Lynne Wong's PhD thesis

1.5.3.2 Sucrose lost in filter cake % sucrose in cane
Data on sucrose lost in filter cake % sucrose in cane are shown in Fig 1.12, and are of
interest because from 1960 to 1975, this parameter had been decreasing, indicating an
improvement in the filter station. Indeed, the industry had been gradually replacing filter
presses by more efficient rotary vacuum filters. However, when mechanized cane loading
was started in 1975, increased trash worsened the work at the filters and more sucrose was
lost in the filter cake from 1975 to 2004. In particular, there is a marked increase from
1990, mainly because the mass of filter cake % cane had increased considerably from 3.6
in 1975 to 5.4 in 2004, because mud from effluent treatment plants is mixed with filter
cake in some factories.
0.7
Sucrose lost in filter cake % sucrose in cane
0.6
0.5
0.4
0.3
1960 1965 1970 1975 1980 1985 1990 1995 2000
Figure 1.12. Changes in sucrose lost in filter cake % sucrose in cane from 1960-2004.
1.5.3.3 Clerget purity of molasses and mass of molasses at 85° Brix % cane
Changes in Clerget purity of molasses and mass of molasses at 85° Brix % cane are shown
in Fig 1.13. Without taking into consideration the cyclonic years in the early 1960s, the
Clerget purity of molasses before 1975 was decreasing steadily implying good molasses
exhaustion. However, during the same period, the mass of molasses at 85° Brix % cane
had increased with the net result that the sucrose lost in molasses % cane remained stable
(Fig 1.14).
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