Volute Pump Sweep-Back Vane Curved Leading Edge

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Solution Overview

Problem

Conventional volute pumps face issues with fibrous substances accumulating on the impeller, leading to clogging, as these substances can get caught by the leading edge of the sweep-back vane and fail to be transferred smoothly into the groove for discharge.

Innovation Solution

The volute pump design features a sweep-back vane with a leading edge having a front-side curved surface, allowing fibrous substances to slide smoothly and be pushed into a groove in the impeller casing, preventing accumulation and ensuring reliable discharge through a carefully controlled radius of curvature and thickness ratio.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional impeller with straight leading edge is used, then the structure is simple and easy to manufacture, but fibrous substances accumulate on the impeller causing clogging

Engineering Contradiction:
Improveprevention of fibrous substance accumulationVSAvoidimpeller structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The leading edge of the impeller vane is designed with a curved surface instead of a straight edge. The curvature radius is specifically controlled to be 0.05 to 0.15 times the thickness of the vane at the leading edge, creating a smooth rounded surface that prevents fibrous substances from catching and accumulating on the impeller.

Inventive Principle:
Principle #14Spheroidality (Curvature)

2Object-affected harmful factors

If the leading edge is made very thin to reduce resistance, then fibrous substances can pass more easily, but the structural strength decreases

Engineering Contradiction:
Improveresistance to fibrous substance passageVSAvoidleading edge structural strength
Core Design Contradiction:
Object-affected harmful factorsVSStrength

Solution Approach 1:

The curvature radius of the leading edge is optimized within a specific range (0.05 to 0.15 times the vane thickness). This parameter optimization allows the leading edge to be thin enough to reduce resistance to fibrous substance passage while maintaining sufficient structural strength through the curved geometry.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The curved leading edge design distributes mechanical stresses more evenly compared to a sharp or straight edge, enhancing the structural strength of the thin leading edge while maintaining its ability to allow fibrous substances to pass through with minimal resistance.

Inventive Principle:
Principle #14Spheroidality (Curvature)

3Reliability

If sweep-back vanes are added to prevent fibrous substance accumulation, then reliability improves, but the impeller design becomes more complex

Engineering Contradiction:
Improveprevention of cloggingVSAvoidvane geometry complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Instead of adding complex sweep-back features, the invention achieves clogging prevention through a relatively simple curved leading edge design. The curvature radius optimization provides the necessary flow guidance and prevention of fibrous substance accumulation without requiring additional geometric complexities.

Inventive Principle:
Principle #14Spheroidality (Curvature)

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 design enables fibrous substances to be effectively transferred to the volute chamber and discharged, preventing clogging and ensuring smooth operation of the pump by avoiding entrapment on the leading edge, thus enhancing the pump's efficiency and reliability.

Implementation Method 1

the leading edge portion has a front-side curved surface extending from an inner end to an outer end of the leading edge portion... allowing fibrous substances to slide smoothly

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3276178B1Volute pump
Publication Date: 2020.11.18 EBARA CORP
  • EP3276178B1 patent drawingFigure 1
  • EP3276178B1 patent drawingFigure 2~3
  • EP3276178B1 patent drawingFigure 4~5

AI summary

The present invention relates to a volute pump for delivering a liquid containing fibrous substances. The volute pump according to the present invention includes an impeller (1) rotatable together with a rotational shaft (11), and an impeller casing (5) having a suction port (3) and a volute chamber (7). A groove (18), extending from the suction port (3) to the volute chamber (7), is formed in an inner surface of the impeller casing (5). The impeller (1) includes a hub (13) to which the rotational shaft (11) is fixed, and a sweep-back vane (2) extending helically from the hub (13). The sweep-back vane (2) includes a leading edge portion (2a) extending helically from the hub (13), and a trailing edge portion (2b) extending helically from the leading edge portion (2a). The leading edge portion (2a) has a front-side curved surface (2e) extending from an inner end (2c) to an outer end (2d) of the leading edge portion (2a).