(96c) A Semi-Quantitative Tool to Estimate the Risk of Dust Fire or Explosion from Process Equipment

Dust explosions can pose a risk of injury to personnel, damage plant and equipment, and cause business disruptions. Preventing dust explosions requires a comprehensive assessment of materials and processes to identify operations posing a risk. Assessing the risk of a particular process or equipment could be expensive and time consuming, even for very low risk operations. When many processes within an organization must be assessed, prioritization of both the assessments and the implementation of safeguards can be difficult. In order to obtain a general overview of the risk of fire and explosion of a process, this work presents a semi-quantitative tool to quickly estimate the risk of dust fire or explosion in a unit operation. This tool has been validated for Bucket Elevators in the grain industry, and additional versions of the tool are in the development and validation process for other unit operations, such as grain dryers, dust collection systems, hammer mills and belt conveyors. Designed for use by on-site supervisors, the tool uses multiple-choice and yes/no questions to assess both likelihood and severity of the risk. Point values are assigned to each response, providing the opportunity to weight the relative importance of each question. The final point totals for Severity and Likelihood are used to automatically show the process risk plotted on a Risk Matrix. The main idea behind this tool is to identify all the preventive, protective and mitigative measures the organization has taken to prevent a dust fire or explosion. When combined with data on the material being handled, this provides a complete picture of the risk. In addition to just providing a level of risk and whether the risk should be considered tolerable or not, the tool provides clear guidance of the safeguard weaknesses and thus a clear guidance for improvement.