Jet Pump Air-Mixing Vent for Washing Appliance Humidity Control

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Solution Overview

Problem

Dishwashers and washing machines face challenges in reducing humidity, leading to condensation issues and mold growth due to sealed chambers, and existing solutions like downdraft venting systems can create condensation problems when high humidity air is exhausted.

Innovation Solution

A humidity reducing duct system with a mixing chamber using a jet pump and a single fan to mix moist air from the washing chamber with dry outside air, featuring a condensation reservoir to collect and dry excess moisture, and polymer tubing with inward ridges for noise reduction and flexibility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a sealed chamber is used to prevent water escape during washing, then water containment is improved, but humidity removal becomes difficult leading to condensation and mold growth

Engineering Contradiction:
Improvewater containmentVSAvoidhumidity accumulation
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The air handling system divides the sealed chamber into functional zones with separate air intake and exhaust pathways. The exhaust duct system segments the humidity removal function from the water containment function, allowing effective moisture extraction while maintaining the sealed chamber integrity during washing.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The air handling system acts as an intermediary between the sealed washing chamber and the external environment. It provides controlled air exchange through dedicated ducts and vents, enabling humidity removal without compromising the water-tight seal of the chamber during operation.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If downdraft venting is used to efficiently remove moisture, then humidity removal is improved, but condensation occurs on cool surfaces like the metal door

Engineering Contradiction:
Improvehumidity removal efficiencyVSAvoidcondensation on surfaces
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The mixing chamber serves as an intermediary space where humid air from the chamber mixes with cooler ambient air before discharge. This gradual temperature equalization prevents the temperature differential that causes condensation on the metal door surface, while still achieving effective humidity removal through the downdraft venting system.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system changes the temperature parameter of the exhaust air by allowing it to cool and mix with ambient air in the mixing chamber before discharge. This parameter modification reduces the thermal energy in the exhaust stream, preventing condensation on cool surfaces while maintaining effective moisture extraction capability.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If multiple fans are used to handle high humidity air, then ventilation effectiveness is improved, but device complexity and energy consumption increase

Engineering Contradiction:
Improveventilation effectivenessVSAvoidnumber of fans
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The system merges the functions of multiple fans into a single fan unit that handles both air intake and exhaust operations. The air handler is configured to use one fan for drawing in ambient air through the intake duct and another fan for exhausting humid air, consolidating what could be multiple separate ventilation devices into an integrated single-unit system.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The air handling system provides multi-functionality with a single integrated unit that performs both air intake and exhaust functions. The duct system and fan assembly are designed to handle multiple air flow paths and operational modes, replacing what would traditionally require multiple separate ventilation devices.

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

4Productivity

If high velocity air jets are used for mixing, then mixing efficiency is improved, but noise levels increase

Engineering Contradiction:
Improveair mixing efficiencyVSAvoidnoise
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The system changes the velocity parameter of the air jets by using variable speed motors that can operate at lower speeds during normal mixing conditions. This parameter adjustment maintains adequate mixing efficiency while significantly reducing the noise generated by high-velocity air movement through the ducts and vents.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The air handling system employs dynamic control with variable speed motors that can adjust fan speed based on operational requirements. During normal operation, lower speeds provide sufficient mixing with reduced noise, while higher speeds are available when enhanced ventilation is needed, optimizing both performance and noise levels.

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

The system effectively reduces moisture extraction from the washing chamber, prevents condensation outside, and uses energy-efficient, low-noise fans to promote counter-convection airflow, reducing humidity and noise while maintaining a clean and dry environment.

Implementation Method 1

The mixing chamber employs a jet pump allowing a single fan to promote the mixing of moist air from the washing chamber with dry outside air. In one embodiment, an electric blower provides high velocity jet into the mixing chamber which draws moist air from the washing chamber as displaced by dry air diverted from the same electric blower.

Methodology Applied
Scientific EffectJet pump action: Jet

Implementation Method 2

Cool air, pulled by convection or by a fan into the chamber through a lower vent, flows upward, augmented by natural convection to dry the heated dishes.

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP2802251B1Washing appliance with improved air handling system
Publication Date: 2019.09.11 ILLINOIS TOOL WORKS INC
  • EP2802251B1 patent drawingFigure 1
  • EP2802251B1 patent drawingFigure 2
  • EP2802251B1 patent drawingFigure 3~4

AI summary

A humidity reducing vent for a washing appliance such as a dishwasher or washing machine employs a jet pumping action allowing a single electric blower to move and mix humid air exhausted from the washing appliance washing chamber and external dry air streams together prior to discharge so as to reduce condensation outside of the washing appliance.