US20140356194A1

US20140356194A1 - Airlift pump with helical flow pattern

Info

Publication number: US20140356194A1
Application number: US13/910,106
Authority: US
Inventors: Wael Hasan Ahmed; Hassan Mohamed Badr; Amro Mohamed Al-Qutub
Original assignee: King Fahd University of Petroleum and Minerals
Current assignee: King Fahd University of Petroleum and Minerals
Priority date: 2013-06-04
Filing date: 2013-06-04
Publication date: 2014-12-04

Abstract

The airlift pump with helical flow pattern includes a nozzle body having a fluid passage therethrough. A plurality of air or gas injector nozzles surrounds the central passage. The outward side of each nozzle is tangent to the fluid passage wall through the body to produce circumferential flow in the fluid passage. Each of the air injector nozzles is also inclined in the direction of flow through the body, the tangential inclination resulting in a helical flow pattern through the body. The centrifugal force generated by the circumferential and helical flow through the body results in a pressure decrease through the core of the fluid passage, thereby enhancing entrainment of fluid into the device to increase its efficiency. The fluid passage through the nozzle body is devoid of any structure, and the inlet end of the passage is smoothly radiused to further increase the efficiency of the device.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention
The present invention relates generally to fluid pump devices, and particularly to an airlift pump with helical flow pattern that has a plurality of helically oriented air injection nozzles for imparting an upward helical flow pattern to the entrained fluid being drawn through the pump.
2. Description of the Related Art
The conventional airlift pump is a simple device, comprising a discharge or jet of air or other gas into the lower end or portion of a substantially vertical standpipe situated in a body of water or other liquid. The air or gas jet entrains the liquid and lifts the liquid within the pipe to expel the liquid from the open top of the pipe, or from a discharge pipe or tube extending from the top of the pipe. Relatively small solid particulates (e.g., sand and gravel) may also be lifted from the bottom of the body of water, depending upon the energy in the airstream and other factors.
Airlift pumps have no moving parts whatsoever incorporated in the pump structure. However, airlift pumps by their nature cannot achieve the efficiency or the lifting height of motorized mechanical pumps. An example of an airlift pump is found in Japanese Patent No, 2005-291,171, published on Oct. 20, 2005, which describes (according to the drawings and English abstract) a bubble jet-type airlift pump for drawing relatively light particulate matter from the bottom of a body of water.
Thus, an airlift pump having a helical flow pattern solving the aforementioned problems is desired.

SUMMARY OF THE INVENTION

The airlift pump with helical flow pattern includes a nozzle body defining a central fluid passage and having a plurality of helically inclined air injection nozzles surrounding the central passage. The laterally outward side of each of the injector nozzle passages is tangent to the inner wall or surface of the central fluid passage of the nozzle body. Air (or other gas) injected into the central fluid passage produces a circumferential flow. Each of the injector nozzle passages is also inclined in the general direction of fluid flow through the body. The tangential and sloping orientation of the air injection passages results in a helical flow pattern for the air or gas injected into the nozzle body. This helical flow pattern imparts a similar flow pattern to the fluid passing through the nozzle body. The rotating flow results in a decrease in pressure through the center of the flow due to the centrifugal effect of the rotating fluid flow. This pressure drop enhances the entrainment of more fluid through the device, thereby increasing its efficiency.
The tangential orientation of the air or gas injection nozzles results in a completely open fluid flow passage through the nozzle body, thereby further increasing the efficiency of the device by removing any structure that would otherwise produce hydrodynamic resistance to flow through the body. The entrance to the fluid flow passage is also smoothly radiused in order to reduce turbulent flow at this point. A riser or standpipe is attached to the upper or outlet end of the nozzle body. The riser preferably has the same internal diameter as the fluid passage of the nozzle body. The fluid passages of both the nozzle body and the riser preferably have uniform internal diameters to maximize smooth flow through the apparatus. The riser or standpipe is preferably sealed to the upper end of the nozzle body to preclude leakage and flow disruption at that point, e.g., by an O-ring or other suitable sealing means.
These and other features of the present invention will become readily apparent upon further review of the following specification and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view in section of the nozzle body of an airlift pump having a helical flow pattern according to the present invention, illustrating the orientation of the air injector nozzles therein.

FIG. 2 is an elevation view in section of the airlift pump having a helical flow pattern according to the present invention, illustrating further features thereof and the attachment of the riser pipe to the nozzle body.

