Dishwasher Airflow Guide Layout to Block Wash Water Backflow

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Solution Overview

Problem

Dishwashers face issues with wash water flowing into the dry air supply part, causing damage to electronic components and potential electric leakage, due to the design of the discharge opening and airflow guide in existing systems.

Innovation Solution

The dishwasher design includes a discharge opening positioned lower than the spray arm, with a blocking rib and channel guide to minimize wash water flow into the airflow guide, and an upper end of the connection duct positioned higher than the discharge opening to prevent reverse flow, along with a blocking wall to redirect wash water droplets, ensuring they do not enter the airflow guide or connection duct.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the discharge opening is open entirely toward the wash space, then dry air can be supplied effectively into the tub, but wash water flows into the dry air spray part and hot air supply device causing damage and electric leakage

Engineering Contradiction:
Improvedrying efficiencyVSAvoidelectronic component safety
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The discharge opening is positioned at a specific location (lower than the lower spray arm in the up-down direction) rather than being uniformly distributed, creating localized quality differences. This positioning combined with blocking ribs provides directional control - allowing dry air to reach the wash space while preventing wash water from entering the hot air supply device.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

Blocking ribs are introduced as intermediary structures between the discharge opening and the hot air supply device. These ribs act as mediators that intercept and redirect wash water, preventing it from reaching the electronic components while allowing dry air to pass through the discharge opening to the wash space.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If the discharge opening is positioned lower to prevent wash water entry, then electronic components are protected, but wash water may remain in the airflow guide

Engineering Contradiction:
Improveelectronic component safetyVSAvoidwash water accumulation
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The airflow guide incorporates curved surface structures that guide wash water flow. The curved surfaces redirect water droplets away from the discharge opening and toward drainage areas, preventing accumulation in the airflow guide while maintaining the lower position of the discharge opening for protection.

Inventive Principle:
Principle #14Spheroidality (Curvature)

3Reliability

If blocking structures are added to prevent wash water flow, then electronic components are protected, but device complexity increases

Engineering Contradiction:
Improveelectronic component safetyVSAvoidairflow guide structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The blocking function is segmented into multiple simple elements (blocking ribs at the discharge opening, blocking walls within the airflow guide) rather than using a single complex barrier. Each segment performs a specific function - the ribs block direct entry at the opening while walls within the guide prevent lateral flow, collectively protecting electronics with modular simplicity.

Inventive Principle:
Principle #1Segmentation

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 effectively prevents wash water from entering the dry air supply part, reducing the risk of damage and electric leakage, while improving drying efficiency and simplifying the assembly and fixation of the airflow guide.

Implementation Method 1

a channel guide minimizing wash water, having passed through the discharge opening and remaining in the airflow guide, and discharging wash water automatically by using gravity is disposed in the airflow guide

Methodology Applied
Scientific EffectGravity: Gravitation

Implementation Method 2

the up-down position of the upper end of the connection duct part to which the airflow guide is coupled and which guide dry airflow into the airflow guide is disposed higher than the up-down position of the upper end of a duct coupling part of the airflow guide, such that wash water is prevented from moving through a gap between the connection duct part and the duct coupling part of the airflow guide because of a capillary phenomenon

Methodology Applied
Scientific EffectCapillary phenomenon: Capillary Action

Data Source

PatentEP4183306A1dishwasher
Publication Date: 2023.05.24 LG ELECTRONICS INC
  • EP4183306A1 patent drawingFigure 1
  • EP4183306A1 patent drawingFigure 2
  • EP4183306A1 patent drawingFigure 3

AI summary

The present disclosure relates to a dishwasher that can minimize the flow of wash water, being scattered in a washing stage or a rinsing stage, into an airflow guide through a discharge opening and the remaining wash water in the airflow guide, and prevent the reverse inflow of wash water having passed through the airflow guide to a dry air supply part. Here, the dishwasher comprises a tub (20) that defines a wash space configured to accommodate a wash target, the tub (20) having a front surface that is open; a dry air supply part (80) disposed below the tub (20) and configured to generate dry air for drying the wash target and to supply the dry air into the wash space; a rack (51) disposed in the wash space and configured to be inserted into and withdrawn from the wash space, the rack (51) being configured to support the wash target; an airflow guide (83) disposed between the rack (51) and a lower surface of the tub (20) and configured to guide the dry air; and a spray arm (61) disposed between the lower surface of the tub (20) and the rack (51), the spray arm (61) comprising at least one nozzle configured to spray wash water for washing the wash target, wherein the airflow guide (83) defines an inner flow space configured to guide the dry air, and a discharge opening (833) disposed at a position below the nozzle and being configured to discharge the dry air to the wash space.