Suction Lance Level Sensor for Rapid Removal Detection

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Solution Overview

Problem

Existing liquid supply systems lack an efficient method to detect the removal of a suction lance from a liquid container, which can lead to malfunctions or incorrect refilling, especially in industrial processes where maintaining the integrity of the liquid is crucial.

Innovation Solution

A liquid supply system equipped with a suction lance featuring a level sensor that detects the liquid level and rate of change, allowing the control device to differentiate between normal operation and lance removal by setting a predefined threshold for the rate of change, thereby generating a signal to stop the pump or prevent refilling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a level sensor is fixed on the suction lance to detect liquid level, then the liquid level can be monitored during normal operation, but it becomes difficult to distinguish between normal liquid withdrawal and lance removal

Engineering Contradiction:
Improveliquid level detectionVSAvoidlance removal detection
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The system dynamically evaluates the rate of change of liquid level rather than relying on static level thresholds. By calculating how quickly the liquid level changes over time, the system can distinguish between normal withdrawal (slow, controlled rate) and lance removal (rapid rate), thereby resolving the contradiction between monitoring liquid level and detecting lance removal

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the parameter used for detection from absolute liquid level to the rate of change of liquid level. This parameter transformation allows the same level sensor to provide two functions: monitoring liquid level during operation and detecting abnormal removal events by identifying rates of change that exceed predefined thresholds

Inventive Principle:
Principle #35Parameter changes

2Reliability

If additional sensors are added to detect lance removal, then detection reliability improves, but device complexity and cost increase

Engineering Contradiction:
Improvelance removal detectionVSAvoidsensor quantity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The level sensor is designed to serve multiple functions: it monitors liquid level during normal operation and simultaneously detects lance removal by analyzing the rate of change. This multi-functionality eliminates the need for separate detection sensors, reducing device complexity while maintaining high reliability

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The existing level sensor system serves itself by utilizing its own output data (liquid level measurements) to detect lance removal. The control device processes the same sensor data for dual purposes, making the system self-sufficient without requiring external or additional sensing components

Inventive Principle:
Principle #25Self-service

3Ease of operation

If the suction lance is easily removable for refilling, then ease of operation improves, but the risk of incorrect refilling and contamination increases

Engineering Contradiction:
Improverefilling operationVSAvoidcontamination risk
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The system applies preliminary anti-action by detecting lance removal before refilling can occur and automatically responding by stopping the pump and alerting the operator. This preventive measure counteracts the potential harmful effect of incorrect refilling or contamination by eliminating the opportunity for such errors

Inventive Principle:
Principle #9Preliminary anti-action

Solution Approach 2:

The system provides immediate feedback when lance removal is detected through the evaluation of liquid level change rate. This feedback mechanism (alarm signal and pump shutdown) creates a closed loop that prevents incorrect refilling operations, allowing easy removal only when properly controlled and monitored

Inventive Principle:
Principle #23Feedback

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

Enables reliable detection of suction lance removal without additional sensors, preventing malfunctions and ensuring the correct refilling of original containers by distinguishing between liquid withdrawal and lance removal based on the rate of liquid level change.

Implementation Method 1

a level sensor for detecting a liquid level inside a liquid container

Methodology Applied
Scientific EffectLevel sensing:

Implementation Method 2

the control device is designed or configured to determine a rate of change of the liquid level which is detected by said at least one level sensor

Methodology Applied
Scientific EffectRate of change detection:

Data Source

PatentEP3933193B1Liquid supply system
Publication Date: 2024.11.20 GRUNDFOS HLDG
  • EP3933193B1 patent drawingFigure 1

AI summary

The invention refers to a liquid supply system comprising a suction lance (6) configured to be inserted into a liquid container (14) and at least one level sensor (10, 12) fixed on said lance (6) and configured to detect a liquid level (22) inside a liquid container (14), having a control device (4) connected to said level sensor (10, 12) and configured to determine a rate of change of the liquid level (22) detected by said at least one level sensor (10, 12) and to detect a lance removal if the rate of change reaches or exceeds a predefined threshold, and a method for detecting the removal of a suction lance (6) from a liquid container