Sealed Vibratory Torrefaction Reactor for Leakage Prevention
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Solution Overview
Problem
Torrefaction systems face safety hazards due to oxygen leakage, potential fires, and thermal runaway, primarily caused by the vibration-induced loosening of flexible couplings and the use of external burners and heat exchangers, which pose risks of explosions and inefficient energy utilization.
Innovation Solution
The system modifies a standard commercial dryer by sealing off most conduits, using a solid unperforated waffle plate to separate the biomass from the heating gas, and employing a syngas-powered gas engine to control reactor temperature, allowing for inert gas injection and waste heat recovery, thereby minimizing leakage points and preventing thermal runaway.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If flexible couplings are used to connect vibrating reactor to fixed piping, then the reactor can vibrate to move biomass, but oxygen leakage and syngas leakage occur due to loosening of couplings
Solution Approach 1:
The patent removes flexible couplings and external piping connections from the vibrating reactor system. Instead, it uses a sealed vibratory chamber where biomass is conveyed through vibration of the chamber walls themselves, eliminating the interface between moving and fixed components that causes leakage.
Solution Approach 2:
The patent introduces an intermediary sealed chamber design where the vibration is contained within the reactor walls rather than being transmitted through flexible couplings to external piping. This intermediary structure maintains both vibration functionality and sealing integrity.
2Temperature
If external burners are used to heat syngas, then syngas can be heated for torrefaction, but fire and explosion hazards increase due to handling of hot flammable gas
Solution Approach 1:
The patent creates an inert atmosphere within the sealed vibratory reactor chamber by maintaining a controlled environment where oxygen is excluded or minimized. This prevents combustion of syngas while allowing thermal processing through controlled heating elements within the sealed chamber.
Solution Approach 2:
The patent removes external burners and heat exchangers from the system, eliminating the need to handle hot flammable gas externally. Heating is achieved through controlled internal elements within the sealed reactor chamber.
3Loss of energy
If multiple conduits are provided for syngas recirculation, then energy efficiency can be improved through heat recovery, but the number of leakage points increases
Solution Approach 1:
The patent removes external syngas recirculation piping and heat exchangers from the system. Energy recovery is achieved through internal heat exchange within the sealed vibratory chamber, eliminating multiple external leakage points while maintaining thermal efficiency.
4Reliability
If a sealed vibratory reactor design is used, then safety is improved by eliminating leakage points, but device complexity increases due to modification of commercial dryer
Solution Approach 1:
The patent segments the reactor into a sealed vibratory chamber portion and a separate material handling portion. This allows the critical sealed section to be simplified while maintaining safety, and the overall system to be assembled from modular components including the adapted commercial dryer.
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 significantly reduces the risk of fires and explosions, enhances safety by isolating volatile gases, and improves energy efficiency by utilizing inert gas for heating and recovering waste energy, allowing for more controlled thermal management.
Implementation Method 1
hot synthetic wood gas or syngas is passed to roast or torrefy the wood in a convective heating operation
Implementation Method 2
The reactor, fed by an inlet airlock device such as a screw, is vibrated causing the roasted or torrefied wood chips to move down the perforated plate
Implementation Method 3
provide an external burner to combust a small amount of excess evolving syngas
Implementation Method 4
provide an external heat exchanger to then heat the larger volume of recirculated syngas so it can be injected into the bottom of the reactor
Data Source
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AI summary
A modified dryer operates on a different principle from that used by the prior torrefaction plants. The subject invention utilizes thermal conduction to torrefy the biomass in a vibratory reactor in which a heated solid unperforated plate is sealed in the reactor to separate the biomass above from the gas used to heat the plate below. This permits using inert flue gas to heat the reactor which in turn permits the use of a cool air damping system to prevent thermal runaway. Also syngas evolved from the process is utilized to power a gas engine, the exhaust output of which is recirculated to heat the reactor plate. When the gas engine is coupled to an electric generator, waste energy is recovered for use in other parts of the plant or exported elsewhere.