Context

Containers for gas-fired cogeneration plants. Belluno's leading food company in the supply of precooked products and snacks.

It is a company that has always given value to technology and innovation, in fact, it has developed a patented system to produce precooked lasagna pasta.

Precisely this attention to innovation and state-of-the-art systems has led the company to introduce a natural gas-fired cogeneration plant within the company, consisting of a 637 Kw engine in order to self-produce electricity for the productive cycle.
The noise level of the cogenerator is 95 dB(A) at 1m.


The cogeneration plant is located outside of the production department, but in the interior courtyard.

The municipality in which the production plant is located has made acoustic zoning of the territory and assigned for that area Class IV: areas of intense human activity (areas with small industries and commercial and handicrafts) Urban Areas Affected by Intense Vehicle Traffic with a high population density, with high presence of business, offices and handicrafts.


Absolute input limit values

Territory use destination class Times of reference
Day
(6.00-22.00) 		Night
(22.00-6.00)
Classe IV areas of intense human activity
65dB
55dB

Absolute output limit values

Territory use destination class Times of reference
Day
(6.00-22.00) 		Night
(22.00-6.00)
Classe IV areas of intense human activity
60dB
50dB
Solution

The customer to obtain permission to start the engine, must respect the zone limits.

The nearest receptors are 10m from the source, so the soundproofing to be reached with the container is of 55 dB(A) at 10m from the perimeter of the container and silencers.

The engine will be placed inside a soundproof container with dissipative baffless to ensure correct air passage.

The container is made of continuously welded steel sheet metal, inside which the sound absorbing sound insulating material is chosen, based on our soundproofing calculations, starting from the frequencies emitted by the cogenerator.

The silencers have been sized based on the air flow rate of the motor unit, load losses and soundproofing.
The climatic conditions of the installation site were also considered: temperature, atmosphere, wind pressure.

The roof of the container has been designed and manufactured to contain the weight of the groups, snow accumulation as well as ensuring waterproofness.

Results

Soundproofing target successfully reached 55 dB(A) at 10m.

-30dB

The intervention allowed the system to operate in compliance with the limits set by the acoustic zoning of the municipality where the system is inserted.