Fixed Radial Anode Drum Dryer to Reduce Parasitic Capacitance

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Solution Overview

Problem

Existing clothes drying technologies using dielectric heating, especially at higher frequencies, face inefficiencies due to parasitic capacitance and the need for complex connections, which hinder uniform heating and energy transfer.

Innovation Solution

A clothes dryer apparatus with a rotating conductive drum acting as a cathode and spatially fixed, insulated radial anodes that minimize parasitic capacitance, utilizing RF power at a single frequency for capacitive coupling, allowing for efficient dielectric heating without moving contacts and optimizing energy transfer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If conventional rotary RF heating capacitive structures are used, then dielectric heating can be achieved, but complex connections and parasitic capacitance reduce energy transfer efficiency

Engineering Contradiction:
Improveenergy transfer efficiencyVSAvoidconnection complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The patent divides the continuous capacitive structure into discrete radial anode segments positioned at specific locations around the drum perimeter. This segmentation eliminates the need for complex continuous rotary connections while reducing parasitic capacitance between adjacent capacitor plates, thereby improving energy transfer efficiency to the laundry load.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Instead of rotating the entire capacitive structure with the drum, the patent inverts the approach by keeping the anodes stationary and fixed relative to the drum exterior. The RF heating field is generated by stationary anodes that capacitively couple to the rotating drum surface, eliminating moving contacts and complex rotary connections while maintaining effective dielectric heating.

Inventive Principle:
Principle #13The other way round (Inversion)

2Productivity

If higher frequency electromagnetic fields are used, then heating can be achieved, but parasitic capacitance and non-uniform heating increase

Engineering Contradiction:
Improvedrying speedVSAvoidheating uniformity
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent positions multiple radial anode segments at different angular locations around the drum perimeter, creating localized heating zones that collectively provide uniform overall heating. Each anode segment creates a concentrated RF field in its local region, and the combination of multiple segments ensures all areas of the laundry load receive adequate heating, eliminating hot and cold spots.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent utilizes the periodic rotation of the drum to bring different portions of the laundry load sequentially past the stationary anode segments. This periodic exposure ensures that all areas of the load receive RF heating over time, achieving uniform heating distribution even with stationary anodes at fixed locations.

Inventive Principle:
Principle #19Periodic 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

This solution enhances energy conversion efficiency, reduces costs, and ensures uniform heating by minimizing parasitic capacitance and eliminating the need for complex connections, leading to faster and more reliable drying processes.

Implementation Method 1

Dielectric heating involves the heating of materials by dielectric loss. A changing electric field across the dielectric material (in this case, a load of clothes) causes energy to be dissipated as the molecules attempt to line up with the continuously changing electric field, creating friction.

Methodology Applied
Scientific EffectDielectric heating: Dielectric Heating

Implementation Method 2

the present invention... caused by a rapidly alternating electric field inside a capacitor, as in the present invention. In the latter case, there is no freely propagating electromagnetic wave.

Methodology Applied
Scientific EffectCapacitive coupling: Capacitance

Data Source

PatentEP3627083B1Fixed radial anode drum dryer
Publication Date: 2021.03.17 LG ELECTRONICS INC
  • EP3627083B1 patent drawingFigure 1
  • EP3627083B1 patent drawingFigure 2
  • EP3627083B1 patent drawingFigure 3

AI summary

The invention provides a clothes dryer apparatus comprising: an electrically conductive, grounded, generally cylindrical rotatable drum (13) having a hollow interior adapted to contain a load (15) of wet clothes to be dried; wherein the drum (13) has a partially indented exterior surface in which at least one generally ring-shaped insulated notch (10) has been formed; positioned within each notch, an electrically conductive anode (11), coupled to each anode, a source of RF power operable at a single fixed frequency; a ground connection adapted to ground electrically conductive surfaces of the drum.