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BR-102025015015-A2 - DETUNING DEVICE AND METHOD

BR102025015015A2BR 102025015015 A2BR102025015015 A2BR 102025015015A2BR-102025015015-A2

Abstract

The present invention relates to a detuning ring for structural resonance detuning in a pump assembly with drive and hydraulic units. The detuning ring is disposed between the drive and hydraulic units. The detuning ring is further configured as fixed relative to the drive unit or the hydraulic unit. The detuning ring has first and second axial faces. The first face has a plurality of first bases, each first base extending in the radial direction and comprising a flat upper first face, in which a plurality of first grooves are provided. Each first groove is delimited by two adjacent first bases and the first axial face. The second face has a plurality of second bases, each second base extending in the radial direction and comprising a flat upper second face, in which a plurality of second grooves are provided. Each second groove is delimited by two adjacent second bases and the second axial face. The invention relates to a vertical pump assembly with a drive unit, a hydraulic unit with an impeller for rotation around an axial direction, a pump shaft connecting the drive unit to the impeller, and a detuning device that is connected to the vertical pump assembly, and the detuning device with a detuning ring to surround the shaft. The invention proposes a method for shifting the natural frequency of a vertical pump assembly by disposing of a detuning ring between the drive and hydraulic units.

Inventors

  • THOMAS FRANCIS KAISER
  • Pharic SMITH

Assignees

  • SULZER MANAGEMENT AG

Dates

Publication Date
20260310
Application Date
20250721
Priority Date
20240822

Claims (15)

  1. 1. Detuning ring (1) for structural resonance detuning in a pump assembly (7), wherein the pump assembly (7) comprises a drive unit (71) and a hydraulic unit (72), wherein the detuning ring (1) is configured to be disposed between the drive unit (71) and the hydraulic unit (72), wherein the detuning ring (1) is further configured to be fixed relative to the drive unit (71) or the hydraulic unit (72), wherein the detuning ring (1) comprises a first axial face (10) and a second axial face (11), characterized in that the first axial face (10) is configured with a plurality of first bases (12), wherein each first base (12) extends in the radial direction and comprises a first flat upper face (13), wherein a plurality of first grooves (14) are provided, wherein each first groove (14) is bounded by two adjacent first bases (12) and the first axial face (10), wherein the second axial face (11) is configured with a plurality of second bases (15), wherein each second base (15) extends in the radial direction and comprises a second flat upper face (16), wherein a plurality of second grooves (17, 51) is provided, wherein each second groove (17, 51) is bounded by two adjacent second bases (15) and the second axial face (11).
  2. 2. Detuning ring (1), according to claim 1, characterized in that the first grooves (14) and the second grooves (17, 51) are arranged so that each first groove (14) overlaps two adjacent second grooves (17, 51) in the circumferential direction (C).
  3. 3. Detuning ring (1), according to any one of claims 1 or 2, characterized in that at least one of the first bases (12) or at least one of the second bases (15) is provided with a through hole or threaded hole (30) extending axially to receive a fastening element, wherein the through hole or threaded hole (30) extends from the first upper flat face (13) or from the second upper flat face (16).
  4. 4. Detuning ring (1), according to any of the preceding claims, characterized in that the detuning ring (1) comprises at least two separate segments, abutting in a circumferential direction.
  5. 5. Detuning ring (1), according to any of the preceding claims, characterized in that the first plurality of grooves (14) or the second plurality of grooves (17, 51) is closed in the axial direction to form a plurality of grooves (51).
  6. 6. Detuning ring (1), according to claim 5, characterized in that at least one groove (51) or at least one groove (14, 17) is filled with a vibration-absorbing material (61).
  7. 7. Vertical pump assembly (7) comprising a drive unit (71), a hydraulic unit (72) with at least one impeller (73) for rotating around an axial direction, a shaft (74, 113) connecting the drive unit (71) with at least one impeller (73), and a detuning device (75), wherein the detuning device (75) is fixedly connected to the vertical pump assembly (7), characterized in that the detuning device (75) comprises a detuning ring (1) as defined in any of the preceding claims, wherein the detuning ring (1) is arranged to enclose a shaft (74, 113).
  8. 8. Vertical pump assembly (7), according to claim 7, characterized in that the detuning ring (1) is disposed between two flanges (92, 93), which are axially adjacent to each other.
  9. 9. Vertical pump assembly (7), according to claim 8, characterized in that the outer diameter of the detuning ring (1) corresponds approximately to the outer diameter of the adjacent flanges (92, 93).
  10. 10. Vertical pump assembly, according to any one of claims 7 to 9, characterized in that the detuning ring (1) is disposed between the drive unit (71) and the hydraulic unit (72).
  11. 11. Vertical pump assembly (7), according to any one of claims 7 to 10, characterized in that an intermediate unit (111) is disposed between the drive unit (71) and the hydraulic unit (72) to provide space for additional components and structural stability, wherein a detuning ring (1) is disposed between the drive unit (71) and the intermediate unit (111).
  12. 12. Vertical pump assembly (7), according to any one of claims 7 to 10, characterized in that an intermediate unit (111) is disposed between the drive unit (71) and the hydraulic unit (72) to provide space for additional components and structural stability, wherein a detuning ring (1) is disposed between the intermediate unit (111) and the hydraulic unit (72).
  13. 13. Vertical pump assembly (7), according to any one of claims 7 to 10, characterized in that the hydraulic unit (72) is in fluid communication with a discharge head (131), which is disposed between the drive unit (71) and the hydraulic unit (72) and configured to be mounted on a base plate (132), wherein the detuning ring (1) is disposed between the discharge head (131) and the base plate (132).
  14. 14. Method for shifting a natural frequency of a vertical pump assembly, comprising a drive unit (71), a hydraulic unit (72) with at least one impeller (73) for rotating around an axial direction, and a shaft (74, 113) connecting the drive unit (71) with the at least one impeller (73), characterized in that it comprises the step of arranging a detuning ring (1) as defined in any one of claims 1 to 6 between the drive unit (71) and the hydraulic unit (72).
  15. 15. Method according to claim 14, characterized in that it comprises the step of disposing of vibration absorbing material (61) within at least one groove (51) or a groove (14, 17) of the detuning ring (1).

