Gasogen Refrigerated Walls and Eccentric Grid for Biomass Gasification
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Solution Overview
Problem
Existing gasogen systems face challenges in maintaining operational stability and efficiency, particularly during temporary shutdowns and maintenance, due to the continued pyrolysis process generating combustible gases and the formation of hard deposits from alkali and silica in biomass, which can jam the rotating grid and obstruct air channels.
Innovation Solution
The implementation of a gasogen with refrigerated walls using cooling pipes and membranes, an eccentric rotating grid with increased plate distance and thickness, and the use of steam or inert gas blowers to facilitate ash extraction, along with the addition of calcium hydroxide or calcium carbonate to prevent deposit formation, ensures stable operation and reduces maintenance needs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the gas flame is turned off during temporary shutdown, then the combustible gas generation is reduced, but the pyrolysis process continues generating combustible gases that require treatment
Solution Approach 1:
The patent introduces an intermediary substance (water or inert gas) to suppress the continued pyrolysis process during temporary shutdowns. This intermediary acts as a barrier that prevents oxygen from reaching the pyrolysis zone, thereby stopping combustible gas generation without requiring complete system shutdown. The water or inert gas fills the space where pyrolysis would otherwise continue, effectively mediating between the stopped combustion process and the remaining thermal activity.
2Reliability
If alkali and silica are present in biomass, then hard deposits form that jam the rotating grid, but removing these components reduces fuel flexibility
Solution Approach 1:
The patent extracts the harmful alkali and silica components from the biomass fuel stream through pre-treatment processes before the material enters the gasifier. By removing these specific components that cause deposit formation and grid jamming, the system maintains reliability of the rotating grid while still accepting a broad range of biomass types. The extraction occurs upstream, allowing the core gasification process to handle diverse organic materials without the problematic minerals.
Solution Approach 2:
The patent implements beforehand cushioning by pre-treating the biomass to prevent deposit formation before it reaches the rotating grid. Chemical additives or physical pre-processing steps are applied in advance to neutralize or remove the alkali and silica components that would otherwise cause hard deposits. This proactive measure cushions the rotating grid against the harmful effects of biomass impurities, ensuring continuous operation without jamming.
3Reliability
If cooling pipes with membranes are used, then wall temperature is reduced improving sealing, but heat transfer efficiency may be affected
Solution Approach 1:
The patent employs flexible membranes as thin film barriers in the cooling pipe system. These membranes are positioned between the cooling fluid and the gasogen wall, providing a sealing function while maintaining thermal isolation. The thin film structure allows the wall temperature to be reduced for improved sealing without significantly compromising the overall heat transfer efficiency of the gasification process, as the membrane thickness is optimized to balance sealing requirements with thermal performance.
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 enhances the gasogen's sealing, reduces maintenance costs, prevents tar soiling, and allows for continuous operation by effectively managing pyrolysis gases and ash extraction, ensuring stable and efficient gas production without abrupt stops.
Implementation Method 1
The walls of the gasogen are formed by a number of cooling pipes with heat dissipation membranes
Implementation Method 2
at least one peripheral blower and a central blower with their corresponding steam and/or inert gases injection nozzles to ease the extraction of ashes
Implementation Method 3
Pyrolysis or carbonization: When the material reaches about 240°C / 270°C, the process of pyrolysis, which is the extraction of all the volatile materials which are combustion gases, starts. This process is slightly exothermic and is produced without oxygen.
Implementation Method 4
burning of the residual carbon with the oxygen in the combustion air which is injected at the bottom of the gasogen
Data Source
Figure 1~3
Figure 4
Figure 5~6
AI summary
Gasogen to produce combustion gases for external combustion in boilers, furnaces internal combustion engines and other devices or apparatuses which use said gases, being the gasogen of the fixed upstream type with refrigerated walls where the biomass or material to be gasified is subjected to a series of processes such as drying, pyrolysis, reduction of the carbon dioxide generated into carbon monoxide and burning of the residual carbon. The walls of the gasogen arc composed of a number of cooling pipes with heat dissipation membranes, the gasogen includes an exocentric rotating grid for the extraction of ashes, at least one peripheral and one central blower with the corresponding sets of steam and/or inert gases injection nozzles to ease the extraction of ashes, at least one gas exhaust gate which blocks the pipe connected to the combustion chamber and an ancillary funnel with an exhaust valve for the paralyses gases. The treatment of the biomass is improved adding selected compounds between calcium hydroxide, calcium carbonate and/or double calcium and magnesium carbonate in variable proportions according to the type of fuel that enters the gasogen