Lesson 7: INDUSTRIAL NOISE CONTROL

1. Lesson 7: INDUSTRIAL NOISE CONTROL ARC 507: ENVIRONMENTAL CONTROL III (ACOUSTICS AND NOISE CONTROL) DEPARTMENT OF ARCHITECTURE FEDERAL UNIVERSITY OF TECHNOLOGY, AKURE.

2. 1. Summary.2. Introduction.3. Hierarchy of Control.4. New Workplaces or New Equipment. Buy Quiet Company Policy. Case Studies. Buy Quiet Manufacturing Standards5. New Workplaces Layout. Case Studies.6. Existing Workplaces.7. Elimination. Case Studies.8. Substitution.9. Isolation. Contents

3. Summary Noise is one of the most common occupational hazardsResults in many workers being affected by noise induced hearing loss.Risk due to exposure to high noise levels can be reduced by: EliminationSubstitutionIsolationEngineering control at source and in the transmission path.This lesson covers:The basics of the noise reduction methodsWith more emphasis on physical means of noise reduction rather than administrative controls or protective hearing devices.

4. Introduction This lecture describes basic principles of noise control and explains how to apply the hierarchy of control of exposure to high noise levels. It outlines the methods, equipment and materials for engineering control of noise and gives many examples that illustrate their use.

5. Hierarchy of Control The hierarchy of control requires that risk is reduced by noise control measures in the first instance and then, if the achieved reduction is not sufficient, by administrative controls and personal hearing protectors.

6. Hierarchy of Control Many countries have introduced legalobligations and guidelines requiring employers to protect their employees and others from exposure to excessive noise. These legal aspects set up the desired steps of a comprehensive prevention management system to achieve reduction in risk due to exposure to noise.

7. Hierarchy of Control Noise control measures are physical means thatreduce noise levels and can be divided into thefollowing categories:● Elimination ● Substitution ● Isolation ● Engineering Control at the source and transmission path.

8. Hierarchy of Control Administrative control is any arrangement that significantly reduces the worker's exposure time to noise hazards. For example, ► Job Rotation, ► Production Scheduling, ► Job Redesign and, ► Introducing Appropriate Training on Noise.

9. Hierarchy of Control The next step in a prevention managementsystem is the provision of personal protective equipment such as; Earplugs or Earmuffs.This should be used as the last line of defence when noise and administrative control measures cannot keep the noise levels below the criteria set for the workplace.

10. Hierarchy of Control Health surveillance also plays an important part because it helps to identify hearing problems so they can be prevented from developing further.All these steps should be considered when developing a noise control program for theworkplace.

11. Hierarchy of Control

12. New Workplaces or New EquipmentIt is very important to incorporate noise aspects inthe early design process for new workplaces, so thedecisions made about what equipment to purchase and how to layout this equipment lead to the quietest practicable workplace.

13. Buy Quiet Company PolicyBuy Quiet is;● most effective means of noise control.For New Workplace;● establish acceptable noise criteria for new equipments.● include them in purchase specifications.

14. CASESTUDIES1. Baulderstone Clough Joint Venture Yanmar Vio50 excavator with a rockbreaker attachment(noise levels at 7mdistance of 65 dB(A)).

15. CASESTUDIES2. Macmahon Contractors (WA) Pty Ltd Earth Moving equipment fitted with acoustically treated cabin.(noise levels 75 dB(A) or below).

16. CASESTUDIES2. Macmahon Contractors (WA) Pty Ltd Typical generator set used by Macmahonon their construction sites.(noise levels below85 dB(A) at 1m.).

17. Buy Quiet Manufacturing StandardsTo help designers, various countries have developed specific standards dealing with noise specifications for new machinery.The European Union (EU) has produced directives addressing groups of machinery which cover noise control as an essential part of machine safety. In The United States, the relevant standard is ANSI S12.16: Guidelines for the Specification of Noise of New Machinery (1992).

18. Buy Quiet (c0nt.d)In Australia the law requires designers, manufacturers, producers, suppliers, importers and installers of plant to be used in workplaces to provide information about any hazard associated with the plant.These standards and directives have already ledto manufacturers placing greater emphasis onthe design of low noise equipment.

