Nov 20, 2015 the new performance benchmark for detonation flame arresters elmac technologies has developed the uca series of unstable detonation arresters with better pressure drop and flow performance than any equivalent stable or unstable detonation arrester available. The major portion of the high pressure central portion of a detonation wave generated by a backflash is received by the cup and reflected back into the pipe. Simple method for predicting detonation pressure of chno. The diference between deflagration and detonation flame arresters flame arresters are mechanical safety devices that prevent a fire flame travelling from one part of a site to another and prevent a flame entering a vessel and igniting vapour. The diference between deflagration and detonation flame arresters. Deflagration and detonation flame arresters stanley s. An initial shock compresses a highexplosive material, heating it and causing chemical decomposition. Policy on stable detonation flame arresters detonation arresters guidance notes because unstable detonation arresters are designed and tested under the worst case conditions that any arrester is likely to experience for a given gasgroup and initial pressure, the physical location of a device within a piping system relative to the ignition. Us4909730a flame arrester having detonationattenuating. The flame arrester elements are optimised for lowest pressure drop while using a modular system of housings.
Fast deflagrations, deflagration to detonation transition. Detonation of a high explosive is complex phenomenon. They prevent flame propagation by absorbing and dissipating heat using spiral wound crimped ribbon flame cells. The enardo detonation flame arrestorrepresents the best value in flame arrestor protection. Once the detonation velocity is known, the mean flow of the following gas can be completely determined without any consideration of the front. The companies worked to develop a solution to protect the dow plant from highpressure flame propagation in their piping system. The assumptions of an instantaneous detonation and the hypothetical surface for the. The design is unique with larger flame channels that limit plugging and make cleaning easier. Protect your process with the proper flame arresters aiche. The highly turbulent and complex flows during flame propagation cannot yet be satisfactorily modelled. Deflagration and detonation flame arresters wiley online. Enardo flame arrestors dimensions may vary somewhat from those given above.
The material is mostly qualitative, aiming to illustrate the physical aspects of the phenomenon. Designed for chemical engineers and other technical personnel involved in the design, operation, and maintenance of facilities and equipment where deflagration and detonation flame arresters ddfas may be required, this book fosters effective application and operation of ddfas through treatment. Nevertheless, there are still unsolved problems as regards the effects of flame speed and transient explosion pressure, tests of unstable detonations and statistics of the deflagration to detonation transition ddt. One of the earliest successes in combustion science was the chapman and jouguet cj model to predict the detonation speed based solely on conservation laws and thermodynamic properties. Investigation of deflagrations and detonations in pipes and.
Enardo detonation flame arrestors provide protection against flame propagation in piping systems that are manifolded or have long runup distances. Pulse detonation engines use the detonation wave for aerospace propulsion. Box 831451115, islamic republic of iran hdepartment of chemistry, isfahan payamnoor university, isfahan, islamic republic of iran. Detonation involves a supersonic exothermic froant accelerating through a medium that eventually drives a shock front propagating directly in front of it. Deflagration and detonation flame arresters general. Liquid product end of line detonation flame arrester. This provides increased fire protection and safety. The design of the model 7758a flame arrester makes it ideal to protect liquid storage tanks containing both nec group d and group c vapors iec class iia and iib1 through iib3 vapors with a maximum experimental safe gap mesg equal to or greater than 0.
Critical parameters of the dust cloud providing complete suppression of the detonation wave and the flame propagating behind the latter at a reduced initial pressure of the gas mixture are determined. Investigation of deflagrations and detonations in pipes and flame arresters by highspeed framing. The formation of international journal of protective structures volume 6 number 4 2015 631. Deflagration to detonation transition fueled by dust layers.
