Base: Furnish and install an induced-draft, crossflow, factory- assembled, steel cooling tower of ____ cell(s), as shown
on plans. Tower shall be similar and equal in all respects to Marley Series 4900 Aquatower, Model _______. Tower
must be warranted by the manufacturer for one year from date of shipment.
Performance: Tower shall cool ____ m3/hr of water from ____ °C
to ____ °C at a design entering air wet-bulb temperature
of ____ °C and its thermal rating shall be certified by the
Cooling Technology Institute.
Construction: Structural components of the tower, including the cold water basin, framework, mechanical equipment supports, casing, hot water basin, and fan cylinder shall be fabricated of heavy-gauge steel, protected against corrosion by Z-600 galvanizing per BS EN 10327:2004. All components subjected to factory welding shall be hot dip galvanized after fabrication per BS EN 150 1461:1999. Cold galvanizing is not acceptable.
Motor: Motor(s) shall be ____ kW, Totally Enclosed, specially
insulated for cooling tower duty. Speed and electrical characteristics shall be 1500 (or 1500/750) RPM, single- winding, ____ phase, ____ hertz, ____ volts. The motor
must be located out of the saturated discharge air stream.
Mechanical Equipment: Fan(s) shall be adjustable-pitch propeller type. Fan shall be driven through V-belt(s) with a minimum service factor of 1.5 based on full motor kW and protected with a belt guard. The fan and fan pulley shall be supported by oil lubricated tapered roller bearings in a cast iron housing with externally accessible remote oil reservoir for easy maintenance.
Fill, Louvers and Drift Eliminator: Fill shall be film-type, thermoformed PVC, with louvers and drift eliminator formed as part of each fill sheet. Fill shall be suspended from hot dip galvanized 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 splash-out. Guaranteed drift losses shall not exceed 0.005% of the design flow rate.
Hot Water Distribution System: An open basin above the fill bank shall receive hot water piped to each cell of the tower. The basins shall be equipped with removable covers to keep out debris. This basin shall be installed and sealed at the factory. Water shall enter the basin through a removable wave-suppressor splash box. The basin shall be no less than 162mm deep to provide adequate freeboard against overflow and splash-out. Removable and replaceable polypropylene nozzles installed in the floor of the basin shall provide full coverage of the fill by gravity flow. Nozzles must all have the same orifice size and be spaced symmetrically in both longitudinal and transverse directions.
Cold Water Basin and Accessories: The cold water basin shall be factory sealed. For maximum installation flexibility, basin accessories shall include both a side suction connection and a hole and bolt circle in the basin floor suitable for gravity flow. Both connections shall include a debris screen and anti-cavitation device. A factory- installed, float-operated, mechanical makeup valve shall be included, having a 3⁄4" diameter inlet connection.
