Extractor Assembly Air Duct Noise Reduction
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Solution Overview
Problem
Existing air duct extractor assemblies generate annoying noise due to irregular air flow and point contacts with the external case, particularly exacerbated by metal cases.
Innovation Solution
The extractor assembly features a support with internal and external walls that define a passage for air flow, fins to direct air linearly, and a panel to prevent air contact with the case, along with a blocking element to guide air efficiently, reducing noise by minimizing air flow contact with the case.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If air is moved by the impeller blades, then air flow is generated, but noise is generated due to discontinuities and point contacts with the external case
Solution Approach 1:
A panel is introduced as an intermediary element between the impeller blades and the external case. This panel prevents direct contact between the moving air flow and the case walls, eliminating the point contacts that generate noise while still allowing the impeller to generate air flow effectively
Solution Approach 2:
The panel acts as a thin barrier that guides the air flow smoothly along the impeller blades without allowing direct interaction with the rigid external case. This creates a controlled flow path that reduces turbulence and noise generation
2Strength
If the external case is made of metal, then structural strength is improved, but noise is aggravated due to air flow contact
Solution Approach 1:
The panel serves as a mediator that allows the metal case to maintain its structural strength while preventing the air flow from directly contacting the metal surfaces that would amplify noise. The panel absorbs and redirects the air flow away from the case walls
3Ease of operation
If the support walls define a passage for air flow, then air movement is directed, but turbulence occurs causing noise
Solution Approach 1:
The passage defined by the support walls is designed with curved surfaces rather than sharp angles. This curvature allows the air flow to transition smoothly through the passage, reducing turbulence and the associated noise while maintaining effective flow direction control
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
This configuration significantly reduces noise generation by ensuring a smooth, continuous air flow and minimizing turbulence, achieving a negligible noise output.
Implementation Method 1
an actuating element for imparting rotational momentum to the impeller such that it generates an air flow by means of the blades
Implementation Method 2
the fins are curved in order to eliminate a tangential component of the air flow generated by the blades such that the air flow can be directed according to a rectilinear path
Implementation Method 3
the external wall makes radial and internal contact against the first portion and the second portion, as well as against a joining area of the first portion and the second portion with each other, such that an air outlet along the external wall remains blocked
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
The invention relates to an extractor assembly to be installed inside an air duct, which comprises an impeller (1); an actuating element (2) for imparting rotational momentum to the impeller (1); a support (3); and a case (4) for surrounding the impeller (1), actuating element (2) and support (3). The support (3) comprises an internal wall (3.3) that determines, with the first face (3.1), a housing (6) for accommodating the actuating element (2); and an external wall (3.4) that is disposed radially and externally with respect to the internal wall (3.3), such that the walls (3.3, 3.4) define a passage (7) for the movement of air. When the extractor assembly is mounted in a use position, the external wall (3.3) radially covers part of the inside of the case (4), such that the case (4) does not come into contact with the air driven by the impeller (1) along the external wall (3.4).