The installation and the flow direction can be chosen freely. Overview flammability refers to the ability of a mixture of fuel and air to sustain combustion when ignited. Detonation flame arrestor has the heat capacity and structural design to withstand all dynamic conditions of flame propagation and still stop the flame. At our 150 acre environmental research and service center, we can conduct fullscale tests that will replicate your actual plant configurations and duplicate your flammable gas vapor conditions. Designed for chemical engineers and other technical personnel involved in the design, operation, and maintenance of facilities and equipment where deflagration and detonation flame arresters ddfas may be required, this book fosters effective application and operation of ddfas through treatment of their principles of operation, selection. Stabilized burning is an even, steady flame that is stabilized at or near the flame arrester element. Protect your process with the proper flame arresters p figure 1. Our detonation arresters are typically used for extended pipe length or multiple pipe bend configurations to stop high pressures and flame velocities associated with detonations and overdriven detonations. Investigation of deflagrations and detonations in pipes. Our detonation arrester element offers maximum flow to pressure drop characteristics enhancing the value of our product in any system. We make them in many standard and custom configurations. Our extensive range of unstable detonation arresters incorporates the patentprotected heds technology and offers protection in all explosion scenarios with no installation limitations. This new product, tested and approved for elevated preignition pressures.
Center for chemical process safety of the american institute of chemical engineers 3 park avenue, new york, new york i001 65991. Detonation is most often used for explosives and the acceleration of projectiles. Flame arresters are used in pipes to allow gas to flow but at the same time to prevent flame transmission. Understanding and specifying flame and detonation arresters. The variation of this velocity was measured for several dif ferent dusts and dust concentrations and compared to the. Its primary function is to allow the flow of gases or vapor of flammable liquids through the enclosure, but prevent the transmission of a flame. An atmospheric deflagration occurs in the open air. They provide protection against flame propagation in piping systems that are. Whilst offering an unrivalled level of customer support we have developed an innovative range of flame arresters, valves and ancillary products that have been engineered to meet the specific requirements of fuel distribution applications.
Fill a long tube with a fueloxygen mixture, ignite it with a spark at one end, and you are likely to observe a supersonic combustion wave or detonation moving with a remarkably constant speed that is between five and ten times the velocity of sound in the original mixture. A detonation flame arrester also spelled arrestor is a device fitted to the opening of an enclosure or to the connecting pipe work of a system of enclosures and. When properly applied, protectoseal flame arresters and detonation arresters are effective in preventing the propagation and transmission of a flame or flame front in locations where flammable vaporair or. Elmac technologies has developed a new range of unstable detonation arresters with pressure drop and flow performance which is better than any equivalent stable detonation arrester currently on the market. Protect your process with the proper flame arresters. Some of the detonation wave passes around the cup and impinges on the arrester elementhowever it has been delayed sufficiently to ensure complete quenching of the flame front in the element. Detonation flame arrestors is different from deflagration flame arrestors as it is supersonic and propagates through shock. All gas must be blocked and pressure safely vented.
Detonation flame arresters, arrestors barton firtop eng co. Detonation flame arresters, arrestors barton firtop eng. These cells allow maximum flow with maximum protection. Enardo dfa series detonation flame arrestors represent the best value in flame arrestor protection. Numerical analysis of the deflagration to detonation. Flametransmissionproof kito devices for storing and. Investigation of deflagrations and detonations in pipes and flame arresters by highspeed framing article in journal of loss prevention in the process industries 171. Difference between deflagration and detonation flame. Connection sizes range from 34 inch up to 36 inches.
It is ideal for engineers and graduate students with a background in thermodynamics and. By jef snoeys fike corporation chemical processing. Try our industry leading endofline deflagration flame arresters acting as a fire trap in even that harshest of industry conditions. En model detonation flame arrestor dimensions indicates a 6 concentric detonation flame arrestor with a 12 carbon steel housing, ansi 150 lb. Flame arresters in piping systems paradox intellectual properties.
Flame and detonation arrestors advanced energy solutions, llc. Inline deflagration flame arrester inline detonation arrester. Arresters protect low flash point liquids from externally caused sources of heat and ignition. The groth model 7758a flamedetonation arrester is available in standard flange sizes of 2 12 and in carbon steel, stainless steel or hastelloy c. Download fulltext pdf download fulltext pdf an evaluation of new procedures for testing explosion arresters article pdf available in process safety and environmental protection 764. Typical kito flame arrester elements, which prevent the propagation of flames and explosions both deflagration and detonation in all kinds of tank farms.
