Nortec DRAABE Pure Water System - Manual (Page 25)

Created: 21.09.2006
Changed: 29.02.2008
Printed: 02.03.2009
page 25 of 59
Figure 11: PerPur with double softener (WSD)
EXAMPLE 2
A DRAABE Pure Water System is to be installed in the paper warehouse of a printing plant
for air humidification and for process water. The following data are known:
humidification rate:
100 kg/h (220 lbs/h)
process water rate: 150 kg/h (330 lbs/h)
humidifier type: unitary nozzles, DRAABE TurboFog
raw water:
hardness = 16°dH
conductance = 400µS
With a total rate of 250 kg/h (550 lbs/h) for humidification water and process water one
needs tree 120 litre system. Tree PerPur 120 are selected.
For uninterrupted water treatment, each resin cartridge must work for at least 8 hours be-
fore its resins wear out and have to be regenerated. This assumption is used for the follow-
ing computation of the minimum capacity required of the resin cartridges. The formula is:
W
W
= W x (H
K
+ 5°dH) x 8
W
W
: soft water
W: water requirement ( {humidification_rate + process_water_rate} x 2 )
H
K
: customer dependent water hardness
5°dH: safety term
8: minimum working hours for resin cartridges