Modal Attenuator Ring-and-Screen Structure for Valve Noise Reduction
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Solution Overview
Problem
Existing noise reduction devices for control valves and regulators either restrict fluid flow or are heavy and difficult to assemble, failing to effectively reduce noise while maintaining efficiency.
Innovation Solution
A modal attenuator with a perforated screen and rings that disrupt sound waves by reflecting them, creating an annular space to target specific sound frequencies, allowing for efficient noise reduction with minimal flow restriction and reduced size and weight.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If multi-port cages or trims are used to reduce noise, then noise is reduced, but fluid flow rates are reduced
Solution Approach 1:
The noise reduction function is segmented from the flow control function. The attenuator body with perforated screen and rings provides noise reduction, while the control valve handles flow regulation. This segmentation allows each component to optimize its specific function without compromising the other.
Solution Approach 2:
The modal attenuator acts as an intermediary device placed in the downstream flow path. It receives turbulent flow from the control valve and transforms it into smoother flow, reducing noise without restricting the overall fluid flow rate through the system.
2Object-affected harmful factors
If sound absorbing materials are disposed in the flow path, then sound waves are absorbed, but fluid flow through the material is reduced
Solution Approach 1:
The attenuator body incorporates a perforated screen with numerous small holes that allow fluid to pass through while providing noise reduction. The porous structure absorbs sound waves through the perforations while maintaining sufficient open area to prevent significant flow restriction.
3Object-affected harmful factors
If modal coincidence suppression device is used downstream, then noise is reduced, but the device is heavy and difficult to assemble
Solution Approach 1:
The attenuator is divided into modular segments including the attenuator body, perforated screen, and multiple rings that can be independently manufactured and then assembled. This segmentation simplifies manufacturing of individual components and facilitates easier assembly compared to monolithic designs.
Solution Approach 2:
The attenuator employs thin-walled cylindrical segments and rings that achieve the required noise reduction function with minimal material thickness. This reduces the overall weight and complexity of the device while maintaining effectiveness.
4Productivity
If modal attenuator with perforated screen and rings is used, then noise is reduced with minimal flow restriction, but the device complexity increases
Solution Approach 1:
The combination of the perforated screen and rings serves multiple functions simultaneously: the perforated screen provides sound absorption and flow straightening, while the rings create acoustic reflections and further smooth the flow. This multi-functionality achieves noise reduction and flow maintenance with a relatively simple integrated structure.
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 modal attenuator significantly reduces noise downstream of regulators or control valves with minimal flow restriction, enabling its use in smaller systems and potential customization for specific applications, while being lighter and easier to integrate.
Implementation Method 1
sound waves pass through the perforated screen and are reflected back by the plurality of rings to disrupt other sound waves
Implementation Method 2
reflected back by the plurality of rings to disrupt other sound waves, thereby reducing fluid noise
Implementation Method 3
a modal attenuator with a perforated screen and rings that disrupt sound waves by reflecting them, creating an annular space to target specific sound frequencies
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
A modal attenuator (10) may include an attenuator body (12) having a lead-in segment and a lead-out segment joined by a connection segment, a perforated screen (32) disposed within the attenuator body and spaced apart from the attenuator body to form an annular space, and a plurality of rings (38) disposed between the perforated screen and the attenuator body. When fluid flows through the modal attenuator, sound waves pass through the perforated screen and are reflected back by the plurality of rings to disrupt other sound waves, thereby reducing fluid noise in the modal attenuator.