Dishwasher Sump Cap Design to Prevent Backward Flow Contamination
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional dishwashers experience a backward flow phenomenon where wash water from the filter unit flows back into the washing tub, potentially reintroducing filtered contaminants, which contaminates the wash water and affects cleaning efficiency.
Innovation Solution
A dishwasher design featuring a cap within the filter unit that moves upward and downward with water flow to open and close a flow channel, preventing wash water from flowing backward from the filter unit to the washing tub, utilizing water pressure to operate without additional power sources.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional sump structure with filter unit is used, then the structure is simple and easy to manufacture, but wash water flows backward from the filter unit to the washing tub causing contamination
Solution Approach 1:
The cap is designed to move dynamically between open and closed positions based on water flow direction. During washing, the cap opens to allow water flow; during drainage, the cap closes to prevent backward flow. This dynamic positioning resolves the contradiction by providing reliable backward flow prevention without requiring a permanently complex sealed structure.
Solution Approach 2:
The cap operates automatically using the kinetic energy of water flow itself. The flowing water directly moves the cap to the appropriate position without requiring external motors, sensors, or control systems. This self-service mechanism maintains structural simplicity while achieving reliable backward flow prevention.
2Object-affected harmful factors
If a cap is added to prevent backward flow, then contamination is prevented, but the device complexity increases
Solution Approach 1:
The backward flow prevention function is extracted as a separate, movable cap component rather than being integrated into the filter unit structure itself. This allows the filter unit to remain simple while the cap provides the necessary contamination prevention through its movement between open and closed states.
Solution Approach 2:
The cap acts as an intermediary element between the washing tub and sump. It mediates water flow by opening during washing to allow flow and closing during drainage to prevent backward flow, thereby preventing contaminant reintroduction without requiring modifications to the filter unit structure.
3Reliability
If additional power sources are added to control flow direction, then backward flow can be prevented, but energy consumption increases
Solution Approach 1:
The cap uses the kinetic energy of the water flow itself to move between open and closed positions. During washing, incoming water opens the cap; during drainage, the water column closes the cap. This self-powered operation achieves reliable backward flow control without any external power sources, motors, or control systems.
Solution Approach 2:
The system uses hydraulic principles where water pressure and flow directly actuate the cap mechanism. The weight and pressure of the water column in the sump automatically close the cap during drainage, while incoming water pressure opens it during washing, eliminating the need for electrical or mechanical power sources.
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 prevents wash water and contaminants from flowing back into the washing tub, maintaining cleanliness and efficiency while maintaining the conventional sump structure, and achieving a backward flow blocking function solely through water power.
Implementation Method 1
a cap configured to move upward and downward by a stream of water
Data Source
AI summary
A dishwasher includes a washing tub defining a space that is configured to receive dishes to be washed by wash water, a sump configured to receive and collect wash water flowing from the washing tub, a filter unit disposed at the sump and configured to filter the wash water flowing from the washing tub to the sump, and a cap configured to prevent the wash water received in the sump from flowing from the filter unit to the washing tub.