Acoustic Particle Size Analysis via Waveguide Isolation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing passive acoustic methods fail to provide representative measurement results for real-time grain size distribution of granular materials, especially when measuring a wide range of grain sizes from micrometers to decimeters in various conveying streams.
Innovation Solution
A passive acoustic method that records flow energy using a force transducer and processes vibration sensor signals to normalize and calibrate acoustic signals, allowing for real-time determination of grain size distribution by correlating signal intensity with known flow energies and grain size distributions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If passive acoustic methods are used to measure grain size distribution in conveying streams, then measurement capability is provided, but measurement precision and reliability are insufficient
Solution Approach 1:
The patent introduces a waveguide as an intermediary element that mediates between the impacting granules and the acceleration sensor. The waveguide conducts structure-borne sound waves from the impact zone to the sensor while isolating the sensor from direct particle impact and external vibrations, thereby improving measurement precision and reliability simultaneously
Solution Approach 2:
The patent replaces direct mechanical contact measurement (acceleration sensor exposed to particle impact) with acoustic wave transmission through a waveguide. This substitution allows indirect measurement of impact forces while protecting the sensor from harmful mechanical effects, resolving the contradiction between measurement capability and reliability
2Productivity
If acceleration sensor is exposed to conveying stream for direct measurement, then real-time measurement is enabled, but external vibrations and signal distortions increase
Solution Approach 1:
The waveguide serves as a protective intermediary that transmits acoustic signals from the impact zone to the acceleration sensor without exposing the sensor to harmful external vibrations and particle direct contact, enabling real-time measurement while filtering out harmful factors
Solution Approach 2:
The patent extracts the acceleration sensor from the harsh conveying stream environment and places it in a protected position behind the waveguide. Only the necessary acoustic information is transmitted through the waveguide, while harmful external vibrations and particle impacts are left behind in the conveying stream
3Device complexity
If acoustic transducer is used instead of acceleration sensor, then signal processing is simplified, but measurement precision for wide grain size range is reduced
Solution Approach 1:
The patent changes the operating parameters of the acceleration sensor system by using the waveguide to transmit structure-borne sound waves in specific frequency ranges. This parameter optimization enables the sensor to accurately measure both fine particles (micrometers) and coarse particles (decimeters) simultaneously, maintaining high precision across the entire grain size spectrum
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, real-time grain size analysis across a wide grain size spectrum in any conveying flow, improving signal quality and reproducibility by minimizing external vibrations and signal distortions.
Implementation Method 1
collide with at least one impact body set up as a waveguide and generate acoustic signals which appear in each impact body as structure-borne sound waves spread
Implementation Method 2
at least one acceleration sensor (2), which is attached to the impact body (1) in a conveying direction behind the impact body (1) in such a way that no solid particles from the conveying flow come into direct contact with the acceleration sensor (2)
Implementation Method 3
the electrical signals of each vibration sensor is processed taking into account the electrical signals of each force transducer for recording the flow energy of the conveying flow
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The invention relates to a passive acoustic method for continuously determining the particle size distribution of granular material in a delivery flow. Said granular material consists of solid particles of different particle sizes that are delivered in a delivery flow in a delivery device, collide with at least one impact element in the form of a waveguide and produce acoustic signals that propagate as solid-borne sound waves in each impact element. In order to devise a passive acoustic method for determining the particle size distribution of granular material which allows representative results when measuring the particle size distribution in real time, the flow energy of the delivery flow is detected by means of at least one force sensor and the electrical signals of each vibration sensor are processed while taking into account the electrical signals of each force sensor. The invention also relates to a measuring device for carrying out the method.