Compressor Noise Reduction Unit with Acoustic Foam

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Solution Overview

Problem

Compressors used in domestic and small-scale industrial environments cause significant noise and vibrational pollution, with existing solutions like acoustic cancellation chambers or blankets being costly, unsightly, or ineffective in reducing downstream vibrations and noise.

Innovation Solution

A noise and vibration reduction unit with an elongate encasing body filled with multiple layers of acoustic foam of different densities and Noise Reduction Coefficients, which are arranged sequentially to minimize sound and vibrational disturbances while maintaining airflow and avoiding back-pressure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If an acoustic cancellation chamber is used to encase the compressor, then noise cancellation is improved, but space requirements increase and cost increases

Engineering Contradiction:
Improvenoise cancellationVSAvoidspace requirements
Core Design Contradiction:
Object-affected harmful factorsVSVolume of stationary object

Solution Approach 1:

The patent uses acoustic foam, a porous material, to line the interior surfaces of the enclosure. The foam absorbs sound waves through its porous structure, converting acoustic energy into thermal energy through friction and viscosity effects within the pores. This provides effective noise cancellation without requiring a large voluminous chamber, as the absorbing material is applied as a surface treatment rather than requiring extensive empty space for sound propagation and cancellation.

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The patent varies the density and acoustic properties of the foam material to optimize noise cancellation performance. By changing parameters such as foam density, thickness, and cellular structure, the enclosure achieves effective noise reduction in a compact form factor. This allows tuning of the acoustic absorption characteristics without proportionally increasing the overall enclosure volume.

Inventive Principle:
Principle #35Parameter changes

2Object-affected harmful factors

If an acoustic blanket is used to wrap the compressor, then noise reduction is achieved, but downstream vibrations and noises are not resolved

Engineering Contradiction:
Improvenoise reductionVSAvoiddownstream vibrations
Core Design Contradiction:
Object-affected harmful factorsVSObject-generated harmful factors

Solution Approach 1:

The patent divides the noise control solution into two distinct functional segments: (1) an acoustic enclosure with absorptive foam lining to handle airborne noise, and (2) a separate vibration isolation system using elastomeric mounts to handle structure-borne vibrations. This segmentation allows each system to be optimized for its specific function without compromising the other, thereby addressing both noise reduction and vibration isolation independently and effectively.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces vibration isolation mounts as an intermediary element between the compressor and the enclosure/ground. These elastomeric mounts act as a mediator that decouples the vibration source from the surrounding structure, preventing vibration transmission while allowing the acoustic enclosure to function independently for noise control. This intermediary approach resolves the downstream vibration issue without interfering with the noise reduction function.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Object-affected harmful factors

If a large acoustic cancellation chamber is used, then noise cancellation is improved, but the installation becomes unsightly and costly

Engineering Contradiction:
Improvenoise cancellationVSAvoidinstallation complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent employs flexible acoustic foam linings that can be conformally attached to the interior surfaces of the enclosure. This thin-film approach to acoustic treatment provides effective noise cancellation without requiring a bulky chamber design. The flexible nature of the foam allows it to adapt to various enclosure shapes and sizes, simplifying installation and allowing the system to be integrated into existing spaces without creating unsightly protrusions or requiring complex custom fabrication.

Inventive Principle:
Principle #30Flexible shells and thin films

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 unit achieves a 55% reduction in noise and vibrations produced by the compressor and an 85% reduction in noise transmitted downstream, while maintaining aeration quality and avoiding equipment issues, with a cost-effective and space-efficient design.

Implementation Method 1

the internal volume is substantially filled by at least two cancellation media comprising acoustic foam, said cancellation media having different densities respectively

Methodology Applied
Scientific EffectAcoustic absorption: Acoustic Absorption

Data Source

PatentEP3734071B1Noise & vibration reduction unit
Publication Date: 2022.03.16 MARSH BOYER STEPHEN
  • EP3734071B1 patent drawingFigure 1a
  • EP3734071B1 patent drawingFigure 1b
  • EP3734071B1 patent drawingFigure 1c

AI summary

A noise and vibration reduction unit (101) comprises an air inlet (117), an elongate encasing body (108), a cancellation medium (121) and an air outlet (118). The inlet (117) allows influx of air from a compressor into an internal volume of the elongate encasing body (108) that is filled with the cancellation medium (121). The air passes through the cancellation medium (121) and the associated sound and vibrational disturbances that are produced by the compressor are dampened by the medium (121). The air then passes out of the elongate encasing body (108) by way of the air outlet (118) and is transferred downstream via tubing to an apparatus or environment for oxygen uptake.