Dishwasher Exhaust Vent Valve Layout for Wash-Cycle Noise Blocking
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Solution Overview
Problem
Conventional dishwasher exhaust vents allow noise to escape during the wash cycle due to the presence of an upstream space that resonates noise frequencies, leading to consumer complaints about noise levels.
Innovation Solution
A modular exhaust vent system with a valve that is normally open but can be actuated to close during the wash cycle, eliminating the upstream space and preventing noise transmission by positioning the valve directly adjacent to the interior wall of the door, thereby sealing the inlet and preventing noise from entering the exhaust flow path.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the exhaust vent is positioned in a duct leading from the interior surface of the door to the exterior surface, then air can be vented from the wash chamber during the drying cycle, but noise from the wash chamber can escape through the exhaust vent and resonate in the upstream space of the duct
Solution Approach 1:
The exhaust vent is divided into separate functional components: a valve body with a valve element that can be independently actuated, a duct structure, and a control system. This segmentation allows the valve to be positioned directly at the inlet opening to seal the exhaust path during wash cycles, preventing noise transmission while maintaining exhaust functionality during drying cycles
Solution Approach 2:
The valve is positioned upstream at the inlet opening of the exhaust vent, closing before noise can enter the duct during wash cycles. This preliminary sealing action prevents noise from entering the exhaust flow path in the first place, eliminating the resonance problem in the upstream space
2Reliability
If the valve is positioned downstream in the duct, then the exhaust flow path can be sealed, but an upstream space is formed that allows noise resonance
Solution Approach 1:
Instead of positioning the valve downstream as in conventional exhaust vents, the invention inverts the valve position to be upstream at the inlet opening. This reversal allows the valve to seal the exhaust path at the source, preventing noise from entering the duct while eliminating the formation of a resonant upstream space
3Object-generated harmful factors
If the valve closes during the wash cycle, then noise transmission is prevented, but the exhaust vent structure becomes more complex
Solution Approach 1:
The valve element is designed to be automatically actuated by the control system based on the wash cycle status. The valve body and valve element form a self-contained sealing mechanism that requires no additional actuating components, allowing the system to self-regulate noise prevention based on operational conditions
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
Significantly reduces noise transmission to the exterior during the wash cycle by eliminating the upstream space and resonation issues, as demonstrated by comparative sound amplitude graphs showing reduced noise levels at specific frequencies.
Implementation Method 1
Heated, moisture-laden air travels upward within the wash chamber due to convection and exits the wash chamber through an exhaust vent
Implementation Method 2
Noise at specific frequencies can enter the upstream space in the duct and resonate in the space and to the exterior of the dishwasher
Data Source
AI summary
A modular exhaust vent for use in venting a wash chamber of a dishwasher, such as during a dry cycle, comprises a housing that forms an exhaust flow path from the wash chamber to the exterior of the dishwasher and a valve operable for pivotal movement about a pivot axis between an opened and closed position for selectively closing the exhaust flow path. An actuator for moving the valve is connected to the valve by a link such that activation of the actuator effects movement of the link to pivot the valve to either the opened or closed position. Further, the valve selectively closes the exhaust flow path at an inlet to impede introduction of sound into the exhaust flow path.