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added makeup water to compensate for loss of return flow. Inaddition, the CIP
solution conductivity dropped due to excessive dilution. (A number of system
alarms were disabled to allow the CIP program to continue to completion.
Normally, the CIP system would abort the program either due to valve position,
excessive water addition, or low conductivity alarms. This circuit was run for
demonstration purposes.) After aperiod of time to create this record, the outlet
valve was again opened and the program performed normally after dumping the
excessive water to drain (no record ofthis) following which the accumulated cold
water was again brought to temperature.
The resultant pressure/flow trends, as recorded on paper, ordisplayed on
screens, revealed the serious performance problem that would normally be
recognized and corrected by operating personnel.
Aproblem occasionally found with nearly all CIP systems is an occasional
partially plugged spray ball (Fig. 13). This will cause supply pressure to be
somewhat higher, but this will often not be noticed as the normal location of a
pump discharge pressure sensor is immediately downstream ofthe pump and will
FIGURE 13 Historical trend with partially plugged sprayball.
Andersen