VESSELS / VALVES
The eco-ATWB-E is an induced draft, counterflow design closed circuit cooler with a capacity range of 1320 to 9225 MBH (377 to 2636 kW). Standard construction includes the patented, high efficiency Ellipti-fin Coil and G-235 (Z-725 Europe) galvanized steel casing and basin. Type 304 or 316 stainless steel construction is available for the basin or the entire unit.
eco-ATWB-E Closed Circuit Cooler - Design Features
The New eco-ATWB-E line of Closed Circuit Coolers offers the same great design benefits and features as the eco-ATWB but it has also been specifically designed to optimize both the evaporative (latent) and dry (sensible) modes of cooling simultaneously. This unique design joins an evaporative cooler and a dry cooler into one unit.
The eco-ATWB-E utilizes the EVAPCO Ellipti-fin coil which features elliptical spiral fin technology to maximize the surface area available for heat transfer. This decreases water consumption and offers additional cost savings through reduced water make-up, blow-down, and chemical consumption. Evaporative cooling provides lower system operating temperatures and higher overall system efficiencies.
The eco-ATWB-E is the ideal solution for: Lower Energy Costs, Reducing Water Consumption, High Dry Bulb Switchover, Super Low Sound Levels. This new product is designed with IBC Compliant construction and CTI Certified Performance.
Principle of Operation Evaporative Mode (Latent Heat Transfer) In the evaporative mode, the process fluid enters the eco-ATWB-E cooler through the top coil connections and circulates through the finned coils. With both pumps energized, the heat from the process fluid is transferred through the coil tubes to the water cascading downward over the coils while simultaneously air is drawn upward over the coil opposite the water flow using the fan drive system (Fan on, Pump A & B on). A small portion of the water is evaporated to dissipate the heat to the atmosphere in a latent heat transfer. This mode of operation provides fan energy savings and lower leaving water temperatures by utilizing evaporative cooling. Water Efficient Mode (Evaporative and Sensible Heat Transfer) The joint wet and dry operation mode provides water savings as well as low approach temperatures. In this joint mode of operation, the fan is on and the process fluid enters the coils through the top coil connections (Fan on, Pump A on, Pump B off). Recirculating pump B is turned off and coil B rejects a portion of the heat load to the atmosphere through the tube and fin walls to the air passing over the coils using sensible heat transfer. Pump A is left on where heat from the process fluid is transferred through the coil tubes to the water cascading downward over coil A. This mode of operation minimizes the amount of water used while maintaining the cooling capacity required. The cooled fluid then returns to the process via the bottom coil connection. Dry Mode (Sensible Heat Transfer) In the dry mode, the recirculating spray pumps are deenergized (Fan on, Pump A & B off). The process fluid enters the eco-ATWB-E cooler through the top coil connection and circulates through the coil with the Fan On. Heat from the process fluid is dissipated to the atmosphere by sensible heat transfer through the tube walls to the air passing over the coils. The coils are finned to promote optimal airflow over the coil and to maximize heat transfer area. Air is drawn over the finned coils by the fan drive system. The process fluid then returns to the heat source via the bottom coil connection. This mode of operation eliminates water consumption when the dry bulb temperature is favorable. Efficient Drift Eliminators An extremely efficient drift eliminator system is standard on the eco-ATWB-E Closed Circuit Cooler. The system removes entrained water droplets from the air stream to limit the drift rate to less than 0.001% of the recirculating water rate. With a low drift rate, the eco-ATWB Closed Circuit Cooler saves valuable water and water treatment chemicals. The eco-ATWB-E Closed Circuit Cooler can be located in areas where minimum water carryover is critical, such as parking lots. The drift eliminators are constructed of an inert polyvinyl chloride (PVC) plastic material which effectively eliminates corrosion of these vital components. They are assembled in sections to facilitate easy removal for inspection of the water distribution system. Superior Air Inlet Louver and Screen DesignThe air inlet louver screens on the eco-ATWB-E are constructed of corrosion-freePVC. They are a two pass design that minimizes splashout and reduces the potential for algae formation inside the cooler. In single pass louver systems used by other manufacturers, circulating water droplets tend to splashout, especially when the fans are shut off. With the two pass louver system, the water droplets are captured on the inward sloping pass, minimizing splashout problems. This unique louver design completely encloses the basin area. Direct sunlight is blocked from the water inside the cooler, thereby reducing the potential of algae formation. Water treatment and maintenance costs are substantially reduced. While effectively containing the recirculating water and blocking sunlight, the louver design has a low pressure drop. The low pressure drop results in lower fan energy consumption, which reduces