New hydrocyclone design for high starch yield: Effect of cylindrical-conical length proportion on the starch, sulfur and protein separation efficiencies

• Published in: Powder technology 2019-03, Vol.346, p.1-8
• Main Authors: Saengchan, Kanchana, Nopharatana, Annop, Songkasiri, Warinthorn
• Format: Article
• Language: English
• Subjects: Bradley's geometry; Cassava; Design; Hydrocyclones; Impurities; Manihot esculenta; Overflow; Pressure drop; Protein purification; Proteins; Separation; Starch; Starch refinery; Sulfur; Underflow; Wastewater
• ISSN: 0032-5910; 1873-328X
• DOI: 10.1016/j.powtec.2019.01.077

This research aimed to develop a new hydrocyclone design that matches the desired capacity and starch properties in each refining stage of cassava starch production process. The designed hydrocyclone dimension was adjusted to the proportion of cylindrical-conical length (Lcy/Lco ratio) at 0.00–0.14 and underflow-overflow diameter (Du/Do ratio) at 0.25–0.67 to yield a better starch-impurity separation efficiency. The Lcy/Lco dimensions affected the pressure drop (ΔP) within the hydrocyclone, while Du/Do affected the underflow discharge shape. An Lcy/Lco ratio of 0.11 and a Du/Do ratio of 0.67 provided the highest starch-impurity separation efficiency for the refining unit, but a Du/Do ratio of 0.25 was more suitable for the starch recovery from wastewater with a low concentration of starch (2.78% (w/v)), due to the high solid content of the underflow. The starch, sulfur and protein separation efficiencies of the newly designed hydrocyclone were 88.5–91.0%, 81.1–82.2% and 88.8–90.4%, respectively. [Display omitted] •Bradley's geometry hydrocyclone is designed for fine particle separation.•Hydrocyclone dimension effects on discharge flow pattern and pressure drop.•Spray discharge shape was suitable for cassava starch-water separation.•Rope discharge shape was suitable for impurity separation and starch recovery.•Pressure drop increased with decreasing cylindrical and conical lengths.