A screw oil press machine is an oil expeller that pushes the material forward continuously in the press chamber and extracts crude oil under dynamic extrusion. Each screw has a certain pitch and depth, and the pitch of each screw on an axis gradually shortens from the feed port to the discharge port, and the screw depth gradually becomes shallower, so that the volume of the press chamber gradually decreases from the inlet to the outlet. After the material enters the press chamber, it is pushed toward the outlet along the direction of the screw rotation, and the pressure it is subjected to gradually increases, thereby squeezing out the oil one after another. Gaskets are installed between the bars of the cylindrical press cage to form an oil outlet gap, and the extruded crude oil flows out through this gap.
Generally speaking, as the moisture content of the press increases, the plasticity of the oil press equipment also gradually increases. When the moisture reaches a certain point, the oil is squeezed out best, and the moisture content at this time is called the optimal moisture or critical moisture. For a certain type of press material, under certain conditions, there is a narrower optimal moisture range. Of course, the optimal moisture range is also closely related to other factors, first of all, temperature and protein denaturation.
The main factors affecting the oil extraction effect of the oil press equipment are determined by many factors, mainly including the structure of the material and the pressing conditions. In addition, the structure of the oil press equipment and its selection will also affect the oil extraction effect to some extent. The structural properties of the material mainly depend on the quality of the pretreatment and the composition of the oil itself. It is required that the viscosity and surface tension of the oil in the material should be as low as possible, and the particles of the material should have sufficient plasticity. In fact, the properties of the material are reflected by the mutual cooperation of factors such as moisture, temperature, oil content, and protein denaturation.
When the oil press equipment requires a low residual oil rate, reasonable low moisture and high temperature of the material are necessary. Different pretreatment processes may obtain the same inlet moisture and temperature. Excessive protein denaturation will reduce the plasticity of the material, thereby increasing the necessary working pressure of the press. In short, the appropriate degree of protein denaturation can ensure a good oil extraction effect.
The pre-treatment screw oil press machine used as a pre-pressing machine pre-presses the oil with a large pressure, and then puts the pre-pressed cake into the oil press for further pressing or extracting oil by leaching. Therefore, the volume of the press chamber at the inlet and outlet ends varies greatly, and the production capacity is also large. The screw oil press can operate continuously, with low labor intensity, and the residue cake after the oil is discharged is thin and small, which is convenient for comprehensive utilization.
