Electrostatic Spray Nozzle Stabilization Electrode

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing electrostatic spray devices face instability in atomization when a large amount of liquid is supplied, leading to uneven particle diameters and difficulties in coating applications, as the increased liquid flow disrupts the formation of a stable Taylor cone and causes non-uniform electrostatic explosions.

Innovation Solution

The introduction of a central rod within the nozzle with a larger opening diameter and a stabilization electrode that adjusts the equipotential curves to concentrate the electrostatic force, ensuring stable atomization even with increased liquid flow by dispersing the electrostatic force and maintaining a uniform charging state.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a large amount of liquid is supplied to the nozzles, then the application time is shortened and productivity is improved, but the atomization state becomes unstable and manufacturing precision deteriorates

Engineering Contradiction:
Improveapplication speedVSAvoidatomization uniformity
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The electrode is divided into multiple segments (first electrode and second electrode) arranged in sequence along the liquid flow direction. This segmentation allows different regions of the electrode to control different aspects of the electric field, enabling stable atomization even with high liquid flow rates by creating a more distributed and controlled electrostatic force profile along the liquid path.

Inventive Principle:
Principle #1Segmentation

2Productivity

If a large amount of liquid is supplied to the nozzles, then the coating efficiency is improved, but the particle diameter variation increases and manufacturing precision deteriorates

Engineering Contradiction:
Improvecoating efficiencyVSAvoidparticle diameter uniformity
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The segmented electrode structure distributes the electrostatic force generation along the liquid flow path, with each electrode segment contributing to the atomization process. This ensures that even with increased liquid flow, the electric field acts uniformly across different regions of the liquid stream, maintaining consistent particle diameter throughout the spray.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different electrodes are positioned at different locations relative to the nozzle opening, with the first electrode closer to the nozzle and the second electrode further away. This local differentiation allows the electric field to be optimized at different stages of liquid discharge, ensuring uniform atomization quality across the entire liquid flow regardless of the total flow rate.

Inventive Principle:
Principle #3Local quality

3Productivity

If a large amount of liquid is supplied to the nozzles, then the application rate is increased, but the liquid fails to atomize properly and manufacturing precision deteriorates

Engineering Contradiction:
Improveapplication rateVSAvoidatomization completeness
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The segmented electrode arrangement ensures that the electric field is applied progressively along the liquid flow path. The first electrode initiates atomization at the nozzle exit, while the second electrode continues the atomization process further downstream, ensuring complete atomization even for high-volume liquid flows that would overwhelm a single electrode system.

Inventive Principle:
Principle #1Segmentation

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 configuration allows for stable atomization of liquids with varying viscosities, maintaining particle diameter uniformity and preventing nozzle clogging, even at higher liquid supply rates, thereby enhancing the efficiency and consistency of the electrostatic spray process.

Implementation Method 1

a voltage application unit that applies a voltage between the liquid spray unit and heteropolar portion

Methodology Applied
Scientific EffectElectrostatic force: Electrostatics

Implementation Method 2

atomizes a liquid body by electrohydrodynamics

Methodology Applied
Scientific EffectElectrohydrodynamics: Electrohydrodynamics

Implementation Method 3

the liquid is supplied in a state of being pressurized... formation of a stable Taylor cone

Methodology Applied
Scientific EffectTaylor cone formation:

Implementation Method 4

causes non-uniform electrostatic explosions

Methodology Applied
Scientific EffectElectrostatic explosion: Electrostatic Discharge

Data Source

PatentEP3375530B1Electrostatic spray device and electrostatic spray method
Publication Date: 2020.11.04 ANEST IWATA CORP
  • EP3375530B1 patent drawingFigure 1
  • EP3375530B1 patent drawingFigure 2
  • EP3375530B1 patent drawingFigure 3A~3B

AI summary

There is provided an electrostatic spray device and an electrostatic spray method that ensure stable atomization even when an amount of supplied liquid is large. The electrostatic spray device includes a liquid spray unit including a nozzle configured to spout a liquid; voltage application unit configured to apply a voltage between the liquid spray unit and a heteropolar portion functioning as a pole opposite from a pole of the liquid spray unit to generate an electrostatic force for causing the liquid to separate from a distal end of the nozzle in a charging state; and a stabilization electrode configured to maintain a spraying state of the liquid in a stable state even when a pressure is applied to the liquid to supply the nozzle with the liquid. The stabilization electrode has an electric potential identical to an electric potential of the liquid spray unit, and is disposed near the nozzle such that a jet portion formed at a front of the nozzle by a linear extension of the liquid has a length longer than a length of the jet portion before the stabilization electrode is provided.