I am interested in the torque characteristics of a liquid ring compressor for the purpose of specifying a driving motor. My questions are:
- Is the speed torque characteristic (starting torque) constant torque or variable torque?
- Is the duty cycle (running torque) constant or variable? By variable, I mean similar to a reciprocating piston compressor in that the torque varies from high to low during the compressor rotation.

I will appreciate any answers and explanations and would also greatly appreciate answers that include a reference document.