Blower Curved Air Guide Diameter for Backflow Reduction
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Solution Overview
Problem
Typical exhaust fans experience volume loss and increased noise due to backflow and inefficient air flow, leading to reduced work efficiency of the blower.
Innovation Solution
A blower design featuring a volute with air inlets and a wind wheel, where air collectors have a curved air guide with a specific diameter relationship and an air-blocking boss, along with a transfer tube configuration that reduces noise and turbulence, enhancing wind resistance and static pressure recovery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the air collector has a tubular structure with decreasing inner diameter, then the air flow guidance is improved, but the minimum inner diameter being equal to the wind wheel inner diameter creates space f that causes air flow back and volume loss
Solution Approach 1:
The patent changes the geometric parameters of the air collector by introducing a curved air guide with a minimum inner diameter D0 that is larger than the wind wheel inner diameter D1. Specifically, D0 is set to be between D1+1/3(D2-D1) and D1+2/3(D2-D1), where D2 is the outer diameter of the wind wheel. This parameter change eliminates the space f between the air collector terminal and wind wheel end faces, preventing air flow back and reducing volume loss while maintaining efficient air flow guidance.
2Device complexity
If the air collector terminal is positioned close to the wind wheel end faces, then the structure is compact, but it creates space f that leads to air flow back and increased noise
Solution Approach 1:
The patent adjusts the dimensional parameters to ensure the minimum inner diameter D0 of the curved air guide is sufficiently large to eliminate the space f between the air collector terminal and wind wheel end faces. This parameter adjustment prevents air flow back and the associated noise generation while maintaining structural compactness through the curved air guide design.
3Ease of manufacture
If the transfer tube is horizontally placed with openings in the same plane, then the installation is simple, but it creates turbulence and whirlpool noise at the air outlet
Solution Approach 1:
The patent introduces asymmetry in the transfer tube configuration by positioning the second opening at a different height than the first opening. The second opening is located at a height H2 while the first opening is at a different height, creating an asymmetric arrangement that eliminates the horizontal alignment. This asymmetric design prevents the formation of whirlpool noise and turbulence at the air outlet while maintaining ease of installation.
4Power
If the wind wheel rotates to generate pressure differential, then air flow is driven from high pressure end to low pressure end, but it creates backflow through space f that reduces work efficiency
Solution Approach 1:
The patent changes the geometric parameters of the air collector to eliminate the space f that causes backflow. By setting the minimum inner diameter D0 of the curved air guide to be between D1+1/3(D2-D1) and D1+2/3(D2-D1), the design ensures that the air collector terminal does not create unwanted backflow paths, thereby maintaining the pressure differential generated by the wind wheel and improving work efficiency.
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 reduces volume loss, improves working efficiency, decreases noise, and enhances exhaust efficiency by minimizing unwanted air flow and whirlpool noise, resulting in improved performance and reduced motor input power.
Implementation Method 1
a curved air guide extending into the volute, with an inner diameter that decreases stepwise
Implementation Method 2
when the wind wheel b rotates, a low pressure end is formed in the air inlets c, while a high pressure end is formed in the volute g
Implementation Method 3
two ends of the inner surface protrude towards the air inlets to form an air-blocking boss
Data Source
AI summary
A blower, including: a volute including air inlets and an air outlet; a wind wheel disposed in the volute; and air collectors. Each air collector includes a curved air guide. The air inlets are disposed at two sides of the wind wheel, respectively. The air collectors correspond to the air inlets. The curved air guide extends into the volute, and the inner diameter of the curved air guide decreases stepwise. The relationship between a minimum inner diameter D0 of the curved air guide and an inner diameter D1, an outer diameter D2 of the wind wheel fulfills the following formula: D1+⅓(D2−D1)≤D0≤D1+⅔(D2−D1). An exhaust fan that includes the blower is also provided.