SPX Cooling Technologies Cooling Tower Marley MD, Инженерные данные, Страница: 29 / 40

Specifications Specification Value
Marley
/
MD Cooling Tower / Specifications: Base
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4.0
Design Loading:
4.1 The tower and its components shall be
designed to withstand a wind load of
1.44kPa. The cooling tower shall be de-
signed to withstand shipping and hoist-
ing loads of 2g horizontal or 3g vertical.
Guardrails, where specified shall be
capable of withstanding a 890N con-
centrated live load in any direction and
shall be designed in accordance with
OSHA guidelines.
5.0
Construction:
5.1 Except where otherwise specified,
all components of the cooling tower
shall be fabricated of heavy-gauge
steel, protected against corrosion by
EN10142:2000 grade Z600 galvaniz-
ing. After passivation of the galvanized
steel (8 weeks at pH 7-8, and calcium
hardness and alkalinity at 100-300
mg/L each), the cooling tower shall be
capable of withstanding water having a
pH of 6.5 to 9.0; a chloride content up
to 500 mg/L as NaCl (300 mg/L as Cl-);
a sulfate content (as SO4) up to 250
mg/L; a calcium content (as CaCO3)
up to 500 mg/L; silica (as SiO2) up to
150 mg/L; and design operating ranges
up to 10°C. The circulating water shall
contain no oil, grease, fatty acids, or
organic solvents.
5.2 The specifications, as written, are
intended to indicate those materials
that will be capable of withstanding
the above water quality in continuing
service, as well as the loads described
in paragraph 4.1. They are to be regard-
ed as minimum requirements. Where
component materials unique to indi-
vidual tower designs are not specified,
the manufacturers shall take the above
water quality and load carrying capabili-
ties into account in the selection of
their materials of manufacture.
6.0 Mechanical Equipment :
6.1 Fan(s) shall be propeller-type, incorpo-
rating heavy aluminum alloy blades and
electrogalvanized hubs. Blades shall be
individually adjustable and both stati-
cally and dynamically balanced. Fan(s)
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The indicated design values are the minimum allowables under
accepted design standards. They give you assurance that the cool-
ing tower can be shipped, handled, hoisted—and ultimately oper-
ated in a normal cooling tower environment. Most MD models will
withstand significantly higher wind and seismic loads. If your geo-
graphic location dictates higher wind load or seismic load values,
please make the appropriate changes, after discussion with your
Marley sales representative.
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In the history of cooling towers, no other coating for carbon steel
has exhibited the success and longevity of galvanization in expo-
sure to the normal cooling tower water quality defined at left. No
paints or electrostatically-applied coatings, however exotic they
may be, can approach galvanization's history of success.
If extended longevity of the cooling tower is required—or unusually
harsh operating conditions are expected—consider specifying stain-
less steel as either the base construction material, or the material
utilized for specific components of your choice. See Stainless Steel
Options on page 16.
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Propeller-type fans require only half the operating hp of blower-type
fans. However, they should be readily adjustable to permit compen-
sation for jobsite conditions. The fans of one manufacturer require
the purchase of special positioners for each increment of fan blade
pitch. The Marley Power Belt drive system features all-aluminum
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