Molecular pump is a momentum-type vacuum acquisition device. In the molecular flow state, the gas molecules collide with the high-speed moving surface to gain momentum in a certain direction, so that the gas molecules can be compressed step by step and finally removed.
Molecular pumps there are three types
Traction molecular pumps, turbo molecular pumps, and composite molecular pumps. According to the manufacturing structure, they are classified as follows: oil lubrication, grease lubrication, magnetic levitation — single magnetic permanent magnet levitation and full magnetic levitation.
Molecular pumps characteristics
A clean vacuum can be obtained by continuously removing the gas to save energy
Oil lubricated molecular pump: small amount of lubricating oil, and in the vacuum section of the front stage, little pollution to the vacuum chamber.
Grease lubricated molecular pump: the amount of grease is very small, the front stage of the dry pump can obtain approximately oil-free clean vacuum.
Full maglev molecular pump: no lubrication, with the use of dry pump, can be obtained without oil clean vacuum environment.
Molecular pump oil of characteristics
1. The molecular pump oil shall have a very low saturated vapor pressure, so that the equipment can quickly obtain a better vacuum limit;
2. The molecular pump oil shall have excellent low temperature performance and excellent operating performance under high and low temperature conditions;
3. Molecular pump oil should have excellent emulsification characteristics and oil-water separation;
4. The molecular pump oil shall have good thermal stability and be able to maintain good serviceability under the condition of long-term high temperature friction;
5. Molecular pump oil should have excellent lubricity, easy to start pump, low energy consumption, so that the equipment can reduce wear and keep clean.
Molecular pumps oil of use
Industrial process (decoration, ITO, PVD, crystal vibration, glass coating, lighting, vacuum furnace exhaust) scientific research, military equipment instruments, equipment semiconductor industry. Lamp making, glass coating, flexible solar cell equipment: molecular pumps and leak detectors are used in electronics, electric power, vacuum equipment, cryogenic vessels, pressure vessels and other fields.
Molecular pump oil of replacement and maintenance
1) in order to ensure good lubrication of the molecular pump bearings, the molecular pump oil should be replaced regularly.
Molecular pump oil is a kind of special oil with low saturated vapor pressure. The molecular pump oil specified by the manufacturer should be used. No other pump oil shall be used instead.
2) replacement time of molecular pump oil
For oil lubrication molecular pump, in the first use of about 2000 hours, it is recommended to replace the molecular pump oil. It will be replaced every half a year after operation.
It is suggested to shorten the replacement time when the pump body is often baked, the working air load is large and the gas contains suspended particles.
3) amount of molecular pump oil
Different pump types of molecular pump oil consumption is different, general specifications will be given molecular pump oil consumption. The molecular pump cup is graduated.