Progressive Cavity Pumps
Attributed to the 1930's French aviation turbine pioneer, Rene Moineau, progressive cavity pumps are designed to move fluids by means of rotating a sequence of small, fixed shape, cavities, enclosed within the pump casing, similar in principal to the Archimedean screw. The progressive aspect refers to the tapering and overlapping of the cavities toward their ends, thereby avoiding any pulsations in the flow. Some of the other main advantages of this type of pump are that the volumetric flow rate is proportional to the rate of rotation, enabling them to be used in fluid metering, whilst the low levels of shearing lends them to being suitable for pumping viscous materials.
Also known as positive displacement pumps or eccentric screw pumps, they can act as motors, by reversing the process, pumping fluid through the interior, as used in oil field drilling with mud injection. Other industrial applications include food processing, sewage treatment, viscous chemicals handling and mine tailings slurry disposal. They can also often be found in use as lubrication and fuel pumps.
Many progressive cavity pump manufacturers use a chromium coated steel rotor, with the body made of a moulded elastomer to form the required complex cavities, inside a metal tube body. These types of pumps can usually offer relatively long service lives, provided they are not exposed to transporting abrasive materials.
Often referred to by generic trademarks, some being named after the inventor, there is a good selection of quality progressive cavity pump suppliers to choose from, including such leading brand names as; Mono, Grundfos, Lowara, Flygt, KSB and ABS.