Specifications
Specification Value
Marley
/
Sigma F Series
Cooling Tower
/
Specifications: Base
16
5.4
A stainless steel oil fill and drain line
shall extend from the gear reducer to
the vicinity of the motor, and shall be
equipped with a bronze-bodied oil level
sight-glass gauge.
5.5
The complete mechanical equipment
assembly for each cell shall be sup-
ported by a rigid, unitized support that
resists misalignment between the
motor and the gear reducer. Support
shall be heavy-wall tubular steel, to
which heavy plate platforms for the
motor and gear reducer have been
welded and the assembly shall be hot-
dip galvanized after fabrication. The
support assembly shall also provide
an inlet connection for incoming hot
water, and shall serve as a crossover
pipe to deliver water to both sides of
the tower.
5.6
The mechanical equipment assembly
shall be warranted for no less than five
(5) years. This warranty shall cover the
fan(s), speed reducer(s), driveshaft(s),
couplings, and the unitized supports.
6.0
Fill, Louvers and Drift Eliminators
:
6.1
Fill shall be film-type, 15 mil (0.38 mm)
thick, thermoformed PVC, with louvers
formed as part of each fill sheet. Fill
shall be suspended from stainless
steel structural tubing supported from
the upper tower structure, and shall
be elevated above the floor of the cold
water basin to facilitate cleaning. Air
inlet faces of the tower shall be free of
water splashout.
6.2
Drift eliminators shall be 15 mil
(0.38 mm) thick PVC, formed as part of
each fill sheet, triple-pass, cellular type,
and shall limit drift losses to 0.005% or
less of the design water flow rate. The
final pass of the eliminators shall direct
the air toward the fan.
The extended oil line to an oil gauge
provides a safe and convenient means
of checking the level of oil in the
Geareducer.
Fans of the size used on large cool-
ing towers are applied at speeds and
horsepowers that generate consider-
able torque—and structural tubular
steel resists this torque very effectively.
The Marley torque-tube design assures
that all of the mechanical equipment
remains aligned, and that the rotating
fan is properly positioned within the fan
cylinder. Hot-dip galvanizing after fabrication assures that all steel
surfaces will be heavily coated with zinc for long-term protection
against corrosion.
Even in aggressive water conditions, the heavy construction of
the unitized support normally precludes the need for stainless
steel. It is available, however, at extra cost.
The value of a 5 year mechanical equipment warranty speaks for
itself. Except for the motor, all of the mechanical equipment on
a Marley tower is made by Marley. Cooling tower vendors who
purchase commercial fans, gear boxes, driveshafts, etc. may
require that you deal directly with those commercial suppliers for
warranty satisfaction.
■
Louvers integral with the fill keep the flowing water within the
confines of the fill. The separate external louvers used by oth-
ers permit water to escape the fill and form ice or produce an
unsightly situation adjacent to the tower. If you plan to use your
tower in the wintertime, particularly for free cooling, integral lou-
vers will put your operating concerns to rest.
Vertical blade-type eliminators, as well as misdirected cellular
types, cause much of the fan power to be wasted in turning the
horizontal flow of air vertical for its exit through the fan cylinder.
This power is, of course, not available for contribution to thermal
performance.
Drift rate varies with design water loading and air rate, as well as
drift eliminator depth and number of directional changes. A drift
rate of 0.001% is readily available in standard configuration with-
out premium cost. If a lower rate is required, please discuss with
your Marley sales representative.
