Page 257 - Applied Process Design For Chemical And Petrochemical Plants Volume II

246 Applied Process Design for Chemical and Petrochemical Plants

Figure 9-6LL. Montz-Nutter high-efficiency structured packing assembly (Type B-1 TM with wiper bands and seal strip). Used by permission of
Nutter Engineering, Harsco Corp., Bull. 8-1.

those separately supported above or below it. If any inter-
mediate supports or redistributors are not separately sup-
ported on the tower wall but rest on the packing itself, the
bottom support would carry the entire tower load of pack-
ing as mentioned, plus the weights of intermediate support
and redistribution plates. This is riot good practice as it
complicates the packing arid repacking of the tower in
addition to possibly imposing heaky loads on the bottom
supports.
As a general rule packing heights per support plate
should not exceed 12 ft for Raschig rings or 15-20 ft for
most other packing shapes. Other types fit within these
limits. The mechanical, vibrational and thermal shock
loads become important and sometimes affect the tower
operation beyond these limits.

Liquid Distribution

Liquid distribution probably plays the most important
part in the efficient operation of a packed tower. A good
packing from the process viewpoint can be reduced in
effectiveness by poor liquid distribution across the top of
Figure 9-6MM. Nutter BHSTM structured packing with expanded metal its upper surface or the packing sections below any feed
texture, which maintains high mass transfer efficiency across all oper-
ating conditions. Nutter Engineering designs and manufactures BSH in inlet(s) or reflux inlets.
North America under exclusive license from Julius Montz GmbH of Ger-
many. Used by permission of Nutter Engineering, Harsco Corp.