Fluidized-Bed Classification Without Sieve Mesh
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing fluidized-bed classification methods face challenges in efficiently removing foreign matter and impurities from fluidized media without using sieve mesh, particularly in systems with large incombustibles like aluminum pot lids, and require significant modifications to existing facilities for effective operation.
Innovation Solution
A fluidized-bed classification method and apparatus that utilize a two-stage classification process with a coarse and fine classification section, employing fluidizing air supply configurations to separate foreign matter by size and specific gravity, allowing for the removal of large and small incombustibles without mesh sieving, and can be applied to existing facilities with vibrating sieves.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a vibrating sieve is used to classify foreign matter from fluidized medium, then classification can be achieved, but the sieve may be clogged with foreign matter, worn by friction to have holes, or cause sympathetic vibration on plant
Solution Approach 1:
The invention extracts and removes the problematic sieve mesh from the classification system entirely. Instead of using a vibrating sieve, the patent employs a classification mechanism based on fluidized bed dynamics and particle trajectory control, where foreign matter is separated through differences in settling behavior in a controlled fluidized environment without mechanical contact from sieve surfaces.
Solution Approach 2:
The patent replaces the mechanical vibrating sieve system with a fluid dynamic classification system. The classification is achieved through controlled fluidization and particle trajectory management rather than mechanical vibration and physical sieving, eliminating friction, clogging, and vibration transmission issues.
2Measurement precision
If vibrating sieve mesh is frequently inspected and cleaned to prevent clogging, then classification precision is maintained, but dust deteriorates environment around the vibrating sieve
Solution Approach 1:
The invention removes the sieve mesh component that causes dust generation during cleaning operations. By eliminating the physical barrier approach in favor of fluidized bed classification, there is no mesh to clog or clean, thus preventing environmental dust contamination entirely.
Solution Approach 2:
The fluidized bed classification system is self-cleaning by nature, as the fluidized medium continuously circulates and prevents accumulation of foreign matter on classification surfaces. The system maintains itself without requiring external cleaning operations that would generate dust.
3Device complexity
If fluidized bed classifier does not have mechanism for discharging foreign matter properly, then classification simplicity is maintained, but foreign matter difficult to move horizontally cannot be removed effectively
Solution Approach 1:
The invention segments the classification process into distinct zones within the fluidized bed chamber: a classification zone where particles are separated based on settling characteristics, and a discharge zone where foreign matter accumulates and is removed. This segmentation allows effective removal of horizontally-resistant foreign matter while maintaining overall system simplicity.
Solution Approach 2:
The patent transitions from horizontal movement-based classification (as in vibrating sieves) to vertical settling-based classification in the fluidized bed. Foreign matter is separated through vertical settling differences in the fluidized medium, allowing effective removal of objects that would not move horizontally, while the discharge mechanism remains structurally simple.
4Productivity
If facility is modified on large scale to apply fluidized bed classification technique, then classification effectiveness is improved, but applicable facilities are limited to newly constructed facilities
Solution Approach 1:
The invention designs a classification apparatus with universal applicability that can be integrated into existing fluidized bed facilities of various types and scales. The modular design and flexible configuration allow the system to adapt to different facility requirements without requiring large-scale modifications, making it suitable for both new constructions and retrofits of existing plants.
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
Effectively separates and discharges foreign matter and impurities from the fluidized medium, maintaining grain-size distribution and preventing blockages, while being compatible with existing facilities and avoiding the need for frequent mesh cleaning.
Implementation Method 1
supplying a fluidizing air into the coarse classification section
Implementation Method 2
removing a foreign matter having a relatively large size and a foreign matter having a large specific gravity in the coarse classification section
Implementation Method 3
introducing the mixture, from which the foreign matters have been removed, into the fine classification section by mainly passing the mixture over the partition wall
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The present invention relates to a fluidized-bed classification method applicable to a fluidized-bed furnace system which requires to draw out incombustibles together with a fluidized medium in a fluidized bed furnace for combusting wastes such as municipal wastes, refuse derived fuel (RDF), waste plastics, waste FRP, biomass waste, automotive waste and waste oil, or solid combustibles such as solid fuel containing incombustibles like coal. The fluidized-bed classification method includes supplying a mixture (A) into a coarse classification section (1) partitioned by a partition wall (3) from a fine classification section (2); removing a foreign matter (L) having a relatively large size and a foreign matter (H) having a large specific gravity in the coarse classification section (1) while supplying fluidizing air to the coarse classification section (1); introducing the mixture from which the foreign matter (L, H) has been removed into the fine classification section (2) by mainly passing the mixture over the partition wall (3); and further removing the foreign matter (S) in the fine classification section (2) while supplying fluidizing air to the fine classification section (2).