Volumetric gas flow

FIG. 17-14 Biihhling-hed model of Kunii and Levenspiel. dy = effective hiih-ble diameter, = concentration of A in hiihhle, = concentration of A in cloud, = concentration of A in emulsion, y = volumetric gas flow into or out of hiihhle, ky,- = mass-transfer coefficient between bubble and cloud, and k,. = mass-transfer coefficient between cloud and emulsion. (From Kunii and Leoen-spiel, Fluidization Engineering, Wiley, New York, 1.96.9, and Ktieger, Malahar, Fla., 1977.)... 

Contac ting power is defined as the power per unit of volumetric gas flow rate that is dissipated in gas-liquid contacting and is ultimately converted to heat. In the simplest case, in which all the energy is... 

When a gas is blown steadily through an orifice into an essentially inviscid liquid, a regular stream of bubbles is formed. A theoretical expression that relates the bubble volume V to volumetric gas flow rate G and gravitational acceleration g is the following ... 

The gravimetric method depends on the sampling of flowing, particulate-laden gas from different positions across the exhaust gas duct and the determination of the mass of the particulate material. The sample is collected over a certain time period from each point. The volumetric gas flow is measured. The result is obtained by the following steps ... 

According to their measurements, the gas holdup increases with the gas velocity but the average contact time drops. This is not surprising, as will be shown. The volumetric gas flow rate is... 

The same exponent was obtained in both works, although in one case a vaned-disk impeller was used, and in the other, arrowhead-shaped blades. Although the nominal residence time can be determined from a knowledge of gas holdup and volumetric gas flow rate, the nominal residence time (Eq. 36) will equal the statistical average residence time (Eq. 34) for certain cases only (L2). 

Under constant operating conditions, the number of bubbles in the vessel is constant, and their total volume or gas holdup is equal to Q0, where 0 is the average residence-time of the bubbles and Q is the volumetric gas flow rate. The number of bubbles in the vessel at any instant is then given by... 

Fig. 13. Total average volumetric absorption rate in the dispersion, l9T/F, as a function of gas holdup ratio Qf)/V, chemical reaction rate k (in sec ), and the following values of volumetric gas flow late Q (in cm3/sec) A) 50, B) 150, C) 500, D) 2000 [after Gal-Or and Resnick (G2,G6)] (a = 0.1 cm.)...

Variation of bubble size, bubble frequency, and the standard deviation of -APbed with variation of Ug in the conical fluidized beds with a uniform gas distributor (Fopen = 3.87 %) is shown in Fig. 7. As can be seen, the standard deviation of - APbed and the bubble size increase with increasing Ug in the fully fluidized region. However, bubble frequency remains unchanged with variation of Ug that may imply the bubble size will increase as much as the volumetric gas flow increases. As shown, the bubble size dramatically increases with increasing Ug. Also, it is confirmed that the increase of standard deviation of -APbed is closely related to bubble size. 

Where Q, is the minimum detectable amount, R the detector noise level and s the detector sensitivity [135,146,151,152]. For a concentration sensitive detector the minimum detectable concentration is the product of Q, and the volumetric gas flow rate through the detector. The minimum detectable amount or concentration is proportional to the retention time, and therefore, directly proportional to the column radius for large values of n. it follows, then, that very small quantities can be detected on narrow-bore columns. 

Determination of the rodded cell rod position, as a function of time(Figure 2 shows a typical set of results), permits computation of the volumetric gas flow rate into the foam generator. 

Determine the volumetric gas flow rate at the conditions below the grid. For this example, assume the temperature of the gas below the grid is the same as in the bed. This may not be the case in an actual plant. 

Ns Number of spiral barrel traverses by particle stream Q Volumetric gas flow/unit time Vi Gas inlet velocity... 

Where Qa is the volumetric gas flow-rate under the reactor conditions. In the case where two co-axial impellers are used, the installed power should be doubled. 

The sparged gas power per unit volume, and volumetric gas flow per sparger opening, must be maintained constant. 

The change in volumetric gas flow rates between inlet and outlet of the reactor and regenerator. 

The volume-equivalent diameter, or volume diameter (see Eq. (1.3)), of an initial bubble formed at a single upward orifice, dbi, may be related to the volumetric gas flow rate through the orifice Q0[ by [Davidson and Harrison, 1963 Miwa et al., 1972]... 

Transmissometers in simplest form consist of a light source and a detector located some distance along the axis of the light beam. Among their applications, these devices are commonly used at airports to provide data in visual ranging conditions and are used to measure particle loadings in smokestacks. When calibrated for the type of particles present in this aerosol, a semiquantitative measure of the particulate emissions can be made, with knowledge of the volumetric gas flow. 

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