VESSELS / VALVES
The ATC-DC is an induced draft, counterflow design evaporative condenser. Standard construction includes the patented, high efficiency EVAPCO Ellipti-fin Coil, EVAPCO’s new ARID fin Pak™ dry 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.
ATC-DC Evaporative Condenser - Design Features
The ATC-DC line of evaporative condensers represents EVAPCO’s newest advancement in thermal heat transfer research and development. Utilizing the NEW ARID finPak™ heat transfer coil, the ATC-DC offers improved heat transfer during dry operation and significant water savings due to extended periods of dry operation. The ATC-DC is the latest example in EVAPCO’s on-going commitment to quality, environmentally friendly products.
Principle of OperationEvaporative (Wet) Mode – Spray Pump(s) Energized The refrigerant gas is discharged from the compressor into the inlet of the ARID finPak™ Dry Coil which is positioned in the discharge air stream above the unit’s drift eliminators and below the fan section. Ambient air is drawn into the unit, by the condenser’s fans, through inlet louvers located in the lower section above the water basin. The air is drawn upward through the wet coil into the drift eliminators (which remove entrained water droplets from the air stream) and into the ARID fin Pak ™ Dry Coil Heat from the refrigerant gas is transferred to the air as it comes into contact with the tubes and densely packed fins of the ARID fin Pak ™ Dry Coil. The refrigerant gas exits the ARID fin Pak ™ Dry Coil and travels via inter-connecting piping (by others) to the inlet of the Ellipti–fin® Coil located in the lower section of the ATC-DC Condenser. Water from the condenser’s sump is circulated over the wet coil as the ambient air is simultaneously drawn into the unit and travels up through the Ellipti–fin ® . A portion of the spray water is evaporated into the air stream as it travels through the wet coil. This evaporative process cools the spray water, which in turn cools the coil tubes and extended surface fins. The cool tube walls and extended surface fins cause the refrigerant gas to give up heat and condense into a liquid. The condensed liquid flows out of the Ellipti–fin ® to the high pressure receiver for return to the system. The water which has not evaporated falls into the sump and is recirculated by the spray pump to the water distribution system located above the Ellipti–fin ® . The amount of water consumed during this mode of operation is a function of the amount of heat rejected. Water consumption includes the volume of water which is evaporated during the cooling process and the amount of water which is discharged (referred to as “blow-down”) to maintain the required cycles of concentration in order to meet water quality guidelines. Dry Mode – Spray Pump De-energized The refrigerant gas is discharged from the compressor into the inlet of the ARID finPak™ Dry Coil which is positioned in the dry air stream above the unit’s drift eliminators and below the fan section. Ambient air is drawn into the unit by the condenser’s fans, through inlet louvers located in the lower section above the water basin. The air is drawn upward through the Ellipti–fin® into the ARID fin Pak ™ Dry Coil above. Heat from the refrigerant gas is transferred to the air as it comes into contact with the tubes and densely packed fins of the ARID fin Pak ™ Dry Coil. The refrigerant gas exits the ARID fin Pak ™ Dry Coil and travels via the inter-connecting piping to the inlet of the Ellipti–fin ® . The ambient air entering the unit travels upward through the Ellipti~fin Coil which in turn cools the coil tubes and extended surface fins. The cool tube walls and extended surface fins cause the refrigerant gas to give up heat and condense into a liquid. The condensed liquid flows out of the Ellipti–fin ® to the high pressure receiver for return to the system. There is NO WATER consumed during this mode of operation.Ellipti-fin® Cooling Coil The new ATC-DC Evaporative Condenser utilizes Evapco's patented Ellipti-fin® coil design which assures even greater operating efficiency. The elliptical tube design allows for closer tube spacing, resulting in greater surface area per unit plan area than round-tube coil designs. In addition, the revolutionary Ellipti-fin® design utilizes elliptical spiral fin coil technology which has an inherent air side pressure drop lower than finned round tube designs. This permits greater water loading, making the new Ellipti-fin® coil the most effective design available. The coils are manufactured from high quality steel tubing following the most stringent quality control procedures. Each circuit is inspected to ensure the material quality and then tested before being assembled into a coil. Finally, the assembled coil is pneumatically tested at 400 psig 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.Maintenance Free ZMII® Spray NozzleWater Distribution System 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. 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, making it the industry’s best performing non-corrosive, maintenance-free water distribution system.Superior Air Inlet Louver and Screen Design The air inlet louver screens on the ATC-DC are constructed of corrosion-free PVC. 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.Efficient Drift Eliminators The ATC-DC is equipped with an efficient drift eliminator system that effectively reduces entrained water droplets from the air discharge to less than 0.001% of the spray water flow rate. The eliminators are constructed of non-corrosive PVC with a multi-pass design for maximum drift reduction. They are assembled in modular sections for easy removal and access to the water distribution system. In addition to reducing drift, the eliminators also function as effective debris screens which protect the spray system from sunlight and debris.ARID fin Pak™ Dry Cooling Coil The new ATC-DC Evaporative Condenser utilizes the ARID fin Pak™ Dry Cooling Coil. Installed in the air discharge of the condenser the ARID fin Pak™ dry cooling coil is piped in series with the evaporative cooling coil. The ARID fin Pak™ dry cooling coil is constructed of 304L Stainless Steel tubes and tubular Stainless Steel header with carbon steel coil connections for easy field piping. The fins have fully drawn collars to maintain consistent fin spacing and continuous surface contact over the entire tube to maximize heat transfer. The fins are constructed of Aluminum/Manganese alloy for superior corrosion resistance.Principle of OperationEllipti-fin Cooling CoilPressurized Water Distribution SystemSuperior Air Inlet Louver and Screen DesignEfficient Drift EliminatorsARID fin Pak™ Dry Cooling Coil
ATC-DC Evaporative Condenser - Maintenance Features
Designed for easy maintenance, the ATC-DC Evaporative Condenser leads the industry in service friendly features. The three most critical areas for evaporative condenser maintenance are the basin, drive system, and coil. The ATC-DC 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 exclusive Ellipti–fin™ Technology (Patent Pending) and EVAPCO’s new ARID fin Pak™ dry coil are designed for trouble-free maintenance and long life straight from the factory.
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 and working platforms are available as an option to facilitate maintenance.
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.
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.
Sloped Access Ladders
A sloped access ladder is available for 8.5' and 12', (2,6 and 3,7m) wide ATC-DC models. The EVAPCO designed access ladder features a sloped "ships type" ladder arrangement which provides fast and easy access to the water distribution system and drive components. A grab bar is attached to the sloped ladder for safe and easy ascent and descent. There is no need for safety cages or railings with this design. The ladder(s) will ship loose and must be field mounted. The sloped ladder meets all applicable OSHA requirements.
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.