Agitation by air

Gargles A gargle is a liquid medicine intended to be retained in the mouth and placed in contact with the back of the throat by throwing back the head and agitated by air released from the larynx. ... 

Until recently most industrial scale, and even bench scale, bioreactors of this type were agitated by a set of Rushton turbines having about one-thind the diameter of the bioreactor (43) (Fig. 3). In this system, the air enters into the lower agitator and is dispersed from the back of the impeller blades by gas-fiUed or ventilated cavities (44). The presence of these cavities causes the power drawn by the agitator, ie, the power requited to drive it through the broth, to fall and this has important consequences for the performance of the bioreactor with respect to aeration (35). k a has been related to the power per unit volume, P/ U, in W/m and to the superficial air velocity, in m/s (20), where is the air flow rate per cross-sectional area of bioreactor. This relationship in water is... 

Blast air, preheated to 650°C, is deflvered by centrifugal blowers through a refractory-lined busde main to the furnace. Zinc vapor from the reduced sinter is carried out with the furnace gases to a condenser fitted with mechanical rotors that are partly immersed in a shallow pool of molten lead. The lead flows countercurrenfly to the gas and is vigorously agitated by the rotors to create an intense shower of lead droplets throughout the condenser. 

Air- or dry-laid pulp machinery can be envisioned as a series of forming-unit modules. Each module consists of two to four perforated dmms through which airborne fibers are circulated and further agitated by mechanical beaters placed in close proximity to the inner dmm surfaces. As the fibers... 

Dispersed-Solids Leacbing Equipment for leaching fine solids by dispersion and separation includes batch tanks agitated by rotating impellers or by air and a variety of continuous devices. 

Mechanical agitation is needed to break up the gas bubbles but must avoid rupturing the cells. The disk turbine with radial action is most suitable. It can tolerate a superficial gas velocity up to 120 m/h. (394 ft/h) without flooding, whereas the propeller is limited to about 20 i7i/h (66 ft/h). When flooding occurs, the impeller is working in a gas phase and cannot assist the transfer of gas to the liquid phase. Power input by agitation and air sparger is 1 to 4 W/L (97 to 387 Btu/[fF-h]) of liquid. 

The medium was contained in a 100 liter stainless steel baffled fermenter, agitated by a TA inch vaned disc impeller at 140 rpm. Sterile air was supplied at 75 liters per minute and the tank incubated for 72 hours at 26°C. 

This medium was incubated in a 100 gallon stainless steel fermentor, at 24°C with sparged air being introduced at the rate of 50 C/min and with agitation by an impeller. After 66 hours of fermentation the beer was harvested. To 100 gal Ions of harvested beer was added 17 pounds of diatomite, and 35 pounds of activated carbon. The mixture was stirred well and then filtered, the cake was water-washed with 10 gal Ions of tap water, and then washed with 25 gallons of acetone followed by 30 gallons of 1 1 aqueous acetone. The acetone solutions of strepto-zotocin were pooled and dried in vacuo to 3.88 pounds. 

Aeration, either by agitation or by air injection, that impregnates the pulp thoroughly with bubbles, which are essentially gas-filled holes of macroscopic dimensions in the pulp, is carried out. 

Sallack (1955) was the first to publish a study of dissolver-tank explosions. He was motivated by incidents which occurred in a soda pulp operation with a dissolver tank 4.3 m in diameter and 3.7 m tall. Molten smelt entered the tank at the top and was to be broken up with a jet of recirculating green liquor. Agitation of the bulk liquid was also accomplished by air jets. Operation was normally smooth, but if a boiler upset led to a sharp increase in smelt flow, then the smelt-green liquor breakup operation was inefficient and unbroken slugs of smelt could enter the bulk green liquor in the tank. Explosions could then occur. 

In 1630 Jean Rey noticed the increase of weight of tin on calcination, and believed that it comes from the air, which in the vessel has been rendered denser, heavier, and in some measure adhesive, by the vehement and long-continued heat of the furnace which air mixes with the calx, . . and becomes attached to its most minute particles not otherwise than water makes heavier sand which you throw into it and agitate, by moistening it and adhering to the smallest of its grains (82, 83, 84, 85). 

Before casting, the casting solvent is usually evacuated in a desiccator for at least 16 hours, maintaining the pressure below 10 mm. Hg. To increase the efficiency of removing volatiles, the casting solvent is often agitated by allowing a small stream of dry air to bubble up from the bottom of the solvent desiccator. 

Kinsella (13, 14) summarized present thinking on foam formation of protein solutions. When an aqueous suspension of protein ingredient (for example, flour, concentrate, or isolate) is agitated by whipping or aeration processes, it will encapsulate air into droplets or bubbles that are surrounded by a liquid film. The film consists of denatured protein that lowers the interfacial tension between air and water, facilitating deformation of the liquid and expansion against its surface tension. 

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