Microwave Resonator Quantile Sizing for Fluidized Bed Monitoring
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Solution Overview
Problem
Existing methods for determining particle size distribution in a moving particle stream are unreliable and lack the ability to accurately measure quantiles, particularly in fluidized bed processes, due to sensitivity to contamination and limitations in density-independent measurements.
Innovation Solution
A method using microwave resonators to determine quantiles of particle size distribution by evaluating resonance frequency shift and resonance curve broadening, combined with additional parameters like supply air flow and fluidized bed fill level, allowing for density-independent quantile determination through linear approximation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If optical measurement methods are used to determine particle size in moving particle streams, then measurement capability is provided, but reliability deteriorates due to sensitivity to contamination and limitations in density-independent measurements
Solution Approach 1:
The patent replaces optical measurement methods with microwave resonator-based measurement. The microwave resonator system uses electromagnetic fields instead of optical fields to interact with particles, providing density-independent measurements that are not sensitive to contamination. The resonator measures changes in resonance frequency and Q-factor caused by particle presence, enabling reliable particle size determination in moving particle streams where optical methods fail.
2Measurement precision
If average particle size is determined using conventional methods, then a size value is obtained, but the ability to accurately measure quantiles and distribution proportions is lost
Solution Approach 1:
The patent segments the particle size distribution measurement into multiple quantile determinations (e.g., D10, D50, D90) rather than providing a single average value. By using the microwave resonator to measure particle flux at different size thresholds and applying cumulative distribution calculations, the system reconstructs the full particle size distribution, preserving information about proportions and quantiles that would be lost in average-only measurements.
3Quantity of substance
If density-dependent measured values are used from microwave resonators, then measurement data is obtained, but density-independent quantile determination cannot be achieved
Solution Approach 1:
The patent transforms density-dependent measured values (resonance frequency shift and Q-factor changes) into density-independent quantile determinations through mathematical processing. By measuring particle flux at different resonance conditions and applying cumulative distribution functions, the system eliminates density dependence and achieves accurate quantile determination that is independent of material density variations.
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 measurement of particle size distribution quantiles, including number, length, area, and volume distributions, enhancing process monitoring and product quality control in fluidized bed processes.
Implementation Method 1
evaluating a quantile of the particle size distribution from two measured values of the microwave resonator, in particular from a resonance frequency shift and a resonance curve broadening
Implementation Method 2
evaluating a quantile of the particle size distribution from two measured values of the microwave resonator, in particular from a resonance frequency shift and a resonance curve broadening
Implementation Method 3
WO 2009/030314 discloses a method for measuring the moisture content of dielectric materials using at least one resonator
Data Source
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AI summary
The invention relates to a method for determining at least one characteristic of a particle size distribution in a moving particle flow using at least one microwave resonator which provides at least two measurement values for the particles flow, wherein at least one fineness feature and/or quantile of the particle size distribution is determined from the measurement values. The invention also relates to a device for generating a moving particle flow, comprising measuring equipment for determining at least one characteristic of a particle size distribution in the moving particle flow, said equipment having at least one microwave resonator which provides at least two measurement values for the particle flow, wherein the measuring equipment is designed to analyze at least one fineness feature and/or a quantile of the particle size distribution from the at least two measurement values of the microwave resonator.