Disc pump

Abstract

A pump is disclosed having one or more rotating discs within a housing. The discs have a plurality of relatively small surface perturbations covering at least half of one side of their surface. The perturbations may be recessed or raised. In operation, a boundary layer is formed near the surface of the rotating discs. The fluid within the pump flows in a circular and outward direction, thus moving fluid from a central coaxial inlet to an outlet located at the peripheral wall of the housing. The surface perturbations produce turbulence within the boundary layer during operation. The pump is suitable for pumping liquids with entrained gases, liquids with entrained solids, liquids with both gases and solids, and thick liquids.

Description

FIELD OF THE INVENTION[0001]The invention relates to a pump, and more particularly to a disc pump wherein the disc or discs have a plurality of surface perturbations covering at least half the surface area of one side of the disc or discs.BACKGROUND OF THE INVENTION[0002]Boundary layer or bladeless turbines, pumps, and other related turbo-machinery have been known for 100 years or more. Nikola Tesla obtain a patent (U.S. Pat. No. 1,061,142) for such a device in 1913. The Tesla patent disclosed a multiple-disc pump that utilized rotating flat discs with no blades, vanes, or propellers. Such pumps have been referred to as disc pumps, boundary layer pumps, or bladeless pumps.[0003]In related U.S. Pat. No. 1,061,206, Tesla disclosed a fluid-driven boundary layer or bladeless turbine which may be utilized as a prime mover in various applications. The Tesla bladeless turbine, when used as the driving force for a hydro-electric generator, could transform the kinetic energy of a flowing flu...

AI Technical Summary

Benefits of technology

[0018]The present invention utilizes a unique design for the discs that makes the pump particularly suited handling multiphase fluids with solids, liquids, and gases. Such fluids are typical of oil and gas wells, geothermal energy production and tar sands oil extraction applications. The invention provides improved pump performance without reducing the long-wear and high-reliability attributes described above. These benefits may be of value in many industrial settings.

[0019]The present invention utilizes discs having a plurality of surface perturbations covering more than half the surface of one side of the disc. These surface perturbations may be recessed (e.g., dimples) or raised (e.g., bumps). Each perturbation is small relative to the size of the full disc and is recessed or raised only a small distance. In the embodiments where raised surface perturbations are used, the perturbations protrude only a short distance away from the disc surface and should not, under most operating circumstances, extend beyond the surface boundary layer. Many distinct, yet small, surface perturbations are used to increase the turbulence in the boundary layer near the disc surface and thus increasing pump performance.

Problems solved by technology

The vanes, buckets, or the like, of traditional pumps wear and lose effectiveness due to normal friction and / or impingement with particles such as sand or other abrasives.

Typical vaned centrifugal pumps often require precise gaps between the impellors and the pump housing.

When the impellor vanes or blades of such a pump begin to wear, the pump becomes less efficient and may either pump less fluid or produce less outlet pressure, depending upon the application.

Cavitation is another problem that sometimes arises with traditional axial, bladed, centrifugal, and mixed-flow pumps Cavitation describes a vacuum-like condition in the pump which can occur when liquid in the low-pressure area of the pump vaporizes.

Cavitation can create a shock wave powerful enough to damage a pump, other equipment, or connections to the pump or other equipment.

Such a fluid can quickly wear down the impellor blades in a typical centrifugal pump, while the same fluid may cause little or no damage to a disc pump.

Other problems related to more traditional pumps include vapor lock problems, and pump efficiencies being limited by affinity laws.

The flow to head ratio is often restricted by design limitations in traditional pumps.

Turbulent flow in the stage to stage transition can be problematic as well.

Radial and side loading thrust is often inconsistent relative to rotational speed.

Upon startup, up thrust can be detrimental to the ultimate balance of the pump.

Not only do these large thrust issues require substantial thrust bearings, but these forces produce wear that leads to greater vibration over time.

Traditional centrifugal pumps are highly subject to vibrations as a natural result of impact of the vanes and blades with the fluids pumped.

This vibration problem is highly exacerbated when multiphase fluids are pumped that may include solids, liquids, and gases.

Accordingly, the shaft rotation speed of traditional pumps, especially those used for pumping multiphase fluids, is limited to avoid destroying the pump due to vibration damage.

The limited shaft rotational speeds result in lower pump output, limited horsepower, and generally less pumping capability.

Adding the equivalent of small blades or vanes on the surface of the discs may improve pump performance in some situations, but it may come at the expense of reliability and longevity.

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