Furnish and install as shown on the plans an EVAPCO Model _____ induced draft counterflow cooling tower. Each unit shall have the capacity to cool _____ GPM (liters/sec) of water from _____ °F (ºC) to _____ °F (ºC) with a _____ °F entering wet bulb temperature. Total fan motor horsepower shall not exceed _____ HP (kW), consisting of _____ @ _____ HP (kW) fan motors.
Cold Water Basin Section
The cold water basin section, vertical support columns and louver frames
shall be constructed of Type 316 stainless steel for long life and durability.
The stainless steel cold water basin section area shall include all components
from the base of the unit up to the top of the air inlet louver screens.
Standard accessories shall include stainless steel overflow, drain, anti-vortexing
hood, strainers and brass make-up valve with plastic float. The entire
cold water basin area shall incorporate a stepped configuration for reduced
water volume, lower operating weight and easier basin maintenance. The
upper and lower cold water basins shall be sloped to provide positive
drainage of the complete basin section. Depressed side or bottom outlet
sumps which are not an integral part of the basin shall not be acceptable.
Fiberglass or epoxy coated galvanized steel pans will not be acceptable.
Casing
The casing and fan sector panels shall be constructed of type 304 stainless
steel for long life and durability. The casing panels shall totally
encase the sides of the fill section to protect the surface from direct
atmospheric contact.
Models
USS 19-56 to USS 39-942
Fan Motor(s)
_____ HP (kW) totally enclosed fan cooled (T.E.F.C.) ball bearing fan motor(s) with 1.15 service factor shall be furnished suitable for cooling service on _____ volts, _____ hertz, and _____ phase. Motor(s) shall be mounted on an adjustable base which is mounted on the side of the unit for service. A Type 304 stainless steel hinged protective cover shall shield the motor and sheave from the weather.
Drive
The fan drive shall be a multi-groove, solid back V-belt type with taper
lock sheaves designed for 1.5 service factor of the motor nameplate
horsepower. The belt material shall be neoprene reinforced with polyester
cord and specifically designed for cooling tower service.
A Type 304 stainless steel hinged protective cover shall shield the motor and sheave from the weather. Belt adjustment shall be accomplished from the exterior of the unit. Bearing lube lines shall be extended to the exterior of the unit for easy maintenance. All sheaves located in the airstream shall be constructed of aluminum alloy.
If internal belt adjustment is necessary, an internal working platform and ladder shall be provided to access the drive system.
Models
USS 112-012 to USS 428-1248
Fan Motor(s)
_____ HP (kW) totally enclosed air over (T.E.A.O.) ball bearing fan motor(s) with a 1.15 service factor shall be furnished suitable for cooling tower service on _____ volts, _____ hertz, and _____ phase. Motor(s) shall be mounted on an adjustable base which allows the motor to swing to the outside of the unit for servicing.
Drive
The fan drive shall be a multi-groove, solid back V-belt type with taper
lock sheaves designed for 1.5 service factor of the motor nameplate
horsepower. The belt material shall be neoprene reinforced with polyester
cord and specifically designed for cooling tower service.
Fan and motor sheaves shall be aluminum alloy construction. Belt adjustment shall be accomplished from the exterior of the unit. Bearing lube lines shall be extended to the exterior of the unit for easy maintenance.
All sheaves located in the airstream shall be constructed of aluminum alloy. If internal belt adjustment is necessary, an internal working platform and ladder shall be provided to access the drive system.
Axial Propeller Fans
Fans shall be heavy duty axial propeller type statically balanced. The fans shall be fabricated by the cooling tower manufacturer for single source responsibility and reliability. The fans shall be constructed of extruded aluminum alloy blades, installed in a closely fitted stainless steel cowl with venturi air inlet for maximum fan efficiency. Each fan blade shall be individually adjustable. Fan cowl shall be covered with a heavy gauge stainless steel wire fan guard.
Galvanized fan guards will not be acceptable.
Fan Shaft Bearings
Fan shaft bearings shall be heavy duty self-aligning ball type with self locking collars and grease fittings extended to the outside of the unit. Bearings shall be designed for a minimum L-10 life of 75,000 hours.
Bearings with a 40,000 hour L10 life will not be acceptable.
Fill
The cooling tower fill shall be PVC (polyvinyl chloride) of cross-fluted design for optimum heat transfer efficiency. The cross-fluted sheets shall be bonded together for strength and durability. The fill shall be fabricated, formed, and installed by the cooling tower manufacturer and shall be elevated a minimum of 4 feet (1,2 m) above the floor of the cold water basin to facilitate cleaning. The PVC fill shall be self-extinguishing for fire resistance with a flame spread rating of 5 per ASTM E84-81a. It shall also be resistant to rot, decay, and biological attack. The fill shall be able to withstand a continuous water temperature of 130°F (54,4ºC).
The fill shall be suitable for use as a working platform.
Non-Corrosive Water Distribution System
Each cell of the cooling tower shall have one (1) hot water return inlet connected to a main spray header. The spray header and branches shall be constructed of Schedule 40 polyvinyl chloride (PVC) pipe for corrosion resistance and shall have a stainless steel connection which is beveled for weld/grooved for a mechanical coupling to attach the external piping. The spray header and branches shall be removable for cleaning purposes and have threaded end caps to allow debris to be removed. The water shall be distributed over the fill by precision molded ABS spray nozzles with large 3/8 by 1 inch orifice openings and integral sludge ring to eliminate clogging.
The nozzles shall be threaded into the water distribution piping to assure positive positioning. If open type gravity distribution pans are used, they shall be constructed of non-corrosive materials (stainless steel, FRP or PVC).
If two (2) gravity distribution pans are required, pipework to convert to a single inlet per cell must be included and top perimeter handrailing with a ladder to the top of the tower must also be provided for servicing the pans.
Eliminators
The eliminators shall be constructed entirely of inert polyvinyl chloride (PVC) in easily handled sections and be completely separate from the fill section for maximum efficiency. The eliminator design shall incorporate three changes in air direction to assure removal of all entrained moisture from the discharge air stream. Maximum drift rate shall be less than 0.001% of the circulating water rate.
Air Inlet Louver Screens
The louver screens shall be constructed of polyvinyl chloride (PVC)
and mounted in easily removable Type 316 Stainless Steel frames on all
four sides of the cooling tower for access to the entire basin area
for maintenance. The louvers shall have a minimum of two changes in
air direction to prevent splashout, block direct sunlight from entering
the basin, and have a 3/4” (19mm) opening to prevent debris from
entering the basin.
5-Year Warranty
The unit shall be warranted against failure caused by defects in materials and workmanship for FIVE (5) years from the date of shipment. All cooling tower and drive system components are included.
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