Fuller Austin Insulation Inc.
SCOPE OF WORK
The study’s purpose was to assess the occupational noise exposure levels within the new Compaction Plant at the Potash Corporation of Saskatchewan Allan Mine against the Saskatchewan Occupational Health and Safety Regulations; and if possible, provide noise control recommendation to reduce occupational noise exposure.
The new Compaction Plant at the PCS Allan mine consists of a single large, multi-level insulated metal building housing a variety of the process equipment such as conveyers, compactors, blowers, screens, heaters, fans, etc.
The project included the following components:
- Performing sound level measurements in the main operating areas of the Compaction Plant building;
- Performing sound level measurements on selected pieces of equipment deemed as the worst offenders operating individually;
- Establishing sound power levels for all identified noise sources associated with the project;
- Building a detailed acoustic model for the Compaction Plant building interior;
- Perform sound level predictions and noise mapping for each production floor;
- Identifying suitable noise mitigation measures for selected equipment to reduce occupational noise exposure.
The occupational noise level criteria are governed by the Saskatchewan’s Occupational Health and Safety Act – 1993 and the Occupational Health and Safety Regulations, 1996. The regulation establishes maximum 8-hour occupational noise exposure at 85 dBA. It was therefore desirable if practical and economically feasible to reduce the noise levels inside the new Compaction Building to below 85 dBA.
The main noise sources included various drag and screw conveyers, large process and vacuum blowers, compactors, screen cages, electric motors, building ventilation fans, heaters, and water pumps. Drag conveyers and blowers were found to be the dominant noise sources.
UNIQUE PROJECT HURDLES
The main building of the new compaction plant was extremely complex comprising various operating areas located on different levels with common structural steel and open grating floors. The interior of the building walls was solid lined resulting in a fairly live and reverberant building. The main challenges of the project centered on properly capturing and quantifying the reverberant field inside the building in order to develop a realistic noise model; and identifying the extent to which the noise inside the building was structure-borne radiation.
The development of suitable noise control specifications required a detailed calibration and validation of the model. The analysis suggested that over most of the plant floor areas the occupational noise levels could be reduced to below 88 dBA, although it was not feasible to attempt any further reduction to below 85 dBA everywhere within the building. Suitable noise control measures were developed and conceptually designed.
The project was successfully completed over a four-month period.