Vacuum pump type

 A container is placed in the natural environment. If the internal gas pressure is not changed, the gas pressure inside and outside the container reaches an equilibrium state, which is equal to the atmospheric pressure. In order to bring the inside of the container to a vacuum, it is necessary to discharge the gas inside the container so that the internal gas pressure is less than the external atmospheric pressure. A device that removes gas from a container to obtain a vacuum by mechanical, physical, chemical, or physicochemical methods is called a vacuum pump. Vacuum pumps are classified into two types: compression type (variable volume type) and adsorption type according to their working principles. The compression type vacuum pump works by compressing the gas at the inlet end of the pump to the outlet end and discharging it to the outside of the pump.Roots_Vacuum_Pump

Common compression type vacuum pumps include: a rotary mechanical pump that utilizes a expansion-compression-discharge process, a turbomolecular pump that uses a turbine blade to remove gas, and the like. The working principle of the adsorption type vacuum pump is to adsorb the gas in the pump body, and the purpose of reducing the gas pressure has been achieved. Common adsorption vacuum pumps include: ion pumps that use ionizing suction, adsorption pumps that use physical or chemical adsorption, suction pumps, and cryogenic condensate pumps. The biggest difference between the adsorption type vacuum pump and the compression type vacuum pump is that the adsorption type vacuum pump does not discharge the gas outside the pump, but is stored in the pump. The former can achieve a higher degree of vacuum than the latter, but the pumping speed is small, and the applicable container is also small. The vacuum resistance furnace uses a compression type vacuum pump such as a mechanical pump, a Roots pump, and a diffusion pump.single-stage-liquid-ring-vacuum-pump-and-double-stage-liquid-ring-vacuum-pump

All kinds of vacuum pumps have their own working range. Some pumps can work directly from the atmosphere. For example, mechanical pumps and adsorption pumps, some pumps can't work directly from the atmosphere, such as diffusion pumps, molecular pumps, ion pumps. Wait, the inlet vacuum must reach a certain value before starting work.rotary_vane_vacuum_pump