Assessing the explosive dust concentration and explosion risk in Shahroud high-risk industries

Intoduction: Combustible dust particles when dispersed in the air under special conditions have a risk of explosion. Distribution of dust particles in sufficient amount and concentration can cause rapid ignition and explosion. The aim of this study was to assess the risk of combustible dust explosions, in the some related industries in shahroud. Methods: To evaluate dust concentration, the NIOSH 0500 method was used. To determine the combustion risk, risk assessment was conducted using the Failure Mode Effects Analysis (FMEA). The main sources of possible secondary explosion were determined by observation and interviews with managers and supervisors. Results: The concentration of combustible dust in industries showed that the most explosive dust generation was related to the PVC industry with a concentration of 43 ± 74 mg per cubic meter. The FMEA risk assessment results also showed that the most risky equipment in creating sparks and combustion include conveyors, dryers, cutting and drilling equipment, motors and switchgear lightning. Also, the study showed silos with their high storage capacity can be the most likely sources of secondary explosions. conclusions: This study showed that combustible dust concentration is much lower than the minimum explosive concentration. However, due to the existence of combustion vast resources and huge storage resources of powder products, dust explosion in some of these industries is very important. Received: 17.04.2016 Accepted: 22.08.2016