Column packings rings

Whitt, F. R., A Correlation For Absorption Column Pack-rings, British Chem. ng., July, p. 395 (1959). 

The commercial production equipment consists of a furnace, heat-exchanger tubes, a fractionating column packed with Rachig rings, a KCl feed, a waste removal system, and a vapor condensing system (Fig. 1). 

Under typical Hquid-phase chlorination conditions the maximum conversion to benzyl chloride of about 70% is reached after reaction of about 1.1 moles of chlorine per mole of toluene (39). Higher yields of benzyl chloride have been claimed 80% for low temperature chlorination (40) 80—85% for light-catalyzed chlorination in the vapor phase (41) and 93.6% for continuous chlorination above 125°C in a column packed with glass rings (42). 

Many operating data for carbonate plants are cited by Kohl and Riesenfeld (Gn.s Purification, Gulf, 1985) but not including tower heights. Pilot plant tests, however, are reported on 0.10- and 0.15-m (4- and 6-in) columns packed to depths of 9.14 m (30 ft) of Raschig rings hy Benson et al. (Chem. Eng. Prog., 50, 356 [1954]). 

Figure 1.17 Separation of large ring polycyclic aroaatic hydrocarbons extracted from carbon black on a 1.8 x 0.2 n I.D. fused silica capillary column packed with 3 micrometer spherical octadecylsllanized silica gel eluted with a stepwise solvent gradient at a flow rate of 1.1 mlcroliters/min with an inlet pressure of about 360 atmospheres. Under isocratic conditions this column yielded ca. 225,000 theoretical plates. (Reproduced with permission from ref. 238. Copyright Friedr. Vieweg t Sohn).

In orthorhombic a-sulfur, the modification stable at normal conditions, S8 rings are stacked to form columns. Consecutive rings are not stacked one exactly above another (as in a roll of coins), but in a staggered manner so that the column looks like a crank shaft (Fig. 11.3). This arrangement allows for a dense packing of the molecules, with columns in two mutually perpendicular directions. The columns of one direction are placed in the recesses of the perpendicular crank shafts . In S6 and in S12 the rings are stacked exactly one above another, and the rolls are bundled parallel to each other. In the structures a... 

Extraction column packed column, diameter 0.5 m, height 4 m, packed height 3 m, packing 25 mm stainless steel pall rings, design pressure 2 bar, material carbon steel. 

Random packings rings, saddles and proprietary shapes, which are dumped into the column and take up a random arrangement. 

Two heat-sensitive organic liquids of an average molecular mass of 155 kg/kmol are to be separated by vacuum distillation in a 100 mm diameter column packed with 6 mm stoneware Raschig rings. The number of theoretical plates required is 16 and it has been found that the HETP is 150 mm. If the product rate is 5 g/s at a reflux ratio of 8, calculate the pressure in the condenser so that the temperature in the still does not exceed 395 K (equivalent to a pressure of 8 kN/m2). It may be assumed that a = 800 m2/m3, /x = 0.02 mN s/m2, e = 0.72 and that the temperature changes and the correction for liquid flow may be neglected. 

An early CO distillation pilot plant described by Johns (in London (1961), reading list), used a two section vacuum insulated column packed with wire gauze rings. The upper section was 5.2 m long with a diameter of 3.2cm, the lower 4.6 m x 1.9 cm. The column contained about 600 plates. An intermediate boiler re-evaporated part of the downward flowing liquid at the junction. This plant accumulates product in the liquid and enriches toward the bottom. Enriched CO (0.4 g day-1 of 65% 13C and 0.05 g day-1 of 5% lsO) was withdrawn from the bottom... 

Monomeric styrene is destabilized as in Example 3-1 and pre-dried with calcium chlo-ride.The monomer is now allowed to stand over calcium hydride for 24 h and then distilled under reduced pressure of nitrogen into a previously flamed-out Schlenk tube. Pure 4-vinylpyridine is distilled twice over KOH pellets in vacuum.lt is then vacuum distilled under nitrogen through a column packed with Raschig rings into a previously flamed out Schlenk tube (bp 62 °C/12 torr).The closed Schlenk tubes containing the monomers are stored in a refrigerator until required.The preparation of the initiator solution (sodium naphthalene) is described in Example 3-19. 

Raschig ring -as distillation column packings [DISTILLATION] (Vol 8)... 

Filter units are broadly classified into two types (1) fabric or cloth bag systems and (2) deep columns packed with rock or other contactors such as fiber plates or glass beads or rings. Commerical fiber materials are selected for... 

---