Pressure Balance Ports for Multistage Pump Thrust Compensation
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Solution Overview
Problem
Existing multistage fluid transport systems, particularly those handling multiphase fluids, face issues with unbalanced thrust forces due to varying pressure differentials across stages, leading to increased wear and reduced reliability of thrust bearings, and the need for larger, more costly compensation devices.
Innovation Solution
The system incorporates a thrust compensation mechanism with pressure balance ports and flow seals on the rotor disk to equilibrate pressures between stages, reducing individual and overall thrust forces, and uses smaller thrust compensation devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If thrust compensation devices are used to compensate for axial thrust forces generated by pump stages, then the thrust forces are balanced, but the capital costs and maintenance costs increase due to additional hardware features
Solution Approach 1:
The pump is divided into multiple stages, each with its own impeller and diffuser combination. The thrust compensation is segmented by providing individual balance ports for each stage on the rotor disk, allowing localized pressure equalization rather than requiring a single large compensation device
Solution Approach 2:
The invention uses hydraulic pressure balance ports that allow fluid to pass through the rotor disk, equalizing pressure between the upstream and downstream sides of each stage. This pneumatic/hydraulic approach replaces mechanical thrust compensation hardware with fluid-based pressure equalization
2Force
If thrust compensation devices are used to compensate for axial thrust forces, then thrust balance is achieved, but maintenance costs increase due to operational wear over time
Solution Approach 1:
The thrust compensation system is self-regulating through the balance ports that automatically equalize pressure across the rotor disk. The system uses the pump's own operating fluid to provide compensation, eliminating the need for external thrust bearings that would require maintenance
Solution Approach 2:
Hydraulic pressure equalization through balance ports eliminates mechanical contact and wear between thrust compensation components. The fluid-based compensation system has no moving parts that experience operational wear, thereby extending service life and improving reliability
3Force
If thrust compensation devices compensate for overall pressure differential across the pump, then overall thrust is balanced, but unbalanced thrust force develops when gas slugging occurs in individual stages
Solution Approach 1:
The rotor disk is provided with multiple balance ports, each associated with specific stages, allowing independent pressure equalization for each stage. This segmentation enables the system to respond to gas slugging in individual stages without affecting the compensation for other stages
Solution Approach 2:
The balance ports dynamically equalize pressure across the rotor disk based on local conditions in each stage. When gas slugging occurs in a particular stage, the corresponding balance port adjusts the pressure distribution locally, allowing the system to adapt to varying operating conditions in real-time
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach reduces thrust forces, extends the life of thrust bearings, and enhances the system's reliability by adapting to variable gas volume fractions, thus improving operational robustness.
Implementation Method 1
at least one pressure balance port defined within the rotor disk such that the pressure balance port extends from a pressure balance cavity proximate the downstream side of the rotor disk to an impeller inlet portion proximate the upstream side of the rotor disk
Data Source
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AI summary
A fluid transport device defining a centerline axis therethrough includes at least one rotatable member including a first portion and a second portion axially opposite the first portion. The fluid transport device also includes at least one stationary member positioned proximate the at least one rotatable member. The at least one rotatable member and the at least one stationary member define at least one stage. The at least one rotatable member defines at least one pressure balance port extending from the second portion to the first portion. The at least one pressure balance port is configured to substantially equalize a fluid pressure proximate the second portion with a pressure of a fluid proximate the first portion.