Induction-Heated Yankee Dryer to Replace Steam Heating

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Solution Overview

Problem

Traditional Yankee dryers for paper production rely on steam for heating, which is energy-intensive, requires complex steam generation and transport systems, and poses challenges related to CO2 emissions, structural integrity, and chemical management.

Innovation Solution

A Yankee drier using an electromagnetic induction system with a conductive mantle heats the paper surface without steam, generating heat through induced currents in the mantle, reducing the need for steam-related systems and simplifying the process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If steam heating system is used in traditional Yankee dryer, then heating function is achieved, but system complexity and energy consumption increase

Engineering Contradiction:
Improvesteam generation and transport systemsVSAvoidheating capability
Core Design Contradiction:
Device complexityVSTemperature

Solution Approach 1:

The patent replaces the mechanical steam heating system with an electromagnetic induction heating system. The induction system uses electromagnetic fields to directly heat the paper web through induced eddy currents, eliminating the need for steam generation, transport pipes, condensate removal systems, and associated mechanical components. This substitution dramatically reduces system complexity while maintaining effective heating capability.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent extracts and removes the steam generation and transport infrastructure from the Yankee dryer system. By eliminating the boiler, steam pipes, valves, condensate collectors, and associated control systems, the invention simplifies the overall system architecture while achieving the same thermal processing function through electromagnetic induction.

Inventive Principle:
Principle #2Taking out (Extraction)

2Object-generated harmful factors

If steam is used for heating, then CO2 emissions occur, but electromagnetic induction reduces emissions

Engineering Contradiction:
ImproveCO2 emissionsVSAvoidenergy efficiency
Core Design Contradiction:
Object-generated harmful factorsVSUse of energy by moving object

Solution Approach 1:

The patent changes the fundamental parameter of the heating process from chemical combustion (steam generation requiring fuel burning and producing CO2) to electromagnetic energy conversion (induction heating with direct electromagnetic-to-thermal energy conversion). This parameter change eliminates harmful emissions while improving energy efficiency through direct heating of the paper web without intermediate heat transfer media.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces the thermal-mechanical steam heating process with an electromagnetic field-based heating process. The induction system generates electromagnetic fields that induce currents in the paper web, converting electrical energy directly to thermal energy without combustion, thereby eliminating CO2 emissions and improving overall energy efficiency.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Loss of energy

If steam heating is used, then energy loss occurs during steam generation and transport, but induction heating minimizes energy loss

Engineering Contradiction:
Improveenergy loss in steam systemVSAvoidenergy consumption of Yankee dryer
Core Design Contradiction:
Loss of energyVSUse of energy by stationary object

Solution Approach 1:

The patent extracts and eliminates the intermediate heat transfer medium (steam) from the heating process. By removing the steam generation, transport, and condensation infrastructure, the system eliminates energy losses associated with heat transfer through pipes, radiation from steam surfaces, and condensate handling, achieving direct electromagnetic heating of the paper web with minimal energy loss.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent substitutes the indirect thermal heating mechanism (steam) with direct electromagnetic heating. The induction system creates electromagnetic fields that penetrate the paper web and generate heat directly within the material being processed, eliminating energy losses inherent in steam-based heat transfer and significantly improving overall energy efficiency.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 reduces CO2 emissions, simplifies system complexity, enhances controllability, and improves energy efficiency by directly producing thermal power within the Yankee, minimizing energy loss and structural complications.

Implementation Method 1

Inside the Yankee dryer (1) is arranged a fixed electromagnetic induction heating system made up of one or more inductors (H; HN) positioned and configured to produce alternating electromagnetic fields with pre-established frequency and amplitude according to the thermal power to be generated

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

The electromagnetic fields produced by the inductors, which vary over time, generate induced currents in the metallic material of the mantle which, due to the Joule effect, produce localized overheating

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 3

The heat produced at the internal surface of the Yankee diffuses by conduction through the thickness of the mantle, until it reaches the external surface with which the sheet being dried is in contact

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP4532827B1Yankee drier for paper production
Publication Date: 2025.12.24 TOSCOTEC
  • EP4532827B1 patent drawingFigure 1~2
  • EP4532827B1 patent drawingFigure 3
  • EP4532827B1 patent drawingFigure 4

AI summary

Yankee drier (1) for paper production consisting of a body comprising a metal mantle (2) with circular cross-section and two side heads (3) on which are formed or mounted two respective coaxial pins (4) arranged along a rotation axis (x-x) of the Yankee, said body being configured to rotate with a predetermined angular speed around said rotation axis (x-x). Inside said body is arranged a fixed electromagnetic induction heating system comprising one or more inductors (H; HN) interacting electromagnetically with the mantle (2) to produce induced electric currents in the same mantle, said one or more inductors (H; HN) being arranged near the radially innermost surface of the mantle (2).