Vacuum pump, for condensing and aggressive gases, is a dry pump with a membrane pump stage and a spiral scroll pump stage

摘要

The vacuum pump has two stages, with the first pump stage (1) at the vacuum side and a second pump stage (2) at the pressure side in succession behind each other. The second pump stage is a membrane stage, with at least one membrane pump unit (3). The first pump stage is preferably a spiral scroll pump, with an orbiting rotor, with at least one scroll pump unit (4). The interior of the scroll pump stage is at least partially of fluorine plastics with a high resistance to chemicals and especially at the sides of the spirals (5,6) towards the impeller zone. The plastics are preferably reinforced carbon fibers or particles or other chemical-resistant plastics, or of a metal with a chemical-resistant plastics cladding. The sealing bellows (10) between the impeller zone (11) of the scroll pump and the working zone (12) is of a chemical-resistant and elastic plastics.