Multi-Wavelength Light Scattering for Crystallization Kernel Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Controlling the amount of unwanted sub-wavelength sized kernels in a crystallization process, particularly in sugar crystal growth, is difficult due to challenges in accurately measuring and managing the crystallization process.
Innovation Solution
A method involving the detection of light reflected or scattered from a solution at multiple wavelengths, using LEDs or broadband light sources, to determine intensity ratios and generate control signals for adding additives or adjusting process parameters like temperature and vacuum, effectively monitoring and controlling the crystallization process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional single-wavelength light scattering methods are used, then the measurement setup is simple, but the ability to detect sub-wavelength sized kernels is insufficient
Solution Approach 1:
The detection system is segmented into multiple wavelength channels (blue, green, red LEDs) that independently detect light scattering at different wavelengths. This segmentation allows the system to resolve sub-wavelength kernels by analyzing the wavelength-dependent scattering pattern, where each wavelength channel provides information about specific size ranges of particles in the solution.
Solution Approach 2:
The measurement approach transitions from single-wavelength detection to multi-wavelength detection, adding the wavelength dimension to the measurement. By detecting light scattering across multiple wavelengths simultaneously, the system gains the ability to distinguish sub-wavelength kernels from larger crystals through their distinctive scattering signatures at different wavelengths.
2Reliability
If real-time monitoring of crystallization is implemented, then process control is improved, but the complexity of the control system increases
Solution Approach 1:
The system implements feedback control by continuously monitoring light scattering at multiple wavelengths and using this information to detect unwanted kernel formation. The control unit processes the wavelength-resolved scattering data to determine kernel presence and size, then provides feedback signals to adjust crystallization parameters such as temperature, supersaturation level, or stirring speed to prevent excessive kernel formation.
Solution Approach 2:
The control system replaces complex mechanical or chemical analysis methods with optical detection. Instead of using elaborate mechanical filtration or chemical analysis to detect and control kernel formation, the system uses multi-wavelength light scattering to non-invasively monitor and control the crystallization process in real-time.
3Measurement precision
If multiple wavelengths are detected simultaneously, then the detection of crystal size distribution is improved, but the energy consumption increases
Solution Approach 1:
The system merges multiple LED light sources (blue, green, red) into a single integrated illumination unit that simultaneously provides multi-wavelength light for detection. This combining approach allows the system to obtain comprehensive crystal size distribution information across different wavelength ranges while using a compact, energy-efficient LED array rather than separate light sources for each wavelength.
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
This method allows for precise detection and control of unwanted sub-wavelength sized kernels, optimizing the crystallization process by determining the presence, size, and amount of crystals, and adjusting parameters to prevent excessive supersaturation and unwanted crystal formation.
Implementation Method 1
detecting light reflected or scattered from the solution at at least two wavelengths or wavelength ranges
Implementation Method 2
The light is collected inside the probe and is transmitted back through the same path as the laser source but separated by a splitter
Data Source
Figure 1
Figure 2
AI summary
The present invention relates to a method for analysing and controlling a crystallisation process of a solution, the method comprising the steps of exposing, along an axis of exposure, at least part of the solution to light covering a predetermined wavelength range, detecting, at a position being along the axis of exposure, light transmitted through the solution and/or light reflected or scattered back from the solution, and determining the intensities of the transmitted and/or reflected or scattered light within a first and a second portion of the predetermined wavelength range. The present invention also relates to an apparatus for performing the present invention.