Dishwasher Vent Mixing Chamber Using Jet Pump Air Handling
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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 either create condensation problems or require complex designs.
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
Engineering 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
Solution Approach 1:
The air handling system is divided into separate functional components: a first duct for introducing dry air, a second duct for exhausting moist air, and a mixing chamber that separates the introduction and exhaust paths. This segmentation allows independent optimization of each function while maintaining overall system effectiveness in removing humidity from the sealed chamber.
Solution Approach 2:
The mixing chamber acts as an intermediary component that receives dry air from the first duct, mixes it with air from the sealed chamber, and directs the mixed air toward the exhaust duct. This intermediary structure facilitates controlled air mixing and moisture removal without compromising the sealed nature of the washing chamber.
2Productivity
If efficient moisture removal is implemented, then humidity control is improved, but condensation occurs on cool surfaces such as the metal door
Solution Approach 1:
Dry air is introduced into the mixing chamber before the moist air from the washing chamber is fully exhausted. This preliminary introduction of dry air preconditions the air that will contact cool surfaces, reducing the temperature differential and preventing condensation on the metal door and other cool surfaces.
Solution Approach 2:
The system converts the harmful effect of rapid moisture removal (which causes condensation) into a beneficial outcome by mixing the exhaust air with dry air. This mixing raises the dew point of the exhaust air, allowing efficient moisture removal without the harmful condensation side effect.
3Productivity
If multiple fans are used to handle high humidity air, then ventilation effectiveness is improved, but system complexity and cost increase
Solution Approach 1:
A single fan is designed to perform multiple functions: it draws dry air through the first duct, exhausts moist air through the second duct, and maintains pressure balance within the mixing chamber. This multi-functional design achieves effective ventilation without the complexity and cost of multiple fans.
Solution Approach 2:
The air introduction function, air exhaust function, and pressure regulation function are merged into a single integrated air handling system with one fan. This consolidation simplifies the overall system while maintaining the productivity needed to handle high humidity air effectively.
4Object-generated harmful factors
If a mixing chamber is added to handle humid air, then condensation is reduced, but device complexity increases
Solution Approach 1:
The mixing chamber is designed as a simple segmented structure with distinct inlet regions for dry air and chamber air, and an outlet region for mixed air. This segmentation provides the necessary condensation reduction function while maintaining a simple, easy-to-manufacture structure that does not significantly increase device complexity.
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
Effectively reduces moisture extraction, prevents condensation, and provides a low-cost, energy-efficient venting system that minimizes noise and moisture accumulation, while maintaining effective airflow and reducing mold risks.
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.
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.
Data Source
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.