Flow Switch Inner Tube Segmentation for Dirt Resistance

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Solution Overview

Problem

Flow switches used in high-pressure cleaning devices are susceptible to mechanical stress and dirt particles, which can impair the mobility of the switching body and lead to inadequate heat exchanger operation, risking overheating.

Innovation Solution

A flow switch design featuring an inner tube surrounded by an annular space with offset outflow openings, which reduces the impact of dirt particles on the switch body's mobility and decelerates the switching body to prevent demagnetization, ensuring reliable operation under high pressures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the flow switch is used in high-pressure liquid flow with dirt particles, then the flow switch can monitor flow rate accurately, but dirt particles can impair the mobility of the switching body

Engineering Contradiction:
Improveflow rate monitoring accuracyVSAvoidswitching body mobility
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The flow channel is segmented into multiple paths using the inner tube with first and second outflow openings. Liquid is divided into partial streams that flow through different paths, reducing the concentration of dirt particles in any single path and minimizing their impact on the switching body's mobility while maintaining accurate flow rate monitoring.

Inventive Principle:
Principle #1Segmentation

2Speed

If the switching body is displaced quickly by high-flow liquid, then the switching response is fast, but the switching body may be subject to high mechanical stress and demagnetization

Engineering Contradiction:
Improveswitching response speedVSAvoidswitching body mechanical stress resistance
Core Design Contradiction:
SpeedVSStrength

Solution Approach 1:

The annular space surrounding the inner tube acts as a cushioning zone. When the switching body is displaced quickly by high-flow liquid, the annular space provides a buffer that reduces mechanical stress and prevents demagnetization, allowing fast switching response while protecting the switching body from excessive forces.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

3Device complexity

If the flow channel has a simple single outflow opening, then the device structure is simple, but dirt particles can accumulate and impair switching body mobility

Engineering Contradiction:
Improveflow channel structureVSAvoidswitching body mobility
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The flow channel uses an inner tube with multiple outflow openings (first and second outflow openings) that segment the liquid flow into partial streams. This segmentation prevents dirt particle accumulation by distributing particles across different flow paths, maintaining switching body mobility while adding only moderate structural complexity.

Inventive Principle:
Principle #1Segmentation

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 significantly reduces the susceptibility to dirt particles and minimizes the risk of demagnetization, maintaining efficient heat exchanger operation by ensuring the switch body moves smoothly and accurately, even under high pressures.

Implementation Method 1

a permanently magnetized switching body that can be displaced by the liquid as a function of the flow, and with a switching element that can be actuated magnetically depending on the position of the switching body

Methodology Applied
Scientific EffectMagnetic field: Magnetic Field

Data Source

PatentEP2810292B1Flow switch
Publication Date: 2015.11.25 ALFRED KARCHER SE & CO KG
  • EP2810292B1 patent drawingFigure 1
  • EP2810292B1 patent drawingFigure 2

AI summary

The invention relates to a flow switch (10) comprising a flow channel (34) which has a liquid inlet (20) and a liquid outlet (28), through which a liquid can flow, and in which a permanently-magnetised switching body (54) is arranged that is able to be displaced, by the liquid, as a function of the flow, said switch also comprising a switching element (58) that can be magnetically actuated depending on the position of said switching body. In order to improve the flow switch (10) such that it is less sensitive to dirt particles carried along by the liquid, the invention suggests that an inner pipe (36) surrounded by an annular space (38) is arranged in the flow channel (34), receives said displaceable switching body (54), and has an inflow opening (42) fluidically connected to the liquid inlet (20), as well as at least one first and at least one second outflow opening (48, 50, 51), wherein said at least one second outflow opening (50, 51) is axially offset to the at least one first outflow opening (48) and said outflow openings open into the annular space (38). The annular space (38) is fluidically connected to the liquid outlet (28).