Heat Exchanger Regeneration for Inkjet Exhaust Cleaning

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Solution Overview

Problem

Fouling of exhaust air cleaning units, particularly heat exchangers, occurs during the operation of inkjet printing devices, leading to reduced thermal transfer efficiency and potential blockages, necessitating costly and disruptive maintenance.

Innovation Solution

A method and device that alternates between standard and regeneration phases in the operation of the heat exchanger, adjusting the output temperature to condense out hydrocarbons and water, and optionally introducing a cleaning fluid to enhance condensate liquefaction and dilution, facilitating automated and efficient cleaning without interrupting the printing process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the heat exchanger operates continuously in standard phase to condense hydrocarbons, then exhaust air cleaning efficiency is maintained, but fouling accumulates and thermal transfer efficiency decreases

Engineering Contradiction:

Improveexhaust air cleaning efficiencyVSAvoidthermal transfer efficiency

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The system alternates between standard phase (hydrocarbon condensation) and regeneration phase (fouling removal) operations. During regeneration phase, the heat exchanger temperature is reduced to condense water that dissolves accumulated contaminants, and the condensed liquid is removed to restore thermal transfer efficiency. This periodic regeneration maintains both cleaning efficiency and thermal performance.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The system changes operational parameters by adjusting the heat exchanger temperature between two distinct modes: standard operating temperature for hydrocarbon condensation, and reduced temperature for water condensation and fouling removal. This parameter switching enables the heat exchanger to perform both cleaning functions effectively.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If the heat exchanger is cleaned manually, then fouling is removed, but the printing process must be interrupted and maintenance costs increase

Engineering Contradiction:

Improveheat exchanger performanceVSAvoidprinting process interruption

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The heat exchanger performs self-cleaning through automated regeneration phases. The system automatically reduces temperature, condenses water to dissolve fouling, and removes the contaminated liquid without requiring manual intervention or printing process interruption. This eliminates downtime and reduces maintenance costs.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The regeneration phase is integrated into the continuous operation cycle, allowing the heat exchanger to maintain its cleaning function without interruption to the printing process. The alternating phases ensure continuous exhaust air cleaning capability while periodically restoring thermal efficiency.

Inventive Principle:

Principle #20Continuity of useful action

3Reliability

If the output temperature is reduced to condense water for cleaning, then fouling is removed, but hydrocarbon condensation efficiency decreases

Engineering Contradiction:

Improveheat exchanger cleanlinessVSAvoidhydrocarbon condensation amount

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The system alternates between standard phase (higher temperature for hydrocarbon condensation) and regeneration phase (lower temperature for water condensation and cleaning). During standard phase, hydrocarbon condensation efficiency is maximized; during regeneration phase, temperature is temporarily reduced to condense water for fouling removal. This periodic switching resolves the contradiction by separating the two condensation functions in time.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The regeneration phase is performed periodically to prevent fouling accumulation that would otherwise degrade hydrocarbon condensation efficiency. By proactively removing fouling through water condensation, the system maintains optimal conditions for hydrocarbon condensation during standard operation phases.

Inventive Principle:

Principle #10Preliminary 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

Enables efficient and reliable cleaning of the heat exchanger by increasing condensate quantity, reducing contaminants, and maintaining continuous operation of the printing device with reduced maintenance needs.

Implementation Method 1

hydrocarbons are condensed out of the exhaust air

Methodology Applied

Scientific EffectCondensation: Condensation

Implementation Method 2

water—in particular additional water—is condensed out of the exhaust air

Methodology Applied

Scientific EffectCondensation: Condensation

Data Source

PatentUS12447738B2Device and method for cleaning exhaust air

Publication Date: 2025.10.21 CANON PRODN PRINTING HLDG BV

AI summary

Provided is a device for cleaning exhaust air from a printing device by means of a heat exchanger. The device is configured to operate the heat exchanger in a standard phase such that an output temperature of the exhaust air exhibits a standard value such that hydrocarbons are condensed out of the exhaust air. The device is also configured to operate the heat exchanger in a regeneration phase such that the output temperature of the exhaust air exhibits a value. The value is reduced relative to the standard value, such that water is condensed out of the exhaust air.