Ignition temperature methods

Volume of vessel (free volume V) Shape of vessel (area and aspect ratio) Type of dust cloud distribution (ISO method/pneumatic-loading method) Dust explosihility characteristics Maximum explosion overpressure P ax Maximum explosion constant K ax Minimum ignition temperature MIT Type of explosion suppressant and its suppression efficiency Type of HRD suppressors number and free volume of HRD suppressors and the outlet diameter and valve opening time Suppressant charge and propelling agent pressure Fittings elbow and/or stub pipe and type of nozzle Type of explosion detector(s) dynamic or threshold pressure, UV or IR radiation, effective system activation overpressure Hardware deployment location of HRD suppressor(s) on vessel... 

Hazard or event identification provides information on situations or chemicals and their releases tliat can potentially hanii tlie emaromiient, life, or property. Inforniation that is required to identify hazards includes chemical identities, quantilics and location of chemicals in question, chemical properties such as boiling points, ignition temperatures, and to.xicily to hmnans. There arc sci cral nictliods used to identify hazards. The methods that will be discussed later in tliis Part w ill include tlie process checklist and tlie hazard mid operability study (HA20P). 

The results of the catalytic activity for methane combustion are summarised in Table 1 and fig. 1. The methane conversions of the Pd2HZSHe catalyst are higher than those of the Pd2HZIHe sample. In fact, the ignition temperatures T10% (temperature necessary to have 10% of methane conversion) are respectively 355 and 371°C. This result suggests that the catalyst prepared by solid-exchange method is more active than that prepared by impregnation. 

Furthermore, no significant differences are observed on the methane conversion or on the ignition temperatures of the Pd2HZSHe and the Pd2HZS02 catalysts. This result presumes that the catalyst pre-treatment with oxidant or with inert gas has the same effect on the activity of the Pd-HZSM-5 catalysts prepared by the solid-exchange method. Moreover, a noticeable methane conversion increase is observed when the NaZSM-5 support is used instead of the HZSM-5 zeolite. The ignition temperatures... 

As a result of these new testing methods the following terminology for ignition temperature definitions has been proposed ... 

An improved method for determining the AIT of solids has been described, and the effect of catalytically active inorganics on the reactivity and ignition temperature of solid fuels has been studied. Sodium carbonate markedly lowers the ignition temperatures of coal and coke [7], The volume of the vessel (traditionally a 200 ml flask) used to determine AIT has a significant effect on the results. For volumes of... 

The MIE of gas — air or vapour—air mixtures can be determined from the structural formula and the molar heat of combustion of the compounds studied, and equations for the calculation are presented. The method is stated to give more accurate results than conventional methods used to assess flammability of mixtures of gas or vapour with air [1], It is claimed that in oxygen MIEs are about a hundredfold lower than in air [2], A study of the ignition behaviour of dusts, including correlation of electrical and mechanical minimum ignition spark energies and ignition temperature is made [3],... 

Marshall 2(1917) Falling Weight Test (Lenze) (p 423) Friction Sensitivity Test (423) Sensitiveness to Detonation (429) Sensitiveness to Heat (434) Ignition Temperature (434) Heat of Explosion (440) Trauzl Test (469) Strength by Ballistic Pendulum (473) Velocity of Detonation by Dautriche Method (479) Brisance Meter of Hess (495)... 

Davis, Vol 1 (1941) Determination of Detonation Velocity by Dautriche Method (pp 14-18) Impact or Drop Test (p 21) Ignition Temperature Test (21-22) Stability Tests (22) Power by Trauzl Method (24-5) Brisance Tests by Small Lead Blocks (25-6) Aluminum Plate and Lead Plate Tests for Detonators (26-7)... 

Numerous tests exist for determining ignition temperature, but few of them give the same result. Results may vary as much as 100° depending on the method used, on the rate of heating, on the size of the sample used, on the state of division etc. See Thermal Explosions for a discussion of why measurement variables affect ignition temp results... 

Explosion (Detonation, Deflagration or Ignition) Temperature, It is the temperature at which an explosive, propellant or pyrotechnic composition explodes, detonates, deflagrates or ignites within a definite time, say 0.1t 1-0 or 5.0 seconds. Various methods for its determination arebriefly described in Vol 1, p XVI under Ignition (or Explosion) Temperature Tests... 

Flash Point or Ignition Temperature may be detd by various methods such as those outlined in Refs 89 and 101. According to Ref 89, pure AN can be decompd by a flame at a temp of 395—6°, while a petrolated AN decomp at ca 380°. According to US Dept Agric Circ No 719 the fl p of AN is ca 500°... 

Ignition temperature was used with partial success (52, 57, 74, 135,189). Results depended critically on the method used—e.g., adiabatic compression, ignition limits in tubes, or crucible method. Jackson (70, 86, 87) determined ignition temperatures for a large number of hydrocarbons by the crucible method and developed correlations with structure. 

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