivati, sono in grado di
garantire una modulazione continua della portata in un ampio range,
nominalmente dal 40 o 20 al 100% (20% per pompe 50, 100 e 200 l/h,
40% per 400, 800, 1000 l/h) della portata massima.
The groups of nozzles are normally confi gured when selecting the
optiMist system, and the procedure is clearly described in the documents
supplied with the water distribution system (rack).
The continuous fl ow control guarantees maximum humidifi cation and
evaporative cooling precision as capacity is controlled continuously and
across a wide range.
