Wednesday, May 29, 2019

FACET3D Viewer

ABS Consulting provides a free viewer for clients to read and query their facility siting study results. This single executable reads a provided viewer file and displays the various contours (pressure, impulse, thermal) and allows the users to pan, zoom, and query points on the plot plan and obtain a listing of results. Buildings and scenarios can be turned on and off to show subsets of results which can be very helpful during turnarounds and portable building placement. Download the viewer executable below (requires the .NET framework 4.8) and ask your ABS representative for a viewer file of your site. 

FACET3D View Download



Tuesday, May 28, 2019

Multi-Energy Method (MEM) Vapor Cloud Explosion Calculator

The Multi-Energy Method (MEM) is one of the two main vapor cloud explosion prediction methods along with the Baker-Strehlow-Tang (BST) method. The MEM has been publicly available for over 15 years [1], it has been continually and recently updated [2,3], and it provides very good comparisons to test data [4]. The MEM is a blast curve based method. The blast curves are pressure-distance and duration-distance plots divided into 10 curves with each of the curves being called a severity level ranging from 1 to 10. These pressure curves are shown below. Similar curves exist for blast pulse duration.

Here is a spreadsheet which implements the core MEM method curve lookups. The user enters the congested flammable cloud volume along with the explosion severity level and downrange distance of interest and the worksheet returns the free-field pressure and impulse at that distance.

MEM Calculator and Data.xlsm





[1] Berg, A.C. van den, “The Multi-Energy Method, a framework for vapour cloud explosion blast predictions, TNO Prins Maurits Laboratory report No 1984-C72.
[2] Eggen, J.B.M.M., “GAME: development of guidance for the application of the multi-energy method,” Prepared for Health and Safety Executive, Prepared by TNO Prins Maurits Laboratory, 1995 (work completed in 1995 but subject to a publication embargo until 1998).
[3] Mercx, W.P.M., van den Berg, A.C., and van Leeuwen, D., “Application of correlations to quantify the source of strength of vapour cloud explosions in realistic situations – Final report for the project: ‘GAMES’,” TNO Report PML 1998-C53, TNO Prins Maurits Laboratory, October 1998 (work completed in 1998 but subject to a publication embargo until 2001).
[4] Fitzgerald, G.A., “A Comparison of Simple Vapor Cloud Explosion Prediction Methods,” Presented at the Mary Kay O’Connor Process Safety Center Symposium, College Station, TX, October 30-31, 2001.

Thursday, May 23, 2019

PHA Guidance for H2S Releases

I worked with some talented Marathon employees to develop a framework for PHA teams to assess the hazards from H2S streams on workers near a potential release. You can find the full article here at the Journal of Loss Prevention.