Our Expertise

Noise protection and vibration control

Silencers – Noise Protection Enclosures – Machine Casing – Steel Spring Elements – Spring Mounts – Structure Borne Noise Protection

Steam Exhaust Silencer

Steam exhaust silencers (also: tension release silencers) are often placed behind safety equipment such as valves or flaps. When these open, a large amount of steam flows, with an overpressure, into the tension release expansion stage (perforated steel plate throttle) which has been fitted with a silencer. In the upper part of the silencer there are sound-absorbing fittings, which reduce the noise of the valve and the flow noise according to the sound requirements.

Project Information 
Material: stainless steel 1.4301
Measurements: DN 1200, length approx. 4 m
Medium: water vapour
Sector: paper technology
Location: Fulda, Germany

Foundation bearing with heavy load spring elements

Gas and steam turbines are positioned on concrete foundations in order to technically guarantee their smooth operation and proper alignment. The entire cement foundation is mounted on spring elements which bear the total load of the block and the machines. Taking the spring rates of the elements into consideration, the required tuning frequency, and thereby the quality of the isolation, is structurally adjusted.  The foundation is placed during the assembly with cooperation of the commissioning engineers.

Project Information 
Engineering: design – spring rate and strength
Material compression spring: spring steel, powder coated
Material enclosure: S235JR, galvanised
Sector: power plant technology
Location: Germany

Large spring elements for turbines

Large spring elements are used for vibration-isolated mounting of heavy machinery, such as turbines, large blowers, or mechanical or hydraulic presses. Viscoelastic dampers are integrated into the production series in areas prone to earthquakes. The spring characteristics are tested and determined by our pre-load tester. Assembly is usually performed in two steps: the elements are placed after the bare brickwork is finished; releasing and alignment of the elements are done after the turbines are mounted.

Project Information 
Material: S235JR, spring steel, powder coated
Load: up to 250 t per element
Tuning frequency: approx. 3-5 Hz
Sector: mechanical engineering
Location: worldwide

Noise protection enclosures for helicopter test stands

The noise enclosure is equipped with an extensive, horizontal intake silencer for cooling-air. The exhaust air silencer is mounted flat on the roof of the enclosure. The sides of the enclosure are constructed of detachable wall elements to facilitate the mounting of the engines being tested. The design and the drawing are made by LBF – of course, always incorporating the customer’s wishes, e.g. with regard to openings, lighting and observation windows.

Project Information 
Material: DX 51 (galvanised) – powder-coated
Dimensions: approx. 2,5m x 2,8m x 5m
Level of reduction: approx. 20 dB
Sector: military
Location: Germany

Industrial silencers for centrifugal fans

Centrifugal fans generate high pressures. Therefore, the casings for the splitter silencers must be adequately dimensioned for this overpressure or low-pressure. The welded casings are generally produced of 2-6 mm thick sheet metal and usually fitted with reinforcement profiles. The “industrial grade” silencers consist of riveted perforated sheet metal and aerodynamic baffles for flow distribution and reduction of loss of pressure.

Project Information 
Material: S235JR, painted
Dimensions: approx. 1,8m x 1,8m x 3m
Overpressure: 5.000 Pa
Level of reduction: approx. 35 dB
Sector: Steel manufacturing

Noise protection barrier with intake silencers

Noise protection barriers reduce the radiation of noise from the power units – in the project presented on this page, refrigeration machinery is being enclosed. The air supply for the facility is ensured through the intake openings, where silencers are used to provide noise protection. The noise protection barriers can be produced in the same material and colour to match the facility or the adjacent buildings.

Project Information 
Material: DX 51, galvanised and painted
Dimensions: approx. 8m x 3m
Engineering: sound design, design and drawing, static calculations
Level of reduction: approx. 12 dB
Location: Germany