Laundry Dryer Drum Speed Scanning for Faster Moisture Extraction

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Solution Overview

Problem

Existing laundry dryers with rotary drums face inefficiencies in moisture extraction, leading to longer drying cycles and increased energy consumption, as they lack a systematic approach to optimize rotational speed based on varying moisture content throughout the drying process.

Innovation Solution

A method and dryer design that includes a speed scanning subphase during the drying phase, where the drum rotates at different speeds to measure and record moisture content, then adjusts to the speed corresponding to the highest moisture extraction, allowing for repeated scans to optimize moisture removal and reduce cycle time.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the drum rotates at a constant high speed throughout the drying phase, then moisture extraction efficiency is improved, but the laundry may stick to the drum walls and the drying uniformity deteriorates

Engineering Contradiction:
Improvemoisture extraction efficiencyVSAvoiddrying uniformity
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent applies dynamics by making the drum rotation speed variable rather than constant. The control unit adjusts the rotation speed dynamically based on real-time moisture content measurements from sensors. During different phases of the drying cycle, the drum rotates at different speeds: higher speeds for initial moisture removal, lower speeds for uniform drying, and variable speeds during speed scanning subphases. This dynamic adjustment resolves the contradiction between maintaining high moisture extraction efficiency and preventing laundry from sticking to drum walls.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the operational parameter of rotation speed based on measured moisture content. The control unit receives moisture content signals from sensors and adjusts the rotation speed parameter accordingly. The system implements speed scanning subphases where the rotation speed is varied systematically to find the optimal speed for current drying conditions. This parameter change approach allows the system to optimize both moisture extraction efficiency and drying uniformity at different stages of the drying process.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If the drum rotation speed is frequently adjusted to optimize moisture extraction, then drying efficiency is improved, but the device complexity increases

Engineering Contradiction:
Improvedrying efficiencyVSAvoidcontrol system complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent implements feedback control where moisture content sensors continuously monitor the drying process and send signals to the control unit. The control unit adjusts the drum rotation speed based on this feedback. The system includes speed scanning subphases where the rotation speed is varied systematically based on moisture content measurements, and the results are used to determine optimal speeds for subsequent drying phases. This feedback mechanism enables automated optimization of drying efficiency without requiring complex manual intervention.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The drying system performs self-optimization through automated speed scanning and adjustment based on moisture content measurements. The control unit autonomously determines the optimal rotation speed by scanning through different speeds and selecting the one that produces the highest moisture content signal from the sensors. This self-service capability reduces the need for external control intervention and simplifies the overall system operation while maintaining high drying efficiency.

Inventive Principle:
Principle #25Self-service

3Reliability

If the drying cycle is extended to ensure thorough drying, then drying completeness is improved, but energy consumption increases

Engineering Contradiction:
Improvedrying completenessVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent implements periodic speed scanning subphases during the drying cycle where the drum rotation speed is systematically varied to find the optimal speed for current moisture content levels. Between these scanning subphases, the drum operates at optimized speeds determined from previous scans. This periodic optimization approach ensures thorough drying by adapting to changing moisture conditions while avoiding unnecessary extended cycle times, thereby reducing energy consumption compared to continuous operation at fixed high speeds.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The system dynamically adjusts the drying cycle duration and intensity based on real-time moisture content measurements. Rather than running at constant high intensity for a fixed extended period, the control unit modifies rotation speeds dynamically according to moisture levels. This allows the drying process to be completed more efficiently by matching the drying intensity to the actual moisture removal needs at each moment, reducing energy consumption while ensuring drying completeness.

Inventive Principle:
Principle #15Dynamics

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 shortens the drying cycle, enhances efficiency, and reduces power consumption by ensuring the highest possible moisture extraction from laundry, adapting to changing conditions throughout the drying process.

Implementation Method 1

sensing means comprising at least one moisture sensor arranged at the outlet of the rotary drum for determining the moisture content of the airflow exiting the drum

Methodology Applied
Scientific EffectMoisture content sensing: Hygrometer

Implementation Method 2

ventilation means suitable for forcing the circulation of the airflow

Methodology Applied
Scientific EffectForced convection: Forced Convection

Data Source

PatentEP2770102B1Method for drying laundry contained in a laundry dryer and a laundry dryer implementing said method
Publication Date: 2015.12.30 FAGOR SCOOP LTDA
  • EP2770102B1 patent drawingFigure 1

AI summary

Method for drying laundry contained in a laundry dryer (1) and a laundry dryer (1) implementing said method. The method for drying laundry comprises a drying phase in which an airflow (F) is forced to circulate through the inside of a rotary drum (2) while said drum (2) rotates initially according to a first rotational speed. The drying phase also comprises at least one speed scanning subphase where the drum (2) rotates at different speeds, and the moisture content of the exiting air corresponding to each speed being measured and recorded. At the end of said subphase, the drum (2) rotates according to the speed corresponding to the highest moisture content measured.