Abstract: A pump for pumping a gas, the pump comprising: a rotor and a stator; the rotor comprising at least one liquid opening configured for fluid communication with a liquid source. The liquid opening is configured such that in response to a driving force a stream of liquid is output from the opening, the stream of liquid forming a liquid blade between the rotor and the stator, gas confined by the stator, the rotor and the liquid blade being driven through the pump along a pumping channel from a gas inlet towards a gas outlet in response to relative rotational motion of the rotor and the stator. A cross sectional area of the pumping channel is configured to increase from the gas inlet to the gas outlet.

Abstract: A pump includes: a rotor and a stator; the rotor having at least one liquid opening configured for fluid communication with a liquid source. The liquid opening is configured such that a stream of liquid is output to form a liquid blade between the rotor and the stator, and gas confined by the stator, the rotor and the liquid blade is driven through the pump . The pump is configured such that a pumping channel has side walls that slope towards each other from the rotor that comprises the liquid opening towards a further wall of the pumping channel remote from the rotor, such that a distance between the side walls decreases with increasing distance from the liquid opening, a tangent to a midpoint of the side walls having an angle of between 5° and 40° with respect to a line perpendicular to an axis of rotation of the rotor.