THE EFFICIENCY OF HYDROCYCLONES FOR THE SEPARATION OF DIFFERENT STARCHES

Since many years the starch industry uses hydrocyclones to purify starch. The starch is washed countercurrently with water in a number of washing stages. For a good washing effect, in each stage a separation of starch and impurities must be obtained. Different methods can be used to describe the efficiency of separation. As most suitable, the reduced grade efficiency is chosen. This efficiency is quantified for different starches: maize, potato, rice, wheat. From the measured efficiencies, relative sizes for washing batteries are calculated. The results correlate well with existing plant practices. The influence of starch damage on the separation efficiency was also investigated. Damaged starch appears more difficult to separate.