FIG. 3 is a top plan view of the nozzle body of the airlift pump having a helical flow pattern according to the present invention, illustrating the tangential orientation of the air injection nozzles to the fluid passage of the nozzle body.

FIG. 4 is a diagram of the flow pattern within the nozzle body of the airlift pump having a helical flow pattern according to the present invention.

FIG. 5 is a diagram of gas and particulate flow through the nozzle body of the airlift pump having a helical flow pattern according to the present invention.

Similar reference characters denote corresponding features consistently throughout the attached drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The airlift pump having a helical flow pattern includes a plurality of air or gas injection nozzles disposed tangentially to the wall of the central passage and inclined toward the upper or outlet end of the passage to impart a helical flow to liquid entrained in the device. This helical flow pattern imparts additional energy to the liquid flow through the device in comparison to conventional flow patterns, thereby increasing the lift height of the liquid pumped through the device.
FIG. 1 of the drawings provides a perspective view in section of the airlift pump with helical flow pattern, designated generally as 10 in the drawings. FIG. 2 provides an additional elevation view in section of the airlift pump 10 that also shows the attachment of a riser pipe to the upper end of the device. The airlift pump 10 comprises a nozzle body 12 having a lower inlet end 14 and an opposite upper outlet end 16. A fluid flow passage 18 is disposed concentrically within the nozzle body 12, as shown clearly in FIG. 3 of the drawings. The fluid flow passage 18 extends completely through the nozzle body 12, from the inlet end 14 to the outlet end 16 thereof. The lower or inlet end 14 of the fluid flow passage 18 has a smoothly rounded radius 20 to minimize turbulent flow of liquid entering the passage 18. The wall 22 of the fluid flow passage 18 defines the internal diameter 24 of the fluid flow passage, which is constant and uniform throughout the length of the fluid flow passage 18. It will be seen in the top plan view of FIG. 3 that the fluid flow passage 18 is completely open and devoid of any internal structure, e.g., air inlet nozzles, etc., as found in conventional airlift pumps.
Rather than the conventional air inlet nozzle or nozzles extending into the flow path through the fluid flow passage 18, the airlift pump 10 utilizes a plurality of tangentially disposed and inclined air injection nozzles 26 evenly spaced circumferentially about the nozzle body 12. Four such nozzles 26 are shown in hidden lines in FIG. 3. More or fewer such nozzles may be provided in the nozzle body, as desired. Each of the nozzles 26 has an inlet end 28 communicating with the exterior of the nozzle body 12 for the connection of an air (or other gas) supply line thereto, and an opposite outlet end 30 communicating with the fluid flow passage 18 through the nozzle body 12. Each of the air injection nozzles 26 is upwardly inclined in the direction of flow through the nozzle body 12, as shown in FIGS. 1 and 2. The inlet ends 28 are disposed toward the lower or inlet end 14 of the body, and the outlet ends 30 are higher in the body, toward the upper or outlet end 16 thereof.
It will also be seen particularly in FIG. 3 that the outlet ends 30 of each of the air injection nozzles 26 are laterally offset relative to the axial centerline of the fluid flow passage 18 through the nozzle body 12, i.e., they are tangent to the wall 22 of the fluid flow passage. More specifically, as shown in FIG. 3, the laterally outward side 32 of the wall of each of the air injection nozzles 26 forms a tangent with the wall 22 of the fluid flow passage 18 at the outlet end 30 of the nozzle. The combination of the upward inclination and tangential disposition of the air injection nozzles 26 relative to the central fluid flow passage 18 of the nozzle body 12 produces a helical flow path for air (or other gas) flowing into the central fluid flow passage 18. As the air (or other gas) entrains the liquid within the fluid flow passage 18, the liquid also develops a helical flow path through the fluid flow passage. The mass of the fluid within the fluid flow passage 18 is impelled to follow the contour of the wall 22 of the fluid flow passage 18 as it flows upward in the passage, thus producing a pressure drop in the center of the fluid flow passage 18. This reduction in pressure through the center of the fluid flow passage 18 enhances the suction produced at the inlet end 14 of the nozzle body 12. As additional mass and velocity of liquid is entrained through the fluid flow passage 18 by the suction, the result is a greater lift height of the fluid at the nozzle body outlet end 16.
