RF Laundry Drying With Capacitive Field Control

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Solution Overview

Problem

Conventional microwave drying technologies for laundry articles can cause runaway thermal effects and arcing due to random energy distribution, making them unsuitable for drying textiles, whereas radio frequency (RF) drying is more controlled but lacks efficient methods for deterministic power application.

Innovation Solution

A laundry drying method using a radio frequency (RF) applicator with capacitively coupled anode and cathode elements, generating a controlled electromagnetic field to dielectrically heat liquid in articles, thereby promoting efficient drying without thermal runaway or arcing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If microwave frequencies are applied for drying laundry articles, then drying speed is improved, but thermal runaway and arcing occur due to random energy distribution

Engineering Contradiction:

Improvedrying speedVSAvoidthermal stability

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent changes the frequency parameter from microwave range to radio frequency range, and modifies the electromagnetic field generation method from random distribution to controlled deterministic distribution through capacitively coupled anode and cathode elements. This parameter change achieves both fast drying and thermal stability.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The system employs sensors to detect moisture content and provides feedback to the control system, which adjusts the RF power application accordingly. This closed-loop feedback mechanism prevents thermal runaway by monitoring and controlling the drying process in real-time.

Inventive Principle:

Principle #23Feedback

2Productivity

If conventional microwave drying is used, then drying efficiency is improved, but controlled and deterministic power application cannot be achieved

Engineering Contradiction:

Improvedrying efficiencyVSAvoidpower application control

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The patent introduces capacitively coupled anode and cathode elements as intermediary components between the RF power source and the laundry load. These elements create a controlled electromagnetic field that enables deterministic power application, bridging the gap between power generation and controlled heating.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The system replaces the mechanical/random microwave generation method with an electronic RF field generation method using capacitively coupled elements. This substitution enables precise control over power distribution and eliminates the random energy distribution characteristic of conventional microwave systems.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If RF drying with capacitively coupled elements is used, then controlled power application is achieved, but device complexity increases compared to simple microwave systems

Engineering Contradiction:

Improvecontrolled power applicationVSAvoidapplicator structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The RF applicator is segmented into multiple anode and cathode elements arranged in a capacitively coupled configuration. This segmentation allows for controlled electromagnetic field generation while maintaining a relatively simple overall structure that can be integrated into conventional dryer designs.

Inventive Principle:

Principle #1Segmentation

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 drying method effectively dries laundry by dielectrically heating liquid within the electromagnetic field, ensuring controlled power application and reducing energy wastage, while minimizing the risk of thermal runaway and arcing, thus providing a reliable and efficient drying process.

Implementation Method 1

Dielectric heating is the process in which a high-frequency alternating electric field heats a dielectric material, such as water molecules. At higher frequencies, this heating is caused by molecular dipole rotation within the dielectric material

Methodology Applied

Scientific EffectDielectric heating: Dielectric Heating

Implementation Method 2

At higher frequencies, this heating is caused by molecular dipole rotation within the dielectric material

Methodology Applied

Scientific EffectMolecular dipole rotation:

Data Source

PatentUS10184718B2Method for drying articles

Publication Date: 2019.01.22 WHIRLPOOL CORP

AI summary

A method for drying an article with a radio frequency (RF) applicator having anode elements and cathode elements includes capacitively coupling the anode elements, capacitively coupling the cathode elements, capacitively coupling an anode element to a cathode element, and energizing the RF applicator to generate an RF field between anode and cathode elements wherein liquid residing within the field will be dielectrically heated.