Sound muffler arrangement and method of controlling such an arrangement

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing silencer arrangements for ventilation systems require separate control flaps to regulate air flow, leading to increased space and cost requirements, as well as disturbing noises like rattling and whistling due to these flaps.

Innovation Solution

A silencer arrangement with a muffler having two segments that take on the function of the control flap unit, featuring a curved or angled duct design to absorb sound waves and adjust flow resistance, eliminating the need for separate flaps and reducing noise.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If separate control dampers are installed upstream or downstream of the silencer to regulate air flow, then the volumetric flow and mass flow can be controlled, but the space requirements increase, costs increase, and disturbing noises (rattling, whistling) occur outside the silencer

Engineering Contradiction:
Improveflow control capabilityVSAvoidnumber of additional components
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent combines the flow control function with the silencer structure by making the silencer duct itself movable. Instead of using separate control dampers, the silencer's first and second duct sections can be moved relative to each other to adjust the cross-sectional area and control air flow. This merging eliminates the need for additional control components while maintaining the silencing function.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The silencer is designed to perform multiple functions simultaneously: it provides sound attenuation while also serving as the flow control mechanism. The movable duct sections allow the silencer to regulate volumetric and mass flow of air without requiring separate control devices, making the system more compact and cost-effective.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Ease of operation

If separate control dampers are installed to regulate air flow, then flow control is achieved, but annoying noises (rattling, whistling) are generated outside the silencer

Engineering Contradiction:
Improveflow regulationVSAvoidnoise from control dampers
Core Design Contradiction:
Ease of operationVSObject-generated harmful factors

Solution Approach 1:

By integrating the flow control function into the silencer structure itself through movable duct sections, the patent eliminates separate control dampers that generate rattling and whistling noises. The silencer becomes the sole component responsible for both silencing and flow control, removing the noise source.

Inventive Principle:
Principle #5Merging (Combining)

3Object-affected harmful factors

If the silencer duct has a curved or angled course with bends to absorb sound waves, then sound attenuation is improved, but flow resistance increases

Engineering Contradiction:
Improvesound attenuationVSAvoidflow resistance
Core Design Contradiction:
Object-affected harmful factorsVSLoss of energy

Solution Approach 1:

The patent employs movable duct sections that can dynamically adjust the cross-sectional area of the silencer channel. By changing the position of the duct sections, the system can optimize the balance between sound attenuation and flow resistance. The movable design allows the silencer to adapt to different operating conditions, maintaining acceptable flow resistance while achieving good sound attenuation through the curved/angled duct path.

Inventive Principle:
Principle #15Dynamics

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 reduces space and cost requirements while effectively absorbing sound waves and maintaining acceptable flow resistance, minimizing noise disturbances and ensuring a homogeneous air flow profile.

Implementation Method 1

all sound waves entering the silencer from a ventilation duct at different angles hit the inner wall of the silencer duct at least once and are partially absorbed there, i.e. reflected in a weakened form

Methodology Applied
Scientific EffectSound wave absorption: Acoustic Absorption

Data Source

PatentEP3117156B1Sound muffler arrangement and method of controlling such an arrangement
Publication Date: 2022.08.17 ZEHNDER GROUP INTERNATIONAL AG
  • EP3117156B1 patent drawingFigure 1A~1B
  • EP3117156B1 patent drawingFigure 2A~2B
  • EP3117156B1 patent drawingFigure 3A~3B

AI summary

The invention relates to a sound absorber (1) for a ventilation system for absorbing sound that propagates along a ventilation duct (LK) in the interior of said ventilation duct, through which ventilation duct air flows, wherein the sound absorber can be integrated into the ventilation duct intended for conducting air or forms a partial segment of the ventilation duct and the sound absorber (1) has at least two sound-absorber segments (2, 3), which are spaced apart from each other in order to form a sound-absorber duct (4) between the surfaces (2a, 3a) of the two segments (2, 3) that face each other, which sound-absorber duct extends from the inlet (5) to the outlet (6) of the sound absorber (1). The two segments (2, 3) are supported in such a way that the two segments can be moved in relation to each other such that at least partial regions of the surfaces (2a, 3a) of the segments (2, 3) can be moved toward each other or away from each other. The invention further relates to a method for controlling the sound absorber according to the invention.