Flexible Impeller Pumps
What is a flexible impeller pump?
A flexible impeller pump is a type of rotary positive displacement pump, which uses a rubber rotor (it is called an impeller, even though it really isn’t) with flexible radially oriented vanes or blades that bend and rub against the eccentrically shaped casing in which they rotate. The main advantages of flexible impeller pumps are that they are self-priming, relatively low in cost, and they can handle all kinds of fluids, including those containing solids, without causing any damage.
How do they work?
In flexible impeller pumps, the rubber impeller has radially oriented blades which are in contact with the inner walls of the eccentrically shaped casing. As the impeller rotates, the blades bend as they pass across the eccentric part of the casing. This creates a vacuum which draws fluid into the pump inlet. The flexible impeller then carries the fluid between the blades of the impeller and the casing, and directs the fluid to the discharge, where it pushes the fluid out the discharge. This type of pump is only capable of generating relatively low pressures (about 60 psi) and relatively low flows (about 150 gpm), so that may limit its applications. The rotation of the pump can be reversed to change the direction of flow in the pump. Since the impeller is rubber, this pump cannot be run dry, as the rubber would be damaged by rubbing against the pump casing.
Where are they used?
The most common application for flexible impeller pumps is in the marine industry, where they are used as ballast and bilge pumps in small and medium sized marine craft. They are ideal for handling fluids that are delicate, usually with relatively low viscosities, and are also used across the pharmaceutical, cosmetic, and food industries. Sanitary versions of this pump are available, with FDA approved rubber materials for the impeller.
So now what do you do? As many of you know, this is a fairly common occurrence, particularly with pumps that have been around a long time. Here's some advice on what to do.
Article explains three common pump problems - including cavitation, air entrainment and recirculation - and provides tips on how to fix them.
Incorrectly installed suction and discharge piping can create stresses on the pump casing and thus reducing the reliability of the seal and bearings. Read tips on how to eliminate this occurance.
Agilent Technologies Inc.has acquired P.V.R. s.r.l., a long-established vacuum pump manufacturer based in Valmadrera, Italy.
Grundfos is now the official pump and pump systems provider for the Kansas City Royals.
Pump manufacturer Grundfos A/S earned the Productivity 2012 Award from the Confederation of Danish Industries, the company recently announced.
NETZSCH Mohnopumpen GmbH introduces a new version of its TORNADO rotary lobe pump. The new lobe pump is built to have a long service life and virtually eliminates any possibility of transmission damage due to leakage or contamination.