Noise reduction device
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Solution Overview
Problem
Existing noise reduction devices for appliances that displace fluids, such as vacuum cleaners, often require significant space and are not efficiently integrated due to their size, and they may introduce turbulence and resistance when reducing noise levels.
Innovation Solution
A noise reduction device with a main tube having a narrowed pass-through area and acoustically transparent, impermeable side-branches that are tuned to specific frequencies, allowing for reduced size and effective noise cancellation without increasing fluid resistance, using a membrane or mesh to prevent turbulence and dirt entry.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If quarter wave resonators are used for noise reduction, then noise attenuation is improved, but device size increases significantly
Solution Approach 1:
The side-branch resonators are nested within or alongside the main tube structure, allowing the noise reduction functionality to be integrated into the existing fluid displacement path without requiring separate dedicated space. The resonators are positioned to utilize the same spatial envelope as the main tube, effectively nesting the noise reduction function within the appliance's existing structure.
Solution Approach 2:
The patent transitions from traditional quarter wave resonators that extend perpendicular to the flow path into side-branches coupled to a narrowed section of the main tube. This dimensional reconfiguration allows the resonators to be integrated along the length of the tube rather than extending outward, reducing the overall device footprint while maintaining noise attenuation functionality.
2Volume of stationary object
If the pass-through area of the main tube is reduced to make the device smaller, then device size is reduced, but fluid resistance increases
Solution Approach 1:
The main tube features a localized narrowed section rather than a uniformly reduced diameter throughout. This localized narrowing is positioned specifically where the side-branch resonators are coupled, concentrating the space-saving effect in a specific region while maintaining adequate cross-sectional area in other sections to minimize overall fluid resistance. The narrowing ratio is carefully controlled (at least 25% smaller than the first pass-through area) to balance size reduction with flow performance.
3Object-generated harmful factors
If side-branches are added for noise reduction, then noise cancellation is improved, but turbulence and dirt entry risk increase
Solution Approach 1:
An acoustically transparent cover is introduced as an intermediary element that seals the side-branch resonators from the fluid flow path. This cover allows acoustic waves to pass through (maintaining noise cancellation functionality) while physically blocking dirt and debris from entering the resonators. The cover is positioned at the opening of each side-branch where it couples to the main tube, serving as a selective barrier between the acoustic field and the fluid flow.
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 achieves significant noise reduction with a compact design, reducing the main tube's pass-through area by up to 75% while maintaining effective noise cancellation across a frequency range, minimizing turbulence and resistance, and preventing dirt entry into the side-branches.
Implementation Method 1
The resonators are tuned to a resonant frequency... the side-branch is tuned to a specific frequency to cancel noise at that frequency
Implementation Method 2
the side-branch is sealed-off by a cover that is acoustically transparent, and which may be impermeable for the fluid
Data Source
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AI summary
In a noise reduction device, comprising a main tube (MT) having a first pass-through area (A1) where a fluid enters the main tube, and a side-branch (SB) connected to the main tube (MT), the main tube (MT) comprises a narrowed section (NS) having a second pass-through area (A2) that is at least 25% (preferably, at least 50%, and more preferably, at least 60%, such as 75%) smaller than the first pass-through area (A1), and the side-branch (SB) is connected to the narrowed section (NS) of the main tube (MT). Where the side-branch (SB) is connected to the main tube (MT), the side-branch (SB) is preferably sealed-off by a cover that is acoustically transparent, which may be impermeable for the fluid. Such a noise reduction device is advantageously used in a fluid displacing appliance (e.g. a vacuum cleaner), comprising a motor for displacing a fluid (e.g. gas or liquid).