Annealing Furnace Muffle Thermal Deformation Control

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Annealing furnace muffles experience significant deformation due to heating and cooling cycles, leading to increased wear and inefficient heating processes, as the base body material changes shape and expands, causing inhomogeneous heating and reduced muffle lifespan.

Innovation Solution

A furnace muffle design with a base body that uses external actuators to apply controlled forces, detected by sensors, to maintain the base body's shape and expansion constant, compensating for thermal deformations and preventing collapse during heating and cooling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If the furnace muffle base body is heated to generate annealing temperatures, then the heating function is achieved, but the base body undergoes considerable deformation due to thermal expansion

Engineering Contradiction:
Improveannealing temperatureVSAvoidbase body shape
Core Design Contradiction:
TemperatureVSShape

Solution Approach 1:

The patent applies counterforces through actuators to compensate for thermal deformation, dynamically adjusting mechanical parameters to maintain the base body shape constant despite temperature changes and thermal expansion

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses actuators to apply counterforces that balance the thermal deformation forces, effectively creating a counteracting mechanism that prevents shape change during heating and cooling cycles

Inventive Principle:
Principle #8Anti-weight (Counterweight)

2Loss of energy

If the furnace is switched off temporarily to save energy, then energy consumption is reduced, but the cooling and heating cycles cause clear deformations of the furnace muffle

Engineering Contradiction:
Improveenergy consumptionVSAvoidfurnace muffle shape
Core Design Contradiction:
Loss of energyVSShape

Solution Approach 1:

The control device dynamically adjusts the counterforces applied by actuators based on temperature sensor feedback, modifying mechanical parameters to compensate for deformation during temperature transitions caused by energy-saving shutdown cycles

Inventive Principle:
Principle #35Parameter changes

3Temperature

If the base body of the muffle is used as a radiation source for heating the volume enclosed by it, then heating function is provided, but deformation of the furnace muffle leads to inhomogeneous heating

Engineering Contradiction:
Improveheating capabilityVSAvoidheating uniformity
Core Design Contradiction:
TemperatureVSManufacturing precision

Solution Approach 1:

By maintaining the base body shape constant through counterforces, the patent ensures that the radiation source geometry remains stable, producing homogeneous heating distribution throughout the enclosed volume

Inventive Principle:
Principle #35Parameter changes

4Temperature

If the furnace muffle undergoes deformation during heating and cooling, then thermal expansion occurs, but the muffle is subjected to increased wear and has to be replaced soon

Engineering Contradiction:
Improvethermal cycling capabilityVSAvoidmuffle lifespan
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The patent dynamically adjusts counterforces to maintain constant base body shape during thermal cycling, preventing deformation-induced wear and extending muffle service life

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The actuators apply preventive counterforces before significant deformation occurs, cushioning the base body against thermal stresses that would otherwise cause wear and damage during heating and cooling cycles

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

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 solution significantly reduces muffle wear and maintains efficient heating by counteracting thermal deformations, ensuring consistent heating and extending the muffle's lifespan by using sensors and actuators to manage forces applied to the base body.

Implementation Method 1

the base bodies of furnace muffles themselves undergo a considerable deformation, due to the heating of the volume delimited by them

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 2

it is necessary to detect the initial deformation of the base body by means of the sensor, and then to counteract this deformation as a function of a value or a measure for the deformation, which is detected by the sensor

Methodology Applied
Scientific EffectMechanical force: Mechanical Force

Implementation Method 3

the control device is set up so that it controls the actuator during operation of the furnace muffle in such a manner that the shape and the expansion of the base body are kept essentially constant

Methodology Applied
Scientific EffectFeedback control: Feedback

Data Source

PatentEP3004769B1Furnace muffle for an annealing furnace
Publication Date: 2020.10.07 SANDVIK MATERIALS TECH DEUTLAND GMBH
  • EP3004769B1 patent drawingFigure 1
  • EP3004769B1 patent drawingFigure 2
  • EP3004769B1 patent drawingFigure 3

AI summary

A furnace muffle for an annealing furnace with a base body which is set up so that it delimits a volume to be heated, comprising at least one actuator which is connected to the base body in such a manner that the actuator, during the operation of the furnace muffle, can exert a force on the base body, at least one sensor which is arranged and set up so that it detects a force exerted by the base body during the heating or cooling and/or a change in the length of the base body during the heating or cooling, and a control device connected to the actuator and the sensor, which is set up so that, during the operation of the furnace muffle, it controls the force exerted on the base body as a function of the force or change in length detected by the sensor.