The 96 dB(A)Leq recorded from a 250 ton Rhodes billet hydraulic guillotine was cut by 17dB(A) – without using an acoustic enclosure. This was not only very low cost, but it also avoided the associated access, maintenance, and temperature issues.
Diagnosis showed that the overall noise from the guillotine was dominated by high levels of vibration transmitted from the hydraulic pump into the machine frame (and through rigid pipework to the remainder of the machine). In addition, there was also a significant transmission of impacts from the hydraulic valve bank.
The engineering solution was to mount the hydraulic motor-pump unit on a damped rigid frame that was then isolated from the machine body. The valve bank was also vibration-isolated from the machine frame using a tuned section of rubber-cork composite.
These modifications reduced the hydraulic power pack noise from 96 dB(A) down to 79 dB(A) at a fraction of the cost and without the operational and maintenance issues that would have been introduced by the previously proposed acoustic enclosure.