VESSELS / VALVES
The ATC-E line of evaporative condensers represents Evapco’s commitment to product development. The line is comprised of 181 models ranging in size from 25 to 2,637 nominal ammonia tons (107 kW to 11,360 kW). The induced draft counterflow condensers are designed especially for easy maintenance and long, trouble-free operation.
ATC-E Evaporative Condenser - Design Features
The ATC-E Evaporative Condenser is an Advanced Technology, induced draft counterflow design condenser featuring EVAPCO’s patented THERMAL-PAK II ® COIL – the most efficient in the industry. The counterflow design provides the ATC-E Evaporative Condenser with inherently better operational and maintenance features. These features are described below.
Principle of Operation The refrigerant is circulated through the coil of the evaporative condenser. Heat from the refrigerant is dissipated through the coil tubes to the water cascading downward over the tubes. Simultaneously, air is drawn in through the air inlet louvers at the base of the condenser and travels upward over the coil opposite the water flow. A small portion of the water is evaporated which removes the heat. The warm moist air is drawn to the top of the evaporative condenser by the fan and is discharged to the atmosphere. The remaining water falls to the sump at the bottom of the condenser where it is recirculated by the pump up through the water distribution system and back down over the coils.Therma-Pak II Coil EVAPCO's Thermal-Pak II ® coils feature a patented design which assures maximum cooling capacity. The airflow through the coil is counterflow to the fluid flow, providing the most efficient heat transfer process. A special coil design is utilized to reduce the air pressure drop through the unit while maximizing tube surface area and increasing its heat transfer capabilities. The uniquely shaped tubes of the coil are staggered in the direction of airflow to obtain a high film coefficient. The coils are manufactured from high quality steel tubing following the most stringent quality control procedures. Each circuit is inspected to assure the material quality and then tested before being assembled into a coil. Finally, the assembled coil is pneumatically tested at 400 psig (2758 kPa) under water to ensure it is leak free. To protect the coil against corrosion, it is placed in a heavy steel frame and then the entire assembly is dipped in molten zinc (hot-dip galvanized) at a temperature of approximately 800°F (427º).Efficient Drift Eliminators An extremely efficient drift eliminator system is standard on the ATC evaporative condenser. 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 ATC Evaporative Condenser saves valuable water and water treatment chemicals. The ATC Evaporative Condenser 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 Design The air inlet louver screens on the ATC are constructed of corrosion-free PVC. They are a two pass design that minimizes splashout and reduces the potential for algae formation inside the condenser. 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 condenser, 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 condenser.Pressurized Water Distribution System EVAPCO's Zero Maintenance ZMII® Spray Nozzle remains clogfree 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 1-1/4" diameter opening and a 1-1/4" splash plate clearance. 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 OperationThermal-Pak II CoilEfficient DriftEliminatorsSuperior Air Inlet Louver and Screen DesignPressurized Water Distribution System
ATC-E Evaporative Condenser - Maintenance Features
Designed for easy access, the ATC-E Evaporative Condenser leads the industry in maintenance friendly features. The three most critical areas for evaporative condenser maintenance are the basin, drive system, and coil. The ATC-E basin section is designed to allow quick and easy access from outside the condenser. Just like the basin, all service to the drive system can be safely performed from the side of the condenser, and EVAPCO’s Power-Band drive system is the easiest belt drive system to maintain in the industry! The exclusive Thermal-Pak II® Coil is designed for trouble-free maintenance and long life straight from the factory.
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 evaporative condenser and lifting out the lightweight louver. The basin can be accessed from all (4) four sides of the condenser. This open basin design enables the ATC basin to be easily cleaned.
Clean Pan Basin Design
The ATC 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 evaporative condensers 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.
Stainless Steel Strainers
The EVAPCO standard for many years, the stainless steel strainer is one component of the evaporative condenser subject to excessive wear and corrosion. With stainless steel construction, this component will last the life of the cooling tower.
Belt Drive Units - 8 1/2' & 17' (2.6 & 5.2 m) Wide Models
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 and working platforms are available as an option to facilitate maintenance.
Belt Drive Units - 12' & 24' (3.7 & 7.3 m) Wide Models
The T.E.A.O. fan motor is located inside the fan casing on the large ATC Evaporative Condenser, 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.
Clean Pan Basin Design
Stainless Steel Strainers
8-1/2' & 17' (2,6 & 5,2 m)
Wide Models Motor Mount,
Power Band Belt Adjustment
and Bearing Lubrication
12' & 24' (3,7 & 7,3 m) Wide MModels Motor Mount, Power Band Belt Adjustment and Bearing Lubrication
ATC-DC Evaporative Condenser - Drive Systems
The ATC-DC Evaporative Condenser features the highly successful EVAPCO POWER-BAND Belt Drive System engineered for heavy-duty operation. The POWER-BAND Drive System has consistently provided trouble-free operation in the most severe duty evaporative condenser applications.
All ATC-DC Evaporative Condenser models utilize heavy duty totally enclosed (T.E.F.C. or T.E.A.O) fan motors designed specifically for evaporative condenser applications. In addition to the standard motors offered on each condenser, EVAPCO offers many optional motors to meet your specific needs, including:
8.5' (2,6 m) wide ATC-DC models feature T.E.F.C. motors are located on the outside of the unit, protected by a hinged, swing away cover. 12' (3,7 m) wide ATC-DC 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 ATC Evaporative Condenser 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 Evaporative Condenser 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 evaporative condenser 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.
