Phase measurement stirred vessel

Several researchers have measured the absorption rate at the presence of dispersed organic phase [1,17-18,37,39,49,51-53]. Bruining et al. [37] measured the oxygen absorption in stirred vessels with plane interface in the presence of small amounts of decane, hexadecane, c = 0.01 - 0.1 while van Ede et al. [49] applied octene as a dispersed phase. Littel et al.[39] used carbon dioxide for absorption in dispersion of toluene droplets with c = 0 - 0.4. The theoretical data in the literature were mostly verified by the experimental results of the above... 

The measurement of the phase equilibria can readily be carried out in thermostatically controlled stirred vessels. These preliminary investigations already provide valuable indications of the dispersibility and the time required for phase separation. The required number of stages is calculated on the basis of the phase equilibria. 

The first fiow characteristics of single phase stirred tank reactors were performed using the HFA technique. For example, Gtinkel and Weber [77] used a hot-wire technique to measure instantaneous fluid velocities in the bulk flow and between the impeller blades in baffled stirred vessels. The HFA technique was later used to measure the first instantaneous fluid velocities in dispersed two-phase (gas-liquid) dispersions. Attempts were also performed to measure the local gas void fraction. Many examples of such investigations of two-phase bubble column flows can be found in the literature [67, 72, 76, 135, 199]. 

Other detection methods are based on optical transmittance [228-231], Alcohol sulfates have been determined by spectrophotometric titration with barium chloride in aqueous acetone at pH 3 and an indicator [232] or by titration with Septonex (carbethoxypentadecyltrimethylammonium bromide) and neutral red as indicator at pH 8.2-8.4 and 540 nm [233]. In a modified two-phase back-titration method, the anionic surfactant solution is treated with hyamine solution, methylene blue, and chloroform and then titrated with standard sodium dodecyl sulfate. The chloroform passing through a porous PTFE membrane is circulated through a spectrometer and the surfactant is analyzed by determining the absorbance at 655 nm [234]. The use of a stirred titration vessel combined with spectrophotometric measurement has also been suggested [235]. Alternative endpoint detections are based on physical methods, such as stalag-mometry [236] and nonfaradaic potentiometry [237]. 

Measurements were carried out in a 6-liter brass vessel stirred by means of a flat blade stirrer and equipped with 4 wall baffles. The influence of dispersed phase fraction and of stirring rate was investigated. The dispersed phase fraction was varied from 0.06 to 0.15 while the power input by the stirring was varied from 0.1 to 3 hp./m.8. The interaction rate found was invariably 0.035 sec.-1. Another experiment was carried out by Kramers and de Korver using a short rotary contactor (height = 10 cm., diameter = 9.3 cm., diameter of rotor = 8.0 cm.) which was made entirely of Teflon to prevent wetting of the wall by the aqueous dispersed phase. This reactor... 

The rate experiments were carried out in 3.5 liter glass jars covered with a plexiglass lid. Two baffles of 2 cm width extended from the lid to 1 cm from the bottom of the reactor. Agitation was provided by a stirring motor with polyethylene stirrers, and the speed of the motor was controlled with a variac. Three liters of solution without the adsorbent particles was agitated, and allowed to reach equilibrium with the vessel before withdrawing the initial sample for analysis. At time t - 0, a measured quantity of activated carbon was introduced into the reactor and agitated. Samples, 10 ml each were withdrawn periodically, until equilibrium was reached, and analyzed for the solute concentration in the liquid phase. The numerical procedure developed earlier was adjusted to allow for the volume reduction due to the withdrawal of samples at discrete time Intervals. 

HSS method made it possible to measure both an interfacial concentration and an extraction rate for the first time by a simple principle. When a two-phase system is highly stirred or agitated in a vessel and the interfacial area is extremely extended, the interfacial amount of an adsorbed compound is increased... 

In preparative-scale (10 M 1-naphthol) experiments, an Ace-Hanovia 450-W medium-pressure mercury arc was used with a Pyrex filter sleeve and a magnetically stirred Ace water-cooled reaction vessel. In experiments involving rose bengal as a sensitizer, tungsten lamp illumination was used. Ultraviolet spectral changes were measured with a Perkin-Elmer model 552A spectrophotometer. For GC-MS analysis, a Hewlett-Packard 5985A instrument was used with a fused silica capillary column coated with a bonded nonpolar polymethyl silane phase introduced directly into the electron Impact ionization source. Compounds were tentatively identified by comparison to published spectra and confirmed where possible with authentic standard materials. 

Consider a single-phase liquid in a stirred tank to which a volume of tracer material is added. The mixing time is the time measured from the instant of addition until the vessel contents have reached a specified degree of uniformity when the system is said to be mixed . 

Sodium Chloride Solubilities in Amine-Water Mixtures. The sodium chloride solubilities were determined as a function of the amine concentration at the crystallization temperature in the single liquid phase region. The experiments were carried out in the equilibrium vessel as described in the previous section. The vessel was filled with a saturated sodium chloride solution. At the crystallization temperature a known amount of amine was added, resulting in the crystallization of sodium chloride. After a period of at least 60 minutes the stirring was stopped and liquid samples of the mixture were taken. Conductivity measurements showed that this period of time was sufficient to reach chemical equilibrium. The salt concentrations in the liquid samples were determined gravimetrically. 

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