Working principle and oil press process of screw oil press
After the material embryo of the screw oil press enters the pressing chamber, it gradually advances from the feeding end to the cake outlet end under the rotation of the screw thread. Due to the change in the bottom diameter of the screw thread from small to large, the volume of each section in the pressing chamber gradually decreases; Due to the continuous pushing of the material into the pressing chamber by the screw thread, the product pressure is pushed forward and backward, compressing the material and squeezing out the oil. At the same time, adjust the gap between the cakes to change the thickness of the cakes. The smaller the gap, the thinner the cake, and the greater the pressure inside the squeezing chamber. In addition, the material embryo is in a moving state in the pressing chamber, causing friction between the material embryo and the strip or circular row, between the material embryo and the pressing screw, and between the material embryo and the material embryo, and generating a large amount of heat. This increases the temperature of the material embryo in the pressing chamber, which is beneficial for the oil to flow out of the material embryo and improve the oil yield.
Before the raw material is pressed, it must undergo a pre-treatment process, and the quality of the pre-treatment will directly affect the normal operation and oil yield of the oil press. Different oils have different pre-treatment process requirements, but mainly include the following:
1. Cleaning. The oil entering the processing plant contains certain impurities (mud, stones, iron filings, etc.). If not carefully cleaned, it will accelerate the wear of internal components of the oil press, reduce the oil yield, and even cause malfunctions and accidents. The supporting equipment includes cleaning screens, stone removal machines, magnetic separators, etc.
2. Peeling. For oil materials with shells, they should be peeled before pressing, which can improve the production capacity and oil yield of the oil press. The supporting equipment includes: shelling machine, separation screen, separator, etc.
3. Crushing. Some oils and fats can be crushed and pressed as a whole, but after crushing, rolling, and pressing, the oil yield can be significantly improved. The supporting equipment includes crushers, embryo rolling machines, etc.
4. Steam fry. Steaming and frying is an important step in improving oil yield. The commonly used method is to wet the oil first, and then dry it in a frying pan to ensure that the oil meets the required water content and temperature for processing. The accompanying equipment includes a steaming frying pan and a seed frying pan.