Soundproofing of a fan

Kaolin AD was founded in 1924, and it is based in Tsenovo, Bulgaria. They mine, produce and sell mineral resources for customers in Europe, the Middle East, and North Africa. The company is a subsidiary of Quarzwerke GmbH and it mines kaolin, feldspar, silica sand, limestone, dolomite, and chamotte.

Within recent years, Kaolin faced a problem as a result of noise generated from a rotary fan which increased noise levels within their production facility in Vetovo city. Increased noise levels created an adverse working environment, and created stress among employees. 

Many production facilities have similar problems - it is known that noisy environments have an adverse effect on productivity and health. Kaolin recognised the problem and engaged Decibel to create a better working environment.

Source

The noise levels at the intake of the rotary fan created sound levels of above 113 dB, a level of noise that would cause permanent hearing loss to individuals that were not wearing appropriate PPE. Kaolin asked Decibel to design and install a soundproof cabin, specially designed to meet 4 specific requirements. The cabin needed to be:

-       Detachable

-       With natural ventilation

-       With lighting

-       Accessible

Decibel's engineering team's extensive experience in similar situations attracted Kaolin to choose Decibel as their partners to resolve their problem. Kaolin were impressed that the final solution exceeded their expectations.

Challenges

One of the challenges our engineering team faced was an extremely tight free area for construction of the cabin. The walls of the cabin were restricted to no more than 66 mm thick (walls in standard soundproofing cabins are nominally 100 mm thick). Decibel's engineering team developed an innovative solution where the panels were very thin, but provided very high sound insulation properties. 

A second challenge was the inlet & exhaust plenums of the fan, which effectively acted as a noise amplifier. The plenums themselves generated 95dB of noise!. 

Decibel Cabin

The final solution was a detatchable lightweight cabin, mounted on high-performing vibroinsulating pads. The soundproof panels used in the cabin were built of stainless steel. Fabricated using state-of-the-art cutting & folding equipment. Welding was completed on a welding robot with digital laser for accuracy. 

All component parts needed also to have a powder paint finish, which carried a life expectancy within harsh environments. 

To resolve the challenge of natural ventilation, Decibel's engineering team designed a high-performance silencer that was designed to cope with the specific frequencies generated by the fan. 

To solve the noise generated from the fan intake and exhaust plenums was resolved through the use of viscoelastic materials coated in high – strength steel.

The Result:

A lightweight cabin that is only 75 mm thick but still reduced the noise from the fan from 113 dB to 82.9 dB. The full project was installed within 5 days.