SPX Cooling Technologies Cooling Tower 600 - Manual (Page 10)

10
/ Casing /
The endwalls of Class 600 towers are cased from the
fan deck level to below the top of the basin curb with
8 oz/sq ft corrugated FRP sheets. FRP is waterproof and
corrosion proof, is immune to biological deterioration,
and requires no maintenance. Sheets are installed
on maximum 4
′-0″ spans with corrugations running
horizontally. Vertical joints are lapped and sealed.
Horizontal joints are lapped one corrugation to shed water
inward. The casing is attached to structural members
with stainless steel screw shank fasteners, complete with
neoprene bonded washers. Corner trim pieces are 12
oz/sq ft molded FRP.
/ Louvers /
42 ″ wide louver blades, made of 9 oz/sq ft corrugated
FRP, prevent splash out. Exterior grade plywood louvers
are used in freezing climates. Continuous 2
″ x 4″
members beneath the louvers provide bearing across the
entire louver width. These supports are rigidly framed into
louver posts by through bolting at the bottom and are tied
near the top by molded structural polypropylene tie bars.
Louvers are supported on 4 ′-0″ centers by 4″ x 4″
structural columns. This scheme provides more than
twice the bending strength compared to designs utilizing
6
′-0″ spans.
The relationship between the louvers and the direction
of water flow results in a uniform, light water cascade
down the inboard edge of the louvers. This cascade
protects the fill from ice formation and possible damage.
Standard FRP louvers are positioned on 4 ′-0″ vertical
centers. Plywood louvers used in freezing climates
are positioned on 3
′-0″ vertical centers. This spacing
eliminates stagnant areas in the fill, thereby reducing the
tendency for fine moisture particles to form sheet ice,
plugging air inlets.