Atmospheric process types

In meteorology, there arc two special types of "ions thal enter into atmospheric processes small "ions and large "ions,"... 

Upper atmosphere chemical processes have been mentioned above, and rocket-borne mass spectrometers have been used to investigate the various species—molecules, atoms and ions—present in the upper atmosphere. Bennett type RF mass spectrometers have been especially useful in view of their small weight compared with conventional magnet spectrometers. Johnson describes a typical mass spectrometer-rocket probe of the atmosphere. 

Lime and Limestone Wet Scrubbing. The problem of atmospheric pollution by sulfur oxides has been given extensive attention by research and development firms in recent years and several process types are being proposed for full scale application. Lime and limestone wet scrubbing appears to be the most promising approach for immediate application. The major diflSculty with the limestone or lime systems is solid deposition in the absorption device which could create unreliability and unscheduled shutdowns for the power plant. 

Atmospheric models can be divided, broadly speaking, into two types physical and mathematical. Physical models are sometimes used to simulate atmospheric processes by means of a small-scale representation of the actual system, for example, a small-scale replica of an urban area or a portion thereof in a wind tunnel. Problems associated with properly duplicating the actual scales of atmospheric motion make physical models of this... 

In the atmosphere, two types of physical processes may be observed as follows ... 

With normal hydrates (i.e. Type N , produced at atmospheric pressure) the putty should be matured for at least 24 hours to develop plasticity. Alternatively, a colloid mill may be used to accelerate the maturing process. Type S hydrates (produced at elevated pressure) develop plasticity within 1 hour of mixing. 

The characteristics of different process layouts are listed in Table 9.6 [22]. The open-cycle layout, which represents the majority of spray dryer systems, is shown in Figure 9.29. The drying air is taken from the atmosphere and the exhaust air is discharged to the atmosphere. Three types of dry collectors and a wet air cleaner can be used in this layout. A relatively large amount of dry powder (in comparison with other layouts) is lost with the exhaust air. Some applications are shown in Figures 9.30 through 9.35 [33]. 

Catalysts can be divided into two broad categories. Homogeneous eatalysts are those that are in the same phase as the reacting substances, whereas heterogeneous catalysts are in a different phase from the reacting species. For gas-phase reactions, the heterogeneous catalyst typically is a solid surface. Both types of catalysis are important in atmospheric processes. 

The above SRU, designed on the basis of modified Claus process, is equipped with a tail gas Incinerator of natural draft, sub-atmospheric pressure type thermal incinerator with air flow controlled using burner air registers. Tail gas inlet line to the incinerator is installed with a Tied Universal type metallic bellow expansion joint to accommodate line expansion and movements. This expansion joint made out of Inconel-65 metallurgy was in operation since Year 2005 which subsequently during May-2011 had developed a crack on the metallic bellow element and started leaking toxic tail gas to atmosphere. 

Chemical vapor deposition refers to the formation of a nonvolatile solid material from the reaction of chemical reactants, called precursors, being in vapor phase in the right constituents. A reaction chamber is used for this process, into which the reactant gases are introduced to decompose and react with the substrate to form thin film or powders There are several main classification schemes for chemical vapor deposition processes. These include classification by the pressure (atmospheric, low-pressure, or ultrahigh vacuum), characteristics of the vapor (aerosol or direct liquid injection), or plasma processing type (microwave plasma-assisted deposition, plasma-enhanced deposition, remote plasma-enhanced deposition)... 

The vacuum is created behind the filter medium, which causes the atmospheric pressure in front of the filter medium to drive the slurry through the medium, filtering out suspended solids in the process. Types of vacuum filters include belt, horizontal pan, vertical disc, and dmm varieties. 

The list of flexible polymeric roll materials suitable for atmospheric plasma processing is expansive. Mainstream resin types include polypropylene (homopolymers, heterophasic copolymers, and random copolymers), polyethylene (low, medium, and high density polyethylene resins), a family of specialty polyolefins which includes polybutene-1, advanced polypropylene resins from in-reactor alloying processes and polypropylene compounds, and fiuoropolymers. By process type, these materials (in mono- or multiple layers) can be generally represented by the following ... 

The various stages of this process depend critically on the type of gas, its pressure, and the configuration of the electrodes. (Their distance apart and their shapes control the size and shape of the applied electric field.) By controlling the various parameters, the discharge can be made to operate as a corona, a plasma, or an arc at atmospheric pressure. All three discharges can be used as ion sources in mass spectrometry. 

These effects of differential vapor pressures on isotope ratios are important for gases and liquids at near-ambient temperatures. As temperature rises, the differences for volatile materials become less and less. However, diffusion processes are also important, and these increase in importance as temperature rises, particularly in rocks and similar natural materials. Minerals can exchange oxygen with the atmosphere, or rocks can affect each other by diffusion of ions from one type into another and vice versa. Such changes can be used to interpret the temperatures to which rocks have been subjected during or after their formation. 

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