Concentric Fluidised Bed Apparatus for Endothermic Reaction Heat Management
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Solution Overview
Problem
Existing endothermic reaction apparatuses, such as those for pyrolysis of carbonaceous materials, suffer from heat loss and inefficiency, requiring additional fuel and lacking effective regulation of gas streams, making them impractical for operation.
Innovation Solution
The apparatus features two concentrically arranged fluidised bed zones separated by an apertured divider with a closed gas loop for recirculating and purging gas, a mass transfer device for particulate matter, and a flow rate regulator to control gas flow, minimizing heat loss and optimizing energy use.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a unitary vessel construction with multiple fluidised beds is used, then heat loss is reduced, but device complexity increases
Solution Approach 1:
The apparatus is divided into multiple fluidised bed zones (combustion zone, pyrolysis zone, cooling zone) separated by dividers with apertures, allowing each zone to function independently while maintaining thermal efficiency through the integrated vessel structure
Solution Approach 2:
The pyrolysis fluidised bed zone is concentrically disposed within the combustion fluidised bed zone, creating a nested configuration where the inner zone benefits from the thermal environment of the outer zone while maintaining operational independence
2Use of energy by moving object
If pyrolysis gas is recycled to the pyrolysis zone, then energy efficiency is improved, but gas stream regulation becomes complex
Solution Approach 1:
A flow rate regulator is implemented in the gas recycle line to control the amount of pyrolysis gas recycled back to the pyrolysis zone, creating a feedback mechanism that optimizes energy efficiency while maintaining manageable system complexity through automated flow control
Solution Approach 2:
The system adjusts the flow rate parameter of the recycled gas to optimize the balance between energy efficiency and operational control, allowing dynamic adjustment of the recycle ratio to match process requirements
3Reliability
If additional fuel is supplied to maintain temperature, then process reliability is improved, but energy efficiency deteriorates
Solution Approach 1:
The combustion zone generates thermal energy that is transferred through the divider with apertures to the pyrolysis zone, allowing the system to be self-sufficient and maintain process temperature without requiring additional external fuel input
Solution Approach 2:
The combustion and pyrolysis zones are integrated in a single vessel with thermal coupling through the apertured divider, merging the heat generation and heat utilization functions to eliminate the need for separate fuel supply systems
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 reduces heat loss, enhances energy efficiency, and allows the apparatus to operate self-sufficiently without additional fuel by effectively recycling and regulating gas streams, improving the overall efficiency of endothermic processes like pyrolysis.
Implementation Method 1
a first combustion zone in which thermal energy is generated by combustion of a carbonaceous material
Implementation Method 2
a second pyrolysis zone in which carbonaceous material is pyrolysed to produce a combustible gas and coke
Implementation Method 3
Hot particles are transferred from the combustion zone to the pyrolysis zone
Implementation Method 4
The two fluidised bed zones are separated by an apertured divider... transferring fluidised bed material from the first fluidised bed zone through the apertured divider to the second fluidised bed zone
Data Source
Figure 1~2
AI summary
The invention provides an apparatus which consists of two fluidised beds 1 and 2 separated by a vertical divides' 5. A positive displacement device such as an auger 3 moves the bed material from the reduction side to the combustion side of the device below the fluidisation zone. The height of the two fluidised beds is equalised by movement of the bed material through a hole 4 In the vertical divider, from the high temperature side 1 (zone 1) to the tow temperature side 2 (zone 2). The bed material that moves through the hole 4 provides energy to drive reactions that may occur on the reduction side. Energy may also be provided to zone 2 by means of conductive and radiative heat transfer through the dividing wall 5. Energy is provided to zone 1 by means of an exothermic reaction, typically combustion of a fuel 13 using air 12.