Biomass Sludge Gasifier with Conductive Heating Floor
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Solution Overview
Problem
Conventional incinerators fail to completely incinerate biomass waste, resulting in the production of black ash containing unburned carbon and organic materials, including harmful substances like dioxins and bacteria, due to inadequate heat intensity and control systems, leading to incomplete combustion and environmental contamination.
Innovation Solution
A continuous hot hearth incineration system with a primary chamber and an afterburner chamber, utilizing a secondary burner to provide initial heat and a heat transfer chamber for conductive and convective heating, along with an auger system to ensure consistent temperature rise and minimize energy input, effectively breaking hydrogen-carbon bonds and oxidizing volatile organic compounds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If conventional incinerators are used to burn biomass waste, then the incineration process can be carried out, but the heat intensity is inadequate resulting in incomplete combustion and production of black ash containing unburned carbon and organic materials
Solution Approach 1:
The incineration process is divided into two distinct stages: a gasification stage occurring in a lower temperature zone where biomass decomposes into volatile gases and charcoal, and a carbon stage occurring in a higher temperature zone where the charcoal is completely combusted. This segmentation allows each stage to operate at optimal conditions, ensuring complete combustion and preventing black ash formation.
Solution Approach 2:
Different regions of the incinerator are maintained at different temperature levels to match the specific requirements of each combustion stage. The gasification zone operates at lower temperature to facilitate decomposition, while the carbon stage zone operates at higher temperature (above 850°C) to ensure complete combustion of charcoal, thereby achieving reliable combustion completeness.
2Reliability
If higher temperature is applied to ensure complete incineration and break hydrogen-carbon bonds, then gasification efficiency improves, but energy input requirements increase significantly
Solution Approach 1:
The gasification stage performs preliminary decomposition of biomass at lower temperatures, converting organic materials into volatile gases and charcoal before the high-temperature carbon stage. This preliminary action reduces the energy burden on the subsequent high-temperature combustion phase, as the more energy-intensive bond breaking has already occurred at lower temperatures.
Solution Approach 2:
The two stages are arranged in continuous sequence where the output of the gasification stage (charcoal and volatile gases) becomes the input for the carbon stage. This continuous process ensures that energy is efficiently utilized throughout, with the exothermic combustion in the carbon stage providing sustained heat for complete incineration without requiring additional external energy input.
3Loss of substance
If biomass sludge with high liquid content is incinerated, then the volume of waste to be disposed is reduced, but the incineration process becomes less efficient and requires more energy
Solution Approach 1:
The gasification stage operates at controlled lower temperatures that are optimal for decomposing wet biomass materials. This parameter optimization allows efficient processing of high-moisture sludge without requiring excessive energy input, as the lower temperature is sufficient for the initial decomposition of water-containing organic materials into gases and charcoal.
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 system achieves complete gasification and incineration of biomass sludge with minimal additional energy input, producing inert ash and reducing hazardous emissions, thereby ensuring environmental safety and energy efficiency.
Implementation Method 1
A secondary burner is situated in the one gasifier so as to produce an initial heating flame within a first vertically disposed portion of the afterburner chamber
Implementation Method 2
heat transfer chamber for conductive and convective heating
Implementation Method 3
heat transfer chamber for conductive and convective heating
Implementation Method 4
Typically, such pyrolysis is carried out at temperatures in the order of 850° C. to 1000° C.
Implementation Method 5
an auger system to ensure consistent temperature rise and minimize energy input
Implementation Method 6
During the carbon stage of incineration, the carbon is oxidized, typically by providing additional air flow, and carbon dioxide will be driven off from the remaining ash
Implementation Method 7
the carbon is oxidized, typically by providing additional air flow, and carbon dioxide will be driven off
Data Source
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AI summary
A device for gasifying biomass sludge having particle size less than 1 cm, and 20% to 100% solids content has a primary chamber, a fume transfer vent, a mixing chamber which accepts fumes from the primary chamber, and an afterburner chamber in fluid communication with the mixing chamber. A secondary burner produces an initial heating flame within a vertical portion of the afterburner chamber. A heat transfer chamber is in fluid communication with the afterburner chamber. Heated gases from the afterburner chamber cause heating of the heat transfer chamber. The primary chamber has a heat conductive floor superimposed over the heat transfer chamber so that conductive and convective heating of the primary chamber occur. At least one primary auger is located crosswise in the primary chamber between a sludge feed hopper and an ash hopper. The heat transfer chamber underlies the primary auger near the end at the ash hopper.