Centrifugal Pump Valve Element Positioning via Fluid Pressure

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Solution Overview

Problem

Existing centrifugal pump units require complex control electronics to manage bidirectional drive motors and valve elements, which complicates the movement and positioning of valve elements based on impeller rotation direction.

Innovation Solution

A centrifugal pump unit design where a movable valve element is fixed to a contact surface within the pump housing using fluid pressure, allowing it to switch positions based on pressure changes, with a control device reducing motor speed to move the valve element between positions, and quickly increasing speed to maintain the applied position, eliminating the need for bidirectional motor control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a bidirectional drive motor is used to control valve element movement based on impeller rotation direction, then the valve element can be positioned accurately, but the control electronics and device complexity increase

Engineering Contradiction:
Improvevalve element positioning accuracyVSAvoidcontrol electronics complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces the complex bidirectional motor control system with a purely mechanical valve element design. The valve element uses its own geometry and the hydraulic forces from the pump operation itself to achieve positioning, eliminating the need for complex control electronics and bidirectional motor control.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The valve element serves itself by using the hydraulic forces generated during pump operation to position itself automatically. The valve element's design allows it to respond to pressure differentials and flow conditions without external control signals, making the system self-regulating.

Inventive Principle:
Principle #25Self-service

2Ease of operation

If control electronics are added to manage bidirectional motor control, then valve element switching can be controlled, but the overall system complexity increases

Engineering Contradiction:
Improvevalve element switching controlVSAvoidcontrol system complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The valve element automatically positions itself based on the hydraulic conditions created during pump operation. The system uses the inherent forces from the pump's operation to control the valve, eliminating the need for separate control electronics and simplifying the overall system.

Inventive Principle:
Principle #25Self-service

3Ease of operation

If the valve element is moved by flow generated by the impeller, then the valve element can switch positions, but the drive motor must operate bidirectionally increasing control complexity

Engineering Contradiction:
Improvevalve element movementVSAvoidmotor control complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent replaces the need for bidirectional motor control with a mechanical design where the valve element responds directly to hydraulic forces. The valve element's positioning is achieved through mechanical and hydraulic interactions rather than controlled motor reversal.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The valve element uses the hydraulic forces generated during pump operation to position itself automatically. The system leverages the natural forces from impeller rotation and pressure differentials to achieve valve positioning without requiring complex motor control.

Inventive Principle:
Principle #25Self-service

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

Simplifies the control of valve elements by using fluid pressure to fix and move the valve element, reducing the complexity of control electronics and allowing operation with conventional drive motors, while maintaining precise switching positions without the need for bidirectional motor control.

Implementation Method 1

at least a section of the valve element can be moved from a released position into an engaged position by a pressure or fluid pressure generated by the impeller in the pump housing, in which position it is fixed to a contact surface

Methodology Applied
Scientific EffectFluid pressure: Pressure Increase

Implementation Method 2

When at least a portion of the valve element comes into contact with this contact surface, there is a frictional and/or positive engagement between the portion and the contact surface, acting as a clutch that prevents rotation of the valve element between switching positions

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 3

The valve element is arranged in the pump housing such that it can be moved between two switching positions by a flow generated by the impeller

Methodology Applied
Scientific EffectFluid flow:

Data Source

PatentEP3765748B1Centrifugal pump assembly and method for moving a valve in such a centrifugal pump assembly
Publication Date: 2024.07.03 GRUNDFOS HLDG
  • EP3765748B1 patent drawingFigure 1
  • EP3765748B1 patent drawingFigure 2
  • EP3765748B1 patent drawingFigure 3~4

AI summary

The invention relates to a centrifugal pump assembly comprising: an electric drive motor (6, 8); an impeller (14) driven by said motor; and a pump housing (2) surrounding the impeller (14), a movable valve element (24; 24') being located in the pump housing such that said valve element (24; 24') can be moved between two selection positions by a flow generated by the impeller (14) and that at least one portion of the valve element (24; 24') can be moved, by means of a pressure produced in the housing by the impeller (14), from a released position into a close-fitting position, in which it is fixed against a contact surface (60); and a control device (64) designed to reduce the speed of the drive motor (6, 8) in order to move the valve element (24; 24') from one selection position into another selection position and then, once the pressure in the pump housing (2) has reduced to such an extent that the valve element (24; 24') is no longer fixed against the contact surface (60) and the valve element (24; 24') has been moved into the other selection position, to increase the speed of the drive motor (6, 8) again. The invention also relates to a method for moving a valve element.