Static discharges effective energy

The practical content of this book is mostly contained in Chapter 5 (gases and liquids) and Chapter 6 (powders and hybrid mixtures) with other chapters providing supporting material. Chapter 2 contains a brief explanation of the nature of static electricity followed by a detailed discussion of the characteristics and effective energies of different static discharges. Since this... 

The effective energy of the static discharge must exceed the ignition energy of the local mixture. 

The maximum effective energy of a static discharge can be compared with the MIE of a dust to determine whether ignition is probable, as discussed in Chapters 2 and 3. MIE test methods are described in S-5.4.2 and special considerations discussed in 6-1.3 through 6-1.5. At the time of writing, ASTM was close to development of a standard for dust MIE measurement. 

The terms represent, respectively, the effect of pressure gradient, acceleration, line friction, and potential energy (static head). The effect of fittings, bends, entrance effects, etc., is included in the term Ke correlated as a number of effective velocity heads. The inclination angle 0 is the angle to the horizontal from the elevation of the pipe connection to the vessel to the discharge point. The term bi is the two-phase multiplier that corrects the liquid-phase friction pressure loss to a two-phase pressure loss. Equation (23-39) is written in units of pressure/density. 

---