SOLID-LIQUID SEPARATION OF AGRICULTURAL PRODUCTS USING TWIN-SCREW PRESS AND ELCTROOSMOSIS

Solid-liquid separation is one of the main processes in the agricultur al and food industry. Screw pressing is one of the methods of solid-li quid separation using mechanical pressing. A new type of screw press ( twin screw press: screw diameter = 136 mm, L/D = 6.5, feeding rate = 5 0-150 kg/h) was designed with partial intermeshing and counter-rotatio n and tested for oil extraction from oilseeds (sunflower, rapeseed), f or squeezing juice from cabbage and dewatering of soy milk residue (ok ara). Oil recovery with a twin screw press increased compared with the use of a single screw press. The oil expressed with a twin screw pres s contained a smaller amount of foreign material than single screw oil . Other properties of the oil were also satisfactory. Energy consumpti on of the twin screw press was the most efficient. Juice recovery from cabbage was also highly efficient (88%) with low energy consumption. Since dewatering of fluid material like soy milk residues was difficul t to attain a high level of efficiency even using a twin screw press, the application of electro-osmosis was examined and found to be suitab le.