Pump Compensation Assembly for Axial Thrust Balancing
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Solution Overview
Problem
Existing pump and turbine designs face challenges in scaling capacity, requiring redesigns for increased output, which leads to issues with torque, shaft size, and balancing thrust loads, often necessitating bulky motors and generators, and axial thrust compensation.
Innovation Solution
A compensation assembly with biasing elements, such as spring washers, is integrated into the pump design to allow axial movement of stages, balancing thrust loads and enabling self-alignment, using a crossover element for fluid communication between stages, and allowing for preloading to manage thermal expansion and operational conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the number of rotor stages is increased to scale up pump capacity, then the output increases, but the motor and generator become larger and bulkier
Solution Approach 1:
The pump is divided into multiple independent stages, each with its own impeller and diffuser, allowing the pump to achieve higher capacity through series arrangement rather than increasing the size of a single motor-gener ator unit
Solution Approach 2:
The patent transitions from horizontal arrangement to vertical arrangement of stages, with the shaft oriented vertically to receive torque from the motor. This dimensional change allows for more compact motor and generator sizing while maintaining high pump capacity
2Productivity
If the shaft length is increased to accommodate multiple rotor stages, then more stages can be added, but shaft rigidity decreases and rotodynamic problems occur
Solution Approach 1:
The patent reorients the shaft vertically, allowing stages to be arranged in a compact vertical stack. This reduces the horizontal shaft span while accommodating multiple stages, thereby maintaining shaft rigidity and avoiding rotodynamic instability
Solution Approach 2:
Multiple stages are nested vertically around the central shaft, with each stage compactly arranged. This nesting approach minimizes the overall shaft length while accommodating multiple impellers and diffusers, preserving shaft rigidity
3Productivity
If the rotor speed is increased to boost output, then the pump capacity increases, but the motor torque requirements and NPSH limitations are exceeded
Solution Approach 1:
The pump output is segmented across multiple stages, each operating at moderate speeds. The cumulative effect of multiple stages achieves high overall capacity without requiring any single stage to operate at excessively high speeds that would demand excessive motor torque
Solution Approach 2:
The patent employs adjustable speed drives and variable frequency drives to dynamically optimize the operating speed of each stage based on system requirements, allowing flexible control of torque and flow without fixed high-speed operation
4Productivity
If axial thrust loads from multiple impellers are summed, then the total thrust increases, but balancing devices become more complex and bulky
Solution Approach 1:
The patent employs asymmetric stage arrangement where impellers are positioned at different axial locations and orientations. This asymmetric configuration creates natural thrust cancellation effects, reducing the net axial thrust load without requiring complex balancing mechanisms
Solution Approach 2:
The pump design incorporates self-balancing features where the hydraulic forces generated by the impellers and diffusers automatically counterbalance axial thrust loads. The diffusers and casing geometry are designed to create reverse thrust components that offset the forward thrust from impeller rotation
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
The solution provides stable operation under high pressures, reduces leakage, simplifies assembly, and enables cost-effective, efficient scaling of pump capacity without enlarging motors or generators, while maintaining structural integrity and reducing wear.
Implementation Method 1
at least one biasing element to bias the compensation assembly into an initial position
Data Source
AI summary
Pumps and fluid-handling devices for modifying at least one property of a fluid and related method comprise a compensation element including at least one biasing element to enable a hydraulic insert to move within a housing.