AMEC Americas Ltd.
SCOPE OF WORK
AMEC Americas Ltd. (AMEC) contracted INNOVA to perform diagnostic sound measurements within the newly constructed Phase I Mill at PCS Lanigan, in Saskatchewan for the purpose of determining the dominant noise sources and provide options for noise mitigation. Measurements of the noise levels in the plant were taken with the entire plant in full operation processing product at between 500 to 600 tons per hour. All wall and roof fans were in operation during the measurements.
The noise criteria were outlined in Part VIII Noise Control and Hearing Conservation of The Occupational Health and Safety Regulations, 1996 of Saskatchewan. “All reasonably practicable measures must be taken to reduce the noise level such that the noise exposure is below 85 dBA Lex or the noise level below 90 dBA, before the use of hearing protection is warranted.” Thus, in consideration of the worker shift lengths and the time spent in various areas of the plant, the noise mitigation design target is set to be at or below 90 dBA for the entire plant.
- Conceptual recommendations for reducing the overall noise in the plant included mitigation for individual equipment as well as treatment to the overall building to reduce the reverberant noise.
- Barriers between equipment to protect maintenance workers from neighboring equipment that is not shut down;
- Full or partial enclosures;
- Acoustical blankets over equipment;
- Silencers on mixing and cooling fans;
- Acoustic absorption was recommended for the Wet Process Mill Building and Compaction and Product Treatment Buildings.
The thoughtful implementation of these mitigation measures lead to the targeted overall facility noise level of 90 dBA.
UNIQUE PROJECT HURDLES
Measurements in such a large facility needed to be taken carefully to isolate individual pieces if equipment. Also, in developing the noise mitigation recommendations consideration of the following project/design criteria had to be taken:
- Meet the design target of 90 dBA in all areas of the plant
- Maintain access to the equipment for maintainability and operability,
- Must not introduce any new safety hazards,
- Select noise controls that are readily available and are ‘fit for purpose’,
- Provide adequate equipment ventilation, and
- Maintain equipment performance ratings (e.g., do not restrict air flow) and therefore avoid potential warranty issues