Movable Plate Microwave Cavity for Uniform Heating
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing microwave cooking appliances are not suitable for large kitchens as they often result in uneven heating due to standing waves, and scaling up requires duplication of coupling and tuning assemblies, which is inefficient.
Innovation Solution
A microwave cooking appliance with movable plate-like members that vary the distance between reflective surfaces by at least a quarter wavelength, allowing interchange of maxima and minima in the standing wave field distribution, ensuring even heating across a larger cooking space without the need for additional assemblies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the cavity height is made less than one wavelength to avoid standing waves, then hot and cold spots are eliminated, but the appliance becomes too small for large kitchens
Solution Approach 1:
The patent applies the dynamics principle by making the cavity height variable rather than fixed. The movable plate allows the cavity dimensions to change during operation, enabling the system to accommodate larger cooking spaces while still preventing standing waves. By dynamically adjusting the cavity height to remain less than one wavelength despite overall size increases, the invention resolves the contradiction between larger volume and heating uniformity.
2Volume of stationary object
If a stack of resonant cavities is provided to increase cooking space, then the appliance can serve large kitchens, but coupling assemblies and tuning assemblies must be duplicated
Solution Approach 1:
The patent merges multiple functions into a single movable plate structure. Instead of creating separate resonant cavities with individual coupling and tuning assemblies, the invention uses one movable plate that simultaneously performs multiple functions: it defines the cavity boundary, acts as a tuning element, and enables volume adjustment. This consolidation eliminates the need for duplicating assemblies while still providing increased cooking space.
Solution Approach 2:
The movable plate serves multiple functions within a single component: it acts as a reflective boundary for the resonant cavity, a tuning assembly for adjusting resonant frequency, and a volume control mechanism. This multi-functionality allows the system to achieve larger cooking capacity without proportionally increasing device complexity through additional specialized assemblies.
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 provides homogeneous energy distribution across a larger cooking space, eliminating hot and cold spots and allowing for efficient use of space without the need for multiple tuning and coupling assemblies, ensuring consistent heating of foodstuffs.
Implementation Method 1
at least one plate-like member having at least one surface reflective to microwaves and facing an opposite surface reflective to microwaves in the interior chamber
Implementation Method 2
an electrically conducting oven liner or member having a polished inner surface defining a resonant cavity
Implementation Method 3
establishing a standing wave field distribution in the interior chamber, in particular in the cooking space
Implementation Method 4
the plate-like member is movable such as to vary a distance to the opposite surface by an amount corresponding to at least a quarter wavelength λ of the microwaves
Implementation Method 5
positions of maxima and minima of a standing wave field distribution established in the interior chamber including the cooking space are interchanged
Implementation Method 6
an apparatus for providing microwaves of at least one wavelength λ to the interior chamber
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A microwave cooking appliance, includes: an interior chamber, including a cooking space (2) for accommodating foodstuffs to be-cooked; an apparatus (20,21) for providing microwaves of at least one wavelength » to the interior chamber; and at least one plate-like member (4,22,23) having at least one surface reflective to microwaves and facing an opposite surface reflective to microwaves in the interior chamber. The plate-like member (4,22,23) is movable such as to vary a distance to the opposite surface whilst the microwaves are provided to the interior chamber. At least one of the plate-like members (4,22,23) is movable such as to allow a change in distance to the opposite surface by an amount of the order of at least a quarter wavelength ».