Dryer and method for controlling the same
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Solution Overview
Problem
Existing dryers using dielectric heating face inefficiencies due to fixed electric field generation, which limits effective heating when objects move within the dryer, and high-temperature air can damage the objects being dried.
Innovation Solution
A dryer with a controller that adjusts the phase difference of voltages applied to electrodes around a rotating drum to dynamically change the location and size of electric field concentration areas based on the object's distribution, movement, and eccentricity, ensuring efficient dielectric heating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If hot air is supplied into the drum to dry the object, then drying function is provided, but heat transfer efficiency is low and the object may be damaged by high temperature air
Solution Approach 1:
The patent replaces the conventional thermal convection drying system with a dielectric heating system using electromagnetic fields. RF electrodes generate an electric field that directly heats water molecules in the object through dielectric loss, eliminating the need for hot air circulation and thereby avoiding thermal damage while improving drying efficiency.
Solution Approach 2:
The patent utilizes the dielectric properties and phase transition characteristics of water molecules under RF electromagnetic field. The alternating electric field causes water dipoles to rotate and collide, generating heat through molecular friction and phase transition effects, achieving efficient and gentle drying.
2Use of energy by moving object
If an electric field is generated in only one direction between two flat electrodes, then dielectric heating is achieved, but the object cannot be effectively heated when moving
Solution Approach 1:
The patent divides the single-direction electric field into multiple directional electric fields by arranging multiple RF electrodes around the drum circumference. Each electrode pair generates an electric field in a specific direction, and collectively they provide omnidirectional heating coverage for the rotating object.
Solution Approach 2:
The patent makes the electric field generation dynamic by synchronizing the RF electrode activation with the drum rotation. The electric field direction and intensity are continuously adjusted according to the object's position and movement, ensuring effective heating throughout the drying cycle.
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 enhances drying efficiency by maintaining effective heating across the drum's circumference, preventing damage from high temperatures and improving overall drying performance.
Implementation Method 1
a radio frequency (RF) power supply 120 configured to apply a voltage to the plurality of electrodes; and a controller 200 configured to control the RF power supply to generate, via the plurality of electrodes, an electric field for dielectric heating of an object to be dried in the drum
Implementation Method 2
The controller may be configured to obtain distribution information of the object in the drum based on at least one from among a vibration pattern of the drum and magnitudes of voltages detected at each of the plurality of electrodes
Data Source
AI summary
A dryer may include a cabinet; a drum configured to rotate in the cabinet; a plurality of electrodes, between the drum and the cabinet, spaced apart from each other along a circumference of the drum; a radio frequency (RF) power supply configured to apply a voltage to the plurality of electrodes; and a controller configured to control the RF power supply to generate, via the plurality of electrodes, an electric field for dielectric heating of an object to be dried in the drum.