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The industry was earlier granted Consent to Operate under the Water (Prevention & Control of Pollution) Act, 1974 and the Air (Prevention & Control of Pollution) Act, 1981 with a special condition to conduct vibration and noise assessment through a reputed institute such as NIT.
In compliance of the said condition, the industry has obtained a “Vibration Assessment Report” from Dr. B.R. Ambedkar National Institute of Technology (NIT), Jalandhar. As per the report, installation of pad-type vibration isolators resulted in reduction of vibration levels by approximately 23–25% in case of 2 Ton hammer operations. Vibration measurements were also recorded at the adjacent plot and at PPCB office premises.
The NIT report suggested some of the prevailing methods/techniques that can reduce level of vibration measures which are listed below:
1. Vibration Isolators:
Floating Plate, Elastic Materials,
2. Vibration Damping,
Shock Absorbers, Viscous Dampers, Damping Materials:
3. Other Considerations:
Mass and Stiffness, Tuning, Force Reduction, Work piece Rigidity, Frequency Analysis:
In compliance to the recommendations of NIT report’s suggestions, the industry has considered all the 03 aspects and has already taken remedial measures under each head which are tabulated below:
• Vibration isolator pads have been installed beneath the hammer block.
• Rubber-based damping elements/shock absorbers have been provided to reduce transmission of vibration.
• The industry has assured good operational practices to reduce vibration by tuning/adjusting the machines parameters such as speed and feed to avoid the resonance frequency that may amplify the vibration.
It is pertinent to mention that presently there are no specific Indian statutory standards prescribing permissible limits for ground vibration levels for such forging operations under the Water/Air Act framework. The NIT report provides RMS velocity measurements but does not indicate any statutory violation.
• However, since vibration levels are influenced by operational load, frequency and surrounding activities, the situation may continue to be monitored during routine inspections to ensure that vibration levels remain controlled and do not cause nuisance or structural concerns.
In view of the above, the industry has complied with the special condition of engaging NIT for vibration assessment and has undertaken vibration mitigation measures as suggested. Further, considerable reduction of vibration has been observed.
Submitted with previous recommendations for grant of CTOs under Water Act 1974 and Air Act 1981 upto 31.03.2031 with suitable terms and conditions and with special condition that the industry shall continue good operational practices to reduce vibration by tuning/adjusting the machines parameters such as speed and feed to avoid the resonance frequency that may amplify the vibration please. (Competency CEE)
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