Entrainer ideal

For a dry application, the frequency and the intensity of the rapping must be such as to shear the deposit as a layer from the plates, rather than attempting to disintegrate the layer completely, as this would lead to severe rapping re-entrainment. Ideally for the particles to reach the hopper and to overcome the horizontal component of velocity, the effective size of agglomerate should be in the order of at least 500 pm in diameter.f ... 

Encrustation can occur in the vapour spaee of evaporating and vaeuum crystallizers (seetions 8.4.2 and 8.4.3), partieularly near the hquid vapour interface. Severe build-up of deposits can increase the vapour velocity and intensify mother liquor droplet entrainment. Ideally, vapour velocities should be limited to not more than 1 m s at atmospherie pressure and to not more than 3 m s for low pressure operation (section 9.3.1). 

Panicles entrained in the airstream deposit along the airway as a function of size, density, airstream velocity, and breathing frequency. Sizes of rougjily spherical or irregularly shaped particles arc commonly characterized by relating the settling velociiy of the particle to that of an idealized spherical particle. For example, an irregular particle which settles at the same rate as a 5 pm spherical particle has a mean mass aerodynamic diameter (MMAD) of. 5 pm. Since spherical particle mass, is a function of particle diameter, J... 

Large reservoirs are desirable for cooling. A large reservoir also reduces re-circulation, which helps settle contamination, and separates entrained air. As a mle of thumb, the ideal reservoir should be two to three times the pump outlet per minute. However, due to space limitations in mobile and aerospace systems, the benefits of a large reservoir may have to be sacrificed. But they must be large enough to accommodate thermal expansion of the fluid and changes in fluid level due to system operation. 

Froude number W1 /( bQ is nearly the same for the near and far field plumes, 1.60 0.1. The entrainment coefficients are much larger, which probably includes pressure effects near the base for the axisymmetric fires and tornado-flame filament effects for the line fire, which are actually three dimensional. It should be realized that the data corresponding to these correlations contain results for finite fires D > 0, not idealized sources. The correlations in Tables 10.1 and 10.2 are one set of formulas others exist with equal validity. 

Equation (10.10) gives the mass flow rate in the plume. This is exactly equal to the entrainment rate if we neglect the mass flow rate of the fuel. The latter is small, especially as z increases. For an idealized point source, the entrainment rate consistent with the far-field results of Table 10.1 is... 

In entrainer sublimation, an entrainer gas is blown into the vaporisation chamber of a sublimer in order to increase the vapour flowrate to the condensing equipment, thereby increasing the yield. Air is the most commonly used entrainer, though superheated steam can be employed for substances such as anthracene that are relatively insoluble in water. If steam is used, the vapour may be cooled and condensed by direct contact with a spray of cold water. Although the recovery of the sublimate is efficient, the product is wet. The use of an entrainer gas in a sublimation process also provides the heat needed for sublimation and an efficient means of temperature control. If necessary, it may also provide dilution for the fractional condensation at the desublimation stage. Entrainer sublimation, whether by gas flow over a static bed of solid particles or through a fluidised bed, is ideally suited to continuous operation. 

Process synthesis and design of these non-conventional distillation processes proceed in two steps. The first step—process synthesis—is the selection of one or more candidate entrainers along with the computation of thermodynamic properties like residue curve maps that help assess many column features such as the adequate column configuration and the corresponding product cuts sequence. The second step—process design—involves the search for optimal values of batch distillation parameters such as the entrainer amount, reflux ratio, boiler duty and number of stages. The complexity of the second step depends on the solutions obtained at the previous level, because efficiency in azeotropic and extractive distillation is largely determined by the mixture thermodynamic properties that are closely linked to the nature of the entrainer. Hence, we have established a complete set of rules for the selection of feasible entrainers for the separation of non ideal mixtures... 

Experiments on the effect of different curing conditions on the compressive and flexural strengths of plain and air-entrained concrete [35] showed that air-entrained concrete has less tendency to lose moisture under drying conditions, which means that if concrete curing conditions are not ideal, air-entrained concrete should develop strength more normally than plain concrete [43],... 

Along with studies of melt inclusions, the study of mantle xenoliths (samples of mantle material entrained and brought to the surface in eruption magmas) and exhumed mantle rocks is one of the most common applications of SIMS for trace element analysis. SIMS is ideally suited to this task, as there is no need to try to make mineral separates from what are often limited amounts of sample, alteration can be prevented, and zoning easily studied. 

For the azeotropic dehydration of aqueous ethanol mixtures approaching the constant boiling mixture, a brief comparison is shown for the entrainers, n-pentane, benzene, and diethyl ether. Since water is most non-ideal in n-pentane, the driest ethanol is expected to be produced if n-pentane is used. 

The high solubility of solid substances in supercritical fluids compared to those in ideal gases (enhancement factors of lO -lO are common) allows their use as solvents in pharmaceutical, biomedical and food industries. Sections 2.4-2.7 are devoted to predictions of the entrainer effect, and of solubility in supercritical fluids with and without entrainer. Reliable predictive methods for solid solubilities in mixtures of a supercritical solvent -i- cosolvent were developed (2.4-2.6). These apply not only to the usual cosolvents such as organic liquids (2.4-2.5), but also to cases in which the cosolvent is a gas or another supercritical fluid (2.6). Our methods provided good agreement with experimental data in all of these cases (2.4-2.6). 

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