Patent attributes
A pumping device and method are described. The pumping device comprises a dry rough vacuum pump equipped with a gas inlet connected to a vacuum chamber, a gas outlet leading to a conduit and an ejector. The pumping method comprises pumping gases contained in the vacuum chamber using the dry rough vacuum pump through the gas inlet, measuring electric power consumed by the dry rough vacuum pump and the pressure of the gases in the conduit, starting the ejector, when the pressure of the gases at the outlet and the electrical power consumed cross respective set point values as they rise and stopping the ejector when the electric power consumed and the pressure of the gases in the conduit at the outlet cross respective set point values as they fall.
