Thompson Converter Biochar Apparatus with Direct Radiation Heating
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Solution Overview
Problem
Current methods for producing biochar using thermal treatment are laborious, slow to start, and inefficient due to indirect convective heat transfer, resulting in high costs and inadequate reduction of Polycyclic Aromatic Hydrocarbons (PAH) compounds, and require extensive preheating with solid fuels or continuous auxiliary flames.
Innovation Solution
A method utilizing a Thompson Converter type apparatus with a continuously operating conveyor system that employs direct radiation heat transfer from a gas burner, counterflow pyrolysis gas cooling with water vapor to minimize PAH compounds, and a large-volume combustion chamber for efficient combustion, enabling rapid startup and reduced PAH levels in biochar production.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If indirect convective heat transfer is used to heat screw conveyors, then the apparatus can be operated, but the cold start time is considerably prolonged and volume efficiency is modest
Solution Approach 1:
The patent replaces indirect convective heat transfer with direct radiation heat transfer from the combustion chamber walls to the screw conveyors. This substitution of heat transfer mechanism dramatically reduces cold start time while improving volume efficiency, as radiation heat transfer is more direct and intense than convective heat transfer through gas phases.
Solution Approach 2:
The patent preheats the combustion chamber and its walls before introducing feedstock to the screw conveyors. This preliminary heating action ensures that the conveyors are already at sufficient temperature when processing begins, eliminating the need for prolonged cold start periods and enabling immediate high-volume processing.
2Temperature
If solid fuel is used to heat the combustion furnace for a long period, then the furnace can be heated, but the process becomes laborious and costly
Solution Approach 1:
The patent changes the fuel parameter from solid fuel to gas fuel (natural gas or biogas). This parameter change allows for more precise temperature control, faster heating rates, and reduced operating costs due to the cleaner combustion characteristics and easier control of gas fuel systems compared to solid fuel systems.
Solution Approach 2:
The patent substitutes solid fuel combustion with gas fuel combustion in the combustion chamber. This replacement eliminates the laborious handling, feeding, and ash removal operations associated with solid fuels, while providing more efficient and cost-effective heating of the combustion furnace to required temperatures.
3Reliability
If continuous auxiliary flame with separate fuel is used, then pyrolysis gas can be burned, but investment and operating costs increase
Solution Approach 1:
The patent designs the system so that the pyrolysis gas generated during carbonization is self-combusted in the combustion chamber. The heat from this combustion automatically maintains the required temperature for continuous operation, eliminating the need for separate auxiliary fuel systems and reducing both investment and operating costs while preserving continuous operation capability.
Solution Approach 2:
The patent merges the pyrolysis gas combustion function with the main combustion chamber operation. Instead of having separate auxiliary flame systems, the pyrolysis gas is integrated into the combustion process, allowing the same combustion chamber to serve dual purposes: generating heat for carbonization and burning pyrolysis gas, thereby reducing overall system complexity and cost.
4Productivity
If traditional Thompson Converter type apparatus is used, then carbonization can be performed, but PAH compounds are not sufficiently reduced
Solution Approach 1:
The patent changes the thermal processing parameters by implementing rapid heating rates and optimized temperature profiles through direct radiation heat transfer. These parameter changes, combined with controlled residence times in the combustion chamber, effectively reduce PAH compound formation while maintaining high carbonization productivity, producing cleaner biochar.
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 solution significantly reduces PAH compounds in biochar, allows for a compact and cost-effective apparatus with faster startup, and achieves higher volume efficiency, making the process more affordable and productive.
Implementation Method 1
burning the pyrolysis gas y in a combustion chamber (4) of the process space, wherein the heat transfer for the conveyor arrangement (3) in the process space (2) is carried out with substantially direct radiation from a flame of the gas burner arrangement (7)
Implementation Method 2
heat transfer for the conveyor arrangement (3) in the process space (2) is carried out with substantially direct radiation from a flame of the gas burner arrangement (7) and from walls of the combustion chamber (4)
Implementation Method 3
supply elements (1a) for introducing a to-be-processed feedstock (x) into the interior of a conveyor arrangement (3) present in and closed relative to a Thompson Converter type process space (2) for moving the to-be-processed feedstock (x) in the process space (2) in a longitudinal direction (s) of the process space
Implementation Method 4
The pyrolysis gas y is conducted within the conveyor arrangement (3) in a counterflow towards a supply end (I) of the conveyor arrangement for transferring the heat present in the pyrolysis gas into the to-be-processed feedstock (x) moving in the longitudinal direction (s)
Data Source
AI summary
A method and an apparatus for manufacturing, with thermal treatment, biocoal which is non-energent, such as functional as a heat sink, by using a conveyor arrangement housed in an essentially Thompson Converter type process space. A to-be-processed feedstock is conveyed in the process space with the conveyor arrangement, which is closed relative thereto, in a longitudinal direction of the process space. A pyrolysis gas, generated from the to-be-processed feedstock present inside the conveyor arrangement as a result of heat transferring from the process space thereto, is conducted into a combustion chamber included in the process space for burning the gas, a thereby generated flue gas being removed from the process space by a discharge arrangement and a resulting non-energent biocoal being removed from the conveyor arrangement for further processing.