Sparge gas

If it is required to quantify inorganic carbon the sparged gas may be directed to the non-dispersive infrared analyser for quantification. 

The impact of frequency on sonolytic processes is significant. The results have varied widely due to the use of different types of ultrasonic emitters such as probes or plates and the diversity of reactors incorporated. The effect of sonolysis on the degradation rate of 1,4-dioxane was studied over a range of frequencies using the same transducer and reactor system for each experiment. The sparge gas ratio used was 75% Ar/25% 02 and the results are shown in Figure 5. The fastest degradation rate occurs at a frequency of 358 kHz followed by 618, 1071, and 205 kHz. 

Figure 5 1,4 dioxane degradation at four ultrasonic frequencies using the glass reactor sparge gas = 75% Ar/25% O2. Ct = 1,4 - Dioxane concentration at time, t, and Co = initial 1,4 — Dioxane concentration. 

Salinity vs. bubble size. In sparged gas tests, Strickland found bubble size decreased with increasing salinity up to about 3%. He noted no further... 

It was observed also m these tests that sparged gas flotation gave higher oil recovery than dispersed gas, demonstrating once again that small bubbles are more effective than larger ones. 

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

Solvent composition Solution temp. (°C) G(scission) breaks/eV Sparging gas... 

Dissolved oxygen control by the adjustment of the oxygen fraction in the sparged gas. Its total flow rate is kept constant and corresponds to the sum of the two controlled gases QI and Q2. 

Here Ut is the terminal velocity of bubble rise in m/sec. The effective power input term Pg combines both sparged gas (Pg) and mechanical energy (PJ contributions in W (M16) ... 

Dissolution. The second step of our proposed process is the dissolution in the nitrate melt (T<300°C) of the sodium diura-nate through addition of nitric acid vapor in the sparge gas. Initial studies used 100% HNO3, but recent tests have demonstrated that commercial white-fuming nitric acid is equally effective. Concentrated nitric acid does not completely dissolve the sodium diuranate. 

In the case of stirred tank fermenters, heat that must be dissipated includes not only that generated by microbial metabolic activity but also that evolved from agitation power (i.e., 2500Btu/shp-hr) and expansion of sparged gas. This can lead to scale-up problems because vessel volume is proportional to vessel diameter cubed, while heat transfer area is proportional only to vessel diameter squared. 

Air Sparging Gas sparging or injection of air bubbles has been effectively used to reduce concentration polarization and enhance mass transfer. " The secondary flows around bubbles promote mixing and reduce the thickness of the concentration polarization boundary layer. When the bubble diameter exceeds that of the membrane (tubular or hollow fiber), slugs are then formed further increase in bubble diameter has no effect on flux improvement. Large slugs can displace most of the boundary layer and cause the pressure to pulsate. This results in enhancing the flux. 

Figure CS11.2a shows a comparison of fractional gas holdup under sparging conditions, with and without the use of a gas-inducing impeller. In the absence of a gas-inducing impeller, such a system behaves like a conventional mechanically agitated contactor (MAC). The comparison is made in terms of gas holdup as a function of power consumption per unit volume for different superficial velocities of sparged gas (uq = 0, 6,18, and 29 mm/s). It can be seen that the fractional...

The net rate at which the sparged gas accnmnlates (Qua) into the head space is calculated as the difference between the rate of sparging and the rate of reaction of the sparged gas. 

Table 2 Global foam parameters and film equilibrium thickness of base wines and of model solvent and model solutions. The analogy between the 1993 and 1994 base wines on one side, and, except for the existence of a residual foam, between the 1990 base wine and the YGP 1 model solution is remarkable. The reported experiments were done early 1996. Nitrogen was used as sparging gas. (.n.m.) = non-measurable with the available test tube...

Stirred tank with sparged gas Continuous, well mixed Discontinuous, but usually assumed well mixed 1... 

Either tjrpe of pinching can also be alleviated by increasing the heating medium temperature or by injecting sparge gas such as nitrogen at the reboiler bottom. Sparge gas iiyection, however, may adversely affect overhead condenser action or top product purity. 

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