Objectives of Gas Dispersion

Objectives of Gas Dispersion The dispersion of gas as bubbles in a liquid or in a plastic mass is effected for one of the following purposes (1) gas-liquid contacting (to promote absorption or stripping,... 

Currently used mathematical models of gas purification formed on simplified theoretical concepts of gas flow. They are not sufficiently taken into account the operational and design parameters of gas cleaning devices, as well as aero-hydrodynamic properties of gas-dispersed flows. These models cannot be used to search for the best options of integrated gas cleaning systems, as they show the properties of objects in a narrow range of parameters. We need more complete and appropriate mathematical models based on the study of the aerodynamics of gas and taking place in these events. 

Fig. 2.4p shows three types of post-column reactor. In the open tubular reactor, after the solutes have been separated on the column, reagent is pumped into the column effluent via a suitable mixing tee. The reactor, which may be a coil of stainless steel or ptfe tube, provides the desired holdup time for the reaction. Finally, the combined streams are passed through the detector. This type of reactor is commonly used in cases where the derivatisation reaction is fairly fast. For slower reactions, segmented stream tubular reactors can be used. With this type, gas bubbles are introduced into the stream at fixed time intervals. The object of this is to reduce axial diffusion of solute zones, and thus to reduce extra-column dispersion. For intermediate reactions, packed bed reactors have been used, in which the reactor may be a column packed with small glass beads. 

The experimentation in the field of gas cloud fires appears to be limited. The unique set of large-scale experiments that involve the release, dispersion, ignition, and combustion of flammable natural gas clouds in the open air is that with the code name Coyote. Coyote series trials conducted by LLNL in 1983 at California s Nevada Test Site, Nevada provided an integrated dataset for use in validation studies [64,65]. The objective of the experiments was to determine the transport and dispersion of vapors from LNG spills, and in addition to investigate the damage potential of vapor cloud fires. Transient simulations... 

The interaction between individual molecules obviously plays an important role in determining, for example, the nonideality of gas, as illustrated in Example 10.2. It is less clear how to apply this insight to dispersed particles in the colloidal size range. If atomic interactions are assumed to be additive, however, then the extension to macroscopic particles is not particularly difficult. Moreover, when dealing with objects larger than atomic dimensions, we also... 

The objectives of liquid mixing in stirred tanks are to (i) make the liquid concentration as uniform as possible (ii) suspend the particles or cells in the liquid (iii) disperse the liquid droplets in another immiscible liquid, as in the case of a liquid-liquid extractor (iv) disperse gas as bubbles in a liquid in the case of aerated (gassed) stirred tanks and (v) transfer heat from or to a liquid in the tank, through the tank wall, or to the wall of coiled tube installed in the tank. 

The object of this study was to characterize the flow and to measure the hold-up and axial dispersion coefficients of the fluid phases (water-nitrogen) in a countercurrent gas-liquid packed column, operating under a pressure up to 1.5 MPa. 

At any stage of condensation the fraction still in the gas phase can be dispersed to other regions of the planetary system. Hence, the accumulating planetary objects may contain different components in varying amounts. As can be seen from Fig. 16, among all objects of which we have samples, the Moon contains the highest proportion of HTC elements, closely followed by several groups of achondrites. 

Thin liquid films bordering a gas phase on both sides, or the so-called free films, are one of the oldest objects of research in the physical chemistry of disperse systems. The reason is probably the ease of their formation, simplicity, uniformity of surfaces, etc. Thin films, including foam films, are an efficient and useful model for the study of many surface phenomena. 

As has been stressed throughout this book, risk has both objective and subjective elements. The objective part of the work means that those working in the area of risk management need to be numerate they need to be comfortable with a variety of quantitative topics such as gas dispersion modeling, the development of F—N curves, and the use of Boolean algebra. 

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