Sauter-diameter

S. Aureus Sausage Sausage casing Sausage casing material Sausages Sauter diameter Sauter mean diameter N.S. Savannah Savard-Lee injectors Savin ase... 

The surface-area mean (sm) diameter, not to be confused with the number-based average surface area (eq. 3), also known as the Sauter diameter, can be calculated as follows ... 

Most of the investigators have assumed the effective drop size of the spray to be the Sauter (surface-mean) diameter and have used the empirical equation of Nuldyama and Tanasawa [Trons. Soc. Mech. Eng., Japan, 5, 63 (1939)] to estimate the Sauter diameter ... 

In order to estimate the specific surface area of the dispersed organic droplets, the mean droplet size (Sauter diameter 32) has to be determined, which can be calculated according to the Okufi equation (Eq. 5) ... 

From experiments, equations have been derived that enable calculation of the minimum velocity in the nozzle, the nozzle velocity, and the Sauter diameter at the drop size minimum. They provide the basis for the correct design of a sieve tray [3,4]. Figure 9.4a shows the geometric design of sieve trays and their arrangement in an extraction column. Let us again consider toluene-phenol-water as the liquid system. The water continuous phase flows across the tray and down to the lower tray through a downcomer. The toluene must coalesce into a continuous layer below each tray and reaches... 

The mean Sauter diameter, d 2, is clearly smaller than the maximum stable diameter. As experimentally proved by many authors, the ratio of these is between 0.4-0.6. 

Influenced by interfacial tension and centrifugal forces, spherical drops of various diameters originate at the holes. If we again assume the Sauter diameter, according to Eq. (9.1), as the mean diameter of the spectrum of particles, the following equation for heavy and light phases results from theoretical and experimental results [10] ... 

Small bubbles and flow uniformity are important for gas-liquid and gas-liquid-solid multiphase reactors. A reactor internal was designed and installed in an external-loop airlift reactor (EL-ALR) to enhance bubble breakup and flow redistribution and improve reactor performance. Hydrodynamic parameters, including local gas holdup, bubble rise velocity, bubble Sauter diameter and liquid velocity were measured. A radial maldistribution index was introduced to describe radial non-uniformity in the hydrodynamic parameters. The influence of the internal on this index was studied. Experimental results show that The effect of the internal is to make the radial profiles of the gas holdup, bubble rise velocity and liquid velocity radially uniform. The bubble Sauter diameter decreases and the bubble size distribution is narrower. With increasing distance away from the internal, the radial profiles change back to be similar to those before contact with it. The internal improves the flow behavior up to a distance of 1.4 m. 

Fig. 10. Bubble Sauter diameter radial profile at different axial positions.

Fig. 10 shows the radial profile of the bubble Sauter diameter at five axial positions. The bubble size is very much decreased after flowing through the internal and then increases with an increase of the distance from the internal. The difference between the values at the positions of 144 and 209 cm above the internal is negligible and their radial... 

The bubble Sauter diameter very much decreases after passing the internal, then increases with increasing distance from it. The bubble size distribution becomes narrower after the internal and its peak is shifted to the left. The bubble size at 144 cm above the internal has increased back to be the same as that below. 

Fig. 10.17. Simulated and experimental Sauter diameters in RDC columns with (C—>D D— C) and without mass transfer (system toluene/acetone/water at 298 K).

For the computation of the heat and mass transfer coefficients, the Sauter diameter 32 is used... 

Figures 16.38 and 16.39 demonstrate that the form of the particle size distributions is once again almost constant during the process time, and consequently the pneumatic recycled dust is not used for seed production. Dust is deposited on the particles because the nozzle position is close to the dust recycle tube (uniform wetted dust), and this leads to an enlarged particle growth. The measured time-dependent gas outlet temperature and the measured time-dependent conversion corresponds with simulations (Fig 16.40). The bed mass growth is linear at constant liquid injection rates (Fig. 16.41). The change in particle size distribution value and of the Sauter diameter is, again, declining.

The function ds2 = f(t) has no boundary value. The progression of the Sauter diameter of experiment V-14 shows an agreement between measurement and analytical solution (Fig. 16.42). Experiment V-14 shows the achievement of a high conversion of the absorbed gas component sulfur dioxide by simultaneous granulation of the reaction product in a fluidized-bed reactor. 

Fig. 16.37. Progression of Sauter diameter and bed mass over time, experiment V-l3 (simulation Ra= 0.075 kg m 2 h-, kos = 0 %, kgrowth =100%, ksep = 0 %).

Fig. 16.42. Progression of the Sauter diameter over time measurement versus analytical solution, experiment V-l 4.

Figure 16.48 presents a comparison of the calculation of bed mass under use of pressure loss and of the Sauter diameter. Although both progressions showed the same tendency, the constant reduction of the particles justified their elutriation and the excessive amount of particles discharged by a industrial vacuum cleaner during the experiments. The total mass balance is listed in Tab. 16.20. 

Here the Sauter diameter calculated from the mass-... 

We get particles of different sizes. Each has a mass equivalent diameter," which is the diameter of a sphere with the same mass as the particle. One can characterize the sizes with a cumulative mass distribution such as in the upper part of Figure 14-6. This shows which mass fraction is in the particle with a diameter smaller than a certain value. The frequency distribution underneath is derived from the upper diagram it gives an indication of which diameters are most common. We can try to characterize the drops with a single diameter there are many different ways in which this can be done. They lead to parameters such as the c 32 (Sauter diameter), dso (mean diameter) and dmax (maximum... 

The values of these averages can be very different. Typically, the higher the values of n and m are, the larger is the value of the average size. Which one you should use simply depends on the application. When it relates to the surface area (think of emulsion stability, amormt of surfactant needed, energy required to make the emulsion, etc.) then the Sauter diameter is probably the best one. If the application is related to the volume (e.g., amount of oil in the product, material dissolved in the particles), the volume average diameter may be more suitable. 

An emulsion typieaUy eonsists of droplets with many different sizes. The properties of an emulsion strongly depend on the droplet sizes present. There are different average droplet sizes that one ean use the Sauter diameter is often used. Next to the average droplet size, the width of the distribution is important. 

In continuous mechanical emulsification systems based on turbulent flow, the power density Py viz. power dissipated per unit volume of the emulsion) and residence time, L, in the dispersing zone have been found to influence the result of emulsification as measured by the mean droplet size 0(3 2 which is called the Sauter diameter . This dependency is in most cases described by the following expression ... 

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