The difference between hydraulic press and screw press
The difference between hydraulic press and screw press
1. Oil extraction method
Hydraulic oil press is a kind of oil press equipment that uses liquid as pressure transmission medium and squeezes oil according to the principle of liquid pressure transmission. It is a closed-loop system composed of hydraulic system and oil press body, mainly composed of hydraulic pump station, control valve, motor, electrical cabinet, oil cylinder, cylinder, frame and other parts.
The screw oil press is a press equipment that is forced to feed through the screw shaft, and generates high temperature and high pressure under the rotating extrusion with the press ring, so that the oil is crushed and squeezed out of the oil and cake. It is mainly composed of frame, control cabinet, screw shaft, pressing ring, slag outlet and so on.
2. Refined oil quality
The hydraulic oil pressing method is a pure physical oil pressing method, which does not generate temperature during the oil pressing process and does not destroy the organic components of the oil. The extracted oil is of good quality and less impurities. It is especially suitable for some oil crops with high oil content (such as sesame, almond, pine nuts, peanuts, walnut kernels and some animal oils) and materials that must be processed by cold pressing (such as chemical raw materials and pharmaceutical raw materials).
During the oil extraction process of the screw oil press, high temperature will be generated due to the friction of the machine ring, which will destroy the organic components of the oil. There will be more impurities in the oil. Due to the high temperature of the oil, the nutrients of the oil are destroyed. After pressing, cooling is required.
3. The recycling rate of cake residue
The hydraulic oil press does not destroy the organic components in the oil during the pressing process. The cake residue has high secondary value and is widely used. For example, some food processing companies make walnut powder, almond milk, peanuts, and some oils that can be reduced or reprocessed into other foods. This has certain requirements on the oil yield. The hydraulic oil press can control the oil output by adjusting different pressures, which must be more suitable for these enterprises; this cannot be achieved on the screw oil press.
The screw oil press will generate high temperature due to mechanical friction during the oil extraction process, and the water in the oil will be lost during the oil extraction process, which will also cause certain losses to the direct sale of the cake residue. (The moisture content of the cake residue of the hydraulic oil press is about 10%, and the moisture content of the cake residue of the screw oil press is only 2-3%)
4. Price of wearing parts and failure rate
A hydraulic oil press works by an oil pump and some control valves. The failure is mainly manifested in the seal of the pipe and the plunger. During maintenance, it can be solved by replacing some gaskets, etc. It is easy to maintain and accessories are cheap.
The screw oil press works by mechanical rotation, which generates a lot of friction during the oil extraction process. The wear between the shaft and the pressure ring is faster. If the workload is large, it is usually replaced once every six months. It is more troublesome to fold and install, and the price of accessories is relatively high.
