Centrifugal Fan Tongue Section Curvature
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Solution Overview
Problem
Existing centrifugal fans in extractor hoods face inefficiencies in energy consumption and noise levels, with conventional designs failing to achieve optimal A+ energy efficiency and experiencing flow irregularities that increase energy consumption.
Innovation Solution
The centrifugal fan design features two symmetrical housing parts with radial impellers, an optimized tongue section comprising specific curvatures and surfaces to maintain laminar flow, and a unique curvature arrangement that minimizes turbulence and enhances energy efficiency without altering the overall design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If conventional centrifugal fan designs are used, then the structure is simple and easy to manufacture, but energy efficiency is insufficient and noise levels are high
Solution Approach 1:
The patent applies local quality by optimizing specific regions of the fan housing, particularly the tongue section and curvatures, while maintaining conventional impeller designs. The housing includes optimized curvatures (first curvature in the throat section, second curvature in the outlet section) and a specifically shaped tongue section that create laminar flow paths. This localized optimization improves energy efficiency without requiring complete redesign of the entire fan system.
Solution Approach 2:
The patent employs curvature principles by incorporating specific rounded geometries in the housing design. The first curvature in the throat section and second curvature in the outlet section, along with the tongue section geometry, eliminate sharp edges and corners that would cause turbulence. These curved surfaces guide airflow smoothly, reducing eddies and improving energy efficiency while maintaining manufacturing feasibility.
2Productivity
If conventional fan housing designs are used, then manufacturing is simple, but turbulence occurs increasing energy consumption
Solution Approach 1:
The housing design implements local quality optimization by focusing geometric refinements on critical flow paths. The tongue section and curvature regions are specifically shaped to maintain laminar flow, while other housing portions can be manufactured using conventional methods. This selective optimization achieves improved energy efficiency without proportionally increasing manufacturing complexity.
Solution Approach 2:
The patent uses curvature geometry to eliminate turbulence-generating sharp transitions in the housing. The first curvature in the throat section and second curvature in the outlet section provide smooth airflow paths. These curved surfaces can be manufactured using standard molding or machining processes, balancing flow optimization with manufacturing ease.
3Use of energy by moving object
If standard impeller configurations are used, then the design is conventional and easy to manufacture, but flow irregularities occur reducing energy efficiency
Solution Approach 1:
The patent maintains conventional impeller designs in the core rotating components while optimizing the stationary housing geometry. The impellers use standard blade configurations that are easy to manufacture, while the housing's tongue section and curvatures are specifically designed to complement the impeller flow patterns. This approach improves energy efficiency without complicating the impeller design itself.
4Object-affected harmful factors
If housing designs with sharp edges are used, then manufacturing is simpler, but turbulence increases noise levels
Solution Approach 1:
The patent eliminates sharp edges and corners in the housing by implementing continuous curved surfaces. The first curvature in the throat section and second curvature in the outlet section, along with the tongue section geometry, ensure smooth airflow transitions. These curved surfaces can be manufactured using conventional molding or machining processes, reducing noise from turbulence without significantly increasing manufacturing complexity.
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 optimized design achieves A+ energy efficiency and reduced noise by maintaining laminar flow and minimizing turbulence, as verified by simulation and experimental analysis, with improved flow rate and pressure performance.
Implementation Method 1
the centrifugal fan uses the centrifugal power supplied from the rotation of impellers to increase the kinetic energy of air/gases. When the impellers rotate, the gas particles near the impellers are thrown off from the impellers
Implementation Method 2
an optimized tongue section comprising specific curvatures and surfaces to maintain laminar flow, and a unique curvature arrangement that minimizes turbulence
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
The present invention relates to a centrifugal fan, in particular a snail type centrifugal fan, particularly designed for extractor hoods. Said snail type centrifugal fan comprises two housing parts which can be coupled to each other in a connection plane K, a motor body mounted into one of the housing parts, at least one radial fan impeller mounted around the motor body coaxially with the rotation axis of the motor body, and a tongue section in the region of an outlet of the housing part defining a throat section narrowing the air passageway cross-section in horizontal axis. Said tongue section comprises a convexly formed first curvature neighboring the impeller forming an extreme point in horizontal direction within the inner volume of the centrifugal fan, and a further curvature convexly formed through the outlet at an upper position of the first curvature with respect to the vertical axis of the centrifugal fan, whereby, said first curvature extends to the second curvature through a surface which is tangential to the first and second curvatures.