Compared with the metal oil diffusion pump, the oil diffusion pump can increase the pumping speed by 30-50%. It is also used in electronic industry, chemical industry, atomic energy industry and space simulation test. The oil diffusion pump is used for high vacuum and ultra-high vacuum pumping in high vacuum system, which has no serious harm to the working liquid. It cannot directly exhaust the atmosphere and needs to be equipped with the pre-stage pump.
Current stage pump to pump the oil diffusion pump so far after about 10 pa pre vacuum at room temperature with low saturated vapor pressure of liquid, by heating heater, oil vapor produced along the steam catheter upward movement, after a few level nozzle directional, high speed, will spread in the oil vapor to the level before the end of the gas. From the former pump to the atmosphere, the oil vapor is sprayed on the wall of the pump, and when it is cooled, it flows back to the bottom of the pump, which is repeated to achieve a high vacuum purpose.
(1) adopt the new working fluid with low saturated vapor and good performance to improve the ultimate vacuum of the pump. Such as polyphenyl ether, polyethylene ether and so on. Silicone oil is now widely used.
(2) improve the structure and improve the pumping speed.
(3) reduce the oil recovery rate of the pump. For example, the use of ptfe in baffle can reduce the oil return rate greatly.
(4) shorten the start-up time of the pump.
(5) expand the pressure range of the pumping work, and the speed of pumping is unchanged between 0.4 and 10-8pa.
(6) increase the maximum anti-pressure, and the better pump pressure in foreign countries is between 79.99-106.66Pa.