Thenewperformancebenchmarkfordetonationflamearresters. The asd 535 aspirating smoke detector performs the task of taking continuous air samples via one or two sampling pipe networks from a monitored area and feeding the samples to one or two smoke sensors. Flammability and flashback prevention a work in progress dan banks, p. Fuel distribution safety unstable detonation arresters, arrestors. Safety protect your process with the proper flame arresters. The general principle is that during the early stages of an explosion the explosion vent cover opens, burnt and unburnt dust and flame enter the flame arrestor element. Enardo flame arrestors use spiral wound, crimpedmetal ribbon flame cell elements to inhibit flame propagation by absorbing and dissipating heat. A flame arrester for a pipe line is provided comprising a detonation attenuator mounted within the arrester chamber between the quenching element and the backflash flame inlet. Flame arresters must be isolated from the gas piping before performing maintenance.
The attenuator is generally cupshaped, aligned with the inlet, of greater diameter than the inlet but of lesser diameter than the arrester chamber, and is positioned close to the inlet so as to circumscribe it. Detonation is an explosion that propagates at supersonic velocity and is. Fuel distribution safety unstable detonation arresters. If explosive vapour or gas mixtures are ignited in a pipe, a deflagration can develop into a stable detonation if the pipe work and runup length are appropriate. Flame arresters prevent flames from entering a pipe in case of ignition and helps to protect the safety of. Detonation flame arrester model cfh paradox intellectual. Pdf an evaluation of new procedures for testing explosion.
A prevolume deflagration takes place within a confined volume. Flameless venting devices typically comprise a vent panel, flanged housing, and a flame arrestor element. Practical use of detonation flame arresters the use of detonation arresters as a means of explosion protection in industries handling flammable liquids, vapours and gases is widespread but is often widely misunderstood a situation which can lead to potentially dangerous installations. The new european standard en 12874 provides guidance for testing such flame arresters. This hydrogen detonation flame arrester is manufactured with currently available offtheshelf components. A detonation is characterized by supersonic flame propagation velocities, perhaps up to 2000 ms, and substantial overpressures, up to 20 bars. Detonation flame arrestor is used when the flame can be in any of the detonation states. Detonation flame arresters meeting this standard as type i devices, which are certified to be effective below 0 c and which can sustain three stable detonations without being damaged or permanently deformed, also comply with the minimum requirements of the international maritime organization, maritime safety committee circular no. Numerical analysis of the deflagration to detonation transition in primary explosives19 cj theory, and the physical phenomena accompanying the accelerating wave of flame in solid explosives is discussed. Hydrogen detonation flame arrester fireflashback arrester. Net free area through the bank is three to four times the unit pipe size, reducing. As a result, the mechanism of ignition in the decaying detonation wave becomes different.
For example, flame arresters can stop the spread of a fire, limit the. This hydrogen detonation flame arrester is manufactured with. When properly applied, protectoseal flame arresters and detonation arresters are effective in preventing the propagation and transmission of a flame or flame front in locations where flammable vaporair or gas mixtures are present. For example, flame arresters can stop the spread of a fire, limit the spread of an explosive. The resultant force of such an detonation is tremendous.
Dfa series detonation flame arrestor uscgatex approved. Details of models of the ddt analyzed in 1 and the results of. Our portfolio includes inline, free vent, deflagration and detonation flame arrestors. Detonation flame arrester dfa 251 tubes and fittings. We manufacture all types and all sizes, including deflecting baffle detonation breakers. Flame arresters should be placed as close as possible to a potential ignition source and no further than 10 feet from a potential ignition source. Gauge hatches 95000 2 5911 butterfield road, hillside, illinois 60162 phone. The new performance benchmark in detonation flame arresters. Health and safety executive flame arresters preventing the spread of fires and explosions in equipment that contains flammable gases and vapours flame arresters preventing the spread of fires and explosions in equipment that contains flammable gases and vapours this is a freetodownload, webfriendly version of hsg158 first edition, published. Elmacs flame arresters incorporate our industryleading eflow technology that delivers higher rates of flow, lower pressure drop and reduced fouling characteristics.
They provide protection against flame propagation in piping. Flame and detonation arrestors advanced energy solutions. Cutaway view of dfa series detonation flame arrestor figure 3. Typical locations for inline and endofline arresters are shown in figure 1, page 4. This design quenches a flame front approaching from either direction, even if it has transitioned to a detonation. By placing them as close as possible, this ensures that the flame arrester is not exposed to a detonation event which the flame arrester has never been intended to stop. The detonation phenomenon this book introduces the detonation phenomenon in explosives.
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