Side Channel Blower Noise Reduction via Interruption Recesses
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Solution Overview
Problem
Side channel blowers experience high noise emissions due to pressure surges when pumping against a closed control valve, which existing designs fail to adequately mitigate without compromising pressure and delivery capacity.
Innovation Solution
The design incorporates additional recesses in the interruption area with specific dimensions and shapes, including a second recess with a smaller depth adjacent to the first recess, to reduce noise emissions by minimizing pressure peaks and turbulence, while maintaining maximum pressure and flow rate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the inlet and outlet are positioned far apart in the circumferential direction to maximize delivery channel usage, then delivery efficiency is improved, but pressure surges and noise emissions increase due to sudden air acceleration against interruption area walls
Solution Approach 1:
The interruption area is divided into multiple segments: the first interruption area with the first recess, the second interruption area with the second recess, and the third interruption area. This segmentation allows progressive deceleration of the air stream through multiple stages rather than a single sudden impact, reducing pressure surges and noise while maintaining effective delivery channel configuration
Solution Approach 2:
The first recess is positioned before the air stream reaches the second interruption area, creating a preliminary deceleration zone. This preliminary action gradually reduces air velocity before the main interruption, preventing sudden pressure surges and reducing noise emissions from the second interruption area
2Object-generated harmful factors
If recesses are added to the interruption area to reduce noise from pressure surges, then noise emissions are reduced, but pressure and delivery capacity may be compromised
Solution Approach 1:
The recesses are designed with specific local geometries and positions: the first recess has a depth of 0.05-0.15 times the delivery channel width and is positioned at a specific distance from the outlet. These localized modifications only affect the pressure surge zones while leaving the main delivery channel flow path intact, thus reducing noise without compromising delivery capacity
Solution Approach 2:
The recess dimensions are optimized as parameters: depth ratio (0.05-0.15 times channel width), positioning distance (0.1-0.3 times channel width from outlet), and angular extent. These parameter changes create optimal deceleration zones that reduce pressure surges while maintaining sufficient flow area for high delivery capacity
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 emissions when the valve is closed without causing pressure or delivery capacity losses when the valve is open, achieving low emission values with almost unchanged maximum pressure.
Implementation Method 1
the conveyed fluid in the pockets is accelerated in the circumferential direction and in the radial direction by the conveying blades, so that a circulating turbulent flow is created in the conveying channel
Implementation Method 2
compressed air is still present in the pockets between the conveyor blades, which was not completely ejected via the outlet, which is suddenly accelerated against the walls of the interruption area when it is reached
Data Source
Figure 1~2
Figure 3~4
AI summary
Side channel blowers having devices for minimizing noise emissions are known that do not, however, sufficiently reduce noise when the control valve is closed. The invention therefore proposes a side channel blower, in which further recesses (72, 64) are formed in the interruption region (32, 34) before the inlet (8) and after the outlet (22), the smallest distance therebetween being 0.5 to 3 times the distance between two conveying blades (26). Such an embodiment achieves further noise reduction, even when the control valve is closed, without reducing the maximum flow rate.