Opposed-Impeller Centrifugal Pump Flow Balancing With Multiple Conduits

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Solution Overview

Problem

Centrifugal pumps with opposed impellers face inefficiencies in conveying liquid from the first impeller to the second impeller, leading to compromised performance.

Innovation Solution

A centrifugal pump design with opposed impellers featuring a plurality of conduits and straightening fins to balance pre-rotation and ensure uniform flow, enhancing the efficiency of the second impeller.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a single conduit is used to convey liquid from the first impeller to the second impeller, then the pump structure is simple, but the liquid conveyance efficiency deteriorates and pre-rotation is unbalanced

Engineering Contradiction:
Improvepump structure simplicityVSAvoidliquid conveyance efficiency
Core Design Contradiction:
Ease of manufactureVSProductivity

Solution Approach 1:

The single conduit is segmented into multiple conduits (at least two) that convey liquid from different peripheral regions of the first impeller to the second impeller. This segmentation balances the pre-rotation effects and improves liquid conveyance efficiency while maintaining reasonable structural complexity

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The conduits are positioned asymmetrically at different peripheral regions of the first impeller to counterbalance the pre-rotation effects. By strategically placing conduits at different locations, the design compensates for rotational imbalances and optimizes flow distribution to the second impeller

Inventive Principle:
Principle #4Asymmetry

2Force

If opposed impellers are used, then axial thrust is balanced and bearing load is reduced, but liquid conveyance efficiency deteriorates due to pre-rotation effects

Engineering Contradiction:
Improveaxial thrust balanceVSAvoidpump performance efficiency
Core Design Contradiction:
ForceVSProductivity

Solution Approach 1:

Multiple conduits are used to distribute liquid from different regions of the first impeller to the second impeller, segmenting the flow paths to balance pre-rotation effects and maintain high efficiency while preserving the axial thrust balance benefit of opposed impellers

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The design changes the flow parameters by using multiple conduits at different positions and angles to convey liquid, optimizing the inlet conditions to the second impeller and eliminating pre-rotation effects that would otherwise reduce pump performance

Inventive Principle:
Principle #35Parameter changes

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 design achieves high performance and efficiency, maintaining high head and efficiency values even at higher flow rates by balancing pre-rotation and preventing circular motion, resulting in a compact and reliable pump.

Implementation Method 1

centrifugal pump with opposed impellers... impeller assemblies adapted to be rotated by a suitable motor member... liquid coming out of the first impeller is conveyed

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Data Source

PatentEP4124757B1Centrifugal pump with opposed impellers
Publication Date: 2026.04.01 PEDROLLO SPA
  • EP4124757B1 patent drawingFigure 1
  • EP4124757B1 patent drawingFigure 2
  • EP4124757B1 patent drawingFigure 3

AI summary

The centrifugal pump with opposed impellers comprises a pump body (10), which has an internal cavity having a longitudinal axis and defining a first chamber (11) and a second chamber (12) adjacent to each other, separated by a partition wall (13). The pump body (10) forms a suction inlet (14) in communication with said first chamber (11) and a delivery outlet (15) in communication with said second chamber (12). A first impeller (21) and a second impeller (22) are arranged, in opposite positions, respectively inside said first chamber (11) and said second chamber (12) of the internal cavity, said impellers (21, 22) being equipped with respective axial hubs (23, 24) adapted to be associated with a driving shaft (20) coaxial to said longitudinal axis. The centrifugal pump comprises a plurality of conduits (30) adapted to convey the liquid coming out of said first impeller (21) to the axial inlet of said second impeller (22).