Vibrating Fluidized Bed for Coal Drying and Separation
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Solution Overview
Problem
Current technologies face challenges in efficiently and reliably upgrading low-quality coal, such as lignitous and low-rank coal, due to high moisture content and low heat value, leading to inefficient separation and pollution, especially in fluidized beds where dense medium particles agglomerate and coal dust is generated during drying, degrading separation performance.
Innovation Solution
A vibrating fluidized bed apparatus that integrates drying and separation using high-temperature hot air, with a design featuring adjustable inclination, porous metal clamping plates, and a dust-removing system, allowing for efficient dehydration and de-ashing without dense media, utilizing hot air to fluidize coal and separate waste rocks from fine coal through heat and mass transfer, and adjustable air flow control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If dense medium fluidized bed is used for separation, then separation efficiency is improved, but dense medium particles cohere and agglomerate under moisture impact, degrading fluidization performance
Solution Approach 1:
The invention removes the dense medium particles from the system entirely, using only air as the fluidizing medium. This extraction of the problematic dense medium eliminates the agglomeration issue while maintaining separation capability through the vibrating fluidized bed mechanism combined with hot air drying.
Solution Approach 2:
The invention applies preliminary drying action by introducing hot air into the vibrating fluidized bed before separation occurs. This pre-drying of the coal surface reduces moisture content that would otherwise cause dense medium particles to cohere, and the drying continues synergistically during the separation process.
2Quantity of substance
If pre-drying procedure is introduced before separation, then moisture content is reduced, but large particles of low-quality coal crack and form coal dust, degrading separation effect
Solution Approach 1:
The invention merges the drying and separation procedures into a single integrated process occurring simultaneously in the vibrating fluidized bed. Hot air drying and density-based separation happen concurrently, eliminating the need for separate pre-drying that causes particle cracking, while the vibration mechanism prevents dust formation throughout the process.
Solution Approach 2:
The invention changes the parameters of the drying process by using moderate temperature hot air combined with vibration, rather than high-temperature conventional drying. This parameter change reduces thermal stress on coal particles, preventing cracking and dust formation while still achieving effective moisture removal during separation.
3Ease of manufacture
If conventional drying and separation are performed separately, then each process can be optimized, but the overall process complexity increases and efficiency decreases
Solution Approach 1:
The invention combines drying and separation into a single integrated machine - the vibrating fluidized bed system. Hot air is introduced into the bed where both drying and density-based separation occur simultaneously, eliminating the need for separate drying equipment and separation equipment, thereby reducing overall device complexity while maintaining process optimization.
Solution Approach 2:
The vibrating fluidized bed system performs multiple functions simultaneously: it dries the coal particles through hot air, separates them by density, and prevents dust formation through vibration. This multi-functionality in a single device simplifies the overall system while achieving optimized drying and separation performance.
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 apparatus achieves efficient and environmentally friendly dehydration and upgrading of low-quality coal, reducing ash content and increasing coal quality, with a stable and cost-effective process suitable for high-moisture coal, eliminating the need for dense media and minimizing coal dust issues.
Implementation Method 1
low-quality coal is fed into a vibrating fluidized bed and is fluidized by hot air
Implementation Method 2
heat transfer and mass transfer occur between the high-temperature air and the wet coal particles
Implementation Method 3
the moisture in the coal is taken out of the fluidized bed by the fluidizing air in the form of water vapor
Implementation Method 4
the coal particles are fluidized by synergistic action of air flow and vibration and settle under interference in a dilute-phase zone created by a bubbling behavior
Implementation Method 5
finally, high-density waste rocks settle down to the bottom of the bed while low-density fine coal floats up to the top of the bed
Data Source
AI summary
Drying and separation vibrating fluidized bed for processing wet coal by high-temperature hot air. Wet coal is fed into a vibrating separation chamber connected to a hot air supply duct. The wet coal is vibrated as it is dried and is layered as heat and mass transfer occur between the high-temperature air and the wet coal particles. Hot air enters the bottom of separation chamber through a distribution plate that includes asbestos fiber cloth sandwiched between clamping plates. The wet coal is fed through a feeding distribution device that separates the coal pieces as they enter the separation chamber. After the coal is dried and layered, the heavy and light material exits the separation chamber through two discharge impellers.