ATC-DC Evaporative Condenser - Optional Equipment
The standard design of the EVAPCO ATC-DC provides the customer with the most efficient and easiest Evaporative Condenser to maintain in the industry. There are additional options which can make maintenance easier, extend the life, or enhance the performance capabilities of the Evaporative Condenser. These options are listed below.
ATC-DC Evaporative Condenser - Unit Specifications
Furnish and install, as shown on the plans, an EVAPCO model _________ induced draft, counterflow evaporative condenser with a condensing capacity of _________ MBH total heat of rejection when operating with _________ refrigerant at ______ °F condensing temperature at a design ______ ambient dry bulb temperature of ____ °F.
IBC 2012 Compliance
The condenser shall be designed and constructed to meet the International Building Code (IBC) specifications for installed components per ASCE. The manufacturer shall provide a certificate of compliance to demonstrate that the equipment/unit has been independently tested and certified in accordance with the IBC.
Basin and Casing
The basin and casing shall be constructed of G-235 hot-dip galvanized steel for long life and durability. Standard basin accessories shall include overflow, drain, type 304 stainless steel strainers, and brass make-up valve with plastic float.
Models ATC-DC-99H-25-1EF to ATC-DC-1714K-35-2EF
_________ horsepower totally enclosed fan cooled motors with 1.15 service factor shall be furnished suitable for outdoor service on _________ volts, _________ hertz, and _________ phase. Motor(s) shall be mounted on an adjustable base which is accessible from the outside of the unit for service. A swing away protective cover shall shield the motor and sheave from the weather.
The fan drive shall be multigroove, solid back V-belt type with taper lock bushings designed for 150% of the motor nameplate horsepower. The belt material shall be neoprene reinforced with polyester cord and specifically designed for evaporative condenser service. Fan sheave shall be aluminum alloy construction. The fans and the fan sheaves shall be mounted on the shaft with a specially coated bushing to provide maximum corrosion protection. 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.
Models ATC-DC-1012I-25-1EF to ATC-DC-2420N-35-2EF
_________ horsepower totally enclosed air over ball bearing fan motor(s), with 1.15 service factor shall be furnished suitable for 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.
The fan drive shall be a multigroove, solid back V-belt type with taper lock bushings designed for 150% of the motor nameplate horsepower. The belt material shall be neoprene reinforced with polyester cord and specifically designed for evaporative condenser service. Fan and motor sheaves shall be aluminum alloy construction. The fans and fan sheaves shall be mounted on the shaft with a specially coated bushing to provide maximum corrosion protection. 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.
Axial Propeller Fans
Fans shall be heavy duty axial propeller type statically balanced. The fans shall be constructed of aluminum alloy or fiberglass reinforced polypropylene blades, installed in a closely fitted cowl with venturi air inlet. Fan screens shall be galvanized steel mesh and frame, bolted to the fan cowl.
Fan Shaft Bearings
Fan shaft bearings shall be heavy duty self-aligning ball type with grease fittings extended to the outside of the unit. Bearings shall be designed for a minimum L-10 life of 75,000 hours.
Water Recirculation Pump
The pump(s) shall be a close-coupled, centrifugal type with mechanical seal, installed vertically at the factory to allow free drainage on shut down. _________ horsepower totally enclosed motor(s) shall be furnished suitable for outdoor service on _________ volts, _________ hertz, and _________ phase.
Heat Transfer Coils
Arid-fin Pak dry cooling coils shall be constructed of 5/8” diameter type 304L stainless steel round tubing with marine grade aluminum fins with a fin density of 10 fins per inch. Tubing shall be hydraulically expanded into the fin plate for consistent contact. Coil shall be pressure tested to 390 psig, evacuated and nitrogen charged prior to final assembly and shipment. Stainless steel tubing meets the requirements of ASME B31.5 of the refrigerant piping code.
Ellipti-fin® condensing coils with standard elliptical tube design shall be all prime surface steel, encased in a steel framework and hot-dip galvanized after fabrication as a complete assembly. All coil rows shall be manufactured with elliptical extended surface fins designed with sloping tubes for liquid drainage and tested to 390 psig air under water, evacuated and nitrogen charged prior to final assembly and shipment. Carbon steel tubing meets the requirements of ASME B31.5 of the refrigerant piping code.
Water Distribution System
The system shall provide a water flow rate of 6 GPM over each square foot of unit face area to ensure proper flooding of the coil. The spray header shall be constructed of schedule 40 polyvinyl chloride pipe for corrosion resistance. All spray branches shall be removable for cleaning. Heavy-duty ABS spray nozzles with large 1-1/4” diameter opening and internal sludge ring to eliminate clogging. Nozzles shall be threaded into spray header to provide easy removal for maintenance.
The eliminators shall be constructed entirely of inert polyvinyl chloride (PVC) in easily handled sections. The eliminator design shall incorporate three changes in air direction to assure complete removal of all entrained moisture from the discharge air stream. Maximum drift rate shall be less than 0.001% of the circulating water rate.
The louvers shall be constructed from polyvinyl chloride (PVC) and mounted in a rugged steel frame. The louvers shall be mounted in easily removable sections for access to the pan for maintenance. The louvers shall have a minimum of two changes in air direction to prevent splashout and block direct sunlight.
All basin and casing materials shall be constructed of G-235 heavy gauge mill hot-dip galvanized steel. During fabrication, all panel edges shall be coated with a 95% pure zinc-rich compound for superior protection against corrosion.