Metal packed column

A flask equipped with a low-temperature reflux condenser was charged with l//-heplafluorobul-2-ene [20 g, 0.11 mol ratio (E/Z) 48 52] and MeCN (30 mL). To the vigorously stirred mixture, NaOCl soln (70 mL) was added at - 10 to 0 C and the reaction was continued under these conditions for 5 h. The lower organic layer was separated, washed with H20, and dried (MgS04). The crude product was bro-minated with dropwise addition of Br2 and external irradiation with UV light to separate any unrcacted starting alkene. The product was obtained by fractional distillation on a packed column (metal spirals) yield 15.2 g (70%) (E/Z) 46 54 bp 22-23 C. 

Fig. 5.4-24 Maldistribution in a packed column (metal Pall rings 35 mm). Column diameter D = 0.63 m, packing height H = 6.8 m. Gas load F = 1.1 Pa, liquid load B = 5.2 w /(jn -h). Ley Uniform liquid feed. Rigte Single point liquid feed...

The technology is based on the rapid equhibrium estabUshed between the reactants and products at high temperatures. The equhibrium shifts to the product side when potassium is removed continuously by distihation through a packed column. This process can produce high purity potassium metal. Appropriate adjustments of conditions give a wide range of potassium—sodium ahoys of specified compositions. 

Example 13 Packed Column Pressure Drop Air and water are flowing coiinterciirrently through a bed of 2-inch metal Pali rings. The air mass velocity is 2.03 kg/s-m (1500 Ihs/hr-fd), and the liquid mass velocity is 12.20 kg/s-m (9000 Ihs/hr-fr). Calculate the pressure drop hy the generalized pres-... 

Next, to determine packed column height use Table 9 for distillation HETP values, leaning tow ards the high side of the range for studies. For use of Kqa values see Section A—Absorbers. Bed height per packed bed runs up to 20-30 ft for metal or ceramic packings, but plastic packing is usually limited to 24 ft. 

Packed column. A distillation column filled with an inert material to enhance vapor/liquid contact. The packing can be beads, pellets, Raschig rings, metal chains, or specifically shaped devices such as saddles, helices, or rings. 

Raschig rings (columns). Metal cubes a few inches long used as packing in distillation columns ... 

The following are examples of incidents involving metal packing fires in packed columns ... 

Methyl vinyl dichlorosilane [124-70-9] M 141.1, 43-45.5°/ll-ll.5mm, 91 /742mm, 92.5°/743.2mm, 92.5-93°/atm, d 1.0917, n 1.444. Likely impurities are dichloromethylsilane, butadienyl-dichloromethylsilane. Fractionate through a column packed with metal filing (20 theoretical plates) at atmospheric pressure. [Isvest Akad SSSR Otd Chem 1474 1957 and 767 7955]. 

Direct vaporisation injection. For packed columns and megabore columns of 530 pm, which typically use a flow rate of 10 ml/min, direct vaporisation is a simple way to introduce the sample. All models of this type of injector are a variation of a simple assembly which uses a metal tube with a glass sleeve or insert. The glass insert is swept by the carrier gas and heated to the vaporisation temperature for the analytes undergoing chromatography. One end of the injector contains a septum made of silicone rubber that allows the syringe needle to pass through it into the system. The other end of the injector is connected to the head of the column (Fig. 2.4). The entire sample is injected into the column in a few seconds. 

Materials. Cyclohexene, obtained by dehydration of reagent grade cyclohexanol (3), was heated at reflux over sodium metal, fractionated on a 60-cm. Helix packed column, stored over sodium, and filtered just before use. No impurity was found by gas chromatography (column, TCP and Si-550 carrier gas, helium). Propylene (Neriki Research Grade) used showed no impurity by gas chromatography (column, active carbon and acetonylacetone). 

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