Stopping the cane sugar factory for cleaning of the evaporator set represents a
major disruption to the production of raw sugar. Elimination or reduction of evaporator
cleaning stoppages would represent a significant increase in the effective factory
crushing rate. Considerable interest has been shown by sugar mills in on-line
cleaning systems. This paper outlines a number of methods for taking part of the
evaporator set off-line for chemical cleaning while the rest of the set remains on-line
for juice evaporation. In some cases it may be desirable to limit, cleaning to only
those vessels that have had the most severe fouling. Arrangements bf piping, valves,
instrumentation, vessels and cleaning procedures are discussed.
The investigation showed that on-line evaporator cleaning systems may be
applied to both plate and Roberts type evaporators. With such systems, a saving in
factory downtime of about four hours every three weeks was possible. It was estimated
that the capital investment involved in setting up on-line cleaning systems
would be returned within one to three years, depending upon factors such as severity
of fouling of the evaporator set, and the level of automation used in the on-line
cleaning system.