Application of Vacuum Pumps in the Vegetable Oil Processing Industry

In the vegetable oil processing industry, vacuum pumps are core auxiliary equipment in the production process and are widely used in multiple key procedures of oil refining. By creating a negative pressure environment, they can lower the boiling point of materials, reduce oil oxidation, and improve refining efficiency and product quality. Meanwhile, they also facilitate basic operations such as solid-liquid separation, degassing and dehydration. The mainstream applicable vacuum pumps are mainly roots vacuum units (matched with water ring/screw pumps) and steam jet ejectors, while water ring vacuum pumps are mostly used in processes with medium and low vacuum requirements. The selection and application of vacuum pumps must align with the vacuum degree, pumping speed requirements and working condition characteristics of each process.

The common types of vacuum pumps used in vegetable oil processing each have their own characteristics and applicable scenarios. The roots-water ring vacuum unit can stably reach a vacuum degree of 0.1 kPa, featuring low energy consumption, flexible installation and low noise. Its only drawbacks are a slightly higher initial investment and the need for regular maintenance of the water ring pump part, making it suitable for deodorization, deacidification, decolorization and other procedures in small and medium-sized oil refining lines. The roots-screw vacuum unit is an oil-free and clean type of equipment with a vacuum degree of up to 0.01 kPa and a long maintenance-free period. However, it has a high equipment cost and is sensitive to dust in the working conditions, making it suitable for links with high requirements for vacuum degree and cleanliness such as deodorization and degassing in high-quality oil refining. The steam jet ejector has a simple structure and good pollution resistance, and can meet the demand for high pumping speed. Its disadvantages include large steam consumption, the need for supporting boilers and condensing equipment, and high operating noise, so it is mostly used in the traditional refining processes of large-scale vegetable oil production lines. The water ring vacuum pump is resistant to water vapor, with low equipment cost and simple maintenance, but its vacuum degree is limited (generally not lower than 3.0 kPa), and it is mainly used in processes with medium and low vacuum requirements such as vacuum filtration, dehydration and preliminary degassing.

The installation and daily maintenance of vacuum pumps also directly affect their operating efficiency and service life. Due to process requirements, steam jet ejectors need to be installed at an elevated height of about 11 meters, with supporting silencing and condensing devices to reduce noise and wastewater discharge. Units such as roots-water ring and roots-screw pumps feature flexible installation, small floor space and no elevated installation requirements. In terms of daily maintenance, the water level and water quality of water ring pumps need to be checked regularly to prevent scaling and cavitation of the pump body; the seals and lubricating oil of roots pumps and screw pumps should be replaced regularly, and the vibration and temperature of the equipment should be monitored in real time to detect potential faults in a timely manner; the nozzles and mixing chambers of steam jet ejectors need to be cleaned regularly to prevent blockage, and the steam pressure should be kept stable to avoid affecting the vacuum effect. In addition, the entire vacuum system must be equipped with vacuum safety valves and rupture discs for proper safety protection; the condensing and silencing devices of steam jet ejectors must operate normally to meet the environmental protection requirements for noise and wastewater discharge.

Overall, the selection and stable operation of vacuum pumps directly determine the product quality, production energy consumption and environmental protection level of vegetable oil processing. For small and medium-sized oil production lines that balance performance and cost, the roots-water ring vacuum unit is the preferred choice; for large-scale production lines or refining processes with high requirements for oil quality, roots-screw vacuum units or high-efficiency steam jet ejectors can be selected. The design of the entire vacuum system must comprehensively combine the process conditions, vacuum degree requirements, pumping speed requirements and long-term operating costs to ensure the efficient and stable operation of the equipment.