the operating costs of the cooler. Ellipti-fin Coil Design The new eco-ATWB-E Closed Circuit Cooler utilizes Evapco's patentpending Ellipti-fin coil design which assures even greateroperating efficiency. The elliptical tube design allows for closertube spacing, resulting in greater surface area per plan areathan round-tube coil designs. In addition, the revolutionaryEllipti-fin design utilizes elliptical spiral fin coil technology andhas lower resistance to airflow than typical finned coil designs.This permits greater water loading, making the new Ellipti-fincoil the most efficient coil design available on the market.The coils are manufactured from high quality steel tubingfollowing the most stringent quality control procedures.Each circuit is inspected to ensure the material quality andthen tested before being assembled into a coil. Finally, theassembled coil is pneumatically tested at 400 psig underwater to ensure it is leak free. eco-ATWB=E Operating Benefits The eco-ATWB-E maintains all of the advantages of the eco-ATW with the additional benefit of enabling simultaneous wet and dry operation. The unique Water Efficient Mode of the eco-ATWB-E allows for a portion of the heat load to be rejected through both evaporative cooling AND dry cooling, even at high ambienttemperatures, this further increases your ability to save water and offers additional associated cost savings through reduced water make-up, blow-down and chemical consumption. The eco-ATWB-E provides an ideal solution for applications where minimizing both energy and water consumption is critical. Depending on the optimum eco-Cooler you select for your job, one can operate 100% wet, 100% dry or simultaneously Wet & Dry in the Water Efficient Mode, offering unique advantages in freezing climates, higher temperature industrial cooling applications where 100% evaporative cooling is not always favorable. Sage 3 Control System The eco-ATWB-E is provided standard with the Sage3® control panel which controls Dry, Water Efficient and Evaporative modes of operation. The control system operates by measuring and analyzing water inlet and outlet temperature simultaneous with ambient dry bulb monitoring in order to minimize the evaporative cooling mode of operation and to save system water. The Sage can also be programmed to operate with a water savings or energy savings priority. The Sage Controller features a NEMA 4 enclosure with UL approval. The panel also includes a 10" touch screen operator interface with color display and a Modbus 485* data port for communication with the building automation system. The data points are: Inlet Temperature, Outlet Temperature, Dry Bulb Temperature, Basin Water Temperature Sensor, Fan Run Time, Pump Run Time, VFD Speed, Fan Motor Status – On/Off, Fan RPM, Pump Status – On/Off. Multiple Water Distribution Systems Each coil in the eco-ATWB-E features its own water distribution system. This allows each coil to operate in a mode independent of the other coil EVAPCO’S Zero Maintenance ZMII® Spray Nozzle remains clog-free while providing even and constant water distribution for reliable, scale-free evaporative cooling under all operating conditions. The heavy duty nylon ZMII® Spray Nozzles have a 1-5/16” diameter opening and a 1-1/2” splash plate clearance enabling EVAPCO to use 75% fewer nozzles. Furthermore, the fixed position ZMII® nozzles are mounted in corrosion-free PVC water distribution pipes that have threaded end caps. Together, these elements combine to provide unequaled coil coverage and scale prevention, and make the industry’s best performing non-corrosive, maintenance-free water distribution system. The water distribution is designed to provide a minimum 6 GPM over each square foot (4 liters per second over each square meter) of unit plan area to ensure proper flooding of the coil. Principle of OperationEfficient DriftEliminatorsSuperior Air Inlet Louver and Screen DesignEllipti-fin Coil Designeco-ATWB-E Operating BenefitsStage 3 Control SystemMultiple Water Distribution Systems
eco-ATWB-E Closed Circuit Cooler - Maintenance Features
Designed for easy maintenance, the eco-ATWB-E Closed Circuit Cooler leads the industry in service friendly features. The three most critical areas for closed circuit cooler maintenance are the basin, drive system, and coil. The eco-ATWB-E basin section is designed to allow quick and easy access from outside the cooler. Just like the basin, all service to the drive system can be safely performed from the side of the cooler, and EVAPCO's Power-Band drive system is the easiest belt drive system to maintain in the industry!
The cold water basin section is easily accessible from ground level by simply removing the (2) two Quick Release Fasteners on the inlet louver assemblies surrounding the closed circuit cooler and lifting out the lightweight louver.
This open basin design enables the basin to be easily cleaned.
Clean Pan Basin Design
The eco-ATWB-E features a sloped basin from the upper to lower pan section. This "Clean Pan" design allows the water to be completely drained from the basin. The closed circuit cooler water will drain from the upper section to the depressed lower pan section where the dirt and debris can be easily flushed out through the drain. This design helps prevent buildup of sedimentary deposits, biological films and minimizes standing water.
