Variable Reflectance Elements for Microwave Energy Steering
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Solution Overview
Problem
Microwave ovens heat food unevenly due to standing waves causing local regions of high and low microwave field intensity, and the mechanism of heating polarized molecules like water, while neglecting items without polarized molecules, leading to inconsistent heating within a single item.
Innovation Solution
The use of variable reflectance elements within the microwave oven chamber, controlled by a system to alter the distribution and intensity of electromagnetic energy by changing the impedance or orientation of these elements, effectively steering the local maxima of energy to ensure more even heating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If electromagnetic waves are used to heat food in a microwave oven, then heating efficiency is improved, but uneven heating occurs due to standing waves creating local regions of high and low microwave field intensity
Solution Approach 1:
The patent applies the dynamics principle by making the reflective elements movable and adjustable within the microwave cavity. The reflective elements can be repositioned to different locations and orientations to dynamically alter the standing wave patterns and energy distribution. This allows the system to adapt the heating pattern in real-time, preventing consistent hot and cold spots that occur with fixed configurations, thereby achieving more uniform heating while maintaining high heating efficiency.
2Productivity
If electromagnetic waves cause polarized molecules to rotate and deliver kinetic energy, then heating of polarized molecules like water is effective, but items without polarized molecules are not heated efficiently
Solution Approach 1:
The patent applies the local quality principle by using adjustable reflective elements that can create localized regions of concentrated electromagnetic energy. These reflective elements can be positioned to direct energy specifically to different areas of the food item, adapting the heating pattern to the local characteristics of the food. This allows effective heating of polarized molecules where present while also addressing areas with different material compositions, thereby improving versatility without sacrificing heating effectiveness.
3Manufacturing precision
If a rotating tray is used to move the heated item, then distribution of electromagnetic energy is homogenized, but the approach is random and does not address specific items being heated unevenly
Solution Approach 1:
The patent applies the feedback principle by incorporating sensors that detect the actual heating patterns and energy distribution within the microwave cavity. This detection system provides information about hot and cold spots, and the control system uses this feedback to adjust the positions and orientations of the reflective elements accordingly. This closed-loop control enables precise targeting of specific areas that need heating, rather than relying on random rotation, thereby achieving both uniform energy distribution and high heating control precision.
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 allows for the even distribution of heat across items, addressing the uneven heating issue by dynamically adjusting the energy pattern within the oven, ensuring consistent heating regardless of the item's composition or structure.
Implementation Method 1
The waves within the microwave oven that are not absorbed by the heated item reflect within the chamber and cause standing waves
Implementation Method 2
The electromagnetic waves in a microwave oven cause polarized molecules, such as water, to rotate back and forth, thereby delivering energy to the item in the form of kinetic energy
Implementation Method 3
Standing waves are caused by the constructive and destructive interference of waves that are coherent but traveling in different directions
Data Source
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AI summary
An electronic oven with a set of variable reflectance elements for controlling a distribution of heat in the electronic oven and associated methods are disclosed herein. The electronic oven includes a chamber, an energy source coupled to an injection port in the chamber, and a set of variable reflectance elements located in the chamber. In some of the disclosed approaches the variable reflectance elements are nonradiative. A control system of the electronic oven can be configured to alter the states of the variable reflectance elements to thereby alter and control the distribution of energy within the chamber.