The safety of a human personnel, machinery and the equipment is of the foremost concern in any environment, system or an industrial space. If the required attention is not paid to these factors while designing the system, it can lead to a catastrophe and a huge loss of life and property. In relation to the impact of the noise and vibration engineering on the humans, the researchers have investigated that a prolonged exposure of humans to higher vibration levels can result in fatigue, reduced efficiency, chronical spinal injuries, etc. while a prolonged exposure to high noise levels may lead to hearing impairment, deafness, hyper tension and other physiological effects.
This stream of noise and vibration engineering pertains to the design, analysis and testing of systems in order to meet the stringent requirements of the various norms and regulations from the standpoint of human comfort and safety. A few examples to list are – testing and analysis of the heavy duty machineries like an earthmover or a wind-turbine, the measurement of acoustical and vibration data in the buildings and open spaces, etc. Envicon possesses the required skillset, experience and the resources to provide consultancy to the businesses and perform a spectrum of experimental testing activities covered in this domain. The core areas of our operation in the realm of environmental and occupational NVH engineering include:
Ground and building vibrations are a significant geo-hazard and have always been an important consideration in the civil engineering design and construction. The causes for the same include, but are not restricted to, natural events like earthquake and artificial events like passing of heavy traffic on a nearby road, explosion of mining site, operation of locomotives and use of heavy industrial machinery. While the effects of ground vibration on humans vary from annoyance to serious illness, excessive vibrations in a structure can cause it to fail, malfunction and potentially damage its foundations.
In case of installation of a precision machinery like a CMM machine or an MRI machine in a hospital, it is mandatory that the machines are isolated from ground vibrations for them to perform as per the specifications. Envicon undertakes the floor vibration assessment work to verify the conformance of a site vis.a.vis the specifications provided by the manufacturer of the precision machine. We help our customers to identify the suitable location for the installation of such an equipment in their premises. If the vibration levels are not within the permissible limits, we also provide solutions on designing the foundations to isolate the vibrations. Envicon also provides solutions on the installation and commissioning of utility equipment such as HVAC systems, AHUs, Compressors, etc. in a residential, commercial or an industrial building in order to maintain the equipment’s conformance to the different IS/ISO standards.
Industrial acoustics is a term often used in relation to the occupational health and safety, as the sustained exposure to high-decibel noise generated by the machines can cause severe illness and may lead to permanent hearing damage. Most industrial machineries such as generator sets, wind turbines, heavy duty motors, etc., irrespective of the condition of their installation sites, have to undergo rigorous testing to meet the given regulatory standards since their operation requires continuous human involvement.
Such tests include, but are not restricted to, Leq measurement, one-third octave analysis, sound power and sound intensity measurement, etc. Since these measurements are made either for statutory requirement or to assess the product quality, the testing is often conducted as per the various norms like ISO 374X, ISO 9614, IEC 61400, ECMA-74, MIL 1474D, etc. Envicon has both, the resources and the expertise, for conducting these measurements and recommend corrective measures based on the results of the measurements.
Quite frequently the construction of a new building such as an industrial facility or the installation and operation of a new equipment (a potential sound source) in an existing facility changes the entire environmental dynamics of the landscape. In such a case, the response of the surrounding communities to the additional environmental noise can be huge factor in the selection of the site, the acoustic design of the plant and may be even the public relations policy of the company. Moreover, there are a numerous norms and regulations regarding the sound levels in a residential or an industrial area, laid out by the statutory bodies like Pollution Control Board, Civic bodies, etc.
Therefore, it is required that the problems related to the environmental noise are anticipated and solved ahead of time. To that end, Envicon conducts the different measurements such as the daily exposure levels, temporal and spectral dBA monitoring, etc. in conformance with the standards published by the organizations like ASHRAE and EPA. We also undertake the investigation of acoustical problems which includes identifying the source and cause of the noise by sound intensity mapping of the complex systems.
Vibration isolation is a technique of attenuating the transmission of the disturbing forces or motions from one structure or mechanical component to another. It generally involves an investigation into the dynamic characteristics of the source, the transfer path and the receiver. Typical vibration isolators are usually a combination of some resilient material along with a dampener for dissipating the mechanical energy.
Vibration isolators are generally employed to protect a sensitive item or equipment from vibrations of a structure to which is attached or to reduce the vibrations that are induced in a structure by a machine that is attached to it. The reduction in structural vibrations may be desirable for reasons such as structural integrity, human comfort, and control of noise radiated from structures among others.
A similar approach as in the case of vibration isolation is followed in solving the problems related to noise isolation and control. The effectiveness of noise isolation is usually measured by computing the transmission loss and the insertion loss. Various techniques employed for isolating the noise from the source to the receiver include the use of acoustically proof materials, design of volumes using the impedance mismatch technique, use of adaptive noise cancellation systems and many other. Quite a few times the noise isolation and control is also achieved in multiple steps and stages. Automotive mufflers, anechoic chambers and sound-proof rooms are a few examples of the noise isolation systems.