Jan Skřínský

Explosions Caused by Corrosive Gases/Vapors

Gas/vapor cloud explosions and fires are responsible for most of the largest property loss events worldwide in the hydrocarbon industry. Motivation for this article is to summarize explosion pressure caused by corrosive gases/vapors in terms of mathematical modeling. Presented explosions based on real scenarios of accidents associated with transport and storage facilities with corrosive flammable chemicals. While explosions of pure flammable chemicals are well described in the literature, the information about explosions of corrosive and toxic flammable substances is rather scarce. This work aims at studying the explosion behavior of pure hydrogen-air, pure ammonia-air, ammonia-hydrogen-air, ammonia-methanol-air, ammonia-ethanol-air mixtures at different initial temperatures and pressures. The results of mathematical modeling of the calculated maximum explosion pressure are described.

Aerosols and the methods of determining the characteristics of nanoparticles

The purpose of this paper is to address the issue of aerosols by defining and dividing them in terms of their size, spatial localization and composition. The paper briefly deals with the issue of the origins and formation of aerosols. Further, it describes the trends in measuring nanoparticles based on their electric field mobility behavior, condensation, optical properties and aerosol particle acceleration in an air-stream.

BLEVE - Cases, Causes, Consequences and Prevention

Corrosion is typical of the damage that occurs in ageing pressure vessels and pipelines used in industrial processes as a result of reactive products inside or harsh environmental conditions on the outside. Motivation for this article is to summarize cases, causes, consequences, and prevention in terms of models for the prediction of explosion pressure from BLEVEs. The contribution deals with real scenarios of accidents associated with transport and storage pressurized facilities with corrosive flammable chemicals. While the LPG, propane, and butane BLEVEs are well described in the literature, the information about corrosive and toxic flammable substances are rather scarce. The study presents the results of hazardous zone calculation for the event of ammonia corrosive non-flammable chemical releases. For calculations of the BLEVE overpressure, AICHE ́s Prugh ́s and Baker ́s models together with Effects 9.0.8. Rupture of vessels model were used for this study.

Explosion characteristics of blast furnace gas

Celem artykulu jest charakterystyka i zagrozenia wynikające z wybuchu gazu wielkopiecowego. Nie-bezpieczenstwo pozaru i wybuchu wywolane jest przez latwopalne skladniki gazu wielkopiecowego. Aby zapobiec wybuchom w trakcie powstawania gazu wielkopiecowego konieczne jest poznanie granic wybuchowości poszczegolnych skladnikow gazu i mieszanin gazowych z powietrzem. Gaz wielkopieco-wy z roznych wielkich piecow moze sie znacznie roznic pod wzgledem skladu. W związku z tym, dla kaz- -dego skladu gazu nalezy określic granice wybuchowości. Wymaga to znacznego czasu i wysilek. Z tego powodu granice wybuchu gazu wielkopiecowego są czesto określane (w literaturze dotyczącej bezpie-czenstwa) tylko przez zawartośc frakcji wodorowej w mieszaninie gazowej. W rzeczywistości gaz wiel-kopiecowy sklada sie z wodoru, tlenku wegla, dwutlenku wegla i innych gazow resztkowych. Granice wybuchowości są generalnie przekroczone.

Explosion characteristics of methane for CFD modeling and simulation of turbulent gas flow behavior during explosion

The effect of initial concentration on the explosion behavior of a stoichiometric CH4/O2/N2 mixture under air-combustion conditions was studied. Two mathematical models were used with the aim at simulating the gas explosion in the middle scale explosion vessel, and the associated effects of the temperature for different gas/air concentrations. Peak pressure, maximum rate of pressure rise and laminar burning velocity were measured from pressure time records of explosions occurring in a 1 m3 closed cylindrical vessel. The results of the models were validated considering a set of data (pressure time histories and root mean square velocity). The obtained results are relevant to the practice of gas explosion testing and the interpretation of test results and, they should be taken as the input data for CFD simulation to improve the conditions for standard tests.

Flashpoint prediction for ternary mixtures of alcohols with water for CFD simulation of unsteady flame propagation during explosion

Aqueous solutions of binary and ternary mixtures of alcohols are of considerable interest for a wide range of scientists and technologists. Simple dimensionless experimental formulae based on rational reciprocal and polynomial functions are proposed for correlation of the flashpoint data of binary mixtures of two components. The formulae are based on data obtained from flashpoint experiments and predictions. The main results are the derived experimental flashpoint values for ternary mixtures of two aqueous-organic solutions and the model prediction of maximum explosion pressure values for the studied mixtures. Potential application for the results concerns the assessment of fire and explosion hazards, and the development of inherently safer designs for chemical processes containing binary and ternary partially miscible mixtures of an aqueous-organic system. The goal of this article is to present the results of modelling using these standard models and to demonstrate its importance in the area of CFD simul...

Analysis and Comparison of Calculation Methods for Release of Corrosive Gases

The rapid growth in the use of corrosive gases transported by pressure vessels and pipelines has brought significant increase of risk to a number of people, both workers and public, whose life could be endangered at any one time by accident involving these chemicals. Due to the complexity of the involved physical phenomena and to the lack of an adequate amount of reliable experimental data, a number of different models and calculation procedures for estimating the consequences following the release of a corrosive gas are presently reported in the literature. The contribution deals with real scenarios of accidents associated with stationary risk facilities with corrosive flammable toxic chemicals. The study presents the results of hazardous zone calculation for the event of various corrosive liquids (Cl2, NH3, CCl2O, C3H4O) toxic releases. The goal of this article is to present the results of the approach of modeling using the standard methods and to demonstrate the importance of the next development stage in the area of corrosive materials accident modeling of releases and dispersions in cases of accident.

CO2 laser photoacoustic spectrometry: sensitivity and drift analysis

Trace gas measurements were performed by the eddy correlation technique. The time domain stability criterion for laminar and turbulent flows measured in the street canyon model was determined. The evaluation of the instrument performance was done by the concentration measurements (CH3OH, C2H5OH). The Allan and Hadamard variance methods were used for stability analysis. The dependence of variances on different degrees of flow turbulence was evaluated. The influence of turbulence on the optimal averaging time for minimum detectable concentrations has been studied. The stability analysis of experimental set up consisting of the CO2 laser photoacoustic detection and the simulated atmosphere in a wind tunnel was performed for different sample concentrations and flows. The sensitivity and stability analysis were determined by 1000 s, 2000 s and 10 000 s measurements.