Reheater Segmentation for Rapid Thermal Processing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current rapid thermal processing systems face challenges in handling higher carbonaceous feedstock rates without producing excessive heat, leading to increased costs and complexity due to larger reheater sizes required to manage rising temperatures from burning additional char.
Innovation Solution
The implementation of an apparatus comprising a reactor, a reheater, and an inorganic particle cooler, where the reheater forms a fluidized bubbling bed to burn char into ash and heat inorganic particles, and the inorganic particle cooler indirectly cools these particles using a shell and tube configuration to prevent excessive temperature rises, allowing for efficient heat management without enlarging the reheater.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the feedstock rate is increased to higher capacity (up to 400 BDMTPD or higher), then productivity is improved, but the reheater size must be substantially increased (diameter up to 12m or greater, height up to 25m or greater) to accommodate additional air for cooling, which increases cost and complexity
Solution Approach 1:
The invention divides the reheater into multiple zones along the flow direction of the fluidized bed, with each zone having different air supply characteristics. The air supply is segmented into multiple stages rather than supplied uniformly, allowing different regions to serve different functions (combustion vs. cooling) simultaneously.
Solution Approach 2:
Different regions of the reheater are given different local qualities - some zones have higher oxygen concentration and air supply rates optimized for combustion, while other zones have lower air supply rates optimized for cooling. This spatial variation in air supply characteristics allows the same reheater volume to handle both combustion and cooling functions efficiently.
2Productivity
If the feedstock rate is increased to higher capacity, then productivity is improved, but the temperature in the reheater rises excessively due to burning additional char, requiring larger volume for cooling which increases cost
Solution Approach 1:
The air supply rate and oxygen concentration are varied locally across different zones of the reheater. Zones where char combustion needs to be promoted receive higher air supply, while zones where cooling is needed receive lower air supply. This local optimization prevents excessive temperature rise while maintaining high productivity.
Solution Approach 2:
The invention uses the fluidized bed itself as an intermediary medium to transfer and distribute heat throughout the system. By controlling air supply to different zones, the fluidized bed particles act as mobile heat carriers that can absorb excess heat in combustion zones and transfer it to other regions, preventing localized overheating.
3Temperature
If the reheater size is increased to accommodate additional cooling air, then temperature control is improved, but the cost and complexity of shipping, installing, and operating the reheater is substantially increased
Solution Approach 1:
The air supply system is segmented into multiple independent zones with controllable air flow rates. This allows precise temperature control in different regions without requiring a uniformly oversized reheater, reducing overall equipment size and associated costs while maintaining effective temperature management.
Solution Approach 2:
The invention changes the parameters of air supply (flow rate, oxygen concentration) across different zones rather than uniformly increasing all parameters throughout the entire reheater. This targeted parameter adjustment achieves temperature control with minimal equipment size increase, reducing manufacturing and operational costs.
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 solution effectively controls temperatures within the reheater, preventing the need for additional volume and reducing costs and complexity associated with larger equipment, while optimizing energy integration by using partially cooled inorganic particles for continued pyrolysis.
Implementation Method 1
The reheater is operating at combustion conditions effective to burn the char into ash and heat the inorganic heat carrier particles
Implementation Method 2
The tube portion receives a cooling medium for indirect heat exchange with the portion of the heated inorganic particles
Implementation Method 3
The reheater is configured to form a fluidized bubbling bed that comprises an oxygen-containing gas, the inorganic heat carrier particles, and the char
Data Source
AI summary
Embodiments of apparatuses and methods for controlling heat for rapid thermal processing of carbonaceous material are provided herein. The apparatus comprises a reactor, a reheater for forming a fluidized bubbling bed comprising an oxygen-containing gas, inorganic heat carrier particles, and char and for burning the char into ash to form heated inorganic particles. An inorganic particle cooler is in fluid communication with the reheater. The inorganic particle cooler comprises a shell portion and a tube portion. The inorganic particle cooler is configured such that the shell portion receives a portion of the heated inorganic particles and the tube portion receives a cooling medium for indirect heat exchange with the portion of the heated inorganic particles to form partially-cooled heated inorganic particles.