KROHNE CORIMASS MFC 85 EN - Manual (Page 11)

11
C onc e ntratio n o f E th ano l in W a te r at 2 0 °C
0
5
10
15
20
25
30
35
40
45
50
0.9 0.91 0.92 0.93 0.94 0.95 0.96 0.97 0.98 0.99 1
D ensity g /cc
Conc. by Mass
E thanol
F it 1
F it 2
As can be seen Fit 1 matches the characteristic from about 0 to 12% ethanol, whereas Fit 2
matches the range 28 to 43%. Note, for these cases, although the liquid carrier is water it is
necessary to set the Liquid type (Fct. 3.10.4) to NON WATER so that the curves can be
adjusted for best fit.
4.3 Determining the General Concentration Parameters
Case 1: Solid suspensions in water.
For these cases the solid particles tend to have a density much greater than that of water and
their density can usually be considered not to vary significantly with temperature. Therefore
set:
Menu Setting Comments
Fct. 3.10.1 SOLUTE R20 Density of the dry solid
Fct. 3.10.2 SOLUTE K1 0 No temperature correction
Fct. 3.10.3 SOLUTE K2 0 necessary
Fct. 3.10.4 LIQUID WATER
This is the simplest case. There are some exceptions where the density of the dry solid differs
greatly from its apparent density when wet. Starch is one such substance, in this case the
starch will actually absorb water when wet.
Case 2: Solid suspensions in other liquids
As for Case 1 the dry solid density can be input in the same manner. However the converter
needs to know how the liquid carrier’s density varies with temperature. If the process always
operates at the same temperature it is acceptable to input the carrier’s density at that
temperature into Fct. 3.10.5 LIQUID R20, and to set Fct. 3.10.6 and 3.10.7 to zero. However
errors will result if the process is then operated at a different temperature.
If the density of the carrier is known only at two different temperatures then only a linear
compensation is possible.