Cyclone Separation Device Exit Ridge Design to Reduce Vortex Noise
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Solution Overview
Problem
Cyclone separation devices in vacuum cleaners generate noise due to air vortices at the exit of the cyclone chamber, which affects the separation performance and noise levels.
Innovation Solution
A cyclone separation device with a dirt duct having an edge protruding at an angle from the cyclone chamber's wall, creating a sharp exit ridge that limits vortex shedding and reduces noise by preventing air from easily transitioning into the dirt duct, thereby minimizing vortex formation and tonal noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the air flow exits the cyclone chamber through a standard exit ridge geometry, then the air flow can easily transition into the dirt duct, but this generates large vortices and tonal noise
Solution Approach 1:
The exit ridge is designed with asymmetric geometry where one side extends tangentially to form a sharp edge while the other side follows the cyclone chamber contour. This asymmetric configuration creates an abrupt flow separation that prevents coherent vortex formation while maintaining effective air flow transition into the dirt duct
Solution Approach 2:
The exit ridge incorporates a sharp edge formed by tangential extension that creates a 90-degree or greater turn angle for the air flow. This sharp geometric feature disrupts the smooth curvature that would otherwise allow large vortex formation, thereby reducing tonal noise while maintaining separation performance
2Object-affected harmful factors
If air flow follows the cyclone chamber wall surface into the dirt duct, then the transition is smooth, but this allows large vortices to form and increase noise
Solution Approach 1:
The exit ridge features asymmetric geometry with one side extending tangentially to create a sharp edge that forces abrupt flow separation, preventing the air flow from following the wall surface in a manner that would generate large coherent vortices
Solution Approach 2:
The sharp edge geometry is designed to preemptively disrupt the air flow before it can follow the cyclone chamber wall surface. By creating an abrupt 90-degree turn requirement, the design prevents the formation of large vortices that would otherwise occur with smoother transition geometries
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 design enhances dirt separation performance while significantly reducing noise levels by restricting vortex formation, maintaining effective air flow and separation efficiency.
Implementation Method 1
Dirt particles are pushed outwards by the generated centrifugal forces and follow a spiral path upwards towards the exit of the cyclone chamber into the dust bucket
Implementation Method 2
The air flow in the cyclone chamber will exit the system at the center. The air inside the cyclone chamber is spinning fast and passes the exit ridges at the top. Due to the large gap in combination with the ridges, vortices are generated that result in air pulsations
Implementation Method 3
These are being amplified by the volumes and shapes of the dust bucket and cyclone chamber exit (resembling the main volume and the neck of a standard Helmholtz resonator mechanism)
Data Source
AI summary
A cyclone separation device includes a cyclone chamber for separating dirt from incoming air, a dirt collecting chamber arranged adjacent to the cyclone chamber for collecting dirt particles separated from air, and a dirt duct between the cyclone chamber and the dirt collecting chamber for allowing dirt particles to exit the cyclone chamber into the dirt collecting chamber. To reduce the generation of noise-generating air vortices, the dirt duct has an edge protruding into a direction at an angle to the dirt duct at an exit ridge of the cyclone chamber that is first encountered by the air rotating in the cyclone chamber. Preferably, the edge is formed by a tangential extension of a wall of the cyclone chamber. A vacuum cleaner advantageously includes such a cyclone separation device.