How a vacuum pump works?
A vacuum pump is a device that removes gas molecules from a sealed volume in order to leave behind a partial vacuum. The first vacuum pump was invented in 1650 by Otto von Guericke, and was preceded by the suction pump, which dates to antiquity.
Vacuum pumps are used in many industrial and scientific processes including composite plastic moulding processes, production of most types of electric lamps, vacuum tubes, and CRTs where the device is either left evacuated or re-filled with a specific gas or gas mixture, semiconductor processing, notably ion implantation, dry etch and PVD, ALD, PECVD and CVD deposition and so on in photolithography, electron microscopy, medical processes that require suction, uranium enrichment, medical applications such as radiotherapy, radiosurgery and radiopharmacy, analytical instrumentation to analyze gas, liquid, solid, surface and bio materials, mass spectrometers to create a high vacuum between the ion source and the detector, vacuum coating on glass, metal and plastics for decoration, for durability and for energy saving, such as low-emissivity glass, hard coating for engine components (as in Formula One), ophthalmic coating, milking machines and other equipment in dairy sheds, vacuum impregnation of porous products such as wood or electric motor windings, air conditioning service (removing all contaminants from the system before charging with refrigerant), trash compactor, vacuum engineering, sewage systems , freeze drying, and fusion research.
Vacuum may be used to power, or provide assistance to mechanical devices. In hybrid and diesel engine motor vehicles, a pump fitted on the engine (usually on the camshaft) is used to produce vacuum. In petrol engines, instead, vacuum is typically obtained as a side-effect of the operation of the engine and the flow restriction created by the throttle plate, but may be also supplemented by an electrically operated vacuum pump to boost braking assistance or improve fuel consumption. This vacuum may then be used to power the following motor vehicle components vacuum servo booster for the hydraulic brakes, motors that move dampers in the ventilation system, throttle driver in the cruise control servomechanism, door locks or trunk releases.
In an aircraft, the vacuum source is often used to power gyroscopes in the various flight instruments. To prevent the complete loss of instrumentation in the event of an electrical failure, the instrument panel is deliberately designed with certain instruments powered by electricity and other instruments powered by the vacuum source.