Pitot tube stabilizer arrangement for centrifugal pumps
A pitot tube assembly for a centrifugal pump includes an extension arm having a tubular body with opposing ends, at least one pickup tube secured to one of the opposing ends of the extension arm, a terminal portion positioned at the other end of the extension arm and a tapered fitting provided toward the end of the extension arm opposite to the end of the extension arm to which the pickup tube is secured, where the tapered fitting provides a frustum surface for registration with a frustoconically-shaped bore of a portion of the pump to provide axial, radial and torsional stability to the pitot tube assembly during pump operation.
1. A pitot tube assembly for a centrifugal pump, comprising:
an extension arm having a tubular body with opposing ends and a central axis extending between the opposing ends;
at least one pickup tube secured to one of said opposing ends of said extension arm;
a terminal portion positioned at the end of the extension arm opposite the end of the extension arm to which the at least one pickup tube is secured; and
a tapered fitting provided toward the end of the extension arm opposite to the end of the extension arm to which the at least one pickup tube is secured, the tapered fitting being positioned between the opposing ends of the extension arm and having an outer surface oriented to register against a pump casing part in friction fit therewith.
2. The pitot tube assembly of claim 1 , wherein the outer surface of the tapered fitting defines a frustum, the base plane of the frustum being oriented toward the end of the extension arm to which the at least one pickup tube is secured and the vertex plane of which is oriented toward the terminal portion of the extension arm.
3. The pitot tube assembly of claim 2 , wherein the outer surface of the tapered fitting defines an angle of from about two degrees to about twenty degrees as measured between a plane extending along the surface of the frustum and a plane extending from the circumference of the base of the frustum parallel to the axis of the frustum and perpendicular to the plane of the base.
4. The pitot tube assembly of claim 2 , wherein said frustum is configured with an annulus adjacent the base of the frustum, the annulus being structured with a channel to receive a sealing device therein.
5. The pitot tube assembly of claim 1 , wherein the terminal portion is formed, at least in part, for receiving a tensioning mechanism in engagement with the terminal portion.
6. The pitot tube assembly of claim 5 , wherein the tensioning mechanism is formed with a threaded surface and the terminal portion is formed with a threaded surface for receiving the threaded tensioning mechanism in engagement therewith.
7. The pitot tube assembly of claim 1 , wherein the terminal portion is structured with an annular channel sized to receive a sealing device therein.
8. The pitot tube assembly of claim 1 , further comprising a keying mechanism positioned at the terminal portion and in proximity to the tapered fitting, the keying mechanism being aligned with and along a plane extending along the central axis of the extension arm, which plane is coextensive with a plane in which a longitudinal axis of the at least one pickup tube lies.
9. A centrifugal pump of the pitot tube type, comprising:
an outer pump casing;
a rotor assembly positioned within said pump casing, said rotor assembly further comprising a rotor having a fluid chamber formed therein, the rotor being engaged by a drive mechanism;
a pitot tube assembly comprising,
an extension arm having a tubular body with opposing ends and a central axis extending between the opposing ends;
at least one pickup tube secured to one of said opposing ends of said extension arm, the at least one pickup tube being positioned within the fluid chamber of said rotor;
a terminal portion positioned at the end of the extension arm opposite the end of the extension arm to which the at least one pickup tube is secured; and
a tapered fitting provided toward the end of the extension arm opposite to the end of the extension arm to which the at least one pickup tube is secured, the tapered fitting being positioned between the opposing ends of the extension arm;
a seal plate configured with a bore structured to receive said tapered fitting of said pitot tube assembly in registration therewith; and
a discharge fitting secured to said seal plate.
10. The centrifugal pump of claim 9 , wherein the bore of the seal plate is frustoconically-shaped.
11. The centrifugal pump of claim 9 , further comprising a tensioning mechanism secured to said terminal portion of said extension arm.
12. The centrifugal pump of claim 11 , wherein said terminal portion is structured with a thread, and further wherein said tensioning mechanism is a locking nut.
13. The centrifugal pump of claim 11 , wherein said terminal portion is structured with a thread, and further wherein said tensioning mechanism is a multi-jack tensioner device.
14. The centrifugal pump of claim 9 , wherein an outer surface of the tapered fitting defines a frustum having an angle of from about two degrees to about twenty degrees as measured between a plane extending along the surface of the frustum and a plane extending from the circumference of the base of the frustum parallel to the axis of the frustum and perpendicular to the plane of the base.
15. The centrifugal pump of claim 9 , further comprising a keying mechanism positioned at the terminal end of the extension arm and in proximity to the tapered fitting, the keying mechanism being aligned with and along a plane extending along the central axis of the extension arm, which plane is coextensive with a plane extending through a longitudinal axis of the at least one pickup tube.
16. The centrifugal pump of claim 9 , wherein said tapered fitting is configured with an annulus, the annulus being structured with a channel to receive a sealing device therein.
17. The centrifugal pump of claim 9 , wherein said terminal end is configured with an annulus being structured to receive a sealing mechanism in registration therewith.
18. A method of fitting a pitot tube assembly in a centrifugal pump, comprising:
providing a pump casing configured with a pump chamber therein for receiving a rotor;
providing a rotor assembly comprising a rotor that is configured with a fluid chamber within and an inlet for introducing fluid into the fluid chamber of the rotor;
providing a pitot tube assembly comprising an extension arm having a tubular body with opposing ends and a central axis extending between the opposing ends, at least one pickup tube secured to one of said opposing ends of said extension arm, a terminal portion positioned at the end of the extension arm opposite the end of the extension arm to which the at least one pickup tube is secured, and a tapered fitting provided toward the end of the extension arm opposite to the end of the extension arm to which the at least one pickup tube is secured, the tapered fitting being positioned between the opposing ends of the extension arm and having an outer surface oriented to register against and in friction fit with a seal plate of the centrifugal pump;
positioning said at least one pickup tube within said fluid chamber of said rotor assembly;
positioning said extension arm of said pitot tube assembly to extend away from said rotor and to extend through said pump casing;
positioning a seal plate, having a bore, about the terminal portion of said extension arm to position said tapered fitting in registration with said bore of said seal plate;
securing said seal plate to said pump casing; and
securing a discharge fitting to said seal plate.
19. The method of claim 18 , wherein said bore of said seal plate is frustoconically-shaped.
20. The method of claim 18 , further comprising attaching a tensioning mechanism to said terminal portion of said extension arm to bring said tapered fitting into compression with said frustoconically-shaped bore of said seal plate, followed by securing said discharge fitting to said seal plate.