Dishwasher Water Inlet Venting Against Negative Pressure Backflow
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Solution Overview
Problem
Dishwashers face the challenge of preventing liquid from escaping into the domestic water supply system due to negative pressure conditions, which existing technologies fail to address effectively.
Innovation Solution
A dual-function water inlet device with a steam outlet opening that allows steam to be ducted out, preventing its escape into the water feed line and domestic water supply system, and includes a ventilation opening to dissipate negative pressure and prevent liquid reversal, ensuring no liquid escapes during negative pressure conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a water inlet device is used to fill the washing chamber with fresh water, then the washing container can be filled efficiently, but liquid may escape into the domestic water supply system due to negative pressure conditions
Solution Approach 1:
The water inlet device is divided into separate functional chambers: a water inlet chamber for receiving fresh water and a steam outlet chamber for venting steam and equalizing pressure. This segmentation allows independent optimization of water filling and pressure management functions, preventing liquid escape while maintaining filling efficiency.
Solution Approach 2:
The steam outlet chamber acts as an intermediary between the washing chamber and the domestic water supply system. It provides a controlled pathway for pressure equalization and steam venting, preventing direct communication that could allow liquid escape into the water supply system under negative pressure conditions.
2Stability of the object's composition
If an expansion system with an expansion line is used to balance pressure in the washing chamber, then volume expansion during heating can be managed, but liquid may still escape due to negative pressure suction effects
Solution Approach 1:
The steam outlet device serves multiple functions: it equalizes pressure during heating cycles, vents steam to prevent pressure buildup, and prevents liquid escape into the water supply system during negative pressure conditions. This multi-functionality eliminates the need for separate expansion lines while maintaining pressure stability and reliability.
3Productivity
If the water inlet device housing is provided with an inlet opening connected to the water feed line, then fresh water can be supplied efficiently, but the device complexity increases to prevent liquid reversal
Solution Approach 1:
The water inlet device housing combines the water inlet function and steam outlet function into a single integrated component. The housing contains both the water inlet chamber and steam outlet chamber, merging what could be separate devices into one unit, thereby reducing overall system complexity while maintaining efficient water supply and pressure management.
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 solution reliably prevents liquid from escaping into the domestic water supply system by effectively managing steam and pressure equalization, ensuring compliance with test requirements and maintaining the integrity of the water supply network.
Implementation Method 1
in the case of the steam outlet chamber a flow path is defined by steam rising against the force of gravity from the washing chamber through the steam outlet chamber into the steam outlet opening
Implementation Method 2
defines a flow path of a liquid flowing due to the force of gravity from the water feed line through the water inlet chamber into the washing chamber
Implementation Method 3
The expansion line can be connected at the steam outlet opening of the water inlet device to provide a condensation route for the exiting water vapor, along which route the water vapor condenses and can be collected as condensate
Data Source
AI summary
A dishwasher includes a washing container with a washing chamber, a water feed line for filling the washing chamber with liquid, and a water inlet device connected on an inlet side to the water feed line and ends in the washing chamber on an outlet side. The water inlet device includes a steam outlet opening that ducts water vapor out of the washing container, and a steam duct that guides steam to the steam outlet opening.