Apparatus and methods for radio frequency heating and defrosting

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Solution Overview

Problem

Conventional capacitive food defrosting systems face challenges with cleaning due to drip and condensation accumulation, inefficiency in power usage, and incompatibility with varying food sizes and shapes, as they have fixed electrodes and compartments.

Innovation Solution

A radio frequency (RF) defrosting system with modular components, including a removable drawer and adjustable electrodes, allows for easy cleaning and accommodates different load sizes and shapes by dynamically matching impedance to optimize energy absorption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If conventional capacitive food defrosting systems use fixed electrodes and heating compartments, then the system structure is simple, but cleaning becomes difficult due to drip and condensation accumulation

Engineering Contradiction:
Improvesystem structure simplicityVSAvoidcleaning ease
Core Design Contradiction:
Ease of manufactureVSEase of operation

Solution Approach 1:

The heating compartment is divided into a stationary housing and a removable drawer assembly. The drawer can be completely removed from the housing for easy cleaning of the heating compartment, while the drawer itself can be rinsed under running water. This segmentation allows both components to be cleaned separately and efficiently.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The drawer containing the food load is extracted as a removable component from the heating compartment. This extraction allows users to easily remove the drawer for cleaning purposes and enables the heating compartment to be accessed and cleaned separately, solving the cleaning difficulty problem.

Inventive Principle:
Principle #2Taking out (Extraction)

2Device complexity

If conventional systems use a fixed size heating compartment, then the device structure is simple, but power efficiency decreases when defrosting loads significantly smaller than the compartment size

Engineering Contradiction:
Improveheating compartment structureVSAvoidpower efficiency
Core Design Contradiction:
Device complexityVSLoss of energy

Solution Approach 1:

The drawer size is made variable through an adjustable back wall that can be positioned at different locations to change the depth of the drawer. This dynamic adjustment allows the heating compartment volume to match the size of the food load, improving power efficiency by reducing energy waste in oversized compartments while maintaining a relatively simple fixed-structure design.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The internal volume parameter of the heating compartment is made adjustable by changing the drawer depth through the movable back wall. This parameter change allows the system to adapt to different food load sizes, optimizing power efficiency without requiring a completely complex reconfigurable structure.

Inventive Principle:
Principle #35Parameter changes

3Device complexity

If conventional systems use fixed electrodes, then the system structure is simple, but adaptability to different food load sizes and shapes is limited

Engineering Contradiction:
Improveelectrode configurationVSAvoidfood load accommodation
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The electrode configuration is made dynamic through adjustable electrode positions. The first electrode can be moved vertically along guides, and the second electrode can be adjusted horizontally and vertically. This dynamic adjustability allows the electrode spacing and configuration to be optimized for different food load sizes and shapes, improving adaptability while maintaining a relatively simple fixed-structure base design.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The adjustable electrode system provides multi-functionality by being able to accommodate various food load sizes and shapes with a single device configuration. The electrodes can be repositioned to create optimal heating fields for different types of loads, making the system universal rather than requiring multiple specialized devices.

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

4Adaptability or versatility

If conventional systems use large fixed electrodes, then the system can accommodate large loads, but power efficiency decreases for smaller loads

Engineering Contradiction:
Improveload size accommodationVSAvoidpower efficiency
Core Design Contradiction:
Adaptability or versatilityVSLoss of energy

Solution Approach 1:

The electrode spacing is made dynamically adjustable so that the distance between electrodes can be optimized for the actual food load size. For smaller loads, the electrodes can be positioned closer together, concentrating the electric field and improving power efficiency. For larger loads, the electrodes can be spaced further apart, maintaining adequate adaptability. This eliminates the need to use large fixed electrodes that would be inefficient for smaller loads.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The electric field distribution is optimized locally by adjusting electrode positions according to the specific food load configuration. Rather than using uniformly large electrodes that create excessive field strength for small loads, the electrode spacing can be locally optimized to match the load size, improving power efficiency while maintaining the ability to accommodate various load sizes.

Inventive Principle:
Principle #3Local quality

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

The RF defrosting system effectively addresses cleaning difficulties and power inefficiencies by enabling efficient defrosting of loads of various sizes and shapes through modular design and impedance matching, ensuring uniform heating and reduced energy waste.

Implementation Method 1

radio frequency (RF) heating or defrosting system

Methodology Applied
Scientific EffectRadio frequency heating: Dielectric Heating

Implementation Method 2

low power electromagnetic energy is supplied to the electrodes

Methodology Applied
Scientific EffectElectromagnetic energy: Electromagnetic Induction

Data Source

PatentEP3462817B1Apparatus and methods for radio frequency heating and defrosting
Publication Date: 2022.02.23 NXP USA INC
  • EP3462817B1 patent drawingFigure 1
  • EP3462817B1 patent drawingFigure 2
  • EP3462817B1 patent drawingFigure 3

AI summary

A radio-frequency (RF) heating system may include a removable drawer, which may be inserted under a fixed shelf of the RF heating system to form an enclosed cavity. The drawer may include conductive channels or side rails that may interface with the shelf of the defrosting system in order to electrically couple the drawer to the RF heating system. The drawer may include an electrode that is electrically coupled to ground or to a RF signal source when the drawer is inserted beneath the shelf. The shelf may include selectable electrodes of varying sizes. The RF heating system may use identification circuitry to recognize the type of drawer that has been inserted beneath the shelf. RF energy may be applied to the electrode of the drawer or the shelf to heat a load in the enclosed cavity.