Accordingly, a riser pipe 34 (shown in FIG. 2) may be attached to the upper end 16 of the nozzle body 12 to accommodate the additional lift height provided by the present airlift pump 10 with its helical flow pattern. The upper end 16 of the nozzle body 12 includes a riser receptacle 36 therein concentric with the fluid flow passage 18, the riser receptacle 36 having a larger diameter 38 than the diameter 24 of the fluid flow passage 18 to seat the riser pipe 34 therein. The riser pipe 34 has an internal diameter 40 equal to the internal diameter 24 of the fluid flow passage 18 of the nozzle body 12, thereby resulting in a smooth, constant and uniform internal diameter for the nozzle body 12 and riser pipe 34 assembly to minimize any impedance to fluid flow therethrough. The riser receptacle 36 in the upper end 16 of the nozzle body 12 further includes a circumferential annular O-ring groove 42. An O-ring 44 is seated therein to seal the lower end 46 of the riser pipe 34 within the riser receptacle 34 of the nozzle housing 16 in order to prevent the escape of fluid between the fluid flow passage 18 of the nozzle body 12 and the riser pipe 34.
FIG. 4 of the drawings provides a schematic representation of the fluid flow vectors within the fluid flow passage 18 of the nozzle body 12 of the airlift pump 10. In FIG. 4, four solid arrows represent the axes of the corresponding four injectors. Each injector axis is inclined in the radial, axial, and tangential directions, i.e., the injector axis does not extend radially inward into the nozzle body in a horizontal plane, but extends radially inward obliquely; similarly, the injector axis does not extend vertically parallel to the central axis of the nozzle body 12, but at an oblique angle relative to vertical, and the injector axis is not tangential to the circumference of the nozzle body, but extends obliquely inward and upward. The injector axis A forms an angle θ with the vertical axis of the nozzle, and an angle φ with the radius of the nozzle. The airstreams thus injected by the nozzles have a combination of axial, radial, and tangential components that affect motion of the fluid flow within the fluid flow passage of the nozzle body, imparting an axial flow upward through the nozzle body 12 and riser pipe 34 that is accompanied by the radial and tangential components contributed by the air injectors 26, result in a helical flow pattern that travels upward in the airlift pump 10.
FIG. 5 is a schematic representation of the particulate and fluid flow through the fluid flow passage 18 of the nozzle body 12 of the airlift pump 10. As the air enters the pipe, the upward and circular flow within the fluid flow passage of the nozzle body produces an upward helical flow pattern that results in a low pressure vortex at the lower end 14 of the fluid flow passage 18, thereby entraining liquid and particulates swept up by the liquid flow into the fluid flow passage. The swirling, helical flow pattern tends to homogenize the solid particles within the liquid phase along the entire flow passage, and further downstream (i.e., ejected from the upper end of the flow passage). The design parameters that affect the liquid and solid mass flow rates for a given input air mass flow rate comprise the pipe riser total length L, the available static height H₅, the pump static lift L_s, the height of the input end of the fluid flow passage above the bottom of the fluid tank or reservoir X_s, and the pump or fluid flow passage diameter D. The pressure of the air or gas inflow P_in, also affects the operation of the pump.
It is to be understood that the present invention is not limited to the embodiments described above, but encompasses any and all embodiments within the scope of the following claims.

