Specific surface of crystal beds formed from high purity massecuite

The fundamental mechanisms for separation in both batch and continuous centrifuge operation include the filtration and drainage of molasses through beds of crystals. The specific surface area of the crystals making up the crystal bed in a fugal is considered to be the major granulometric property which influences the rate of drainage of molasses and the quantity of molasses retained in the crystal bed. As part of a broader study to improve the fugalling performance of high grade centrifuges, the resistance to flow of liquid through beds comprising shipment sugar crystals from several factories has been studied. The specific surface area of the crystal bed has been calculated. For crystal samples which are free of conglomeration, the estimates agree closely with those determined from crystal size distribution analysis by sieving. The specific surface area of the crystal bed has been correlated to crystal size distribution parameters. This paper describes the experimental procedure adopted for the measurement of specific bed resistance and the results of the investigation.