Evaluate the performance of the falling film tube evaporator at Bingera Mill : final report 2019/201

Abstract

For the 2018 season Bundaberg Sugar installed a 4000 m2 falling film tube evaporator (FFTE) of the BMA design at No 1 evaporator position at Bingera Mill. This was the first installation of a FFTE into the Australian industry. An evaluation program was undertaken during the 2019 season to assess the performance with respect to heat transfer efficiency, effect of scaling rates on heat transfer, deentrainment efficiency of the juice droplets from the vapour outflow stream and the general operational performance. As well tracer studies were undertaken to determine the distribution of residence times for juice in the evaporator. Measurements were also undertaken to determine the extent of sucrose degradation occurring within the evaporator. Overall the evaporator has performed well with respect to the above list of test parameters. However, the effect of scaling on heat transfer efficiency was only able to be evaluated for typically 120 hours of operation as the mill was restricted to 5 day crushing operations each week due to the small drought affected crop. A chemical clean of the evaporator was undertaken on shutdown each week.

During the two seasons of operation the FFTE at Bingera Mill has performed very well. The evaluation trials have shown the heat transfer performance is comparable to the better performing Robert No 1 evaporators in the industry, and also the test program has not shown any major disadvantages of the FFTE compared with a Robert evaporator.