Fluid Pump and Method of Pumping a Fluid

Abstract

Embodiments of the invention provide dry gaseous fluid pump apparatus comprising: a fluid inlet and a fluid outlet; at least one pump body having an internal wall defining an internal pump chamber thereof; a compression member provided within the pump chamber; and valve means being operable selectively to allow fluid to be drawn from the fluid inlet and into the pump chamber when at least a portion of the compression member is translated in a first direction and to be exhausted from the pump chamber through the fluid outlet when said at least a portion of the compression member is translated in a second direction opposite the first, the valve means being arranged to be actuated by actuator means under the control of control means to perform at least one selected from amongst the functions of allowing fluid to be drawn from the fluid inlet into the pump chamber and allowing fluid to be exhausted from the pump chamber through the fluid outlet, the apparatus comprising a linear drive assembly operable to drive the at least a portion of the compression member to and fro within the pump chamber.

Description

FIELD OF THE INVENTION[0001]The present invention relates to apparatus for pumping fluids. Embodiments of the invention are directed in particular to apparatus for pumping gases without exposing the gases to lubricating oils.BACKGROUND OF THE INVENTION[0002]Pumping of fluids such as gases, vapours, liquids, slurries and the like is a requirement in a wide range of industrial, domestic and laboratory environments. The fluid may be or comprise a gas, a vapour or a liquid. To accomplish pumping it is known to provide a fluid pump employing a piston arranged to reciprocate back and forth within a pump chamber, typically a cylinder.[0003]As the piston moves in one direction fluid is drawn into the pump chamber through an inlet valve. As the piston moves in the opposite direction fluid is forced out of the chamber through an outlet valve. Lubricant is typically provided between the piston and a wall of the pump chamber. The lubricant may have one or more of a number of effects. For exampl...

AI Technical Summary

Benefits of technology

The invention provides a fluid pump with an actuator that can open and close a valve independently of pressure differences, which prevents the valve from partially blocking the pump and increases the compression ratio. This design reduces the amount of dead space in the pump and improves its performance.

Problems solved by technology

In certain applications it is undesirable to use lubricant.

In some cases this is because the lubricant may cause contamination of the fluid being pumped and / or react with the fluid being pumped.

In the case of vacuum pumps, the use of lubricant may be undesirable due to a risk that lubricant or volatile molecules emanating from the lubricant may be introduced into the apparatus from which fluid is being pumped.

In some applications including pumps and compressors in the medical or food industries, contamination of fluid being pumped by the apparatus with lubricant or vapours associated with lubricant can be harmful to humans or animals by inhalation or ingestion.

Images