Solvent Extraction Plants: Solvent Extraction process mainly comprises of the following steps: 1.Preparation of Bran / Oil cakes suitable for Extraction to remove oil and produce defatted meal. 2.Hexane Extraction of the material obtained from by using food grade n-hexane as solvent.
Preparation : The preparation line has been designed for the input of oil seeds from the field, which is sent to surge bins from where it is passed through cleaning section. Cleaning section comprising of cleaning, and de-stoning ensures proper, cleaning of Rice Bran. With respect to the removal of stones, fines, foreign material etc., from bran.The cleaned brans are then passed through cooker through a magnetic separator to remove all the ferrous material passed through rotary cleaning operation if any. The bran are subjected to thermal conditioning operation where in the moisture level and temperature are raised to the required levels and will be passed through palletizers to make pallets. The pallets material are then passed through a drier-cooler to reduce the moisture content as well cool the pallets prior to convey them to hexane extraction plant for defatting. Extractor: The Extractor is a slow moving articulated band conveyor inside a totally enclosed chamber. The band conveyor is lined with perforated sheet, covered with stainless steel wire mesh for easy percolation of Miscella. The Band Conveyor moves on the rail provided inside the extractor. A series of sprays are located above the band conveyor for spraying miscella and solvent on top of the moving material bed of the extractor. During the movement of the bed through the extractor it is washed continuously at various points with miscella of decreasing concentration and finally with a fresh solvent in a countercurrent manner by means of sprays kept in a line over the meal bed. The miscella percolates through the meal bed, passed through bottom and collects in various hoppers kept below the bed which ultimately flows to the miscella holding tank. The extracted pallets/meal from the band conveyor falls into the discharge bin conveyed to the desolventising section by vapors seal chain conveyor. Desolventizer: the standard designs which incorporate 6 stages De-solventizer Toaster to recover hexane vapors from defatted meal care is taken to protect the quality of protein by desolventizing the meal in only 5 stages with the help of Direct and Indirect heating. Distillation: Is complete in 4 stages at temperatures not exceeding 100ºC to yield an oil of good color and quality, free of volatiles and moisture, which can cause increase of FFA in storage In the first stage 50% of the removal of hexane is done in a Rising Film Evaporator using hot vapors for DT. This specially designed RISING FILM EVAPORATOR is an ENERGY SAVING DEVICE. The next step is a RISING FILM unit where 98% hexane removal is done using steam. The final traces of hexane are removed in a vacuum stripper by open steam stripping and the oil is then dried to desired level in an integral vacuum drier. Hexane Recovery: This steam consists of water cooled condensers, vent condenser and mineral oil absorber system to ensure the lowest hexane loss achieved. he residual vapors from these condensers are evacuated by vacuum pump to a vent condenser cooled by water at 10ºC in close circuit. The residual air is aspirated through an absorption tower where mineral oil absorbs residual hexane in air before being exhausted to the air. A special “Florence Flask” type water separator and water re-boiler completes the hexane recovery circuit.