Targeted damping of low frequencies
Low-frequency sound problems have become increasingly important in recent years.
Especially in flue gas systems of boilers, the highest sound levels occur at low frequencies between 125 and 500 Hz. With block heating stations, these highest level peaks can already be between 50 and 100 Hz.
These low frequencies can be heard in the environment as unpleasant “humming” sounds.
Until now, conventional silencer solutions have lacked the ability to achieve a corresponding effect here in particular.
Structure
A special product feature is the fibre-free hollow chambers. Thus, special openings can be provided for easy cleaning of the smooth chambers.
It may be necessary to clean the silencer chambers after operation with polluted flue gases, e.g. dust, soot or other combustion residues. The result is a long, unrestricted performance of the silencer.
Its robust design enables the service life of the low-frequency silencers to be increased many times over compared to conventional silencers.
The bottoms of the low-frequency silencers are each fixed to the sheath with a clamping ring and an elastomer seal. They are overpressure-tight up to 200 Pa. On request in welded version overpressure-tight up to 5,000 Pa.
They are equipped with condensate drain as standard. Plant operators can enjoy keeping the operating costs of their plant low if they opt for this silencer solution.
This is made possible by the barely detectable pressure loss of these special silencers.
Example of a low-frequency silencer with three chambers
Each of the chambers of the low-frequency silencer damps a specific frequency range
In licence partnership with the Institute for Building Physics of the Fraunhofer Gesellschaft in Stuttgart, a sound absorber with high muffling at low frequencies and high resilience was developed.
Like other products from Kutzner + Weber, the low-frequency silencers (TTS) are protected by patent.
Mode of operation
The effect of the silencer is based on a combination of different types of resonators. Depending on the requirements, one or more external chambers are acoustically coupled to the flue gas pipe via a ring of perforated plate. A specially developed design programme allows easy planning and calculation of these silencers. The programme takes into account both the influence of the temperature and the flow velocity.
The design of the low-frequency silencers by Kutzner + Weber application technology is ideally based on a frequency analysis of the noise of boilers or combined heating stations or on a sound level measurement in the third-octave spectrum. This procedure ensures that all interfering frequencies are really damped.
Silencing properties
The low-frequency silencers complement the Kutzner + Weber product range so well because they enable high muffling even at very low frequencies. With many conventional silencer solutions, low frequencies can only be realised via a large volume, a large mass or via a large installation length.
Range of use
The low-frequency silencers were developed to reduce the sound level of oil and gas boilers. However, they can also be used with all fuels. This means that it can also be used with condensing boilers without any problems. But especially for engine systems, such as block heating stations or emergency power generators, the low-frequency silencers are characterised by a long service life. In fully welded version, the pressure and temperature resistance can be increased.
- Muffling already from 50 Hz
- Muffling of up to 30 dB per frequency possible
- Reduction of the sum level by up to 25 dB(A) possible
- In combination with passive silencers broadband attenuation
- Long service life
- Hardly any pressure loss
- Overpressure-tight up to 200 Pa
- Flue gas temperature up to 400 °C
- Nominal widths 80 to 600 mm
- Outlet silencer with adapted mounting on request
