SnowPure Electropure EXL Series, Oem Engineering Manual, Page: 20 / 81


SNOWPURE, LLC, 2005-2018 VERSION 3.5 (XL+EXL)
–FEBRUARY 2018
PAGE 20
Operating Feed Water Specifications
The following are requirements to operate within SnowPure’s limited warranty. Optimum
performance from Electropure™ EDI modules will result if values that are more stringent
are set as design goals.
Specification Notes Working
Range
Optimum
Performance
Feedwater Source RO water, direct feed, or with intermediate
break tank plus filter
EDI Feed
Conductivity Ionic load determines size of the working bed
and polishing bed within the EDI
1-
20 μS/cm
1-
6 μS/cm
Feedwater
Conductivity
Equivalent** FCE = Conduc 2.79*CO
2
+1.94*SiO
2
see note below**
< 33 μS/cm
< 9 μS/cm
pH Low pH feedwater typically indicates the
presence of CO
2
which will decrease quality.
5.0-9.5
7.0-7.5
Total CO
2
Combined CO
2
and HCO
3
-
<5 mg/l as CO
2
<2 mg/l
Temperature
5°C to 35°C
20 to 30°C
Hardness Ca
+2
and Mg
+2
as CaCO
3
<1.0 ppm at
90% recovery
Organics TOC
< 0.5 ppm
Not Detectable
Metals Fe, Mn, transition metals < 10 ppb Not Detectable
Silica, SiO
2
Typically dissolved, reactive < 0.5 ppm < 0.2 ppm
Oxidizers Cl
2
and O
3
, typically
Not
Detectable
Not Detectable
Particles Recommended direct feed particle-free RO
permeate, or 1
μm pre-filtration of feed from
intermediate tank
Inlet Pressure Depends on flow and temperature
5 bar (75 psi)
max
2-3 bar typical
Outlet Pressure Concentrate and Electrode outlet pressures to
be lower than the Product outlet pressure
** FCE example:
FCE = Conduc 2.79*(CO
2
) + 1.94*(SiO
2
), so if conductivity=5.0 μS/cm, CO
2
=3.5 mg/l,
SiO
2
=0.5 mg/l, then FCE = 5.0 + 2.79*(3.5) + 1.94*(0.5) = 15.7 μS/cm.