EXPELLER
As name suggests, expellers are mechanical machines used to expel / separate oil from the oil-bearing seeds. Now a days most of the expellers consists of screw type shafts enclosed in a perforated cylindrical chamber, hence the expeller is also called as Screw Press.
- Expellers are used for seeds which has High oil content, such as Cotton seed, Sunflower, safflower, Rape seed, mustard, Sesame etc and nuts such as Coconut, Ground nut etc.
- Generally, 50 to 60% of the oil present in the seeds/nuts is extracted in expeller and the balance 50 to 40% oil remaining in pressed cake is extracted in Solvent Extraction Plant (SEP). The DOC (De Oiled Cake) is rich in protein, hence it is having a huge demand from feed industry.
- Since the oil is extracted at low temperature using high mechanical pressure, the oil obtained from expeller is superior in quality and very low impurities compared to Solvent extracted oil / any other process extracted oil.
In a typical screw press, the feed material fed at the one end of the screw shaft and the De-oiled cake/Press Cake is collected the opposite end of the screw shaft, as the feed material travels in the annular space between screw shaft and perforated oil chamber, the oil seeds are subjected to high mechanical pressure which results in rupture of the oil cells. The oil separated from the seed, seeps through the perorations in the oil chamber and the defatted/pressed cake is collected at the opposite end of the shaft.