SPX Cooling Technologies Cooling Tower 600 - Manual (Page 8)

8
/ Drift Eliminators /
Marley towers utilize Marley XCEL ® plus drift
eliminators, a cellular, labyrinthine design which improves
drift elimination by several orders of magnitude over
that achievable by blade-type eliminators. Significantly
lower pressure losses also reduce fan horsepower
requirements.
XCEL eliminators are thermoformed PVC bonded into
easily handled, rigid packs which “nest” together to seal
against drift bypass. Packs are clamped in place at each
girt line, and are self-supporting between girt lines. No
additional structure is required to support the eliminators.
Corrosion and chemical resistant plastic drain boards
return all water stripped from the air to the fill chamber.
/ Tower Structure /
Class 600 cooling towers are designed in accordance
with the latest edition of the National Design Specification
for Wood Construction (NDS) published by the National
Forest Products Association, and CTI STD-114. Wind
load criterion is per ASCE-7, and stability is based upon
an applied lateral load of 2.5% of the total operating
weight. Allowable stress values for all lumber are reduced
for wet service, temperature, and duration as appropriate.
Unless otherwise specified, all lumber regardless of
species is pressure treated after fabrication. Treatment is
Copper Chromate Arsenate (CCA), infused into the wood
as specified by CTI STD-112.
The design is based on 4 ′-0″ x 8′-0″ modules.
Transverse bents consist of 4 ″ x 4″ columns spaced on
8 ′-0″ centers. Transverse bent lines are spaced on 4′-0″
centers longitudinally.
Transverse fan deck and hot water basin girts are
2 ″ x 6″—all other transverse girts and all longitudinal
girts are 2 ″ x 4″ except where loading may require 3″
x 4 ″. Transverse and longitudinal girts are spaced on
6 ′-0″ vertical centers. Girt lines are through bolted to the
columns.
Transverse and longitudinal diagonals are
4 ″ x 4″members spliced across tower columns with FRP
connectors. The connectors transmit lateral loads from
girts to diagonals and columns.