Page 266 - Applied Process Design For Chemical And Petrochemical Plants Volume II

Packed Towers 255

Table 9-17
Packing Type Application
Packing Application Features Packing Application Features

Raschig Rings Earliest type, usually cheaper per unit cost, but some Grid Tile hailable with plain side and bottom or serrated
times less efficient than others. Available in widest sides and drip-point bottom. Used stacked only. Also
variety of materials to fit service. Very sound struc- used as support layer for dumped packings. Self sup
turally. Usually packed by dumping wet or dry, with porting, no side thrust. Pressure drop lower than
larger 4.43 in. sizes sometimes hand stacked. Wall most dumped packings and some stacked, lower
thickness \aria between manufacturers, also some than some K-in. x I-in. and %;-in. x %in. wood grids,
dimensions; available surface changes with wall thick- but greater than larger wood grids. Some HTU kal-
ness. Produce considerable side thrust on tower. Usu- ues compare lbith those using 1-inch Raschig rings.
ally has more internal liquid channeling, and directs Teller Rosette Available in plastic, lower pressure drop and HTU
more liquid to walls of tower. Low efficiency.
(Tellerette) values, higher flooding limits than Raschig rings or
Berl Saddles More efficient than Raschig Rings in most applica- Berl saddles. Very low unit weight: low side thrust.
tions, but more costly. Packing nests together and Spraypak3 Compared more with tray type performance than
creates "tight" spots in bed which promotes channel- other packing materials. Usually used in large diam-
ing but not as much as Raschig rings. Do not produce eter towers, above about 24in. dia., hut smaller to
as much side thrust; has lower HTU and unit pres- 10-in. did. available. Metal only.
sure drops with higher flooding point than Raschig
riiicgs. Easier to break in bed than Kaschig rings. Panapak4 Available in metal only, compared more with tray
type performance than other packing materials.
Intalox Saddles] One of most efficient packings, but more costly. About same HETP as Spraypak for anilable data.
And Other Very little tendency or ability to nest and block areas Used in towers 24 in. and larger. Shows some per-
Saddle-Designs of bed. Gives fairly uniform bed. Higher flooding formance advantage over bubble cap trays up to 75
limits and lower pressure drop than Raschig rings or psia in fractionation service, but reduced adwn-
Berl saddles; lower HTU values for most common tages above this pressure or in vacuum service.
systems. Easier to break in bed than Raschig rings,
as ceramic. Stedman Packing Available in metal only, usually used in batch and
continuous distillation in small diameter columns
Pall Rings" Lower pressure drop (less than half] than Raschig not exceeding 24-in. dia. High fractionation ability
rings, also lower HTU (in some systems also lower per unit height, best suited for laboratory work.
than Berl saddles), higher flooding limit. Good liq-
uid distribution, high capacity. Considerable side Conical and triangular types available. Not much
industrial data available.
thrust on column wall. Available in metal, plastic
and ceramic. Sulzer, Flexipac, High efficiency, generally low pressure drop, well suit-
and similar ed for distillation of clean systems, very low HETP.
!detal IntalOX" High efficiency, low pressure drop, reportedly good
Hy-Pak' for distillations. Goodloe Packing' Available in metal and plastic, used in large and
Chempak' and small towers for distillation, absorption, scrubbing,
Wire Mesh Packing liquid extraction. High efficiency, low HETP, low
Spiral Kings Usually installed as sracked, taking advantage of pressure drop. Limited data available.
internal whirl of gas-liquid and offering extra con-
tact surface over Raschig ring, Lessing rings or cross Cannon Packing Available in metal only, low pressure drop, low
partition rings. Available in single, double and hple HETP, flooding limit probably higher than Raschig
internal spiral designs. Higher pressure drop. Wide rings. Not much literature data available. Used
\ariety of performance data not available. mostly in small laboratory or semi-plant studies.
Lessing Rings Not much performance data available, but in gen- \\rood Grids Very low pressure drop, low effkiency of contact,
eral slightly better than Raschig ring, pressure drop high HETP or HTU, best used in atmospheric tow-
slightly higher. High side wall thrust. ers of square or rectangular shape. Very low cost.

Cross-Partition Usually used stacked, and as first layers on support Poly Gridfi Plastic packing of very low pressure drop, developed
Rings grids for smaller packing above. Pressure drop rela- for wxter-air cooling tower applications.
tively low, channeling reduced for comparative
stacked packings. KO side wall thrust.

Compiled from literature:
1 Trade name of Norton Chemical Process Products Corp.
2 Introduced by Bddische hilin and Sodafabnk. Ludwigshafen am Rhein
3 Trade name of Denholme Inc., Licensed by British Government
4 Trade name of Packed Column Corp.
.5 Trade name of Packed Column Corp.
6 Trade name of The Fluor Product.? Go.
7 Trade name of Chem-Pro Equip. Corp.