Abstract: This study focuses on the efficient and energy-saving operation of screw vacuum pumps. Starting from the fundamental theory of power consumption calculation in screw vacuum pumps, the useful power required during the pumping process of the screw rotor is divided into internal compression power and external compression power (i.e., exhaust power), with corresponding formulas provided for each. Based on this, several common methods for reducing power consumption and achieving energy-efficient operation were introduced, including using a screw rotor with high compression ratio to reduce the exhaust volume, thereby lowering external compression power consumption; installing a small vacuum pump at the exhaust port to create a lower exhaust pressure, thus reducing external compression power; and to prevent excessive internal compression power in high-compression-ratio screw rotors under high inlet pressure, adopting variable frequency speed reduction (though this results in reduced pumping speed) and installing an intermediate pressure relief valve.

Key words: screw vacuum pump, energy-saving, energy consumption calculation, variable pitch rotor, variable frequency speed reduction