Detergent Dispensing Line Pressure Sensing for Reliable Fill Monitoring
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Solution Overview
Problem
Existing fill level monitoring systems for liquid detergents in washing machines and dishwashers are complex, expensive, and prone to measurement errors due to air bubbles, especially with high viscosity agents, and are not suitable for disposable containers.
Innovation Solution
A pressure-based fill level sensor integrated into the dispensing device, connected directly to the connecting line between the reservoir and pump, allowing for reliable empty level detection and real-time filling level display, with robust and cost-effective signal generation, capable of detecting air bubbles and pump functionality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If float switches or complex level monitoring systems are used, then level monitoring capability is provided, but device complexity and cost increase
Solution Approach 1:
The patent replaces complex mechanical level monitoring systems (float switches, resistance measurements) with a simple pressure-based detection system. The pressure switch detects pressure changes in the connecting line caused by liquid level changes, providing reliable monitoring with minimal mechanical complexity. This substitution resolves the contradiction by maintaining reliability while dramatically reducing device complexity.
Solution Approach 2:
The patent utilizes pneumatic pressure changes in the connecting line between the reservoir and pump to indicate liquid level. The pressure switch monitors pressure variations that occur when the liquid level drops, enabling simple yet reliable level detection without complex mechanical or electrical systems. This pneumatic approach resolves the contradiction by providing accurate monitoring through pressure changes rather than complex mechanical float switches.
2Loss of information
If resistance measurement or temperature-based level detection is used, then level information is obtained, but signal strength is low and measurement precision deteriorates
Solution Approach 1:
The patent replaces weak electrical signal-based level detection (resistance measurement, temperature sensing) with a pressure-based mechanical detection system. The pressure switch generates strong, clear signals based on pressure changes in the connecting line, eliminating the low signal strength and measurement precision problems associated with electrical resistance or temperature methods.
3Reliability
If conventional level monitoring systems are used, then empty level detection is provided, but air bubbles cannot be detected and measurement reliability deteriorates
Solution Approach 1:
The patent uses pneumatic pressure detection in the connecting line to identify air bubbles. When air bubbles are present, they cause abnormal pressure fluctuations that the pressure switch can detect, allowing the system to distinguish between actual empty level conditions and air bubble interference. This resolves the contradiction by making air bubble detection possible while maintaining reliable empty level detection.
Solution Approach 2:
The pressure switch provides continuous feedback on pressure conditions in the connecting line, enabling the control unit to distinguish between legitimate level changes and anomalies caused by air bubbles. This feedback mechanism resolves the contradiction by providing the information needed to filter out air bubble interference while maintaining accurate empty level detection.
4Measurement precision
If pressure switches are used for level monitoring, then measurement precision and reliability are improved, but the system requires integration into the connecting line
Solution Approach 1:
The patent merges the pressure switch directly into the connecting line between the reservoir and pump. By integrating the level monitoring function into the existing fluid pathway, the system achieves precise measurement without adding separate monitoring components. This merging resolves the contradiction by improving measurement precision while minimizing integration complexity, as the pressure switch becomes part of the existing connecting line structure.
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 accurate and reliable monitoring of the fill level and pump operation, preventing measurement errors and ensuring proper system functioning, suitable for both internal and external placement within existing systems.
Implementation Method 1
A level sensor (5), designed as a pressure switch in the known manner, is connected to the connecting line (3)
Implementation Method 2
The liquid detergent is drawn from the storage container (1) by a pump (2) and fed to the washing machine
Data Source
Figure 1~3
Figure 4~5
AI summary
The invention relates to a dispensing device for liquid detergents or rinsing agents for a washing machine or dishwasher, with a reservoir (1) for holding the detergent or rinsing agent (8) and with a dosing device, by means of which the washing or rinsing agent is delivered by a pump (2nd ) can be fed to the washing or rinsing process in a metered amount via a connecting line (3) and with a filling level monitoring device for the detergent or rinsing agent present in the reservoir (1). According to the invention, a pressure monitor is used as the filling level sensor (5) for the liquid level present in the reservoir (1). The pressure switch (5) is connected in the connecting line (3) between the reservoir (1) and the pump (2). With the configuration according to the invention, a cost-effective filling level sensor for an adding device of the aforementioned type is created with simple means, with which meaningful signals can be generated.