Having automation installed, we can expect that the process can run smoothly. And if the operation control is good enough, the juice will enter to the clarifier at the appropriate flow, temperature, pH and flocculant concentration. However, there are still other problems to note, namely fluctuations in the quality of sediment.
In the early days and towards the end of the milling season, the quality of sugarcane varies greatly; there is a very young cane, there is old sugar cane, or there is fresh sugar cane also creates that has been logged several days has not been milled to moldy or become dry woody. The diversity of the quality of sugar cane is worsened when the rainy season arrives; soil and mud are also brought into the factory, that creates problems in the processing department.
When this happens, the fresh juice inside the clarifier is always kept to a minimum, slowly but surely up to the maximum level. If the level reaches the maximum level the factory must stop milling because of “flooded” dirty sediment in clarification. Continuing the process will damage the sugar quality.
What’s the solution?
If this has not happened yet, then what is done is to closely monitor the quality of sugarcane that will enter the factory. Young and old sugar cane, moldy cane, sugar cane with too high trash, sugarcane containing soil and mud must be rejected into the factory; because it does not contain sugar and will cause process difficulties.
But if the factory must accept bad cane and the level of dirty sediment began to rise, the first thing to do is to reduce the speed of milling, then do the selection of quality cane in the “cane yard”, bad sugar cane is separated and removed. Strict controls are then performed on the Purification station, mainly: discharge sedimentation rate, temperature control, phosphate addition, defecation, sulphitation, pH and flocculant addition (exact type and dose). Adjustment at the screening station: strict supervision to increase the amount of bagacillo (fine bagasse) to the feed mixer smoothly, and raise the vacuum filter speed to maximum speed when necessary. If this emergency action is done quickly and not too late, the level of dirty sediment can be expected to fall slowly to the minimum.