Bearbetning av potatis
Potato starch is nowadays produced in a number of well-defined and broadly accepted processes. The differences between these processes mainly originate from particular effluent requirements and from the need to recover protein in order to reduce the BOD load. Alfa Laval supplies a complete range of products and systems for use in producing potato starch. These all feature high reliability, low operating costs and excellent performance.
Fruit water removal
Removing fruit water in the beginning of the process leads to improved starch quality and makes it possible to recover proteins as a by-product. Alfa Laval STNX decanter centrifuges provide a high dry solids percentage, high capacity and low maintenance cost. A higher dry solids percentage means fewer impurities need to be washed off during starch washing, and reduces water consumption.
Conical sieve centrifuges are used for efficient fibre removal. Each screening centrifuge consists of a rotating conical basket with sieve plates, a nozzle arrangement from which wash water is continuously sprayed over the pulp layer in the conical sieve, a housing equipped with nozzles for “back washing” of the sieve and cleaning of the housing, and a drive arrangement.
Alfa Laval separators are ideal for use in potato starch production. They are designed for maximum separation efficiency, accurate control, minimum clogging and easy maintenance.
Alfa Laval starch washing systems are characterized by high performance and reliable operation. High-quality materials and low tolerances in the hydrocyclones (cyclonettes) lead to efficient washing and very low levels of impurities in the end product.
Using an STNX decanter centrifuge results in cake with a significantly higher dry solids percentage than from a screw press. This in turn leads to lower energy consumption in the drying stage.
Protein precipitation and recovery
The fruit water is treated in a separate process line that consists of a regenerative spiral heat exchanger system for coagulating the protein, followed by an STNX decanter centrifuge for efficient separation and recovery of the coagulated proteins.
Alfa Laval offers a wide range of equipment for use in starch processing such as strainers and degritting systems.