Низкое потребление энергии
Потребление энергии минимизировано благодаря применению осевых вентиляторов и оптимальному теплообмену. Метод охлаждения противотоком является наиболее эффективным по сравнению с поперечным и параллельным способами теплообмена. Кроме того, осевой вентилятор потребляет в среднем на 50% энергии чем центробежный. Использование этих технологий позволяет достичь оптимальной эффективности при минимальном энергопотреблении.
Низкий уровень шума
Для высокоэффективной работы охладителя в стандартном исполнении используется широколопастной алюминиевый вентилятор. Для условий эксплуатации со строгими требованиями к уровню шума применяются «нискошумные» и «сверхнизкошумные» вентиляторы. При использовании таких типов вентиляторов совместно с глушителями воды достигаются уровни шума до 15 дБ(A).
Простота обслуживания
Конструкция охладителей АTW оптимизирована для облегчения доступа к критическим узлам и компонентам системы. Легкосъемные впускные жалюзи позволяют выполнить очистку резервуара без доступа персонала вовнутрь установки. Широкие инспекционные двери обеспечивают свободный доступ к вентилятору, его приводу, распылителям и элиминаторам.
Лучший выбор чтобы избежать болезни легионеров
Техническое обслуживание является критическим фактором для предотвращения развития бактерий легионелл. Большое влияние на рост бактерий оказывает отсутствие солнечного света во внутреннем пространстве установки, зон застоя циркулирующей воды и возможность несложной очистки системы орошения. Охладитель укомплектован впускными жалюзями, предотвращающими воздействие солнечного света на внутреннее пространство установки. Высокоэффективные каплеотбойники (унос не более 0.001%) предотвращают попадание солнечного света через верхнюю решетку вентилятора. Уклон дна резервуара позволяет избежать зон застоя и полностью дренируется. Система орошения легко очищаемая (включая распылители).
Dry operation possible
The Evapco Thermal-Pak coil is designed for optimized evaporative cooling. But when the cooling load is variable, dry operation might be possible during cold- weather periods. The available dry heat exchange surface is often large enough to cover the heat load during wintertime. Dry operation reduces the water consumption but also creates time for regular cleaning of the sump. This is an important advantage in relation to the avoidance of LD.
Low risk for recirculation
Due to the large distance between the high speed air outlet and the multi-sided low speed air inlet, the risk for recirculation is minimized
Принцип работы
 |
Оборотная вода циркулирует по змеевику охладителя с замкнутым контуром. Тепло оборотной воды отбирается через трубки змеевика водой орошения, которая распыляется на трубки в верхней части охладителя. Проходя через межтрубное пространство змеевиков, вода орошения отбирает тепло и поступает в приемный резервуар. Одновременно воздух засасывается вентилятором через впускные жалюзи и нагнетается через трубки змеевика в направлении противоположном движению воды. Небольшая часть воды испаряется, отбирая тепло. Теплый влажный воздух выталкивается вентилятором в атмосферу в верхней части установки. Циркуляционный насос орошения забирает воду внешнего контура из приемного резервуара, подает ее через систему распылителей на змеевики. |
Cтандартные особенности
1. Кожух и резервуар
Резервуар изготовлен из гальванизированной стали Z-725 и заменяет стандартный резервуар из нержавеющей стали
Высокоэффективные отделители капель
Отделители капель, устанавливаются в верхней части охладителя и помогают снизить унос воды орошения с охлаждающим воздухом до 0.001% объема циркулирующей воды. Установки размещаются даже в регионах, где количество уносимой воды критично. Отделители капель изготовлены из поливинилхлорида (PVC), материала эффективно устраняющего риск коррозии этого важного компонента системы. Отделители изготовлены в виде секция, позволяющих их быстрый демонтаж для доступа к системе орошения.
2. Heat transfer system
Thermal-Pak evaporative coil
EVAPCO’s patented Thermal-Pak condensing coils feature a design which assures maximum condensing capacity. The airflow thru the coil is counter flow to the refrigerant flow, providing the most efficient heat transfer. This 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 elliptical shaped tubes of the coil are staggered in the direction of air flow to obtain a high film coefficient. In addition, all tubes are pitched in the direction of refrigerant flow to give good drainage of liquid refrigerant. The coils are manufactured in accordance with Pressure Equipment Directive “PED” 97/23/EC. High quality steel tubing is used following the most stringent welding and 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 air pressure tested under water at the appropriate pressure, in accordance with the Pressure Equipment Directive. To protect the coil against corrosion, it is placed in a heavy-duty steel frame and the entire assembly is hot dip galvanized at a temperature of approximately 430C.
3. Mechanical design
Power-Band Drive System
The AT Cooling Tower features the highly successful, easy maintenance, heavy duty Power Band Drive System. It consists of Standard heavy-duty pillow block bearings with a minimum L10 life of 75,000 hours, extended lube lines, external motor/belt adjustment, aluminum alloy sheaves, solid-back multi-groove Power- Band belts and totally enclosed motors.
Single speed fan motor
Each unit is equipped as per standard with a heavy duty, single speed IP55 TEFC / TEAO electrical motor.
Standard axial fan
The standard fans are heavy duty statically balanced axial propeller type. The fans are constructed of extruded aluminum alloy blades, installed in a closely fitted cowl with Venturi air inlet for maximum fan efficiency. Each fan blade is individually adjustable. The fan cowl is covered with a heavy gauge hot dip galvanized wire fan guard.