Claims

1. An airlift pump with helical flow pattern, comprising:

a nozzle body having an inlet end and an outlet end opposite the inlet end, the nozzle body defining a concentric fluid flow passage through the body, the fluid flow passage extending from the inlet end to the outlet end of the nozzle body and having a passage wall defining a fluid flow passage diameter;

a plurality of air injection nozzles extending into the nozzle body for the injection of air into the fluid flow passage, each of the air injection nozzles having an inlet end and an outlet end opposite the inlet end, each of the air injection nozzles having an axis wherein the outlet end of each of the nozzles communicates with the fluid flow passage at a non-zero angle away from tangent to the passage wall of the fluid flow passage, each of the air injection nozzles having an axis being inclined vertically, laterally, and radially within the nozzle body in order to produce non-tangential helical flow of liquids through the fluid flow passage from the inlet end to the outlet end of the nozzle body, the outlet end of each of the nozzles being oriented toward the outlet end of the nozzle body;

a riser receptacle disposed within the outlet end of the nozzle body, the riser receptacle having a larger internal diameter than the fluid flow passage; and

a riser pipe having a lower end disposed within the riser receptacle of the nozzle body and extending upward therefrom, the riser pipe having a smooth and uniform internal diameter equal to the diameter of the fluid flow passage.

2. The airlift pump with helical flow pattern according to claim 1, wherein each of the nozzles has a wall having an outward side, the outward side of the nozzle wall being tangent to the wall of the fluid flow passage at the outlet end of each of the nozzles.

3. The airlift pump with helical flow pattern according to claim 1, wherein the inlet end of the fluid flow passage is smoothly radiused and has a curved contour.

4. The airlift pump with helical flow pattern according to claim 1 wherein the diameter of the fluid flow passage is smooth and uniform from the inlet end to the outlet end of the nozzle body, the fluid flow passage being devoid of internal structure.

5. (canceled)

6. The airlift pump with helical flow pattern according to claim 1, further comprising:

a circumferential O-ring groove disposed within the riser receptacle; and

an O-ring disposed within the O-ring groove, the O-ring sealing the riser pipe within the riser receptacle.

7. The airlift pump with helical flow pattern according to claim 1 wherein the plurality of air injection nozzles comprises four air injection nozzles, the nozzles being evenly spaced circumferentially about the nozzle body.

8. An airlift pump with helical flow pattern, comprising:

a nozzle body having an inlet end and an outlet end opposite the inlet end, the nozzle body defining a concentric fluid flow passage extending through the nozzle body, the fluid flow passage extending from the inlet end to the outlet end of the nozzle body and having a passage wall defining a fluid flow passage diameter;

a plurality of air injection nozzles extending into the nozzle body for injection of air into the fluid flow passage, each of the air injection nozzles having an inlet end and an outlet end opposite the inlet end, each of the air injection nozzles having an axis wherein the outlet end of each of the nozzles communicates with the fluid flow passage, each of the nozzles having a wall having an outward side, the outward side of the nozzle wall communicating with the fluid flow passage at a non-zero angle away from tangent to the passage wall of the fluid flow passage at the outlet end of each of the nozzles, each of the air injection nozzles having an axis being inclined vertically, laterally, and radially within the nozzle body in order to produce non-tangential helical flow of liquids through the fluid flow passage from the inlet end to the outlet end of the nozzle body;

9. The airlift pump with helical flow pattern according to claim 8, wherein the outlet end of each of the air injection nozzles is oriented toward the outlet end of the nozzle body.

10. The airlift pump with helical flow pattern according to claim 8, wherein the inlet end of the fluid flow passage is smoothly radiused and has a curved contour.

11. The airlift pump with helical flow pattern according to claim 8, wherein the diameter of the fluid flow passage is smooth and uniform from the inlet end to the outlet end of the nozzle body, the fluid flow passage being devoid of internal structure.

12. (canceled)

13. The airlift pump with helical flow pattern according to claim 8, further comprising:

a circumferential O-ring groove disposed within the riser receptacle; and

14. The airlift pump with helical flow pattern according to claim 8, wherein the plurality of air injection nozzles comprises four air injection nozzles, the nozzles being evenly spaced circumferentially about the nozzle body.

15. An airlift pump with helical flow pattern, comprising:

four air injection nozzles extending into the nozzle body, the nozzles being evenly spaced circumferentially about the nozzle body, each of the air injection nozzles having an inlet end and an outlet end opposite the inlet end, each of the air injection nozzles having an axis wherein the outlet end of each of the nozzles communicates with the fluid flow passage at a non-zero angle away from tangent to the passage wall of the fluid flow passage, the inlet end of the fluid flow passage being smoothly radiused and having a curved contour, each of the air injection nozzles having an axis being inclined vertically, laterally, and radially within the nozzle body in order to produce non-tangential helical flow of liquids through the fluid flow passage from the inlet end to the outlet end of the nozzle body;

16. The airlift pump with helical flow pattern according to claim 15, wherein the outlet end of each of the air injection nozzles is oriented toward the outlet end of the nozzle body.

17. The airlift pump with helical flow pattern according to claim 15, wherein each of the nozzles has a wall having an outward side, the outward side of the nozzle wall being tangent to the wall of the fluid flow passage at the outlet end of each of the nozzles.

18. The airlift pump with helical flow pattern according to claim 15, wherein the diameter of the fluid flow passage is smooth and uniform from the inlet end to the outlet end of the nozzle body, the fluid flow passage being devoid of internal structure.

19. (canceled)

20. The airlift pump with helical flow pattern according to claim 15, further comprising:

a circumferential O-ring groove disposed within the riser receptacle; and