Oil expeller is a machine used for obtaining oil from the crude seeds in which the seeds are firmly pressed under high pressure. The raw seeds are squeezed in a single step to produce oil in this method. This machine was used by Anderson company that is nowadays famous as Anderson International Crop in 1888 for the first time. Valerius D. Anderson discovered this revolutionary way to pull out oil from the seeds in a single step. This oil expeller was soon came in limelight when the companies from Latin America to Europe realize the advantages of this setup.

Construction of oil expeller includes two screw shafts:- linear as well as housing. To begin with structure of screw shaft, it is related to increasing root, decreasing pitch and a screw profile which is trapezoidal shaped including a buttress. All these are arranged in such a way to get highest pressure on the seeds when the seeds are moving towards crushing part. The crushing of seeds is done on the mating part of the screws and then squeezing of these crushed seeds are completed in pressing part that results in the extraction of oil. The main parameters in constructing the screw shafts are Power(P), Torque(T), Pressure(P), Axial load on one thread, Tangential Load on a thread and Theoretical Screw Volume and Mass flow rate. As well as other parameters like Speed, Crest Diameter, Root diameter, Taper angle, Pitch variation, thread height variation, number of turns, crushing head diameter, worm length, crushing head length, total length, housing inner diameter, thickness of the housing, density, filling factor and also length of thread are essential to keep in mind. Outer diameter and inner diameter of screw shafts is 80 mm and 40 mm to 56 mm respectively. Approximate length of the shaft is 420 mm

On the other hand, in barrel design which consists of a liner and two counter rotating shafts is second part of oil expeller machine. These counter shafts are required in the development of pressure as well as increasing the retention time. In the barrel, seeds are moved via a hopper and then these seeds are proceeded through counter rotating shafts. Then the seeds reach in the pressing region where liner gives the path and the oil is extracted and gravity acts on the oil to flow it down. There are three passages in the barrel out of one is for cleaning and pressure relief, second helps inexit of air and third one is present for collecting the extracted oil. There are two barrel configurations are available in designs. First configuration is low costing configuration that aims on mass production having 420 mm length of the housing  and 84 mm inner diameter of housing with 25.4 mm thickness of the barrel, where as the second configuration includes maximum flexibility. Second one is intended for the research works and also for the development intentions that utilize various types of seeds. Second configuration of the barrel has 500 mm length of the barrel, 84 mm housing inner diameter and 10 mm thickness of each plate in the barrel.