Bubble Silencer Reduces Noise During Demolition Work

Obayashi Has Developed Bubble Silencer™—A Device That Reduces Noise by Putting Bubbles Around Chisels That Crush Concrete

Bubble Silencer Reduces Dust and Noise Pollution during Demolition Work with Giant Breakers
Obayashi Corporation has developed Bubble Silencer, which is a device that reduces negative impact on the surrounding environment during demolition work. It contains 90% of the dust and reduces the noise level by 5 dBA (about 70% of sound energy) by releasing bubbles to cover the chisel at the tip of “giant breakers”—heavy equipment used to crush concrete.

Demolition of concrete structures using heavy equipment produces loud noise and dust, so it is necessary to consider the negative impact it has on the surrounding environment. Typically, heavy equipment, such as a crusher with claws, is used to grind concrete because it is quieter. However, there is no space for claws to get in behind the concrete when demolishing underground framework or foundations, so in some cases, there is no choice but to use giant breakers (“breakers”) with a chisel to crush concrete. The drawback of breakers is that they are louder than crushers, and while there are some quieter breakers that have soundproofing on the chisel actuator, this method for soundproofing is not as effective because it reduces the noise by only about 2 dBA (about 30% of sound energy). There was a need for technology to reduce the noise even more. Breakers are louder than crushers, and while there are some quieter breakers that have soundproofing on the chisel actuator, this method for soundproofing is not as effective because it reduces the noise by only about 2 dBA (about 30% of sound energy). There was a need for technology to reduce the noise even more.
Bubble Silencer is a device that reduces noise during demolition work, and it can be installed on a breaker at any time. Bubble Silencer covers the main source of the noise, the chisel, with bubbles that it creates, reducing the noise level by 5 dBA (about 70% of sound energy). It can also be retrofitted to quieter breakers to reduce the noise even more. In addition, bubbles that cover the chisel contain 90% of the dust that is created when crushing concrete. It was demonstrated that Bubble Silencer could consistently control noise and dust during the demolition work at U-port (Client: Japan Post Holdings Co., Ltd. Construction location: Shinagawa-ku, Tokyo).

The main features of Bubble Silencer are as follows.

1. Reduces noise levels and suppresses unpleasant high-pitched sounds

   To find more ways to reduce noise during demolition work, Obayashi visually analyzed how breakers produced noise and the frequencies of the sound. It became clear that chisels make the loudest noise and that the noise is high-pitched, which people find unpleasant.
   There has not been an effective remedy to control the noise that the chisels make because crushed pieces of concrete will hit and break the sound insulator if it is placed around the chisels. Bubble Silencer constantly releases bubbles to cover the chisel to reduce the noise level by 5 dBA (about 70% of sound energy). For quieter models of breakers, the noise level can be reduced by 7 dBA (about 80% of sound energy). Bubble Silencer continuously covers the chisels with bubbles at certain thickness to control high-pitched sounds in particular that people find unpleasant. Bubble Silencer also works for demolition work of underground framework and foundations where breakers must be used. This prevents noise from being generated, which was difficult to do before.

   

2. Effectively contains dust

   Demolition work is dusty in addition to being noisy, and it negatively impacts the surrounding environment. The negative impacts are currently managed by covering the area with a net or by having workers spray water. Bubble Silencer, however, can cover crushed concrete pieces and contain approximately 90% of dust. Bubbles that are released are made of safe ingredients that are commonly used in construction work so they can be disposed of as general construction waste.