Ultrafiltration Dosing Control via Differential Pressure Feedback

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Solution Overview

Problem

Existing ultrafiltration membrane systems face instability and inefficiency due to manual adjustments in flocculant dosage, which fail to timely respond to changes in water quality and operating conditions, leading to membrane blockage and increased energy consumption.

Innovation Solution

A dosing control method and system that sets preset differential pressures for initial and final backwash cycles, calculates allowable pressures, and adjusts dosing based on real-time differential pressure data to perform dosing operations at optimal dosages, ensuring timely adjustments and stable system operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If manual adjustment of flocculant dosage is used, then operational simplicity is maintained, but system stability and responsiveness to water quality changes deteriorate

Engineering Contradiction:
Improveoperational simplicityVSAvoidsystem stability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The system automatically monitors differential pressure across the membrane and adjusts flocculant dosage without manual intervention. The control unit receives real-time pressure data from sensors and autonomously determines optimal dosing rates, enabling the system to serve itself and respond dynamically to changing operating conditions.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system implements a closed-loop feedback mechanism where differential pressure measurements are continuously fed back to the control unit. Based on this feedback, the control unit adjusts the dosing pump operation to maintain optimal filtration performance, creating a self-regulating system that responds to actual membrane fouling conditions.

Inventive Principle:
Principle #23Feedback

2Reliability

If increased flocculant dosage is applied to prevent membrane blockage, then filtration performance is improved, but chemical consumption and cost increase

Engineering Contradiction:
Improvefiltration performanceVSAvoidchemical consumption
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The system dynamically changes the dosing parameter (flocculant dosage rate) based on actual differential pressure measurements. Instead of using a fixed high dosage, the system adjusts the dosage parameter in real-time to match the actual fouling rate, applying only the necessary amount of chemical to maintain performance and avoid waste.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The system applies partial action by using only the minimum necessary flocculant dosage required to maintain filtration performance. Rather than continuously applying excessive dosage to ensure performance, the system monitors conditions and applies chemicals only when and to the extent needed, preventing both over-dosing and under-dosing.

Inventive Principle:
Principle #16Partial or excessive action

3Reliability

If frequent membrane cleaning is performed to remove pollutants, then membrane performance is restored, but system productivity and water output decrease

Engineering Contradiction:
Improvemembrane performanceVSAvoidwater output
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The system takes preliminary anti-action by applying flocculant to prevent pollutant accumulation on the membrane surface before significant fouling occurs. By proactively managing foulant deposition through controlled flocculation, the system delays the need for cleaning operations and maintains stable performance over longer periods.

Inventive Principle:
Principle #9Preliminary anti-action

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 stabilizes ultrafiltration system operation, reduces chemical consumption, extends membrane cleaning cycles, and simplifies water treatment management, thereby reducing costs and membrane pollution.

Implementation Method 1

a flocculant may be introduced through a water inlet end of the ultrafiltration membrane system to initiate the micro-flocculation reaction, so that organic pollutants in the raw water, such as colloids having a particle size smaller than the membrane pore size, will aggregate into larger particles under the action of the flocculant

Methodology Applied
Scientific EffectFlocculation: Flocculation

Implementation Method 2

Ultrafiltration is a membrane filtration technology that is commonly used in water treatment

Methodology Applied
Scientific EffectFiltration: Filter (physical)

Data Source

PatentEP4098628B1Dosing control method for micro-flocculation in ultrafiltration
Publication Date: 2024.04.03 GREENTECH ENVIRONMENTAL CO LTD
  • EP4098628B1 patent drawingFigure 1
  • EP4098628B1 patent drawingFigure 2
  • EP4098628B1 patent drawing

AI summary

A dosing control method for micro-flocculation in ultrafiltration, including: calculating a preset value of a first differential pressure before an initial backwash and a preset value of a second differential pressure before a final backwash in each chemically enhanced backwash cycle; calculating a preset value of a third differential pressure between the first differential pressure and the second differential pressure according to the preset value of the first differential pressure and the preset value of the second differential pressure; obtaining a predicted value of the third differential pressure according to a differential pressure curve plotted based on online filtration differential pressure data; and comparing the preset value of the third differential pressure and the predicted value of the third differential pressure to determine an operation state of an ultrafiltration system, so as to adjust a dosing state or a dosage to ensure a stable operation of the ultrafiltration system. A dosing control system is also provided.