Ignition, flame system

Practically, one of the most important reactions of CO is its exothermic oxidation to CO, from which a very large proportion of the world s useful energy is derived. It has been known for many years that dry CO/O2 flames are difficult to ignite and have lower burning velocities than similar flames derived from moist CO [354]. In this particular, the explosion and flame systems behave analogously. 

Heated flat-flame burners also have been used for the stabilization of cool-flame and two-stage ignitions. These systems were pioneered by Agnew et al. [76], and a definitive study of the spatially resolved chemistry of diethyl ether combustion has been reported [77]. Ballinger and Ryason [78] have described this type of burner in detail and have reported the relative behaviour of some n-alkanes, PRF fuel mixtures, and the effect of anti-knock additives. 

The USS Essex and three other LHD-class amphibious assault ships utilize furnace cameras to observe flame patterns and identify potential problems in a boiler combustion monitoring system and also monitor a pushbutton igniter-control system. Previously, a sailor monitored the fires through a small porthole, and an engineer in a flame-resistant jacket lit the boilers with a torch. If unburned fuel was in the boiler, explosions could occur. 

Operators also monitor flame distribution in the boilers and adjust combustion as necessary. This information can be used in conjunction with other NO reduction equipment. Cameras can monitor and detect the effect of systems that introduce too much oxygen into the combushon process, creating more NO. Cameras also decrease start-up time by several hours because they confirm burner and igniter flames and allow operators to quickly idenhfy faulty flame-scanner indications. 

In contrast to the previously discussed reduction schemes, in which chemical species only are selected if they are in steady state throughout the process, the adaptive method allows species to be selected at each operating point or domain separately, generating adaptive chemical kinetics. This is a dynamic reduction procedure that can be employed to ignition systems that are changing over time and to flame systems that change over the flame coordinate. As discussed for the LOl, in some cases the maximum accumulated value over the computational... 

Zambon, A.C., Cheiiiah, H.K. Explicit reduced reaction models for ignition, flame propagation, and extinction of C2H4/CH4/H2 and air systems. Combust. Flame 150, 71-91 (2007)... 

Adjust the operating conditions of the gas chromatograph to conform to the list in Table 2. Turn on the detector, ignite flame, and allow the system to equilibrate. 

An approximate equilibrium is set up in the plasma, with the electrons, ions, and atoms having velocity distributions similar to those of a gas that has been heated to temperatures of 7,000 to 10,000°C. Since the plasma is ignited toward the end of the concentric tubes from which argon gas is issuing, the plasma appears as a pale-blue-to-lilac flame coming out of the end of the tube, which is why the system is referred to as a torch, as in a welding torch. 

Explosion-proof enclosures are characterized by strong metal enclosures with special close-fitting access covers and breathers that contain an ignition to the inside of the enclosure. Field wiring in the hazardous environment is enclosed in a metal conduit of the mineral-insulated-cable type. All conduit and cable connections or cable terminations are threaded and explosion-proof. Conduit seals are put into the conduit or cable system at locations defined by the National Electric Code (Article 501) to prevent gas and vapor leakage and to prevent flames from passing from one part of the conduit system to the other. 

Detonation arresters are typically used in conjunction with other measures to decrease the risk of flame propagation. For example, in vapor control systems, the vapor is often enriched, diluted, or inerted, with appropriate instrumentation and control (see Effluent Disposal Systems, 1993). In cases where ignition sources are present or pre-dic table (such as most vapor destruct systems), the detonation arrester is used as a last-resort method anticipating possible failure of vapor composition control. Where vent collec tion systems have several vapor/oxidant sources, stream compositions can be highly variable and... 

Particularly reasonably priced explosion isolation of systems involves the use of a relief pipe with which the flow direction can be diverted by 180°. It prevents flame jet ignition with precompression in constructionally protected equipment. If suction is present, explosion propagation can occur. To prevent this, the use of an additional extin-gui ing barrier or a rapid-action gate valve is necessary. If a diverter is installed where positive pressure feed is given, then the diverter is, in general, safe against an explosion propagation. 

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