Progressing Cavity
How they convey fluids:
The ALLWEILER® progressing cavity pump is a rotary‚ self-priming positive displacement pump. The pumping elements are the rotating eccentric screw (rotor) and the fixed‚ abrasion resistant‚ elastomeric lined casing (stator). In the cross-sectional plane‚ both are in contact with one another at two points‚ forming two sealing lines along the length of the conveying elements. The fluid entering the suction area of the casing (typically located adjacent to the bearing frame) enters a cavity which is being formed as the rotor turns. As the pump shaft continues to rotate‚ the cavity is sealed and the captured process fluid is displaced axially along the length of the casing to its ultimate exit point at the casing discharge (typically located at the extreme non-drive end of the pump). This smooth‚ continuous pumping action ensures an even‚ uninterrupted volumetric output from the pump and minimizes pressure pulsations at the pump discharge.
Strengths of the technology:
- Able to handle fluids contaminated with large percentages of abrasive solids
- Simple and economical pump design requiring only one shaft seal
- Low NPSHr / NPIPr due to large internal cavities and low speed operation
- Gently handles shear-sensitive fluids like emulsions
- Designs available to the latest edition of API 676
Maximum Flow Rate | Differential Pressure | Viscosity Range Min to Max | Max Fluid Temperature | Max Solids Content | Max Free Water Content | Max Gas Content | CIRCOR Brand & Series |
---|---|---|---|---|---|---|---|
450 m3/h 1980 usgpm | 40 bar 580 psi | 1 to 270000 cSt | 150°C 300°F | 20% | 100% | 40% | Allweiler AE series |