Continuous Froth Coalescing for Ink Sensor Accuracy

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Solution Overview

Problem

Froth formation in fluid processing systems, such as ink printing systems, leads to inaccurate sensor readings and inefficient ink usage due to premature triggering of out-of-ink sensors and lag in froth dissipation in batch systems.

Innovation Solution

A continuous defrothing device with a frame having an inner chamber with a filter screen that separates froth into coalesced fluid and air, allowing the fluid to be recycled and air to be vented, improving sensor accuracy and system performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If batch froth dissipation system is used, then froth is eventually dissipated, but system operation is delayed and sensor readings become inaccurate

Engineering Contradiction:
Improvesensor reading accuracyVSAvoidsystem operation delay
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent implements a continuous froth dissipation system where the defrothing device operates continuously to break and coalesce bubbles as they form, rather than relying on batch dissipation. This continuous action prevents froth accumulation that would otherwise delay system operation and cause inaccurate sensor readings, maintaining both reliability and time efficiency.

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The defrothing device is positioned to intercept and break bubbles before they can accumulate and form significant froth layers that would interfere with sensor readings. By taking preliminary action to disrupt bubbles early in their formation, the system prevents the harmful effects of froth accumulation before they occur.

Inventive Principle:
Principle #10Preliminary action

2Stress or pressure

If air is introduced into ink reservoir to maintain pressure, then pressure is maintained, but froth forms in the ink

Engineering Contradiction:
Improveink reservoir pressureVSAvoidfroth formation
Core Design Contradiction:
Stress or pressureVSObject-generated harmful factors

Solution Approach 1:

The defrothing device extracts and removes air bubbles from the ink reservoir by providing a dedicated pathway and mechanism (defrothing chamber with filter screen) that separates bubbles from the ink. This allows continuous pressure maintenance through air introduction while simultaneously removing the harmful froth that would otherwise form and interfere with system operation.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The defrothing chamber acts as an intermediary space between the ink reservoir and the printing system. Bubbles are introduced into this intermediate chamber where they are broken and coalesced, preventing them from contaminating the main ink supply while still allowing pressure equilibrium to be maintained.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Measurement precision

If froth accumulates in ink supply, then out-of-ink sensor is triggered, but ink supply is not actually depleted

Engineering Contradiction:
Improveink level detection accuracyVSAvoidpremature ink replacement
Core Design Contradiction:
Measurement precisionVSLoss of substance

Solution Approach 1:

The continuous operation of the defrothing device prevents froth accumulation that would falsely indicate ink depletion. By continuously breaking and coalescing bubbles, the system maintains accurate ink level readings throughout the ink supply lifecycle, preventing premature replacement and ensuring ink is utilized fully.

Inventive Principle:
Principle #20Continuity of useful action

4Productivity

If filter screen is used to separate coalesced fluid from air, then fluid can be recycled, but device complexity increases

Engineering Contradiction:
Improvefluid recycling efficiencyVSAvoiddefrothing device structure
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The defrothing device is segmented into distinct functional zones: a defrothing chamber for bubble breakdown, a filter screen for liquid-air separation, and collection pathways for recycled fluid and vented air. This segmentation allows each component to perform its specific function efficiently while maintaining an overall simple and maintainable structure.

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

The continuous coalescing of froth into coalesced fluid and air enhances system sensor accuracy, increases customer satisfaction, and improves fluid efficiency by preventing premature ink depletion and system failures.

Implementation Method 1

a filter screen that separates the froth into a coalesced fluid and air

Methodology Applied
Scientific EffectFiltration: Filter (physical)

Implementation Method 2

separates the froth into a coalesced fluid and air

Methodology Applied
Scientific EffectCoalescence: Coagulation

Implementation Method 3

the inner chamber is sized to facilitate breaking of the bubbles in the froth

Methodology Applied
Scientific EffectGravity separation: Gravitation

Data Source

PatentEP3436174B1Froth coalescing
Publication Date: 2021.07.07 HEWLETT PACKARD DEVELOPMENT COMPANY LP
  • EP3436174B1 patent drawingFigure 1~2
  • EP3436174B1 patent drawingFigure 3~4
  • EP3436174B1 patent drawingFigure 5~6

AI summary

An example device includes a frame having at least one outer opening and at least one inner opening recessed from the outer opening, at least one filter screen mounted on a perimeter of the at least one inner opening to form an inner chamber, and at least one cover layer mounted on a perimeter of the at least one outer chamber to form an outer chamber. The filter screen separates the inner chamber from the outer chamber, and the filter screen prevents froth from crossing and allows coalesced fluid to cross into the outer chamber.