Centrifugal compressor

Abstract

A centrifugal compressor is shown, comprising: an impeller; a rotatably mounted diffuser surrounding the impeller; and a driving arrangement configured to drive the impeller and diffuser to rotate in opposing directions.

1 . A centrifugal compressor comprising:
 a first impeller;   a first rotatably mounted diffuser surrounding the impeller; and   a driving arrangement configured to drive the first impeller and first diffuser to rotate in opposing directions, the driving arrangement comprising a motor and a first epicyclic gearbox comprising a sun gear, a planetary gear and a ring gear, the first impeller being connected to the sun gear and the first diffuser being connected to the ring gear, the compressor further comprising:   a second epicyclic gearbox comprising a sun gear, a planetary gear and a ring gear;   a second impeller connected to the sun gear of the second epicyclic gearbox and to a second opposing end of the rotor; and   a second diffuser connected to the ring gear of the second epicyclic gearbox; wherein   a first end of a rotor of the motor is connected to the sun gear of the first epicyclic gearbox and a second end of the rotor of the motor is connected to the sun gear of the second epicyclic gearbox and a stator of the motor is fixed relative to the planetary gear.   
     
     
         2 . The centrifugal compressor of  claim 1 , wherein the first and second impeller each comprises vanes angled towards a direction of rotation of the respective impeller. 
     
     
         3 . The centrifugal compressor of  claim 1 , wherein the first and second diffuser each comprises vanes angled towards a direction of rotation of the respective diffuser. 
     
     
         4 . The centrifugal compressor of  claim 1 , further comprising an inlet inducer in an inlet gas path of the compressor. 
     
     
         5 . The centrifugal compressor of  claim 1  further comprising a housing surrounding the first and second diffuser and a seal between the housing and the diffusers. 
     
     
         6 . The centrifugal compressor of  claim 5 , wherein the seal is a labyrinth seal. 
     
     
         7 . A method of compressing a gas, the method comprising:
 rotating a first impeller with a first sun gear of a first epicyclic gearbox, the first sun gear driven by a first end of a rotor of a motor;   rotating a first diffuser surrounding the first impeller in an opposite direction to the first impeller using a first ring gear driven by a first planetary gear in the first epicyclic gearbox;   passing gas through the first impeller and the first diffuser.   
     
     
         8 . The method of  claim 7 , wherein the gas is neon, hydrogen, or helium. 
     
     
         9 . The method of  claim 7 , wherein the method further comprises:
 rotating a second impeller with a second sun gear of a second epicyclic gearbox, the second sun gear driven by a second end of the rotor of the motor;   rotating a second diffuser surrounding the second impeller in an opposite direction to the second impeller using a second ring gear driven by a second planetary gear in the second epicyclic gearbox; and   passing gas through the second impeller and the second diffuser.   
     
     
         10 . The method of  claim 9 , wherein the gas is neon, hydrogen, or helium.