VENT ACCESS RESTRICTION FOR SOLIDS HANDLING SYSTEMS

A multi-disciplinary team developed a guideline for determining access restriction zones around vented solids handling equipment. The guidel ine provides a method for ensuring the discharge from a vented explosi on will not cause injury to personnel. The steps in this method includ e: calculating the extent of external hazards from vented explosions; identifying potential areas where personnel could be exposed to a haza rd; identifying ways to eliminate or reduce the hazard area, and estab lishing and documenting any access restrictions needed. Hazard zone ca lculations use the latest knowledge front research into fireball size, flame length and external pressure equations in VDI 3673. The guideli ne provides guidance for using this information. Options for mitigatin g or reducing external hazards from vented explosions are also describ ed. As part of the project, the team audited several solids handling s ystems to look for potential oversights in existing restricted access areas. Some of the team's learnings from these audits are reviewed.