Fluidized Bed Classifier with Internal Bubble Control
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Solution Overview
Problem
Existing powder classification systems, such as mechanical and airflow classifiers, face challenges in continuously classifying particle sizes without clogging and maintaining high throughput, especially when dealing with fine particles.
Innovation Solution
A classification system using a fluidized bed classifier with an internal structure that reduces the size of fluidized gas bubbles, controlling the flow and scattering characteristics of particles based on size, and utilizing a cyclone for separating fine and coarse powders.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a mechanical classifier using a sieve is used to classify particle sizes, then classification can be performed, but the sieve becomes clogged when particle size is 150 μm or less, resulting in lower classification performance or difficult operation
Solution Approach 1:
The patent replaces the mechanical sieve-based classification system with a fluidized bed classifier that uses gas flow to separate particles. This substitution eliminates the mechanical clogging problem while maintaining classification capability for fine particles down to 150 μm or less.
Solution Approach 2:
The patent employs a fluidized bed classifier that uses gas flow (pneumatic system) to lift and separate particles based on their size and density. The gas flow creates a fluidized state where particles are suspended and separated without mechanical contact, avoiding clogging issues.
2Productivity
If an airflow classifier is used to classify particle sizes by contact between particles and gas, then classification can be performed, but throughput is limited when requiring greater than or equal to saturation carrying capacity of the gas due to short residence time
Solution Approach 1:
The patent modifies the gas flow parameters by introducing a fluidized bed configuration that changes the state of gas-particle interaction. This allows for extended residence time and higher throughput by optimizing the fluidized state and gas velocity parameters.
Solution Approach 2:
The patent transitions from a conventional two-dimensional airflow classification to a three-dimensional fluidized bed system where particles are suspended throughout the entire volume. This spatial expansion increases the effective classification volume and allows for higher throughput.
3Reliability
If fluidized bed classifier is used to classify powder, then continuous classification without clogging is achieved, but bubble size of fluidized gas affects flow and scattering characteristics of particles
Solution Approach 1:
The patent introduces an intermediary structure (such as a mesh or screen) within the fluidized bed that acts as a mediator to control bubble size. This intermediary element breaks large bubbles into smaller ones, thereby controlling particle flow and scattering characteristics while maintaining continuous operation.
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
The system enables continuous classification of powder particle sizes without clogging, maintaining high throughput and classification performance by effectively controlling particle flow and scattering characteristics.
Implementation Method 1
a fluidized bed classifier supplied with powder containing particles of different sizes, flowing the powder into fluidized gas
Implementation Method 2
a cyclone communicating with an upper portion of the fluidized bed classifier, and collecting and discharging fine powder contained in the fluidized gas
Data Source
AI summary
A classification system using a fluidized bed according to the present invention includes: a fluidized bed classifier supplied with powder containing particles of different sizes, which entrains the powder into the fluidized gas, and then discharges coarse powder through a coarse powder outlet positioned in its lower portion. The system further includes a cyclone communicating with an upper portion of the fluidized bed classifier, which collects and discharges fine powder contained in the fluidized gas transferred from the fluidized bed classifier to a fine powder outlet positioned in its lower portion. Additionally, the system further includes a plurality of internal structures positioned in the fluidized bed in the fluidized bed classifier which reduce a size of a bubble of the fluidized gas.