performance evaluation of technos cleaning balls in rdc msf pilot

alls once received certain wear in a particular orientation, keep themselves along the
same axis (due to less resistance) every time they go through a tube.
The consumption of the balls with time was also investigated and found that the rate of
balls replacement due to wear and tear was within acceptable limits. Balls started
becoming under-sized after 15 days of operation and on completion of 30 days of
operation, 1461 balls out of the total charge of 1600 were found under-sized. The ball
lifetime, however, depends mainly on distiller size, its configuration and frequency of
ball cleaning for a particular ball type. The number of balls rejected due to under-size in
each inspection is shown in Figure 3, while cumulative counts of balls damaged and
lost with time are plotted in Figure 4.
4.2.2 Thermal Performance
The plant performance and the brine heater fouling were examined during the test
period. The plant was unstable during the period of 50 to 150 hours of the test. Figure 5
shows the performance of the distiller during the test period including the trends of
fouling factor and heat transfer coefficient in brine heater. Fouling factor fluctuated in
the range of 0.1 to 0.32 m 2 K/kW but most of the time remained within 0.2 m 2 K/kW,
which is lower than the design service-fouling factor of 0.325 m 2 K/kW indicating the
effectiveness of ball cleaning system. Steady trend of fouling factor indicates positive
performance of Technos balls.
Trends of gain output ratio (GOR) and performance ratio (PR) during the test period
revealed that plant performance was constant and thus Technos balls were effective in
maintaining the heat transfer surfaces free from any additional scale deposition.
4.2.3 Chemical Analysis
Chemical analyses of various brine streams in distiller # 9 were carried out daily for
pH, M-alkalinity and chloride contents. These values were found within acceptable
limits. Loss of total alkalinity (LTA) and concentration ratio were calculated in streams
of brine recycle and brine blowdown. Figure 6 shows LTA, M-alkalinity, concentration
ratio and copper content of brine blowdown. Cu contents in the stream of brine
blowdown before and during ball cleaning were found fluctuating between 7 and 23
ppb, which is within normal limit of the Cu content found during normal operation.
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