Flükiger & Co. AG of Oberburg/Switzerland has been operating several double-acting hammers with elastic bearings for many years. After several residential buildings had been constructed in the neighbourhood, it soon began receiving complaints from its new neighbours. Residents were complaining about strong vibrations in their new apartments. Thanks to a new suspension for a double-acting hammer, these emissions were reduced to an extremely low natural frequency level.
Flükiger AG operates the largest Lasco double-acting hammer, a device weighing 213 tonnes and with an impact energy of 125 kJ. This colossus was identified as the cause of the vibration emissions that were increasingly the subject of neighbourhood complaints. The hammer was already being operated on KTI spring isolators. The task was then to reduce vibrations even further.
After vibrations had been comprehensively measured, the engineers at KTI soon found the ideal solution. Twelve spring isolators with integrated KTI safety damping were able to reduce the hammer’s natural frequency from 5.1 Hz to 3 Hz. Never before had a hammer been reduced to such a low natural frequency level. This world innovation reduced the residual vibrations by a full 40 percent. One side effect of the new suspension was that it also resulted in higher vibration amplitude of the hammer. Thorough examinations proved that these changes impaired neither working safety nor production.
This soft direct suspension was initially undertaken in the form of a pilot project. When the project commenced there were in Switzerland still no regulatory limits for vibration emissions. Since then, the standard DIN 4150, Part 2 “Effect of vibrations on people in buildings” also applies there. The KTI team carried out vibration measurements prior to and after the reconstruction, then constructed and delivered the spring isolators for direct suspension with integrated KTI safety damping. The customer assembled the KTI spring isolators and commenced operations with the hammer. Since then, Flükiger & Co. AG has been successfully operating the Lasco double-acting hammer with new suspension.
Yet another KTI solution that proves its value through enhanced flexibility, short delivery times and low cost.