A Fuel Ratio Method for Estimating the MESG of Nitrogen- Diluted and Oxygen-Enriched Fuels, including the Brandes-Redecker Method to Estimate the MESG of Mixed Fuels

摘要

Properly specifying electrical equipment for hazardous (classified) areas requiresinformation about certain properties of the materials anticipated to be present. While it isa straight-forward procedure to test a product or stored intermediate in order to establish aGroup designation, testing is not in-expensive. Additional difficulty can arise when theelectrical equipment design must account for in-process compositional variations.This paper expands on published MESG data for four nitrogen-diluted and oxygenenrichedfuels, hydrogen, ethylene, propane, and methane. The data is compared topredictions of the NFPA-497 pseudo-MESG technique to account for nitrogen dilution.A new Fuel Ratio method is presented, which provides a closer, more conservativeestimation of nitrogen-diluted mixture properties. The Fuel Ratio method is alsoapplicable to oxygen-enriched fuel streams.