Blower Ventilation Passage Porous Insert for Noise Without Flow Loss
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Solution Overview
Problem
Conventional blowers generate noise due to rotor blade rotation, and existing sound absorbing materials cause a loss of gas flow velocity or momentum.
Innovation Solution
A blower design incorporating a noise reducing member made of porous synthetic resin with air bubbles in the ventilation passage to reduce noise and maintain gas flow velocity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If conventional sound absorbing materials (felt, nonwoven fabric) are used in the ventilation passage, then noise is reduced, but gas flow velocity and momentum are lost due to permeation into the material
Solution Approach 1:
The patent applies porous synthetic resin material with controlled pore structure to create a noise reducing member that allows gas to pass through without significant permeation loss. The porous structure absorbs noise through sound wave interaction while maintaining gas flow velocity and momentum by preventing deep penetration into the material matrix.
Solution Approach 2:
The patent uses composite material structure combining synthetic resin base material with porous network formation. This composite approach creates a material that simultaneously provides noise absorption capabilities and maintains gas flow performance by optimizing the balance between solid matrix and void spaces.
2Object-affected harmful factors
If sound absorbing material is placed in the ventilation passage, then noise from rotor blade rotation is reduced, but the material causes flow velocity loss
Solution Approach 1:
The porous synthetic resin member provides noise reduction through sound wave interaction with the porous structure while the controlled porosity prevents excessive gas permeation that would cause velocity loss. The material allows gas to pass through the ventilation passage while maintaining flow velocity.
Solution Approach 2:
The patent changes the physical parameters of the sound absorbing material by using synthetic resin with specific porous structure characteristics. This parameter optimization allows the material to reduce noise while minimizing the negative impact on gas flow velocity and momentum.
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 design effectively reduces noise generation while preventing a decrease in gas flow velocity and momentum by using a porous member with closed or open-cell structures to manage gas flow.
Implementation Method 1
a solid propagation wave propagates to the fiber material or an air propagation wave propagates in the void according to an incident sound wave. In addition, it is considered that sound energy is converted into thermal energy in the material by interaction of a solid propagation wave or an air propagation wave.
Implementation Method 2
a loss of a flow velocity or momentum of the gas flowing through the surface of the material occurs due to permeation of the gas into the material
Data Source
AI summary
A blower includes a rotor blade body rotatable about a central axis extending in an axial direction, a motor that rotates the rotor blade body, a housing including a ventilation passage and surrounding the rotor blade body and the motor, and a noise reducing member located in the ventilation passage. The noise reducing member is an impermeable porous member which includes a plurality of air bubbles opened to the ventilation passage on the surface side of the noise reducing member and in which a flow of gas in the intersecting direction of the surface of the noise reducing member and the plurality of air bubbles does not permeate.