Variable Water Column Control in Anaerobic Reactors

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Solution Overview

Problem

Anaerobic purification devices face challenges in adapting to varying pollutant concentrations and sludge blanket resistances, leading to inefficient gas recirculation and potential overflows, due to fixed water height settings that do not account for fluctuations in gas production and resistance.

Innovation Solution

A variable water height control system within the reactor tank, utilizing a fluid valve and level detector to adjust the fluid level based on gas production rates, ensuring optimal recirculation flow and preventing overflows by allowing fluid to leave or enter the tank accordingly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a fixed water column height H3 is used in the reactor, then the device structure is simple and easy to operate, but the device cannot adapt to varying pollutant concentrations and sludge blanket resistances, leading to inefficient gas recirculation and potential overflows

Engineering Contradiction:
Improveadaptability to varying pollutant concentrations and sludge blanket resistancesVSAvoidcomplexity of water height control system
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies the dynamics principle by transforming the fixed water column height into a variable parameter. The water height in the reaction zone is dynamically adjusted based on gas production rates and operational conditions, allowing the system to adapt to varying pollutant concentrations and sludge blanket resistances. This is achieved through controlled fluid level changes that optimize gas recirculation efficiency under different operating conditions.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements parameter changes by modifying the water column height parameter (H3) according to operational requirements. By changing the water level parameter in response to gas production rates and sludge blanket conditions, the system optimizes the balance between gas recirculation efficiency and overflow prevention, enhancing adaptability without requiring complete system redesign.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If the water column height H3 is increased to provide more gravitational force for water flow, then water can overcome resistance in the bottom compartment, but the uplifted water develops tendency to burst-up causing big shocks and vibrations

Engineering Contradiction:
Improvereliability of water flow through sludge blanketVSAvoidshocks and vibrations from water bursting-up
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies dynamics by making the water column height adjustable rather than fixed. The system dynamically optimizes H3 to provide sufficient gravitational force for water to overcome sludge blanket resistance while preventing excessive height that would cause water bursting and vibrations. This dynamic adjustment ensures reliable water flow through the sludge blanket without generating harmful shocks.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements preliminary anti-action by controlling the water column height to prevent the harmful effect of water bursting before it occurs. By maintaining H3 within an optimal range, the system preemptively avoids the condition where excessive water head causes violent water discharge and vibrations, thereby preventing reliability issues before they arise.

Inventive Principle:
Principle #9Preliminary anti-action

3Use of energy by moving object

If the water column height H3 is decreased to reduce gas requirement for water lifting, then gas consumption is reduced, but the water column lacks enough force to overcome resistance in the bottom compartment, causing water level rise and potential overflow

Engineering Contradiction:
Improvegas consumption for water liftingVSAvoidreliability of water flow through reactor
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The patent applies dynamics by adjusting the water column height H3 according to operational conditions. When gas production is high, H3 can be decreased to reduce the energy required for water lifting. When gas production is low or sludge resistance is high, H3 is increased to ensure sufficient gravitational force for water flow. This dynamic adjustment optimizes the balance between gas consumption and flow reliability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements parameter changes by varying the water column height parameter H3 to optimize system performance. By changing H3 based on gas production rates and sludge blanket conditions, the system achieves efficient gas utilization while maintaining reliable water circulation and preventing overflow conditions.

Inventive Principle:
Principle #35Parameter changes

4Adaptability or versatility

If a variable water height control system is implemented to optimize recirculation flow, then adaptability to different COD concentrations is improved, but the device complexity increases due to additional control components

Engineering Contradiction:
Improveadaptability to different COD concentrationsVSAvoidcomplexity of fluid valve and level detector system
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent implements parameter changes by adjusting the water column height parameter in response to varying COD concentrations and gas production rates. This allows the system to adapt to different wastewater characteristics and optimize recirculation efficiency for each operating condition, enhancing versatility through controlled parameter variation.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies feedback by using level detectors to monitor water height and fluid valves to adjust the water column accordingly. This feedback mechanism enables automatic adaptation to changing operational conditions, maintaining optimal recirculation flow while managing the complexity through automated control rather than manual intervention.

Inventive Principle:
Principle #23Feedback

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 solution allows for efficient fluid recirculation and prevents overflows by dynamically adjusting the water height in response to changing gas production rates, maintaining optimal internal recirculation flow and adapting to different COD concentrations and sludge blanket resistances.

Implementation Method 1

Gas, more specifically, methane, is produced when the fluid with substances dissolved comes into contact with biomass located inside the tank. A circulation cycle of fluid is created, in which fluid is thrusted upwards together with the generated gas through a riser pipe

Methodology Applied
Scientific EffectGas lift: Gas Lift

Implementation Method 2

the fluid flows downwards to the bottom of the reactor in order to be used again in the cycle

Methodology Applied
Scientific EffectGravitation: Gravitation

Implementation Method 3

a separator for separating a mixture in sludge, water and gas and located in an upper part of the device, wherein the separator comprises a cyclone

Methodology Applied
Scientific EffectCyclone separation: Cyclone Separation

Data Source

PatentEP3507250B1Anaerobic purification device with variable water column
Publication Date: 2021.04.21 PAQUES I P
  • EP3507250B1 patent drawingFigure 1
  • EP3507250B1 patent drawingFigure 2
  • EP3507250B1 patent drawingFigure 3

AI summary

An anaerobic purification device for purification of wastewater, the anaerobic purification device comprising: -a reactor tank (10)configured to, when in operation, have a sludge blanket formed at the bottom part; -a fluid inlet (12) for, in operation,introducing influent into the reactor tank, the fluid inlet located in the lower section of the reactor tank (10); -at least one gas-collecting system (13); -at least onegas-liquid separation device (30); -at least one riser pipe (22) connected to the at least one gas-collecting system (13) and discharging into the gas-liquid separation device (30); -a downer pipe (24) connected to the gas-liquid separation device (30) and discharging into the bottom of the reactor tank (10); and -a fluid outlet (16)comprising means for, in operation,varying the height of the fluid level (19) in the reactor tank within a predetermined range, the fluid outlet arranged at the upper section of the reactor tank (10); wherein the fluid level control means comprises: a fluid valve (15) configured to control the height of the fluid in the reactor tank within the predetermined range, a fluid level detector (17), a gas flow meter (33) configured to measure the production rate of gas in the anaerobic purification device, and a controlling unit configured to regulate the fluid valve (15) to vary the height of the fluid level in the reactor tank (10) based on at least one of the fluid level detected by the fluid level detector (17) and the gas production rate detected by the gas flow meter (33).