Multiphase Flow Passage Maintenance for Scale and Corrosion

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Solution Overview

Problem

Existing technologies are inadequate in effectively suppressing the generation of scale and corrosion on the inner walls of flow paths through which hydrophilic liquids flow, particularly in piping systems and heat exchangers.

Innovation Solution

A system and method involving a multiphase flow of hydrophilic and hydrophobic liquids with different specific gravities, where a hydrophobic liquid is injected into a flow path to form a continuous or discontinuous distribution, enhancing contact with the inner wall and reducing adherence of scale and corrosion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If a hydrophilic liquid flows through a flow path, then heat transfer efficiency is improved, but scale and corrosion adhere to the inner wall of the flow path

Engineering Contradiction:
Improveheat transfer efficiencyVSAvoidscale adhesion and corrosion
Core Design Contradiction:
Use of energy by moving objectVSObject-affected harmful factors

Solution Approach 1:

The flow path's liquid phase is segmented into two distinct liquid phases (hydrophilic and hydrophobic) that flow together as a multiphase mixture. This segmentation allows each phase to perform its specific function: the hydrophilic phase maintains heat transfer while the hydrophobic phase protects the wall from scale and corrosion adhesion.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The hydrophobic liquid acts as an intermediary substance between the hydrophilic liquid and the flow path wall. It forms a protective interface that prevents direct contact between the hydrophilic liquid (which causes scale and corrosion) and the wall surface, while still allowing heat transfer to occur.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If cleaning methods are applied to remove scale from flow paths, then scale adhesion is reduced, but the system requires stopping the flow of hydrophilic liquids

Engineering Contradiction:
Improvescale adhesionVSAvoidcontinuous operation capability
Core Design Contradiction:
Object-affected harmful factorsVSProductivity

Solution Approach 1:

Instead of cleaning scale after it adheres to the wall, the hydrophobic liquid is introduced in advance to prevent scale and corrosion from adhering in the first place. This preliminary protective action eliminates the need for subsequent cleaning operations and allows continuous operation.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The hydrophobic liquid continuously flows through the system alongside the hydrophilic liquid, providing ongoing protection against scale and corrosion. This continuous protective action replaces intermittent cleaning operations, enabling uninterrupted system operation and maintaining productivity.

Inventive Principle:
Principle #20Continuity of useful action

3Object-affected harmful factors

If fine air bubbles are mixed into the liquid to suppress scale adhesion, then scale adhesion is reduced, but gas-liquid mixing complexity increases

Engineering Contradiction:
Improvescale adhesionVSAvoidflow structure complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

Instead of using gas bubbles (one phase), the invention uses a second liquid phase (hydrophobic liquid) with different physical properties. This parameter change from gas to liquid simplifies the system because liquid-liquid multiphase flow is easier to control and manage than gas-liquid two-phase flow, reducing device complexity while maintaining the scale suppression effect.

Inventive Principle:
Principle #35Parameter changes

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 effectively suppresses scale and corrosion on the inner walls of flow paths by ensuring continuous contact with a hydrophobic liquid, allowing for continuous operation without stopping the flow of hydrophilic liquids and reducing environmental impact and costs.

Implementation Method 1

generate a multiphase flow of the hydrophilic liquid and the hydrophobic liquid in the flow path by injecting the hydrophobic liquid stored in the storage part into the flow path

Methodology Applied
Scientific EffectMultiphase flow: Two-Phase Flow

Implementation Method 2

a storage part that is disposed at an outlet of the flow path and stores the hydrophilic liquid and a hydrophobic liquid having a specific gravity different from that of the hydrophilic liquid

Methodology Applied
Scientific EffectDensity difference: Density Gradient

Implementation Method 3

adhesion of scale to an inside of the piping is suppressed by utilizing the fact that negatively charged fine air bubbles attract positively charged calcium ions and the like

Methodology Applied
Scientific EffectHydrophobic effect: Hydrophobe

Data Source

PatentEP4722577A1Flow passage maintenance system and flow passage maintenance method
Publication Date: 2026.04.08 NATIONAL UNIVERSITY CORPORATION TOKYO UNIVERSITY OF MARINE SCIENCE AND TECHNOLOGY
  • EP4722577A1 patent drawingFigure 1
  • EP4722577A1 patent drawingFigure 2
  • EP4722577A1 patent drawingFigure 3

AI summary

To suppress generation of scale on an inner wall of a flow path and/or corrosion of the inner wall of the flow path. A scale suppressing system 1 includes: piping 11 through which a hydrophilic liquid L1 flows; a storage part 12 that is disposed at an outlet of the piping 11 and stores the hydrophilic liquid L1 and a hydrophobic liquid L2 having a specific gravity different from a specific gravity of the hydrophilic liquid L1; circulation piping 13 having one end connected to a portion of the storage part 12 in which the hydrophobic liquid L2 is stored and another end connected to the piping 11; and a pump 14 that is disposed in the circulation piping 13 to generate a multiphase flow of the hydrophilic liquid L1 and the hydrophobic liquid L2 in the piping 11 by injecting the hydrophobic liquid L2 stored in the storage part 12 into the piping 11.