Practical Process Engineering

Deflagration – unstable detonation – stable detonation. L= distance to ignition-source D= Diameter of the pipeline V= velocity of the flame front P= pressure DDT = Deflagration to Detonation Transition

#Detonation Detonation is an explosion propagating at supersonic velocity and is characterised by a shock wave [EN 1127-1]. A distinction is drawn between stable detonations and unstable detonations . A detonation is stable when it progresses through a confined system without a significant variation of velocity and pressure characteristic (for atmospheric conditions, test mixtures and test procedures typical velocities are between 1,600 and 2,200 meter/second). A detonation is unstable during the transition of the combustion process from a deflagration into a stable detonation. The transition occurs in a spatially limited area in which the velocity of the combustion wave is not constant and where the explosion pressure is significantly higher than in a stable detonation. NOTE: The position of this transition zone depends, among others, on the operating pressure and operating temperature, on the pipe diameter, the pipe configuration, the test gas and the explosion group and must be predetermined by experiments in each case.

#Stabilized_Burning Steady burning of a flame, stabilized at or close to the flame arrester element. A distinction is drawn between short time burning (stabilized burning for a specific period) and endurance burning (stabilized burning for an unlimited period)

#Pre_Volume_Deflagration An explosion in a confined volume (such as within a vessel) initiated by an internal ignition source

#Atmospheric_Deflagration An explosion that occurs in open air without a noticeable increase in pressure

#Deflagration Deflagration is an explosion that propagates at subsonic velo-city [EN 1127-1]. Depending on the geometric shape of the combustion area, a distinction is drawn between atmospheric deflagration, pre-volume deflagration and in-line deflagration. 👇🏼👇🏼👇🏼👇🏼👇🏼👇🏼👇🏼👇🏼👇🏼

In line deflagration flame arrester internals (discs & cages)

In line flame arrestor for Deflagration

Internals of Flame arrester for Deflagration

End of line flame arrester for Deflagration

API-620 vs. API-650 vs. EN-14015

#T_xy #P_xy #H_xy #Ponchon_Savarit_Method #Binary_Mixture #HYSYS Following spreadsheet helps you extract T-xy, P-xy and H-xy data for binary mixtures from HYSYS. It reports the numeric data and, also, plots it. This spreadsheet is able to connect to HYSYS file whether it is open or close.