Column internals liquid redistributor

When a sparger pipe enters an intermediate feed, vapor jets must not impinge on redistributor liquid surface or other packed-column internals. Liquid surface agitation in redistributors, or mechanical damage to internals, can cause maldistribution, which can be detrimental to column efficiency. 

Select and design the column internal features packing support, liquid distributor, redistributors. 

As indicated above, packed column internals include liquid distributors, packing support plates, redistributors (as needed), and holddown plates (to prevent movement of packing under flow conditions). Costs of these internals for columns with random packing are given in Fig. 14-81, based on early 1976 prices, and a Marshall and Swift cost index of 460. 

The multiple phase contact inside the column is promoted by internal mass transfer equipment. Three groups of mass transfer equipment are commonly differentiated, which are separation trays, random packings and structured packings. Besides mass transfer equipment, further column internals are required in rectification to ensure the proper operation of the mass transfer equipment. Such internals may include support and hold-down plates, liquid distributors and redistributors, vapour distributor devices, gas-liquid phase separators and liquid collectors that usually do not participate on mass transfer. 

The column internals are these important imte of the apparatus idiidi are cxmstructed to ensure i oper conditions fo oi ration of die packiii Ihere are support plates, hoU-4own phrtes, liquid distributors and redistributors, gas (vapour) distributors, gas-liquid phase separators, and liquid collators. As an additional type of column internals, combined devices rinch ensuring redistribution of the phases act also as mass transfer vices. 

FIG. 14-80 Cost of internal devices for columns containing dumped packings, a) Holddown plates and support plates, (h) Redistributors, (c) Liquid distributors. [Pikulik and Diaz, Cbem. Eng., 84(21), 106 (Oct. 10, 1977).]... 

Figure 1335. Packed column and internals, (a) Example packed column with a variety of internals [Chen, Chem. Eng. 40, (5 Mar. 1984)]. (b) Packing support and redistributor assembly, (c) Trough-type liquid distributor, (d) Perforated pipe distributor, (e) Rosette redistributor for small towers. (0 Hold-down plate, particularly for low density packing.

The vapor-liquid separator t5 pe (Fig. 3.96) features an internal knockout drum directly above an orifice redistributor. It consumes more vertical space than the baffle t3q)e, but it has the potential of providing better liquid distribution to the bed below. This device is also most suitable for small columns (386). 

---

See also in sourсe #XX -- [ , ]

---