Gaz kabarcıklı sıvı iki fazlı akışkan tanklarından ani basınç düşüşü yaratarak fışkırma

An important consideration in the design of large pressure vessels containing bubbly liquid two-phase fluid in the process industries, is the assessment of the time history of the internal pressure, the void fraction distribution and the amount of discharge immediately following a sudden failure, such as a fracture on its body ör the operation of an emergency relief system with nearly instant bursting characteristics, due to excess pressure built up. Application of the best known numerical method for the calculation of transient thermo-fluid dynamic problems ; the Method of Characteristics is recalled, but as öne of the extreme cases that involve a bubbly liquid two - phase mixture and a gas medium with a free interface and highly transient process barely taking a second. The program can tackle the problem even for the very extreme conditions in respect to any of the parameters involved and stili produce consistent results and it does not involve any short cut that exploit the ability of the MC of smoothing the adverse effects of errors; it uses a proper third -partide path- characteristic for the void fraction distribution and creates a shock front with fitting strength when required at the non-full to full vessel transformation due to the strong throttling effect. Although the case ignores ali transfer effects, the programme with its very modular structure would allovr to enlarge the field of application to processes that involve heat and mass transfer, such as sub-cooled and overheated liquids; and easily, at least for the full vessel cases. Main results of the program may be summarized as below for the two characteristic cases of Full Vessel and the Non-Full Vessel. * For moderate conditions, sudden discharge of bubbly liquids f rom full pressurized vessels is no more a disorderly process than the ideal gas expulsion under equivalent conditions and uhatever the initial conditions are, the pressure history can never have a peek anyvrhere near the initial pressure at the top, that is no excess pressure built up - hammering effect - can occur that may vrorsen the emergency conditions, especially in the case of pipe like vessels. * The effect of strong throttling at the Non-Full Vessel to Full Vessel transformation stage very much asserts itself on the time history of pressure change in the case of sudden discharge of bubbly liquids f rom initially non-full pressurized vessels, but stili; under normal conditions, the highest pressure peak, the first peak of the instant of transformation, can only reach about half of the initial pressure ör may be just slightly higher; that is, not the value of the peak pressure itself but the speed of its creation may need to be taken into account as the principal design parameter.