The screw pump is an orthogonal screw double-rotor pump that is widely used in chemical, pharmaceutical, food, petroleum and other industries. Its main advantages are a large flow rate, balanced flow rate, strong ability to transport viscous liquids and stable pressure. In chemical, pharmaceutical, food and other industries, screw pumps are usually used to transport high-viscosity and easy-to-solidify liquids, such as asphalt, grease, resin, coatings, adhesives, pulp, paste, etc.
Lubrication method of screw pump
During the working process of the screw pump, the gap between the two screws is very small. Lubricating oil is needed to make the two screws rotate smoothly, reduce wear and friction, and improve the efficiency and life of the pump. The lubrication methods of screw pumps are usually divided into two types: external lubrication and internal lubrication.
External lubrication is an independent lubrication system composed of a separator and a condenser. Lubricating grease is injected from the outside of the pump and acts on the pump bearings and seals to reduce pump wear and friction. Internal lubrication is injecting lubricating oil directly into the pump chamber through the inlet of the pump chamber under pressure, mixing with the transported liquid, and forming a lubricating film in the pump chamber, which plays the role of lubrication and cooling.
What kind of lubricant should be used for screw pumps?
The lubricating oil of the screw pump should be lubricating grease that is not easy to evaporate under high temperature and high pressure, as follows:
1) Lithium stearate grease (LiSA)
Lithium stearate grease is resistant to high temperatures, can effectively reduce the wear and friction of screw pumps, and protect pump bearings and seals. Lithium stearate grease is often used in low-temperature environments and high-power screw pumps.
2) Synthetic polyether lubricant (PAO)
Synthetic polyether lubricant is an excellent high-temperature lubricant that can maintain stability and lubricity under high temperature and high pressure, and can effectively reduce pump wear and friction. Synthetic polyether lubricants are often used in high-power and high-speed screw pumps.
How to check the lubrication system of a screw pump?
The lubrication system of the screw pump is one of the keys to its normal operation. Therefore, during maintenance, it is necessary to carefully check whether the lubrication system is operating normally. First, check whether the oil pump is working properly and whether the oil level is sufficient. Secondly, check whether the oil pipe has any problems such as ageing and damage. If any problem is found, replace it in time. Finally, check whether there are oil stains on the lubricating parts, and if so, clean them in time.
