Washer-Dryer Load-Adaptive Spin Control to Reduce Laundry Adherence

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Solution Overview

Problem

Existing drying methods in washing and drying apparatuses face inefficiencies when dealing with unusually wet laundry, as high-speed spins can cause laundry to adhere to the drum, leading to decreased drying performance and mechanical stress, while normal-wet laundry requires energy-efficient drying without compromising efficiency.

Innovation Solution

A method that detects the load signal indicative of laundry humidity using sensors and adjusts the drying cycle to include a spin cycle for over-wet laundry and air drying for normal-wet laundry, optimizing energy use and preventing laundry adherence by using a range of spin speeds and air circulation strategies.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a high-speed spin is performed at the beginning of the drying cycle to extract water from over-wet laundry, then water removal efficiency is improved, but laundry adheres to the drum and mechanical stress increases

Engineering Contradiction:
Improvewater removal efficiencyVSAvoidlaundry adherence and mechanical stress
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent applies preliminary action by performing a high-speed spin cycle at the beginning of the drying process to extract excess water from over-wet laundry before the main drying phase. This preliminary water removal reduces the initial humidity burden, allowing the subsequent drying cycle to operate more efficiently with lower energy consumption and reduced risk of laundry adherence during normal drying operations.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements dynamics by varying the drum rotation speed throughout the drying cycle. The system dynamically adjusts between high-speed spin phases for water extraction and lower-speed drying phases to prevent laundry adherence. This dynamic speed modulation optimizes both water removal efficiency and prevents the harmful effects of excessive mechanical stress and laundry sticking to the drum surface.

Inventive Principle:
Principle #15Dynamics

2Productivity

If a high-speed spin is performed continuously to maximize water extraction, then drying speed is improved, but energy consumption and mechanical wear increase

Engineering Contradiction:
Improvedrying speedVSAvoidenergy consumption
Core Design Contradiction:
ProductivityVSUse of energy by moving object

Solution Approach 1:

The patent applies periodic action by alternating between high-speed spin phases and lower-speed drying phases throughout the drying cycle. Instead of maintaining continuous high-speed rotation, the system periodically switches between spin and dry modes, achieving effective water removal while reducing overall energy consumption and mechanical wear on the motor and drum.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent implements parameter changes by dynamically adjusting the drum rotation speed parameter throughout the drying process. The system transitions between different speed regimes (high-speed spin at 1350 rpm versus lower-speed drying) based on the laundry's moisture content and drying progress, optimizing the balance between drying speed and energy consumption.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If high-speed spin is used for all laundry types, then water extraction is maximized, but drying uniformity decreases due to laundry adherence

Engineering Contradiction:
Improvewater extractionVSAvoiddrying uniformity
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent applies local quality by applying different drum speed regimes to different stages of the drying process based on local conditions. High-speed spin is applied only at the beginning when laundry is over-wet and needs aggressive water extraction, while lower-speed drying is used in subsequent phases when uniform drying is the priority. This localized approach to speed control ensures both effective water removal and uniform drying results.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent implements dynamics by continuously adapting the drum rotation speed to the specific needs of the laundry at each stage of the drying cycle. The system dynamically transitions from high-speed spin for water extraction to lower-speed tumbling for uniform drying, preventing laundry adherence and ensuring consistent drying results across all garments.

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 enhances drying efficiency for both over-wet and normal-wet laundry by reducing energy consumption and preventing laundry damage, ensuring effective water removal and uniform drying without excessive mechanical stress.

Implementation Method 1

A load detector for detecting a load signal indicative of the load received in the drum

Methodology Applied
Scientific EffectWeight detection: Gravitation

Implementation Method 2

executing a spin cycle or not executing the spin cycle

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Implementation Method 3

drying the laundry received in the drum in a drying cycle

Methodology Applied
Scientific EffectEvaporation: Evaporation

Implementation Method 4

drying the laundry by drying air

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP3109356B1Drying method in a washer-dryer
Publication Date: 2023.11.22 ELECTROLUX APPLIANCES
  • EP3109356B1 patent drawingFigure 1
  • EP3109356B1 patent drawingFigure 2~3
  • EP3109356B1 patent drawingFigure 4~5

AI summary

The invention relates to a method for drying laundry to be implemented in a washing and drying apparatus. The washing and drying apparatus (2) comprises: a tub (30), a drum (36) arranged within the tub (30) and being adapted to receive laundry (40) for treatment within the drum, a washing arrangement adapted to wash the laundry received in the drum (36), a drying arrangement comprising a drying air heater (20, H) and a drying air fan (26, B), and a load detector (46, 60) for detecting a load signal indicative of the load received in the drum (36). The washing and drying apparatus is adapted to dry the laundry received in the drum (36) and the drying method comprises the steps of: Starting (S30) a drying program; detecting (d, S8) the load signal (I); evaluating (S10) the detected load signal (I); in dependency of the load evaluation, executing (S16) a spin cycle (d) or not executing a spin cycle; and drying (f, S22) the laundry (40) received in the drum (36) in a drying cycle.