Compressed gases incidents

Single-unit tank cars are protected from excessive internal pressure by a spring-loaded pressure relief valve located on the manway cover plate. Excess flow-check valves are installed on the liquid eduction and vapor lines of many tank cars in compressed gas service. These excess flow valves are intended to contain the tank contents in transit, in a wreck environment if the valve is sheared off, or during other incidents when uncontrolled release of product may occur. 

Fig. 11.33 Diagram of wave front propagation within a working part A - incident shock wave B - contact discontinuity C - centered rarefaction wave D - reflected shock wave 1 - undisturbed air 2 - air compressed by incident shock wave 3 - combustible gas flowing out of the high pressure pipeline 4 -undisturbed combustible gas 5 - air compressed behind the reflected shock wave 2 and 5 K - gas mixture state in the vicinity of the contact discontinuity [40, 47]...

Nitromethane [75-52-5] is produced in China. Presumably a modified Victor Meyer method is being employed. Nitromethane is transported in dmms or smaller containers. Two tank cars of nitromethane exploded in separate incidents in the 1950s. Both explosions occurred in the switching yard of a railroad station. In both cases, essentially adiabatic vapor compression of the nitromethane—air mixture in the gas space of the tank car resulted in the detonation of the Hquid nitromethane. Other nitroparaffins do not, however, detonate in this manner. 

Some of the latest designs for platforms in the North Sea has segregated the process (i.e., separation, gas compression, etc.) facilities furthest from accommodations and utility support. Drilling modules are sited between the process and utility support modules based on the level of relatively lower risk drilling in a defined reservoir represents versus possible process incidents. 

The approach to the critical point, from above or below, is accompanied by spectacular changes in optical, thermal, and mechanical properties. These include critical opalescence (a bright milky shimmering flash, as incident light refracts through intense density fluctuations) and infinite values of heat capacity, thermal expansion coefficient aP, isothermal compressibility /3r, and other properties. Truly, such a confused state of matter finds itself at a critical juncture as it transforms spontaneously from a uniform and isotropic form to a symmetry-broken (nonuniform and anisotropically separated) pair of distinct phases as (Tc, Pc) is approached from above. Similarly, as (Tc, Pc) is approached from below along the L + G coexistence line, the densities and other phase properties are forced to become identical, erasing what appears to be a fundamental physical distinction between liquid and gas at all lower temperatures and pressures. 

The propellant was simply pent-up water and steam pressure. The destructive pressure buildup occurred as the compressor operated for over five hours with no cooling water flow. Cooling water was trapped in the water jacket on the compression head as the compressor piston continued operating. The team concluded that the fragmentation of the compressor water jacket was a consequence of the operating condition, and a metal failure analysis of the compressor head was not necessary. The damage was immediate and limited, there was no release of gas, and the incident did not require the attention of the available on-site emergency squad. Fortunately, there were no personnel injuries due to this incident. 

Only two poisons in this group require routine exclusion. These are cyanide and carbon monoxide. The main exceptions to diis general recommendation are cases arising from an incident on industrial premises, or the use and abuse of compressed solvent fuels and aerosols. In the former case, a list of the industrial gases used or available on site should be requested in die latter case, most of the relevant compounds are covered by head-space gas chromatography as mentioned above. 

The purpose of our work was to examine whether the compressed hot cluster provides an effective medium for reactions with high barriers. In the simplest case of cluster impact experiments, the reactants are embedded inside a rare gas cluster, and this cold droplet is incident on an inert surface at various velocities. Two classes of reactions were examined in detail using standard molecular dynamics simulations the dissociation of halogen molecules and four-center reactions. ... 

The first source of stress wave relates to the back-momentum exerted by the ejected material. This results in a compressive wave propagating through the substrate [1, 3]. The exact dependence of the peak stress amplitude on the incident fluence depends on the time scale of material removal, as well as the exact nature of the process (e.g., explosive vs surface vaporization). It can be estimated by assuming the ejected material to be an ideal gas expanding against the air and the substrate, resulting in the expression (for surface vaporization) [106] ... 

In the shock initiation mode [2], either an incident or reflected shock wave is the primary means to produce the detonation. Betsically, the shock rapidly heats the gas by compression. Under suitable conditions, an explosion occurs behind the shock wave. This explosion generates accelerating pressure waves, which quickly become a detonation wave before or after catching up with the initially applied shock wave. In the present U.S. Office of Naval Research (ONR) project, the simulation of shock initiation mode has been used to access the numerical accuracy and to validate the code. In the last mid-year review, detailed simulation of detonation initiation by a reflected shock was reported. The results were also summarized and reported in the AIAA Sciences Meeting held in 2002 [3]. 

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