Dynamic Mixer Sludge Hydrolysis Steam Recovery
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current thermal hydrolysis processes for sludge treatment face challenges in efficient energy transfer, particularly for high dryness sludges, leading to increased steam consumption and bulky installations, with issues in vapor transfer and the need for preheating reactors and heat exchangers.
Innovation Solution
Implementing a dynamic mixer that agitates sludge and steam to achieve a single-phase mixture, reducing viscosity and promoting energy transfer without preheating, allowing for efficient thermal hydrolysis in reactors with reduced steam consumption and eliminating the need for preheating reactors or heat exchangers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If flash steam is injected via a steam injector into the reactor sludge bed, then steam injection is achieved, but significant pressure losses occur due to injector design and sludge height
Solution Approach 1:
The patent extracts the steam injection function from a traditional steam injector and relocates it to the dynamic mixer, where steam is injected directly into the sludge under mechanical agitation. This eliminates the pressure losses associated with traditional injectors operating against high sludge columns.
Solution Approach 2:
The dynamic mixer acts as an intermediary device that combines mechanical agitation with steam injection. The mechanical energy from the dynamic mixer facilitates steam distribution without requiring high pressure, thereby reducing pressure losses while achieving effective steam injection.
2Use of energy by moving object
If higher-pressure flash steam is used to compensate for pressure losses, then good energy transfer is achieved, but steam consumption increases
Solution Approach 1:
The patent introduces dynamic mechanical agitation to the steam injection process. The rotating dynamic mixer creates dynamic conditions that enhance steam-slush contact and heat transfer efficiency, allowing effective energy transfer at lower steam pressures and thus reducing steam consumption.
3Quantity of substance
If large volumes of reactors are implemented, then steam injection capacity is sufficient, but installation size increases
Solution Approach 1:
The dynamic mixer introduces mechanical motion into the reactor system, enhancing mass and heat transfer rates. This dynamic approach allows for more efficient steam utilization and shorter treatment times, enabling the use of smaller reactor volumes to achieve the same processing capacity.
Solution Approach 2:
The dynamic mixer operates with periodic rotation, creating cycles of intense mixing that enhance steam distribution throughout the sludge. This periodic mechanical action improves steam injection efficiency, allowing reduced reactor volumes while maintaining adequate steam injection capacity.
4Use of energy by moving object
If preheating reactors and heat exchangers are added, then energy transfer is improved, but device complexity increases
Solution Approach 1:
The patent merges the mixing function and steam injection function into a single dynamic mixer unit. This consolidation eliminates the need for separate preheating reactors and heat exchangers, reducing device complexity while maintaining effective energy transfer through the combined mechanical-agitation-enhanced steam injection process.
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 method enhances energy transfer efficiency, reduces steam consumption, and enables the treatment of sludges with high dryness, shortening treatment cycles and minimizing installation size while maintaining effective sludge hydrolysis.
Implementation Method 1
Implementing a dynamic mixer that agitates sludge and steam to achieve a single-phase mixture
Implementation Method 2
reducing viscosity and promoting energy transfer
Implementation Method 3
injecting live steam to bring it to a pressure P and a temperature T enabling hydrolysis
Implementation Method 4
thermal hydrolysis of sludge involves treating it at a high temperature and under pressure
Implementation Method 5
reducing the sludge to a pressure close to atmospheric pressure by releasing flash steam
Implementation Method 6
injecting recovery steam ('flash steam') to recover heat from the sludge
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Process and plant for thermal hydrolysis of sludge using a group of thermal hydrolysis reactors (71, 72, 73, 74) characterized in that it comprises series of cycles, each of these cycle series being dedicated to one of the reactors, each cycle comprising: a step a) of introducing a batch of non-preheated sludge to be treated into a reactor (71, 72, 73, 74), said introduction step comprising the continuous passage of the sludge from the batch of sludge into a dynamic mixer (3) into which recovered steam is injected; a step b) of injecting fresh steam into said reactor (71, 72, 73, 74) containing the batch of sludge so as to increase the temperature and the pressure reigning therein; a step c) of thermal hydrolysis of the batch of sludge in the thermal hydrolysis reactor; a step d) of draining the contents of the hydrolysed batch of sludge from the thermal hydrolysis reactor to a recovery tank (13), and of concomitant depressurization of the reactor giving rise to the emission of recovered steam from the recovery tank (13); the cycle starts of the series of cycles being offset in time so that the steps a) of one series of cycles are concomitant with the steps d) of another cycle series, the recovered steam emitted during the steps d) of one cycle series constituting the recovered steam injected during the steps a) of another series of cycles.