How to Determine the Limit Vacuum of Vacuum Pump System
If the vacuum pump inhales corrosive gas, it will react with oil and corrode the parts in the pump. The air inhaled by vacuum pump often contains water vapor condensate, which causes the emulsification of vacuum pump oil and corrosion of metal. Therefore, the vacuum pump is required to have good corrosion resistance and emulsification resistance.
Very low vapor pressure is an important performance of vacuum pump oil. Because of the high vacuum requirement of vacuum pump, paraffin-based narrow fraction lubricant is commonly used. For diffusion vacuum pump, silicone oil or other synthetic oil with very low vapor pressure can also be used.
Appropriate viscosity and good viscosity-temperature characteristics. As the volume of the vacuum pump chamber changes continuously, the exhaust effect is formed. It is required that the lubricating oil should have proper viscosity and viscous-temperature characteristics.
Good thermal oxidation stability. Vacuum pumps are developing at a high speed. Because of the high-speed friction between slider and pump body, oil is easy to oxidize and decompose. Especially, diffusion pumps often work in a high temperature environment, which makes the vapor pressure in the system increase and the vacuum degree decrease. Therefore, the vacuum pump oil is required to have good thermal oxidation stability. Different vacuum system configurations are needed in order to meet the requirements of process indexes, working efficiency and equipment working life of different products and different vacuum sections.
In order to achieve a good z* configuration, the following factors should be considered when selecting a vacuum pump:
Determine the working range of the vacuum pump: s* must first check to determine the vacuum required for each process. Because each process has its own suitable vacuum range, it must be carefully studied and determined. Determine the vacuum limit of the vacuum pump: Check the vacuum limit of the vacuum pump system on the basis of determining the vacuum required by the process, because the vacuum limit of the system determines the z* good working vacuum of the system. Generally speaking, the limit vacuum of the system is 20% lower than the working vacuum of the system and 50% lower than the limit vacuum of the front stage pump. Press down the cover, the suction (vacuum) indicator lights on the panel. When the vacuum pump starts to suck, the cover will be automatically sucked. The vacuum knob can adjust the vacuum level according to the packaging requirements. When adjusting, the visual scale will be from low to high, and the range will be small. When the exhaust reaches the set time (i.e. the required vacuum), that is, when the exhaust is over, the exhaust indicator lights out, and the inflatable indicator lights up to indicate the beginning of inflatability. The inflatable knob can adjust the inflatable time (i.e. the amount of inflatable), the method is the same as above. If no inflatable is needed, the power switch is set to the vacuum position, the program automatically enters the vacuum packaging and the inflatable indicator lights out. When the exhaust or inflation is completed, the indicator lights will be extinguished, and the heat seal indicator lights will be on, i.e. enter the sealing procedure. The panel is equipped with heat seal time and temperature adjustment knobs to adapt to different thickness materials. When adjusting time and temperature, the rotation range should be small, so as to prevent the sudden increase of the heat seal temperature and burn out the heat seal accessories.