Anaerobic Fermentation Temperature Control in Transition Zone
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Solution Overview
Problem
Anaerobic fermentation efficiency and stability are poor in the medium temperature-high temperature transition zone (40° C. to 45° C.), making it a 'forbidden zone' in engineering applications, due to low organic substance removal load and yield rate.
Innovation Solution
A method involving heat exchange of hydrolyzed slurry through a front heat exchanger, followed by precise temperature control in an anaerobic tank using a thermal insulation layer and warming device, with an intermittently-operating central agitator to maintain a fermentation temperature of 44±1° C., allowing medium-temperature and high-temperature anaerobic flora to overlap and fully mix, enhancing anaerobic activity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If anaerobic fermentation is performed in the medium temperature-high temperature transition zone (40°C to 45°C), then the operating load rate and organic substance removal rate can be improved, but the stability and reliability of the fermentation process deteriorates due to the valley effect
Solution Approach 1:
The patent applies parameter changes by precisely controlling the fermentation temperature within a specific range (43±1°C) in the medium-high temperature transition zone. This controlled parameter change allows the system to operate in the previously avoided transition zone, achieving higher organic substance removal rates while maintaining stability through automated temperature control and pH regulation
Solution Approach 2:
The patent implements dynamics through an automated control system that dynamically adjusts temperature, pH, and agitation based on real-time monitoring. The system automatically responds to changes in fermentation conditions, maintaining optimal parameters despite the inherent instability of the transition zone, thus improving both productivity and reliability
2Productivity
If the fermentation temperature is precisely controlled at 44±1°C in the transition zone, then the anaerobic digestion efficiency and gas yield rate are improved, but the device complexity increases due to additional control systems
Solution Approach 1:
The control system is designed with multi-functionality, integrating temperature control, pH regulation, agitation control, and data monitoring into a single automated system. This universal approach manages the complexity by consolidating multiple control functions into one coordinated system rather than separate independent systems
Solution Approach 2:
The system implements self-service through automated monitoring and adjustment mechanisms that maintain optimal fermentation conditions without continuous manual intervention. The automated control system self-regulates temperature, pH, and agitation based on preset parameters, reducing the need for complex manual operation while maintaining high gas yield rates
3Reliability
If medium-temperature and high-temperature anaerobic flora are made to overlap through precise temperature control, then the impact-resistance load capacity is improved, but the energy consumption increases due to continuous temperature maintenance
Solution Approach 1:
The patent applies continuity of useful action by maintaining continuous fermentation activity in the transition zone where medium-temperature and high-temperature flora overlap. This continuous operation at optimal temperatures (43±1°C) ensures sustained high activity from both bacterial groups, improving impact resistance without requiring intermittent heating or cooling cycles that would consume additional energy
Solution Approach 2:
By changing the temperature parameter to the optimal transition zone range (43±1°C), the system creates conditions where both medium-temperature and high-temperature anaerobic flora can thrive simultaneously. This parameter optimization improves the system's impact-resistance load capacity while the automated control minimizes energy consumption by maintaining stable temperatures rather than making frequent adjustments
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 approach significantly improves the operating load rate, organic substance removal rate, impact-resistance load capacity, and stability of anaerobic digestion, while reducing engineering and operating costs by optimizing the conditions for methanogenic bacteria activity.
Implementation Method 1
performing heat exchange on hydrolyzed slurry through a front heat exchanger, and then pumping the slurry into an anaerobic tank uniformly from a plurality of water distribution pipes at a bottom of the anaerobic tank, where a temperature of the slurry after the heat exchange performed through the front heat exchanger is 45±0.2° C.
Implementation Method 2
a thermal insulation layer and a warming device are arranged on a wall of the anaerobic tank
Implementation Method 3
the warming device... to control a fermentation temperature of the slurry at 44±1° C.
Implementation Method 4
an intermittently-operating central agitator with upper blades and lower blades is arranged inside the anaerobic tank... to slowly gently stir the slurry in the anaerobic tank, and turning off the central agitator after uniformly mixing upper-layer, middle-layer, and lower-layer slurry
Implementation Method 5
Anaerobic fermentation refers to a process in which waste is stabilized by metabolic activity of microorganisms under anaerobic conditions, accompanied by production of methane and CO2
Implementation Method 6
making medium-temperature anaerobic flora and high-temperature anaerobic flora in methanogenic bacteria in the anaerobic sludge overlap at the fermentation temperature and be fully mixed with and in contact with the slurry, to continuously treat and convert organic substances in the slurry
Data Source
AI summary
A method for improving efficiency of anaerobic fermentation in a medium temperature-high temperature transition zone includes: After being subjected to heat exchange through a front heat exchanger, hydrolyzed slurry is pumped to a bottom of an anaerobic tank. A temperature of the slurry is controlled at 45±0.2° C. A central agitator is turned on after feeding is completed, to slowly gently stir the slurry in the anaerobic tank, and the central agitator is turned off after the slurry is uniformly mixed. In an operating state, making medium-temperature anaerobic flora and high-temperature anaerobic flora in methanogenic bacteria in the anaerobic sludge overlap at the fermentation temperature and be fully mixed with and in contact with the slurry, to continuously treat and convert organic substances in the slurry when the slurry is under an anaerobic fermentation condition in a medium temperature-high temperature transition zone.