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Gaseous Products (gaseous + products)

Distribution by Scientific Domains

Chemistry	80%

Selected Abstracts

Prediction of entrance length and mass suction rate for a cylindrical sucking funnel

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS, Issue 6 2010
Dipti Prasad Mishra
Abstract Conservation equations for mass, momentum and energy have been solved numerically for a cylindrical funnel with louvers (lateral openings on the side wall of the cylindrical funnel through which air can come into it) to compute the suction rate of air into the funnel. The nozzle placed centrally at the bottom of the cylinder ejects high-velocity hot gaseous products so that atmospheric air gets sucked into the funnel. The objective of the work is to compute the ratio of the rate of mass suction to that of the mass ejected by the nozzle for different operating conditions and geometrical size of the funnel. From the computation it has been found that there exists optimum funnel diameter and optimum funnel height for which the mass suction is the highest. The protruding length of the nozzle into the funnel has almost no effect on the mass suction rate after a certain funnel height. The louvers opening area has a very high impact on the mass suction rate. The entrance length for such a sucking funnel is strikingly much lower compared with a simple cylindrical pipe having uniform flow at the inlet at same Reynolds number. A new correlation has been developed to propose the entrance length for a sucking pipe, the rate of mass suction into it and the exhaust plume temperature over a wide range of operating parameters that are normally encountered in a general funnel operations of naval or merchant ship. Copyright © 2009 John Wiley & Sons, Ltd. [source]

Pyrolysis of tetra pack in municipal solid waste

JOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 8 2001
Chao-Hsiung Wu
Abstract The pyrolysis of tetra pack in nitrogen was investigated with a thermogravimetric analysis (TGA) reaction system. The pyrolysis kinetics experiments for the tetra pack and its main components (kraft paper and low-density poly(ethene) (LDPE)) were carried out at heating rates (,) of 5.2, 12.8, 21.8,K,min,1. The results indicated that the one-reaction model and two-reaction model could be used to describe the pyrolysis of LDPE and kraft paper respectively. The total reaction rate of tetra pack can be expressed by the summation of the individual class of LDPE and kraft paper by multiplying the weighting factors. The pyrolysis products experiments were carried out at a constant heating rate of 5.2,K,min,1. The gaseous products were collected at room temperature (298,K) and analyzed by gas chromatography (GC). The residues were collected at some significant pyrolysis reaction temperatures and analyzed by an elemental analyzer (EA) and X-ray powdered diffraction (XRPD). The accumulated masses and the instantaneous concentrations of gaseous products were obtained under the experimental conditions. The major gaseous products included non-hydrocarbons (CO2, CO, and H2O) and hydrocarbons (C1,5). In the XRPD analysis, the results indicated that pure aluminum foil could be obtained from the final residues. The proposed model may be supported by the pyrolysis mechanisms with product distribution. © 2001 Society of Chemical Industry [source]

Quantum Chemical Study on the Interactions of NO3 with RDX and Four Decomposition Intermediates

PROPELLANTS, EXPLOSIVES, PYROTECHNICS, Issue 4 2010
Jidong Zhang
Abstract Recently, NO3 (nitrate radical) was predicted to be formed during the decomposition of RDX. However, experimental studies of the gaseous products have never detected it. In order to verify the prediction, we studied the interactions of NO3 with RDX and four RDX decomposition intermediates (RDR, C3H5N5O4, OST, and TAZ) by using density functional theory (DFT). It is found that NO3 radical can be converted into NO2 during the process of interactions with the above-mentioned five molecules. In other words, NO3 radical can be consumed in these processes, which gives an explanation for the disappearance of NO3. Transition state theory (TST) calculations lead to the same results. The binding energies are calculated to estimate the strength of interactions. The energy of NO3 with RDR is the largest, which indicates this process is most likely to occur. Our calculation provides a support to the prediction of the formation of NO3. [source]

Detonation and Blast Wave Characteristics of Nitromethane Mixed with Particles of an Aluminium,Magnesium Alloy

PROPELLANTS, EXPLOSIVES, PYROTECHNICS, Issue 2 2010
Waldemar
Abstract Investigation of detonation parameters, blast wave characteristics and quasi-static pressures (QSPs) for the mixtures of nitromethane and particles of an aluminium and magnesium (Al3Mg4) alloy was carried out. The mixtures of gelled nitromethane containing 15,60,wt.-% AlMg alloy were tested. Detonation velocity and Gurney energy were determined. Parameters of blast waves produced by charges of the investigated explosives were measured. QSP measurements were conducted in a steel chamber of 0.15,m3 volume filled with air. Thermochemical and gasdynamical calculations were also performed. The degree of combustion of the metallic addition with the gaseous products during detonation and expansion is discussed. [source]

Thermal Decomposition of Energetic Materials 84: Pyrolysis of 5-Substituted 1,3,5-Trinitrohexahydropyrimidines

PROPELLANTS, EXPLOSIVES, PYROTECHNICS, Issue 2 2003
Brian
Abstract Results of slow and fast pyrolysis were compared for 1,3,5-trinitrohexahydropyrimidine compounds in which the 5-position was substituted by H, CH3, NO2, CH2ONO2, and CH2N3. IR and Raman spectroscopy were used to identify and quantify all of the gaseous products. The decomposition process appears to be initiated by reactions at the 5-position of the ring. The gases produced are rather similar for all of the compounds, however the different functional groups impart their own signature on the concentrations of several products. [source]