19. THE BUY QUIET PROCESS

20. New Workplaces LayoutAnother aspect of noise control is the layout of the purchased machinery. Evaluating the location of machinery on paper is much cheaper and easier than physically moving the equipment later. Simple rules to follow are:

21. New Workplaces Layout (cont.d)Keep machines, processes and work areas of approximately equal noise levels together; andSeparate noisy and quiet areas by buffer zones with intermediate noise levels

22. Case Studies John's Engineering and Cranes is a heavy engineering workshop manufacturing andrepairing mining equipment. The premisesconsist of fitting, machining and fabrication sections and a spray booth.

23. Case Studies (cont.d)The fabrication section is further divided into reparation, cutting and boiler making areas.In their previous building, the boiler making section, which is the noisiest, was placed in the middle of the workshop, thus affecting other areas that didn't generate high noise levels.

24. Case Studies (cont.d) About a year ago the company built new premises. Before building the new workshop they decided to address the noise problems at the planning stage.The decision was made to use all the space available to separate noisy sections from quiet ones and provide some buffer zones between.

25. Case Studies (cont.d) Boiler making section situated away from other sections.Spray booth situated in a separated building.

26. Case Studies (cont.d) Administration building (left) separated from the workshop (to the right).

27. EXISTING WORKPLACESA noise control program in establishedworkplaces should encompass; ► Identification,► Assessment and ► Ranking of the Noise Sources.

28. EXISTING WORKPLACES (cont.d)Once the noise sources have been identified and assessed, a decision can be made on the best ways to control them, in accordance with the hierarchy of control.Engineering noise controls are concerned with the noise source, the noise transmission path, or the receiver, hence, can be controlled by;

29. EXISTING WORKPLACES (cont.d) Reducing the amount of sound energy released; Diverting the flow of the energy away from the receiver; or Protecting the receiver from this energy.

30. EXISTING WORKPLACES (cont.d) Quiet lunchroom.Fitting/machining placed away from noisy sections.

31. ELIMINATION Elimination is the first step that should beconsidered when addressing exposure to noiseat a workplace. After a critical examination of allexisting processes it may be possible toeliminate the exposure entirely by changing oneor more operations.

32. Case Studies1. John's Engineering and Cranes changed their metal cutting method to a low noise one, using an oxy-acetylene profile cutter.Oxy-acetylene cutting produces a cleaner finish and eliminates need for grinding

33. Case Studies cont.d2. Macmahon Contractors eliminated the use of hammers when installing or removing bearings.Hammering bearings into their position - a noisy process.

34. Bearings cooled in liquid nitrogen fit easily and silently into casing.Heating bearings in a pie warmer to fit them in theirplace without hammering. Case Studies cont.d

35. SubstitutionIn many areas it is possible to substitute quieter processes for noisy ones.A properly designed purchasing policy that incorporates the "buy quiet" concept is often the best and most cost-effective way of controlling noise exposure.This minimizes the need for noise control later, which can be very costly.

36. Substitution cont.dWhen purchasing new plant:Specify acceptable maximum noise levels during the tendering process, orObtain noise emission data before purchasing to choose the quietest available and affordable plant.

37. E x a m p l e s o f Alternative Low-Noise Processes

38. CASESTUDIES1. Macmahon ContractorsThe4" grinder is less noisy than the 9 " grinder.(reducing noise levelsfrom 108 dB(A) down to 102 dB(A)).

39. CASESTUDIES cont.d1. Macmahon ContractorsFlexovit F16 saw replacesMakita 2414 cut-off saw.(reducing noise levelsfrom 97 dB(A) down to 92 dB(A) cutting a 1" hollow tube).

40. CASESTUDIES cont.d2. Baulderstone Clough Joint Venture Bauer BG22 bore pile. (reducing noise levelsfrom 105 dB(A) (impact sheet piledriverdown to 90 dB(A) at 5m).

41. CASESTUDIES cont.d2. Baulderstone Clough Joint Venture Honda 9 HP portable generators with low noiseYanmar units. (reducing noise levelsfrom 96 dB(A) (impact sheet piledriverdown to 78 dB(A) at 1m).

42. CASESTUDIES cont.d2. Baulderstone Clough Joint Venture middle rangeinstead of large jackhammers. (reducing noise levelsby 10 dB(A)).

43. ISOLATIONIsolation means separating noise sources from people involved in the work or others standing near by. It could mean relocating the noise source or relocating the operators or others to positions away from the noise source.

44. EXAMPLES1. Isolating a Compressor from Workers Reduced Noise Levels.

45. EXAMPLES cont.d2. Operators' Noise Exposure Reduced By Isolating Spray Booth.Noise was reducedby 5-8 dB(A).