Dryer Drum Baffle Airflow for Uniform Laundry Drying

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Solution Overview

Problem

Laundry-drying machines have low efficiency in distributing hot air, leading to uneven drying and increased drying times, particularly when garments adhere to the drum surface during rotation.

Innovation Solution

A laundry-drying machine design featuring a baffle device with radial guide cavities that direct hot air to the cavities of multiple agitation members, ensuring simultaneous traversal by hot air flows, enhancing air distribution and uniformity within the drum.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If hot air is introduced axially into the drum through the rear wall, then the drying air can penetrate into the drum, but the distribution of hot air becomes uneven and drying efficiency is low

Engineering Contradiction:
Improvedrying efficiencyVSAvoiduniformity of drying
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The invention divides the single axial hot air flow into multiple radial flows by introducing the air through several agitation members (paddles) positioned around the drum periphery. Each agitation member receives hot air through its own cavity and distributes it radially across the laundry, segmenting the drying action into multiple simultaneous streams that cover the entire drum cross-section uniformly.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention transitions from axial air introduction (one-dimensional flow along the drum axis) to radial air introduction (two-dimensional flow across the drum cross-section). By positioning air inlets at the periphery and directing air radially inward, the system adds a spatial dimension to heat distribution, enabling simultaneous drying across the entire drum width rather than just along the axial direction.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Manufacturing precision

If a baffle device with radial guide cavities is used to direct hot air to multiple agitation members, then uniform air distribution is achieved, but the device complexity increases

Engineering Contradiction:
Improveuniformity of air distributionVSAvoidstructure complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The agitation members serve dual functions: they act as both laundry-agitation elements that move and tumble the clothes, and as air-distribution channels that receive and redirect hot air radially. This multi-functionality eliminates the need for separate air-distribution components, reducing overall device complexity while achieving uniform air distribution across all agitation zones.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The invention merges the air-distribution system with the agitation member structure itself. The cavities within each agitation member become the air intake channels, and the agitation member walls become the air distribution passages. This integration combines what would traditionally be separate systems (agitation and air distribution) into a single unified component, simplifying the overall device architecture.

Inventive Principle:
Principle #5Merging (Combining)

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 design improves drying efficiency by ensuring all agitation members receive hot air, reducing drying times, containing heat dispersion, and maintaining outflow pressure without significant speed losses, resulting in more uniform and efficient drying.

Implementation Method 1

a fan and air-heating means, wherein the drum is designed to be traversed by hot air, forced by the fan

Methodology Applied
Scientific EffectForced Convection: Forced Convection

Implementation Method 2

hot air, forced by the fan and heated by the heating means before being introduced into the drum

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 3

The hot air traverses the inside of the drum and is saturated with the humidity yielded by the laundry articles contained therein, said articles being thus progressively dried

Methodology Applied
Scientific EffectEvaporation: Evaporation

Implementation Method 4

a baffle device is mounted, configured for directing in a radial direction at least part of the flow of air introduced into the drum, to the inside of the cavity of each agitation member

Methodology Applied
Scientific EffectFluid Flow:

Data Source

PatentEP2604746B1Laundry-drying machine
Publication Date: 2020.03.11 WHIRLPOOL EMEA SPA
  • EP2604746B1 patent drawingFigure 1
  • EP2604746B1 patent drawingFigure 2
  • EP2604746B1 patent drawingFigure 3~4

AI summary

A laundry-drying machine comprises a drum (5) rotatable about a substantially horizontal axis (A) and having an inlet for the air (10a) and an outlet for the air (14, 14a). The drum (5) is designed to be traversed by drying air, forced by means of a fan (13) and heated via heating means (18) before being introduced into the drum (5) through the aforesaid inlet (10a). The fan (13) and the heating means (18) are operatively associated to an air-conveying duct (12) having a delivery section (12b, 12c), which is in fluid communication with the aforesaid inlet (10a), and a suction section (12a), which is in fluid communication with said outlet (14, 14a). Provided inside the drum (5) is at least one laundry-agitation member (20), having a cavity (21) configured for receiving at least part of the hot air introduced into the drum (5), and one or more passages (22) for diffusing the hot air from the internal cavity (21) towards a central area of the drum (5), where the aforesaid inlet for the air comprises at least one passageway (10a) in a position corresponding to the agitation member (20) and in fluid communication with the corresponding cavity (21). Mounted on the outside of the drum (5) is a directing device (25), fixed in rotation with respect to the structure of the drum (5), which is operatively coupled to the delivery section (12b, 12c) of the duct (12) and is configured for conveying at least part of the air coming from the duct (12) to the passageway (10a), and hence the cavity (21) of the corresponding agitation member (20).