Barricade

A great deal of experimental work has also been done to identify and quantify the ha2ards of explosive operations (30—40). The vulnerabiUty of stmctures and people to shock waves and fragment impact has been well estabUshed. This effort has also led to the design of protective stmctures superior to the conventional barricades which permit considerable reduction ia allowable safety distances. In addition, a variety of techniques have been developed to mitigate catastrophic detonations of explosives exposed to fire. 

In general, pilot-plant space can be divided into five basic types separate buildings, containment cells or barricades, open bays, walk-in hoods, and laboratory areas. A summary of the advantages and disadvantages of each has been given (1). 

Protection against explosions is typically provided by explosion-venting, using panels or membranes which vent an incipient explosion before it can develop dangerous pressures (11,60). Protection from explosions can be provided by isolation, either by distance or barricades. Because of the destmctive effects of explosions, improvement in explosion-prevention instmmentation, control systems, or overpressure protection should receive high priority. 

Some vessels may be exposed to a runaway chemical reaction or even an explosion. This requires relief valves, rupture disks, or, in extreme cases, a barricade (the vessel is expendable). A vessel with a large rupture disk needs anchors designed For the jet thrust when the disk blows. 

High pressure autoclaves may be used fitted with remote control behind safety barricades, which are necessary beeause of the danger of explosions. In a typical process the autoclave is half-filled with alcohol containing 15%... 

Consider need for high/low temperature alarms for refrigerated storage these should be inspected and tested regularly. Consider need for mitigatory measures (fire, blast, fragment-resistant barricades/screens), electrical and electrostatic safeguards, personal protection, disposal etc. 

Process units, especially critical equipment and storage areas, should be adequately spaced. When tliis is impossible, barricades, fire protection units, and protective construction should be provided. 

See also under Buildings and Other Structures at Ordnance Establishments in Vol 2, B320-R to B321-R, and Barricades in Explosives and Ammunition Installations in Vol 2, B22-R to B23-R... 

Natural Barricade. See under Barricades in Explosives and Ammunition Installations in Vol 2, B22-R. 

For powders which may be classified dangerous, such as finely divided Ti and Zr and mixts containing these powders, the shaking machine should be grounded and wherever. possible the operation carried out behind a suitable barricade by remote control. Operators should observe all safety precautions, including the use of proper clothing, and a liq antistatic agent should be used to coat the screens and frames. 

The term petard was formerly used to designate an ancient device for bursting open gates, barricades, or doors to which it was attached. Basically a case filled with expls, the petard somewhat resembled a short mortar. 

The Arsenal is located in the central portion of northern New Jersey, near the town of Dover. This places it at the outer rim of the New York metropolitan area. It occupies a ten mile long valley, lying between mountain ridges which serve as natural barricades. The valley also has a natural water supply which, even today, is adequate. These are the three attributes for which the site was selected nearness to the world of commerce means of protection of the surrounding area from the hazards inherent in its work and the availability of the one extremely vital natural resource — water... 

It is strongly recommended that our procedure1 not be used to prepare guanidine nitrate. Mixtures of ammonium nitrate and organic materials not much different from the mixture in the procedure are now used extensively as commercial explosives. The aqueous mixture of Note 101 is similar to some aqueous mixtures used in sizable quantities for rock blasting a confined mixture of this sort is especially hazardous. Only a few laboratories devoted to explosives research have the barricades and remote control devices needed to run this preparation of guanidine nitrate without risk. 

Although it is more desirable to remove unreliable underground tanks, a tank may be abandoned in place, for example, when it is indoors, under a building, beneath a foundation, or barricaded with other constructions. 

The electron-transfer rate between large redox protein and electrode surface is usually prohibitively slow, which is the major barricade of the electrochemical system. The way to achieve efficient electrical communication between redox protein and electrode has been among the most challenging objects in the field of bioelectrochemistry. In summary, two ways have been proposed. One is based on the so-called electrochemical mediators, both natural enzyme substrates and products, and artificial redox mediators, mostly dye molecules and conducted polymers. The other approach is based on the direct electron transfer of protein. With its inherited simplicity in either theoretical calculations or practical applications, the latter has received far greater interest despite its limited applications at the present stage. 

Detonations. Pressure rise ratios of -15 1 for hydrogen-air or methane-air detonations and a ratio of -12 1 for a gasoline-air detonation are normally expected. The impulse created by explosion pressure profile should be taken into account in evaluating explosion damage and in the design of barricades or structures to mitigate explosion consequences. 

Barricades. These are constructed to protect uncontrolled areas from the effects of a hydrogen system failure and to protect a hydrogen system from the hazards of adjacent or nearby operations. Barricades have been shown to be most effective against... 

Barricades should be designed to block the line of sight between equipment from which fragments can originate and protect items. 

Barricades should be placed adjacent to the fragment source for maximum protection. 

The efficiency of barricades depends on the height aboveground and barricade location, dimensions, and configuration. 

Barricades can reduce peak overpressures and impulses behind the barricades, but reflections on obstacles may amplify blast waves behind barricades. 

Single-revetted barricades are more efficient than mounds. 

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