Plot flux and determine flux at 0.7 barg
Plot the calculated flux values against the transmembrane pressure (see the Figure below).
Determine the water flux in LMH at 0.7 barg (10 psig). In Figure 10, the flux at 0.7 barg (10 psig) is 115
LMH.
Transmembrane Pressure (PSIG)
25
20
15
10
5
Fl
ux
(L
M
H
)
50
100
150
200
Figure 6.3: Plot of water flux versus transmembrane pressure
Normalize water flux to 20 °C and 1 psig
Follow these steps to normalize the water flux value to 20 °C and standardize to 1 psig to arrive at flux
in LMH/psig at 20 °C:
Step
Action
1
Multiply the calculated flux value by the appropriate viscosity correction factor in Table
1. For example, if the flux at 0.7 barg (10 psig) is 115 LMH, and the temperature of the
water during permeate flow measurement was 18 °C, then the flux normalized to 20 °C is:
115 LMH x 1.053 = 121 LMH/10 psig
2
To standardize the flux value to 1 psig, divide the normalized water flux value by 10 psig.
For example, 121 LMH ÷ 10 = 12.1 LMH/psig
6 Preparing a Cassette for Use
6.3 Stage 2 – Measuring water flux
32
Learning to Use the Kvick Lab Cassette Holder User Manual 18117269 AI
