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Mixer power for

Sizing continuous stirred-tank reactor (CSTR) requires selecting a standard reactor, given in Table 3, from a manufacturer. Table 7.4 lists the relations for calculating the reaction volume, heat transfer area, and the mixer power for CSTRs. [Pg.382]

Table 7.7 Approximate Mixer Power for Stirred-Tank Reactors... [Pg.387]

What this shows is that, from the definition of off-bottom motion to complete uniformity, the effect of mixer power is much less than from going to on-bottom motion to off-bottom suspension. The initial increase in power causes more and more solids to be in active communication with the liquid and has a much greater mass-transfer rate than that occurring above the power level for off-bottom suspension, in which slip velocity between the particles of fluid is the major contributor (Fig. 18-23). [Pg.1634]

FIG. 18-26 IXpk al curve for ma.s.s tran.sfer coefficient K.,a as i mixer power and superficial gas velocity. [Pg.1635]

Power In general, power requirements are not a major consideration in choosing a sohds mixer since other requirements usually predominate. However, sufficient power must be supplied to handle the maximum needs should there he changes during the mixing operation. Also, when a variety of mixes may be required, power must be sufficient for the heaviest bulk-density materials. If the loaded mixer is to be started from rest, there should be sufficient power for this. When speed variation may be desirable, this should be taken into account in planning power requirements. [Pg.1766]

If the gas is to be intimately dispersed in the liquid, the input power to the mixer will be several times the gas power level for the gas. In other words, the mixer power level must be compared to the gas power level to be certain that the required degree of mixing is achieved. [Pg.208]

The larger the ratio of impeller diameter to tank diameter, the less mixer power required. Large, slow speed impellers require a low er horsepow er for a given pumping capacity, and solid suspension is governed by the circulation rate in the tank. [Pg.209]

For axial flow impellers, the ratio of mixer power to gas stream power for a mixer-controlled flow pattern is approximately 8-10. This means that radial flow impellers are more commonly used for gas-liquid dispersion than axial flow impellers. [Pg.293]

The curve shown in Fig. 22, for an R100 impeller illustrates that there is a break point in the relationship with KGa versus the power level at the point where the power of the mixer is approximately three times the power in the expanding gas stream. The power per unit volume for an expanding gas stream at pressures from 1 to 100 psi can be expressed by the equation P/V (HP/1000 gal) = 15F (ft/sec). The A315 impeller, Fig. 23, is able to visually disperse gas to a ratio of about 1 to 1 in expanding gas power and mixer power level. It does not have a break point in the curve, although slopes are somewhat different than those in Fig. 22. [Pg.294]

Comment. Note that for small bubbles and large bubbles alike, the mass transfer coefficients are independent of both the mixer power consumption and the gas flowrate. [Pg.573]

Finally, calculate the mixer power. Using Equation 7.8.17, we find that for a reaction rvith heat transfer the power required varies from 1.5 to 5 hp/1000 gal. The average is 3.25 hp/1000 gal (640 W/m ). Thus, from Equation 7.8.16,... [Pg.400]

Power consumption of the mixer motor for endpoint determination and scale-up is widely used (Leuenberger and subsequent work, HoW and subsequent work, Landin et al. Faure et and many others because the measurement is economical, does not require extensive mixer modifications, and is well correlated with the granule growth. [Pg.4080]

It may be that the power level for the mixer may be reduced since the energy from the gas going through the tank is higher in order to maintain a particular mass transfer coefficient, KqO-, however, this changes the relative power level compared to the gas and other mass transfer rates, such as the liquid-solid mass transfer rate. The capacity for the blending type flow pattern is not affected in the same way with changes in the mixer power level as is the gas-liquid mass transfer coefficient. [Pg.220]

If it is desired to consider axial flow impellers in a gas-liquid system for any reason, it should be remembered that the upward flow of gas tends to negate the downward action ofthe pumping capacity ofthe axial flow turbine. A radial flow turbine must have three times more power than the power in the gas stream for the mixer power level to be fully effective. On the other hand, the axial flow impeller must have eight to ten times more power than in the gas stream for it to establish the axial flow pattern. [Pg.228]

FIG. 18-29 Typical curve for mass transfer coefficient K /i as a function of mixer power and superficial gas velocity. [Pg.19]

A 76.5 GHz Gunn-oscillator on the radar transceiver delivers the output power for the three beams and the same number of mixers for the demodulation of the received waves. The modulation is controlled by a frequency-locked loop using a... [Pg.376]


See other pages where Mixer power for is mentioned: [Pg.383]    [Pg.373]    [Pg.383]    [Pg.373]    [Pg.428]    [Pg.435]    [Pg.2140]    [Pg.100]    [Pg.67]    [Pg.293]    [Pg.293]    [Pg.297]    [Pg.299]    [Pg.342]    [Pg.1896]    [Pg.379]    [Pg.326]    [Pg.369]    [Pg.2763]    [Pg.211]    [Pg.224]    [Pg.75]   


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