Efficiencies Vaporization

A twin-screw extmder is used to reduce residual monomers from ca 50 to 0.6%, at 170°C and 3 kPa with a residence time of 2 min (94). In another design, a heated casing encloses the vented devolatilization chamber, which encloses a rotating shaft with specially designed blades (99,100). These continuously regenerate a large surface area to faciUtate the efficient vaporization of monomers. The devolatilization equipment used for the production of polystyrene and ABS is generally suitable for SAN production. 

Natural gas requires no fuel treatment however, low-Btu gas, espeeially if derived from various coal gasification processes, requires various types of cleaners for use in a gas turbine. These cycles can get very complex as indicated by a typical system, which utilizes a steam bottoming cycle to achieve high efficiency. Vaporized fuel oil gas is already cleansed of its impurities in the vaporization process. 

The formation of droplets and their rapid, efficient vaporization is the reason that there is more vapor in the cloud than the amount which flashed off originally. Schmidli et al. (1990) determined that 5 to 50% of the mass of the original fuel can be found in droplets. This value depends upon initial mass and degree of superheat, that is, amount by which the fuel s temperature exceeds its boiling point. 

The hydrogen reduction of the metal halides, described in Sec. 1.2, is generally the favored reaction for metal deposition but is not suitable for the platinum-group metals since the volatilization and decomposition temperatures of their halides are too close to provide efficient vapor transport. 1 1 For that reason, the decomposition of the carbonyl halide is preferred. The exception is palladium which is much more readily deposited by hydrogen reduction than by the carbonyl-halide decomposition. 

The sensitivity of atomic absorption can often be enhanced by aspirating solutions in organic solvents. The increased sensitivity is due to a number of factors, but can be attributed in large part to the lower viscosity and surface tension as compared to aqueous solutions. The flow rate is increased and smaller droplets are formed which are more efficiently vaporized. When organic solvents are aspirated, a fuel lean flame must be used in order to burn the solvent. 

Theoretically, the Carnot vapor cycle is the most efficient vapor power cycle operating between two temperature reservoirs. 

If aerosolization is a major contributor to a hazard, a portion of the airborne liquid can be removed by placing an angled plate over the release point. The released material strikes the plate, which disperses much of the momentum and enhances coagulation of liquid droplets. In this way a portion of the liquid will drop out of the cloud. However, the loss of momentum may result in less efficient vapor dispersion and, hence, a larger hazard area. 

The thermal and mass-transport properties of the MOCVD precursor Bi(thd)3 were investigated by Bedoya and coworkers . The authors suggested a temperature window for efficient vaporization of 190-280 °C and determined decomposition of the precursor above 350 °C. 

Liquid rate below which it is difficult to maintain efficient vapor/liquid contact, gpm/ft ... 

The vaporization efficiency was perhaps first employed by either McAdams6 or Carey.5 In 1949, Edmister12 proposed a similar efficiency and called it the absorption efficiency. Vaporization efficiencies have been applied to batch-steam distillation21 and to conventional columns with plates.22,33... 

Conversion efficiency, vaporization energy/electric energy input,. ... 

Eventually, the velocity of vapor in the jets becomes so large that the jets themselves become unstable near the interface as a result of Helmholtz instability (of wavelength XH) as shown in Fig. 15.63). The breakup of the jets destroys the efficient vapor-removal mechanism, increases vapor accumulation at the interface, and leads to liquid starvation at the surface and to the critical heat flux phenomenon. If jet breakup occurs at a vapor velocity UH within the jets, the critical heat flux q"m is given by... 

The laser beam efficiently vaporizes conductors, insulators, and semiconducting materials with a minimum of matrix effects. Laser sampling ICP-MS has also been applied successfully as a semi-quantitative survey tool for a rapid multi-element analysis of geological samples. The samples are pulverized to assure homogeneity. Some paraffin wax is mixed with the sample. The mixture is then placed in an aluminium cup and pressed into a wafer. 

Every effort must be made to maintain a constant vapor level to avoid pumping action resulting in solvent-laden air being expelled from the tank. Sufficient heat input capacity should be provided so that the top of the work will be covered with vapors as quickly as possible for efficient vapor condensation and degreasing. 

The temperature difference AT between the cold surface and the evaporating refrigerant. For an efficient vapor trap it is necessary to have a combination of a large cross-sectional area for the vapor flow (low AP), an efficient deicing system (low AT,, and an efficient refrigerating system (low ATj f,). 

A less efficient vapor trap means a higher AT, thus demanding a lower evaporation temperature of the refrigerating... 

C. At this temperature, the remaining matrix components are not yet efficiently vaporized and do not interfere with the determination. 

This step prepares the chamber for efficient vapor flushing. The presence of a small amount of air can result in the condensing vapor process being controlled by the diffusion of... 

The Kohonen neural networks were chosen to prepare a relevant model for fast selection of the most suitable phase equilibrium method(s) to be used in efficient vapor-liquid chemical process design and simulation. They were trained to classify the objects of the study (the known physical properties and parameters of samples) into none, one or more possible classes (possible methods of phase equilibrium) and to estimate the reliability of the proposed classes (adequacy of different methods of phase equilibrium). Out of the several ones the Kohonen network architecture yielding the best separation of clusters was chosen. Besides the main Kohonen map, maps of physical properties and parameters, and phase equilibrium probability maps wo e obtained with horizontal intersections of the neural network. A proposition of phase equilibrium methods is represented with the trained neural network. 

A less efficient vapor trap means a higher AT, thus demanding a lower evaporation temperature of the refrigerating plant to maintain the required vacuum in the freeze-drying cabinet. Lower evaporation temperature means higher operation costs. In this temperature range, an evaporation temperature 10°C lower means 50% increased energy consumption. 

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