Easy, Removable Air Inlet Louvers with Quick Release Fasteners
A Quick Release Fastener design consisting of (2) two large thumbscrews and a latch system. By loosening the thumbscrews, the latch pulls up and out of the louver frame, allowing the louver to be removed while the latch and thumbscrews stay on the closed circuit cooler.
Motor Mount, Power Band Belt Adjustment and Bearing Lubrication
The fan motor and drive assembly are designed to allow easy servicing of the motor and adjustment of the belt tension from the exterior of the unit. The T.E.F.C fan motor is mounted on the outside on these models and is protected from the weather by a cover which swings away for maintenance.
A large hinged access door is located on the side of the unit for easy access to the fan drive system. The belt can be adjusted by tightening the J-Bolts on the motor base and the tension can be checked easily through the access door, all while standing at the side of the unit. The bearings can also be lubricated from the side of the unit. The bearing lubrication lines have been extended to the exterior casing and are located by the access door, thus making bearing lubrication easy. Sloped access ladders are available as an option to facilitate maintenance.
Motor Mount, Power Band Belt Adjustment and Bearing Lubrication
The T.E.A.O. fan motor is located inside the fan casing on the large eco-ATWB-E Closed Circuit Cooler, and is mounted on a rugged heavy duty motor base. The motor base is designed to swing completely to the outside of the unit through a very large, hinged (14 square feet) (1,3 square meters) access door greatly simplifying motor maintenance.
The unique swinging motor mount designed for these models features easy belt adjustment from the exterior of the unit. The T.E.A.O. fan motor is mounted on an adjustable base which is supported by two heavy duty galvanized steel pipes. The belt is adjusted by tightening an all-thread which runs through the motor base.
The innovative motor base features a unique locking mechanism for a positive belt adjustment and is also used to adjust the belt tension if a wrench is not available.
Bearing lubrication fittings are extended to the side of the unit inside the access door to allow easy application of the bearing lubricant. This external location allows for easy servicing of the bearings and is another important advantage of EVAPCO equipment.
To facilitate motor removal, an optional motor davit is available.
Stainless Steel Strainers
The EVAPCO standard for many years, the stainless steel strainer is one component of the closed circuit cooler subject to excessive wear and corrosion. With stainless steel construction, this component will last the life of the cooler.
Clean Pan Basin Design
Easy, Removable Air Inlet Louvers w/ Quick Release Fasteners
Motor Mount, Power Band
Belt Adjustment and Bearing Lubrication - 3', 4', 8-1/2' & 17' Wide Models
Motor Mount, Power Band
Belt Adjustment and Bearing Lubrication - 12' & 24' Wide Models
Stainless Steel Strainers
The eco-ATWB-E Closed Circuit Cooler is an Advanced Technology, induced draft counterflow design closed circuit cooler featuring EVAPCO's patented Ellipti–fin™ technology. The counterflow design provides the eco-ATW Closed Circuit Cooler with inherently better operational and maintenance features. The eco-ATWB-E is now standard with CTI Certified Performance including the Super Low Sound Fan option.
Closed Circuit Cooler models utilize heavy duty totally enclosed (T.E.F.C. or T.E.A.O) fan motors designed specifically for closed circuit cooler applications. In addition to the standard motors offered on each cooler, EVAPCO offers many optional motors to meet your specific needs, including:
3', 4', 8.5' & 17' (0,9; 1,2; 2,6 & 5,2 m) wide ATWB models feature T.E.F.C. motors are located on the outside of the unit, protected by a hinged, swing away cover. 12' & 24' (3,7 & 7,3 m) wide ATWB models have T.E.A.O. motors located inside the fan section on a heavy duty motor base which swings to the outside for repair or removal.
Fan Shaft Bearings
The fan shaft bearings on the Closed Circuit Cooler are specially selected to provide long life, minimizing costly downtime. They are rated for an L-10 life of 75,000 to 135,000 hours, making them the heaviest duty pillow block bearing in the industry used for Closed Circuit Cooler duty.
Power-Band Belt Drive
The Power-Band drive is a solid-back multigroove belt system that has high lateral rigidity. The belt is designed for closed circuit cooler service, and is constructed of neoprene with polyester cords. The drive belt is sized for 150 percent of the motor nameplate horsepower ensuring long and trouble free operation.
Drive System Sheaves
Drive system sheaves located in the warm, moist atmosphere inside the cooling tower are constructed of an aluminum alloy. Those located externally are protected by a hinged cover.
The standard design of the EVAPCO eco-ATWB-E provides the customer with the most efficient and easiest Closed Circuit Cooler to maintain in the industry. There are additional options which can make maintenance easier, extend the life, or enhance the performance capabilities of the Closed Circuit Cooler.