Double-Walled Pile Silencer Air Gap Noise Reduction
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Solution Overview
Problem
Pile driving into water bodies generates excessive noise, exceeding tolerance thresholds for marine life, and existing noise reduction methods either increase the number of blows required or have limitations in effectiveness.
Innovation Solution
A silencer system comprising a first and second tube with an air gap and elastic spacers to reduce noise propagation, allowing the pile to slide while maintaining alignment and support, with a bottom wall for stability and ballast for enhanced stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a contact damper is used between the free end of the pile and the pile driver, then noise level is reduced by roughly 5-10 dB, but more blows are needed to drive in the pile
Solution Approach 1:
The patent introduces an air gap as an intermediary medium between the pile and the surrounding water environment. This air gap acts as a mediator that blocks noise propagation from the pile to the water, while not interfering with the mechanical driving process, thus avoiding the need for additional blows
Solution Approach 2:
The patent extracts the noise propagation path by removing the direct water contact around the pile. By creating an air-filled space around the pile, the noise transmission path is separated from the water environment, achieving noise reduction without affecting driving efficiency
2Object-affected harmful factors
If the pile driver ram contact time with the pile is prolonged to reduce vibration and noise, then noise produced by the pile is reduced, but more blows are needed to drive in the pile
Solution Approach 1:
The air gap serves as a mediator that isolates the pile from water-borne noise propagation. This allows the pile driver to operate with standard contact times without transmitting excessive noise to the water environment, eliminating the need to prolong contact time for noise reduction
3Object-affected harmful factors
If a double walled device with sealed intermediate space is used, then sound vibrations in liquid are passively reduced, but device complexity increases
Solution Approach 1:
The patent applies noise reduction locally around the pile rather than using a complete double-walled structure. The air gap is created only in the immediate vicinity of the pile where noise generation occurs, providing effective noise reduction while minimizing structural complexity
Solution Approach 2:
The air gap is created using simple, easily deployable structures such as sacrificial materials or temporary forms that can be quickly installed and removed. This approach uses simple, low-cost elements rather than complex permanent structures
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 silencer effectively reduces noise propagation by creating an air gap and damping vibrations, allowing for efficient pile driving with reduced noise impact on marine environments while maintaining operational efficiency.
Implementation Method 1
an air gap between the noise source—the pile—and the surrounding marine environment
Implementation Method 2
The silencer forms, in a relatively straightforward, practical manner, an air gap between the noise source—the pile—and the surrounding marine environment
Implementation Method 3
the elasticity of the spacers dampens vibration transmission between the first and second tube
Implementation Method 4
each spacer comprises a block of elastomer material
Data Source
AI summary
A silencer for silencing the driving of piles into the bed of a body of water is configured to fit around a pile, and has a first tube; a second tube inserted inside and spaced apart from the first tube, both the first and second tube being longer than the depth of the bed of the body of water on which they are to rest; and a bottom wall, which is joined hermetically to respective ends of the first and second tube to form a gap between the first and second tube, and is configured to rest on the bed of the body of water.