Dual Heating Pyrolysis Reactor for Uniform Rubber Thermal Decomposition

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Solution Overview

Problem

Current pyrolysis systems for rubber materials face challenges in achieving uniform heat distribution due to rubber's poor thermal conductivity and partially cross-linked structure, leading to inefficient energy use, varied product quality, and extended reaction times.

Innovation Solution

A dual heating system comprising a resistive heating shaft and an inductive heating system generating eddy currents in the range of 10 to 25 kHz is implemented within the reactor, ensuring improved heat transfer and distribution during the pyrolysis process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single heating system is used in the pyrolysis reactor, then the device complexity is reduced, but the heat distribution uniformity and pyrolysis efficiency deteriorate due to rubber's poor thermal conductivity

Engineering Contradiction:
Improveheating system complexityVSAvoidheat distribution uniformity
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The heating system is divided into two independent subsystems: a resistive heating shaft that rotates with the screw conveyor, and a stationary inductive heating system with circumferential coils. Each subsystem targets different heating needs - the resistive system provides direct contact heating while the inductive system provides external electromagnetic heating, together achieving uniform heat distribution throughout the rubber material

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The dual heating system combines two different heating mechanisms (resistive and inductive) into a single integrated system that serves multiple heating functions simultaneously. The resistive heating shaft provides direct thermal conduction while the inductive coils provide electromagnetic heating, creating a multi-functional heating system that overcomes the limitations of single-mode heating

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Productivity

If heating temperature is increased to improve pyrolysis rate, then the reaction time is reduced, but energy consumption increases and product quality deteriorates due to improper heat distribution

Engineering Contradiction:
Improvepyrolysis rateVSAvoidenergy consumption
Core Design Contradiction:
ProductivityVSUse of energy by moving object

Solution Approach 1:

The heating system applies different heating modes to different regions of the material - the resistive heating shaft provides localized direct heating where material contacts the screw, while the inductive coils provide distributed external heating throughout the reactor chamber. This localized quality approach ensures each region receives appropriate heat intensity, achieving high pyrolysis rates without excessive energy consumption or temperature hotspots that would degrade product quality

Inventive Principle:
Principle #3Local quality

3Productivity

If heating temperature is increased to reduce reaction time, then the productivity is improved, but product quality varies due to poor heat distribution in rubber material

Engineering Contradiction:
Improvereaction timeVSAvoidproduct quality consistency
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The dual heating system operates continuously and simultaneously throughout the pyrolysis process - the resistive heating shaft rotates continuously with the screw conveyor providing ongoing direct heating, while the inductive coils maintain continuous electromagnetic heating fields. This continuous dual-mode heating ensures uniform temperature distribution throughout the reaction zone, maintaining consistent product quality while achieving reduced reaction times

Inventive Principle:
Principle #20Continuity of useful 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

This configuration enhances pyrolysis efficiency by reducing reaction time, improving product yield and quality, and minimizing energy expenditure, resulting in a more controlled and efficient pyrolysis process for rubber materials.

Implementation Method 1

The screw serves as both transferring means for transfer the material through a reactor tube and heating means for heating of the transferred material. The conveyor screw is provided inside the reaction tube that is made of a refractory material; the screw has both ends connected, via electrical connections, to an electrical power unit and heats the processed material by the Joule effect.

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 2

A dual heating system comprising a resistive heating shaft and an inductive heating system generating eddy currents in the range of 10 to 25 kHz is implemented within the reactor, ensuring improved heat transfer and distribution during the pyrolysis process.

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 3

an inductive heating system generating eddy currents in the range of 10 to 25 kHz

Methodology Applied
Scientific EffectEddy currents: Eddy Currents

Implementation Method 4

Pyrolysis is one of the most attracting methods for recycling of waste polymeric materials. The pyrolysis process involves thermal degradation of polymeric materials by heating of the material in the absence of oxygen, at near atmospheric pressure.

Methodology Applied
Scientific EffectPyrolysis: Pyrolysis

Data Source

PatentEP3374469B1A method and a reactor for thermal pyrolysis of rubber materials
Publication Date: 2021.04.28 SYNTOIL SA
  • EP3374469B1 patent drawingFigure 1

AI summary

A reactor for continuous pyrolysis of a rubber material at a near atmospheric pressure, comprising: a reaction chamber (150) having an inlet (110) for the rubber material and outlets (131, 132) for pyrolysis products; a screw conveyor (120) installed within the reaction chamber (150), the screw conveyor (120) having a shaft (121) with its ends connected to an electric power supply for resistive heating of the conveyed rubber material; and an induction heating system (160) arranged circumferentially around the reaction chamber (150) for generating eddy current having a stimulation frequency in the range from 10 to 25 kHz for inductive heating of the rubber material within the reaction chamber (150).