NOISE CONTROL NOISE CONTROL AT SOURCE, AT SOURCE, ALONG PATH,ALONG PATH,AT RECEIVERAT RECEIVER

SUBMITTED TO:-SUBMITTED TO:- SUBMITTED BY:- SUBMITTED BY:-ER. DHEERAJ SONIER. DHEERAJ SONI YASHWANT RAJ YASHWANT RAJ

VERMAVERMA (MECHANICAL) (MECHANICAL)

INTRODUCTIONINTRODUCTION

Noise is unwanted sound. It can cause hearing loss, disturb verbal communication or cause nuisance. The most common sources are industrial noise and traffic. Vibrations can cause damage to assets, radiate noise or cause discomfort to people.

Noise control or noise mitigation is a set of strategies to reduce noise pollution or to reduce the impact of that noise, whether outdoors or indoors.

Source of noiseSource of noise

SOURCE PATH SOURCE PATH RECEIVERRECEIVER

HOW CAN WE CONTROL HOW CAN WE CONTROL NOISE?NOISE?

Control the source.

Block the path.

Enclose the receiver.

WHY NOISE AT SOURCE?WHY NOISE AT SOURCE?

Mechanical shock between two machine parts.

Friction between two machine parts.Unbalance rotating and

reciprocating parts.Vibration of large parts.Loose fitting.Irregular fluid flow.Improper maintenance.

Vibration damping:- Applicable for large vibrating surfaces. The damping mechanism works by extracting the vibration energy from the thin sheet and dissipating it as heat. A common material is sound deadened steel.

Vibration isolation:- Reverts transmission of vibration energy from a source to a receiver by introducing a flexible element or a physical break. Common vibration isolators are springs, rubber mounts, cork etc.

HOW CAN WE CONTROL HOW CAN WE CONTROL NOISE AT SOURCE?NOISE AT SOURCE?

Judicious sitting of the mechanical equipment.

Proper maintenance.Proper material of machine part (For

example:-nylon gears can be used instead of metal gears.).

Choice of low noise mechanical equipment.

BY RESILIENT SCREEN BY RESILIENT SCREEN DECKINGDECKING

The use of resilient screen decking reduces

the impact of rock on metal

VIBRATION ISOLATED VIBRATION ISOLATED MOUNTEDMOUNTED

Noise insulator:- Prevent the transmission of noise by the introduction of a mass barrier. Common materials have high-density properties such as brick, thick glass, concrete, metal etc.

Noise absorber:- A porous material which acts as a ‘noise sponge’ by converting the sound energy into heat within the material. Common sound absorption materials include decoupled lead-based tiles, open cell foams and fiberglass.

HOW CAN WE CONTROL HOW CAN WE CONTROL NOISE ALONG PATH?NOISE ALONG PATH?

Barrier ConceptBarrier Concept

Shadow

Zone

Shadow

Zone

DiffractedDiffracted

PropagatedReflected

Noise Source

Barrier

ACOUSTICAL ACOUSTICAL BLOCKWALLSBLOCKWALLS

STRIP CURTAIN STRIP CURTAIN BARRIERSBARRIERS

VINYL STRIP CURTAINS can be used TO SEPARATE AREAS OF PLANTS AND MILLS.

THE STRIPS NEED TO HAVE A 30 TO 50 % OVERLAP.

IN SOME CASES THESE STRIPS MAY NEED TO BE DOUBLES

Allowable Boundary Allowable Boundary Noise LimitsNoise Limits

Affected Day Evening Night

Premises 7 am – 7 pm 7 pm – 11 pm 11 pm- 7am

Noise 65 dBA 60 dBA 55dBASensitive

Residential 70 dBA 65 dBA 60 dBA

Commercial/ 75 dBA 70 dBA 65 dBA Industrial

Use head sets and ear plugs in industry.Doors and windows should be well sealed.Ventilation opening should be provided

with acoustic attenuators.Internal surface should be made of

absorptive materials.Innovative building design may be used to

prevent or reduce the intrusion of noise. For example, no window openings facing noise source.

HOW CAN WE CONTROL HOW CAN WE CONTROL NOISE AT RECEIVER?NOISE AT RECEIVER?

OPERATOR’S BOOTH MUST OPERATOR’S BOOTH MUST PROVIDE ADEQUATE PROVIDE ADEQUATE

VISIBILITYVISIBILITY

Central Building Plan Unit 30.11.1999