Fluidized Bed Heat Recovery with Swirling Flow
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Solution Overview
Problem
Conventional fluidized-bed boilers face challenges in achieving uniform and stable combustion of diverse solid materials, including incombustibles, due to insufficient dispersion and accumulation of incombustibles, which hinders smooth circulation of the fluidized medium and efficient heat energy recovery.
Innovation Solution
The apparatus incorporates a gas diffuser system with multiple stages of gas diffuser tubes and a downwardly inclined gas diffusion plate to create distinct fluidized regions, allowing for optimized fluidization and separation of incombustibles, enabling uniform combustion and stable heat recovery by controlling the fluidized medium circulation between the heat recovery and main combustion chambers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a bubbling fluidized bed is used with vertical fluidized medium flow, then the system can process solid materials, but dispersion of incinerated materials is insufficient and uniform combustion is difficult
Solution Approach 1:
The patent transforms the static vertical flow system into a dynamic circulating flow system. The gas diffuser creates a swirling motion that causes the fluidized medium to circulate continuously, enhancing dispersion and mixing of incinerated materials. This dynamic circulation replaces the simple vertical flow, achieving both good dispersion and uniform combustion simultaneously.
Solution Approach 2:
The patent introduces horizontal and rotational motion components to the originally vertical flow. The gas diffuser generates a swirling flow pattern that adds a rotational dimension to the fluidized medium movement. This multi-dimensional circulation improves material dispersion in all directions while maintaining uniform combustion conditions.
2Ease of operation
If incombustibles with higher specific gravity are present, then they accumulate extensively on the furnace bed, but this prevents smooth discharge of incombustibles and interferes with operations
Solution Approach 1:
The circulating flow created by the gas diffuser continuously moves incombustibles through the fluidized bed, preventing their accumulation on the furnace bed. The dynamic circulation ensures that incombustibles are carried along with the fluidized medium and can be smoothly discharged, eliminating operational interference caused by accumulation.
Solution Approach 2:
The gas diffuser system effectively separates incombustibles from the combustion process by incorporating them into the circulating fluidized medium flow. This extraction of incombustibles from the furnace bed prevents their harmful accumulation and enables smooth discharge through the circulating flow path.
3Productivity
If the discharge port is located near the outlet of the heat recovery chamber, then the structure is compact, but a fixed layer forms in the upper portion of the discharge port preventing smooth circulation of the fluidized medium
Solution Approach 1:
The gas diffuser creates a dynamic circulating flow that prevents the formation of a static fixed layer in the discharge port. The continuous motion of the fluidized medium carried by the swirling flow eliminates dead zones where fixed layers could form, ensuring smooth circulation even with the compact discharge port location near the heat recovery chamber outlet.
4Use of energy by moving object
If diverse solid materials including incombustibles are incinerated, then energy recovery is possible, but stable combustion and treatment are difficult
Solution Approach 1:
The circulating flow system generated by the gas diffuser continuously mixes and redistributes diverse solid materials including incombustibles throughout the fluidized bed. This dynamic circulation ensures uniform temperature distribution and consistent combustion conditions, achieving stable combustion and reliable energy recovery despite the variability of the input materials.
Solution Approach 2:
The gas diffuser system modifies the flow parameters of the fluidized medium to create optimal combustion conditions. By controlling the gas distribution and circulation patterns, the system maintains stable combustion parameters even when processing diverse solid materials with varying properties, ensuring reliable energy recovery.
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 configuration ensures uniform combustion and stable heat energy recovery by maintaining suitable fluidization conditions in both chambers, facilitating smooth circulation and efficient discharge of incombustibles, thereby optimizing the fluidized medium's circulation and heat recovery process.
Implementation Method 1
a gas diffuser configured to impart a fluidizing velocity to a fluidized medium to form a weakly fluidized region and a strongly fluidized region
Implementation Method 2
the fluidized medium circulates from a heat recovery chamber to a main combustion chamber
Implementation Method 3
stably recovering heat energy
Implementation Method 4
uniformly oxidizing, such as combusting or gasifying, solid materials including municipal wastes, industrial wastes, coal, and incombustibles
Data Source
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AI summary
The present invention relates to a fluidized-bed heat recovery apparatus for uniformly combusting solid materials including incombustibles, and for recovering heat energy while discharging the incombustibles. In a fluidized-bed reactor (1), a gas diffuser configured to give different fluidizing velocities in a fluidized-bed is provided at a furnace bed. A first weakly fluidized region (WF) having a small fluidizing velocity is formed to generate a downward flow of the fluidized medium in the first fluidized region (WF), and a strongly fluidized region (SF) having a large fluidizing velocity is formed to generate an upward flow of the fluidized medium in the strongly fluidized region (SF), thereby forming a swirling flow of the fluidized medium in the fluidized bed. Outside the strongly fluidized region (SF), a second weakly fluidized region (WF) having a small fluidizing velocity is formed to generate a downward flow of the fluidized medium, so that a part of the fluidized medium flows from the strongly fluidized region (SF) into the second weakly fluidized region (WF). A heat recovery device having a heat transfer surface is located in the second weakly fluidized region (WF).