Description

[0001] The present invention relates to a device and a method for reducing vibrations in vertical pump assemblies, according to the preambles of the independent claims. [0002] Vertical pumps are fluid handling machines in which the pump shaft is oriented in the direction of gravity during operation. This type of pump is used in various sectors, including power generation, freshwater and wastewater transport, irrigation, chemical processing, oil and gas production and refining, hot water extraction from geothermal wells, cooling, and many others, often where a positive suction head is required. Although the term vertical pump includes a multitude of variants, such as turbine or centrifugal types, lift or in-line arrangements, single or multi-stage versions, and configurations for a wide range of applications, all configurations benefit from the advantage of extraordinary space efficiency through the minimization of horizontal footprint provided by their vertical orientation. [0003] Regardless of type or use, a typical vertical pump assembly comprises a drive unit, such as an electric motor, a hydraulic unit including a casing and at least one impeller, and a pump shaft connecting the drive unit with at least one impeller. The drive unit is typically bolted directly to the hydraulic unit or to an intermediate unit between the drive unit and the hydraulic unit. This intermediate unit, often acting as a drive support, provides space for additional components and allows for the optimal design of a discharge head, which is frequently located at the upper end of the hydraulic unit and provides a fluid connection from the pump assembly to the piping of a larger system. Here, the drive support may be mounted on the discharge head or integrated into it, while the discharge head comprises only the discharge piping, as in wet well pumps, or a combination of suction and discharge piping, as in so-called double casing pumps. The discharge head can be fixed to a foundation or support structure by means of a base plate. In an example of a wet well pump, the drive unit, the intermediate unit, i.e., the drive support, the discharge head, and the base plate constitute the above-ground part of a vertical pump assembly, while the below-ground structure of the pump comprises columns with flanges on both sides, connected to vessels, and a suction bell at the bottom. [0004] The arrangement of other types of pumps may vary, however, the drive unit, the hydraulic unit, the optional intermediate unit and the pump shaft, which connects the drive unit to at least one impeller in the hydraulic unit, can be considered universal parts of any vertical pump. In this sense, depending on its length, the pump shaft may be composed of multiple elements connected in series by rigid or flexible couplings. [0005] During the operation of a vertical pump assembly, the drive unit exerts a torque on the pump shaft to generate a rotation of at least one impeller mounted on the pump shaft, thereby providing the energy required for the acceleration of the pumped fluid. The rotation can be imposed by the drive unit at a fixed speed or over a range of speeds using a variable frequency drive. [0006] Due to their construction, vertical pumps typically exhibit relatively low stiffness structures, resulting in their lowest structural natural frequencies at or near the relevant excitation frequencies, which can potentially lead to structural resonance conditions and correspondingly amplified structural vibration levels. These amplified vibrations can violate compliance standards and even trigger equipment failures due to fatigue, component wear, or unexpected contact between rotating and stationary parts. While such conditions can also occur in vertical pump assemblies with fixed-speed drives, they are particularly difficult to avoid in vertical pump assemblies with variable-frequency drives. Furthermore, such conditions can occur in above-ground, below-ground, or combined above- and below-ground structural modes. [0007] The severity of a resonance condition depends on several factors, including a) the magnitude of the excitation forces acting on the system, b) the frequency separation between the excitation source and the affected structural modes, c) the amount of modal damping present to dissipate a portion of the vibration energy, d) the transfer function between the excitation force and the system response, and e) the structural robustness of the system. [0008] For most industries, the proper treatment of structural resonance-induced vibration problems in vertical pump assemblies is critical, and a multitude of mitigation strategies have been developed and are now considered common knowledge in the industry. [0009] Although significant efforts and progress have been made in the analytical prediction of potential structural resonance conditions during the development or design phase of a vertical pump, four widely used methods have emerged as effective corr