Component structure of oil-free vacuum system

In recent years, it has been found that vacuum systems that use mechanical vacuum pumps and diffusion pumps to evacuate, because it has enough oil vapor to flow back into the pumped container or device, the performance and technical indicators of many electronic devices are seriously affected. For example, the oxide cathode of an electronic tube reduces its emission performance and life due to oil vapor. Various high-power high-voltage electronic tubes are prone to electrical breakdown due to the presence of oil vapor. The presence of the oil significantly reduces its pressure resistance index, and oil vapor has a significant adverse effect in many places.

Therefore, the vacuum systems used in these areas are required to be replaced by oil-free vacuum systems, that is, instead of using vacuum oil sealing tools (such as mechanical pumps, diffusion pumps) that use vacuum oil seals and vacuum oil as the working fluid, Adsorption of gas molecules, adsorption pumps and pumps that reduce the pressure in the container to obtain the required vacuum.

The adsorption pump uses the porous surface of certain solid materials to strongly adsorb gas in a cold state, so that the closed system obtains a low vacuum of 10-2 mm mercury column. It is used as the front stage of an oil-free system .

Generally, in addition to activated carbon, the adsorbent used by the adsorption pump uses a molecular sieve (artificial zeolite) to adsorb the gas and obtain a vacuum. Because, after cooling with liquid nitrogen, each kilogram of molecular sieve can draw a 50-100 liter container from the atmosphere into a vacuum of 10-2 mm mercury column, so it is a kind of pump with a large air intake. After it is baked at about 400 ° C, the gas it absorbs is released again (called activation or regeneration), and the ability to re-inhale is restored. 5A molecular sieves currently used (large absorption capacity, suitable for exhausting air, but need to be "activated, with an average pore size of about 5 Angstroms) and 13X molecular sieve (its adsorption capacity is smaller than 5A molecular sieve, but it can absorb oil vapor molecules) .

Vacuum Pump Sizing Calculations

Water Ring Vacuum Pump Extraction Technology

Screw Vacuum Pump Application Conditions