Centrifugal Blower Rectifying Plate for Static Pressure and Casing Size
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional single suction type centrifugal fans face challenges in downsizing while maintaining static pressure performance, particularly when forming the casing from steel plates to ensure strength, as the complex shape of the motor fixing side plate complicates processing and is not easily applicable.
Innovation Solution
The design includes a rectifying plate with an inclined surface surrounding the rotation shaft, reducing the cross-sectional area orthogonal to the shaft towards the impeller, allowing the area of the flow passage cross section to be enlarged in the rotation shaft direction of the motor, thereby simplifying the motor fixing side plate shape and maintaining static pressure performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stress or pressure
If the area of the flow passage cross section is enlarged in the radial direction of the impeller, then the static pressure performance is improved, but the casing size increases
Solution Approach 1:
The patent changes the enlargement direction of the flow passage cross-sectional area from the radial direction to the axial direction of the motor. This dimensional shift allows the flow passage area to be increased without increasing the radial dimensions of the casing, thereby improving static pressure performance while maintaining compact casing size.
2Volume of stationary object
If the area of the flow passage cross section is enlarged in the rotation shaft direction of the motor, then the casing size is reduced, but the shape of the motor fixing side plate becomes complicated
Solution Approach 1:
The patent introduces a rectifying plate as a separate component that divides the flow passage into distinct regions. This segmentation allows the motor fixing side plate to maintain a simple, planar shape while the rectifying plate handles the flow guidance and area enlargement function, thus reducing overall structural complexity.
Solution Approach 2:
The rectifying plate acts as an intermediary element between the impeller and the motor fixing side plate. It mediates the flow conversion process and enables the motor fixing side plate to remain simple in shape while still achieving the required flow passage area enlargement in the rotation shaft direction.
3Ease of manufacture
If the rectifying plate cross-sectional area is reduced toward the impeller, then the flow passage area enlargement in rotation shaft direction is achieved, but the first rectifying plate diameter must be smaller than the impeller diameter
Solution Approach 1:
The patent employs parameter changes by defining the rectifying plate with a specific geometric configuration where the cross-sectional area decreases toward the impeller. The first rectifying plate diameter is set smaller than the impeller diameter, creating a controlled geometric progression that simplifies manufacturing while achieving the desired flow passage area enlargement.
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 approach enables the downsizing of the centrifugal fan casing without compromising static pressure performance, reduces turbulence and pressure losses, and simplifies the processing of the motor fixing side plate, ensuring effective air flow conversion from dynamic to static pressure.
Implementation Method 1
A pressure of an air blown out from impeller 103 is boosted in spiral shape casing 102, the dynamic pressure is converted into a static pressure
Data Source
AI summary
A single suction type centrifugal fan includes a casing, an impeller, and a main plate. The casing includes a side plate and a motor fixing side plate, and the side plate and the motor fixing side plate are arranged in parallel. A rectifying plate is provided between the motor fixing side plate and the main plate, and the rectifying plate is formed from an inclined surface in which an area of a cross section orthogonal to a rotation shaft is reduced toward the impeller around the rotation shaft of a motor. A first rectifying plate diameter at another side of the rectifying plate closer to the impeller is smaller than an impeller diameter of the impeller.