Microwave Oven Beverage Heating Using Humidity Curves

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Solution Overview

Problem

Microwave ovens lack an automatic and efficient method for reheating beverages to the optimal drinking temperature without requiring user input on the volume of the drink, leading to variability in temperature and user inconvenience.

Innovation Solution

A method that uses absolute humidity measurement and pre-recorded evolution curves to automatically control the heating process, stopping the microwave when a predetermined temperature is reached, and displaying the remaining heating time, allowing for optimal beverage heating without user input on volume or container type.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a timer-based reheating function is used, then the heating duration can be controlled, but the temperature consistency varies significantly depending on drink volume and container type

Engineering Contradiction:
Improvetemperature consistencyVSAvoiduser input requirements
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The system uses an absolute humidity sensor to automatically detect when the drink reaches the optimal temperature without requiring user input about volume or container type. The control unit compares real-time humidity measurements with pre-stored evolution curves to determine the exact stopping point, making the system self-regulating and eliminating the need for manual volume input while ensuring consistent temperature results.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system implements continuous feedback by monitoring absolute humidity levels during heating and comparing them against pre-stored evolution curves. This real-time feedback mechanism allows the control unit to identify the optimal stopping point accurately, ensuring temperature consistency regardless of drink volume or container characteristics, while eliminating the need for manual user input.

Inventive Principle:
Principle #23Feedback

2Adaptability or versatility

If the microwave generator runs for a fixed duration, then the operation is simple, but it cannot adapt to different drink volumes and container types

Engineering Contradiction:
Improveadaptability to different drink volumesVSAvoidcontrol mechanism complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The system performs preliminary action by pre-storing multiple evolution curves in the control unit's memory, each corresponding to different drink volumes and container types. During operation, the system simply needs to measure absolute humidity and compare it against these pre-stored curves to identify the correct stopping point. This approach provides adaptability to various drink conditions without requiring complex real-time calculations or user input about volume and container type.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system uses parameter changes by monitoring the absolute humidity parameter throughout the heating process. The control unit compares the real-time humidity measurements with pre-stored evolution curves that represent different drink volumes and container types. This parameter-based approach enables the system to adapt to various heating scenarios using a relatively simple control mechanism that only requires humidity sensing and curve comparison.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If humidity measurement is used to detect optimal stopping point, then temperature precision improves, but the system requires pre-recorded evolution curves for different conditions

Engineering Contradiction:
Improvetemperature detection precisionVSAvoiddata storage requirements
Core Design Contradiction:
Measurement precisionVSQuantity of substance

Solution Approach 1:

The system performs preliminary action by pre-recording and storing evolution curves that represent absolute humidity changes for different drink volumes and container types. These pre-stored curves are saved in the control unit's memory before actual use. During operation, the system only needs to measure current humidity and compare it against these pre-prepared curves to determine the optimal stopping point, achieving high temperature detection precision without requiring complex real-time analysis or extensive user input.

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

Ensures beverages are heated to an optimal temperature of 75°C, providing convenience and consistency across various container sizes and initial temperatures, with enhanced discrimination between humidity evolution curves using specific temperature ranges.

Implementation Method 1

starting a microwave generator at a predefined power

Methodology Applied
Scientific EffectMicrowave radiation heating: Microwave Radiation

Implementation Method 2

heating a beverage in a cavity of a microwave oven

Methodology Applied
Scientific EffectDielectric heating: Dielectric Heating

Implementation Method 3

measurement of absolute humidity in the cavity of the microwave oven

Methodology Applied
Scientific EffectElectromagnetic sensing of humidity: Dielectric

Implementation Method 4

evaporation of the liquid in the cavity during the heating of the drink depends on these various parameters

Methodology Applied
Scientific EffectEvaporation: Evaporation

Data Source

PatentEP1850641B1Beverage heating method and microwave oven capable of implementing the method
Publication Date: 2010.03.31 FAGORBRANDT
  • EP1850641B1 patent drawingFigure 1~2
  • EP1850641B1 patent drawingFigure 3A
  • EP1850641B1 patent drawingFigure 3B

AI summary

The method involves starting up of a microwave generator with a predefined power, and measuring an absolute humidity in a cavity of a microwave oven. The absolute humidity is compared with pre-recorded absolute humidity values. An evolution curve is identified among an assembly of evolution curves pre-recorded in the time of the absolute humidity. The microwave generator is shutdown, when the measured absolute humidity reaches a threshold value associated to the identified evolution curve and corresponding to a preset temperature attained by a drink e.g. coffee. An independent claim is also included for a microwave oven comprising a cavity.