Noise control

2. 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)

3. 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.

4. Source of noiseSource of noise

5. SOURCE PATH RECEIVERSOURCE PATH RECEIVER

6. HOW CAN WE CONTROL HOW CAN WE CONTROL
NOISE?NOISE?
Control the source.
Block the path.
Enclose the receiver.

7. 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.

8. 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?

9. 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.

10. BY RESILIENT SCREEN BY RESILIENT SCREEN
DECKINGDECKING
The use of resilient
screen decking
reduces the impact
of rock on metal

11. VIBRATION ISOLATED VIBRATION ISOLATED
MOUNTEDMOUNTED

12. 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?

13. Barrier ConceptBarrier Concept
Shadow
Zone
Diffracted
Propagated
Reflected
Noise Source
Barrier

14. ACOUSTICAL ACOUSTICAL
BLOCKWALLSBLOCKWALLS

15. STRIP CURTAIN BARRIERSSTRIP CURTAIN BARRIERS

16. 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

17. Allowable Boundary Noise Allowable Boundary Noise
LimitsLimits
Affected Day Evening Night
Premises 7 am – 7 pm 7 pm – 11 pm 11 pm- 7am
Noise 65 dBA 60 dBA 55dBA
Sensitive
Residential 70 dBA 65 dBA 60 dBA
Commercial/ 75 dBA 70 dBA 65 dBA
Industrial

19. 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?

20. OPERATOR’S BOOTH MUST OPERATOR’S BOOTH MUST
PROVIDE ADEQUATE VISIBILITYPROVIDE ADEQUATE VISIBILITY

21. Central Building Plan Unit 30.11.1999