Simplified Criteria for the Application of Blast Loads from Accidental Explosions in Plant Design

• Main Authors: Sabatino Ditali, Fulvio Ragno, Roberto Fiore, Jumriani Jumriani
• Format: Article
• Language: English
• Published: AIDIC Servizi S.r.l. 2018-09-01
• Series: Chemical Engineering Transactions
• Online Access: https://www.cetjournal.it/index.php/cet/article/view/8918

The criteria for the application of accidental design loads - in relation to the required performance to each system of a process plant - need to be established during the design activities. This includes the consideration of blast loads on critical items required for safety, emergency and evacuation purposes, and any equipment whose failure can cause escalation, which shall be designed to resist to accidental explosions. Based on the typical characteristics of the pressure wave (magnitude, duration, and shape), the force acting on the item of interest needs to be determined for the structural design of supporting structures, process equipment and piping, both in onshore and offshore facilities. This paper aims to present a guideline, with a set of simplified relations, that can be used for the calculation of the force acting on components subject to accidental explosions, depending on the type of blast loading, and the shape, size and response of the affected object. The characteristics of the blast load can be calculated with a variable degree of accuracy using explosion models of different sophistication, like CFD (Computational Fluid Dynamic) software. A key issue in the design activities is establishing a link between the results that such models may provide and the information actually needed by the structural engineer to consistently design a system capable of resisting to the anticipated explosion scenarios. This is a typical multi-disciplinary field, that challenges the CFD expert, the safety specialist, and the structural engineer to share their experiences, and speak the same language.