Ultrasonic Transducer Dry Running Detection in Pumps
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing dry running detection systems for pumps are either slow due to reliance on electrical conductivity measurements or require additional components and complex setups, such as an oscillating fork, which can interfere with the detection process.
Innovation Solution
A compact dry running detection system using an ultrasonic transducer and analyzing unit within the pump housing, which generates a predefined frequency signal and evaluates changes in impedance to quickly determine contact with liquids, allowing for rapid detection of dry running without additional hardware.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If electrical conductivity measurement is used to detect dry running, then the detection system is simple, but the detection speed is slow and response time is delayed
Solution Approach 1:
The patent replaces the electrical conductivity measurement system with an ultrasonic detection system. The ultrasonic transducer converts electrical signals to mechanical ultrasonic vibrations, and by measuring the mechanical impedance changes of the ultrasonic transducer, the system rapidly detects whether the pump is running dry. This substitution of measurement principle dramatically improves detection speed while maintaining system simplicity.
Solution Approach 2:
The patent changes the detection parameter from electrical conductivity to mechanical impedance. By monitoring the mechanical impedance of the ultrasonic transducer, which changes rapidly when transitioning from liquid contact to air contact, the system achieves fast detection response. This parameter change enables real-time detection without the delays inherent in conductivity-based systems.
2Reliability
If an oscillating fork is used for dry running detection, then detection can be achieved, but additional tube flange and complex structure are required
Solution Approach 1:
The ultrasonic transducer serves multiple functions: it generates ultrasonic vibrations for detection, acts as an impedance sensor for liquid contact detection, and can be integrated into the existing pump housing structure. This multi-functionality eliminates the need for separate detection components like oscillating forks and additional tube flanges, reducing structural complexity while maintaining reliable dry running detection.
Solution Approach 2:
The patent merges the detection function into the existing pump housing by integrating the ultrasonic transducer directly into the housing structure. This consolidation eliminates the need for separate oscillating fork assemblies and additional tube flanges, simplifying the overall structure while achieving reliable dry running detection through impedance measurement.
3Reliability
If low frequency excitation is used with oscillating fork, then detection is possible, but multiple excitations are needed and excitation influences detection
Solution Approach 1:
The ultrasonic transducer operates at high frequency ultrasonic vibrations (typically 20-100 kHz), creating continuous periodic mechanical oscillations. This high-frequency periodic action allows for rapid, continuous impedance measurement without the need for multiple low-frequency excitations, significantly reducing detection time while maintaining accurate liquid contact detection through impedance changes.
Solution Approach 2:
The patent uses mechanical ultrasonic vibration of the transducer to detect liquid contact through impedance changes. The high-frequency mechanical vibrations enable rapid detection cycles, eliminating the time delays associated with multiple low-frequency excitations required by oscillating fork systems. The mechanical vibration principle provides both the detection mechanism and the timing advantage.
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 quick and accurate detection of dry running conditions, preventing pump damage by rapidly identifying changes in contact with liquids, and can be easily integrated into existing pump designs without interfering with the pumping action.
Implementation Method 1
The ultrasonic transducer is designed to convert electrical oscillations into mechanical oscillations. The oscillating frequency here lies in the ultrasonic range.
Implementation Method 2
The term impedance here denotes the complex resistance, wherein only the real part of the impedance can be considered here. If the ultrasonic transducer is in contact with air, it can oscillate with little attenuation at its excitation frequency. It here exhibits certain electrical features, such as for example a certain impedance.
Data Source
AI summary
The dry running detection system for a pump includes an ultrasonic transducer (8) designed for arrangement inside a pump housing (24) and electrically connected to a frequency generator (2) producing an electrical signal having a predefined frequency. An analyzing unit (10) of the system analyzes the electrical signal applied to the ultrasonic transducer (8) and is designed to detect whether the ultrasonic transducer (8) is in contact with a liquid or not on basis of the signal level of the electrical signal.