4. Water distribution
Spray pump
The spray pump is optimized for high water flow at relative low pressure. The motor is totally enclosed and protected with an end-cap to ensure a long trouble free operation
Spray-water distribution system
The water distribution system is enclosed and completely protected by the casing panels and drift eliminators. The water distribution system is made with non-corrosive materials including schedule 40 PVC pipe and durable ABS plastic nozzles. The spray branch piping is easily removed and designed with threaded end-caps for easy cleaning. The design avoids the problems of biological growth and clogging.
ZM Zero-Maintenance spray nozzles
The ZM (Zero Maintenance) nozzle is constructed of heavy duty nylon for corrosion resistance and long operating life. Zero maintenance is made possible with large 41mm diameter openings and a clearance of 38mm between the nozzle opening and water diverter plate. This allows the largest debris to flow easily through the ZM spray nozzle. The design avoids the problems of biological growth and fouling that can occur to a water distribution system.
5. Maintenance and inspection
Large access door
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 tensioning-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.
6. Operational control
Mechanical water level control
Simple but reliable water level control system with adjustable mechanical float boll and brass float-valve.
Optional equipment
1. Casing and basin design
Anti-vibration rails
Vibration absorbing rails to be installed between cooling equipment and steel support.
Evapcoat external coating
2-Component high quality epoxy coating for additional corrosion protection.
Full stainless steel AISI304 / AISI316 execution
All galvanized steel panels will be replaced with stainless steel panels AISI304 / AISI316 (moving parts not in sst). For the UAT only full sst AISI316 is possible.
Nitrogen charged coils
To protect the thermal-pak coils against internal corrosion during longer periods of transportation or stand-still, a optional nitrogen charge is recommended.
Remote sump execution
Remote sumps are commonly used where extreme freezing conditions are expected. For these applications the unit can be provided on oversized bottom outlet to allow the pan water to drain from the unit to an indoor sump. Units arranged for remote sump applications are provided without a spray pump in case of closed circuit coolers of condensers. The spray pump in these cases is provided by others and installed by the contractor alongside an indoor sump.
Special RAL-color
This option can be selected for all types of galvanized units. Stainless steel units or sections cannot be painted
Stainless steel sump
To improve the corrosion resistance, the sump will be executed in stainless steel AISI304. This option is standardized for LR-style units. Upgrades to AISI316 are possible.
2. Heat transfer system
Additional coil circuits
The coil can be splitted in multiple parts when different processes / liquids have to be cooled by the same closed circuit cooler.
Flanged coil connections
All closed circuit coolers can be executed with DIN-flanges.
Stainless steel AISI304 or AISI316 coils
For cooling in difficult environments or for the cooling of corrosive fluids, alternative stainless steel coils can be supplied. Both qualities stainless steel AISI 304 and 316 are available.
3. Mechanical design
2 speed / 1 winding motor (Dahlander)
Driving the fans with dahlander-motors is a simple but effective capacity control method.
PTC/PTO motor protection
Thermal protection of the motor-windings.
Special drift eliminators
Upon request, special eliminators like high temperature or steel eliminators, can be supplied.
4. Control of airflow
Vibration switch
A vibration switch can be installed on the fan-support to protect the cooling equipment against damage due to extensive vibrations caused by the fan. Possible causes of the fan-vibrations are ice or snow formations on the fan blades.
5. Water distribution
Flanged water in- and outlet connection
Flanges at the water inlet and outlet connections are available. Smaller connections like drain, make-up and overflow can also be flanged.
Low level cut-off switch for heater protection
Water level detection to protect the heater from overheating.
Low level cut-off switch for pump protection
Water level detection to protect the spray-pump from running dry.
Stand-by-Spray pump
For maintenance and security reasons, stand-by-pumps can limit the risk for thermal capacity loss due to spray-pump failure.
Sump heaters
Electric immersion heaters are available factory installed in the basin of the cooling tower. They are sized to maintain a +4 or +5C pan water temperature with the fans off and an ambient air temperature of -18C. They are furnished with a combination thermostat/low water protection device to cycle the heater on when required and to prevent the heater elements from energizing unless they are completely submerged. All components are in weather proof enclosures for outdoor use.
6. Operation control
Electrical water level control with solenoid valve
An electric water level control package is available as an alternative to the standard mechanical makeup valve and float ball. This package provides accurate control for the basin water level and does not require field adjustment, even under varying operating conditions. A solenoid valve for the make-up connection is included.
7. Sound attenuation
Low Sound Fan
The Low Sound Fan offered by EVAPCO is a wide chord blade design available for sound sensitive applications where low sound levels are desired. It is aluminum blade construction with a steel fan hub. The Low Sound Fan is capable of reducing the unit sound pressure levels 4 dB(A) to 7dB(A), depending on specific unit selection and measurement location. The fans are high efficiency axial propeller type and operate with no loss of thermal performance.
Super Low Sound Fan
The Super Low Sound Fan offered by EVAPCO utilizes an extremely wide chord blade design available for sound sensitive applications where the lowest sound levels are desired. The fan is one-piece molded heavy duty FRP construction utilizing a forward swept blade design. The Super Low Sound fan is capable of reducing the unit sound pressure levels 9 dB(A) to 15 dB(A), depending on specific unit selection and measurement location. The fans are high efficiency axial propeller type and operate with no loss of thermal performance.
Water silencers
The water silencer option is available for all AT models and is located in the falling water area of the cold water basin. The water silencer will reduce the high frequency noise associated with the falling water and is capable of reducing overall sound levels 4 dB(A) to 7 dB(A) measured at 1,5 m from the side or end of the unit. The water silencers reduce overall sound levels 9 dB(A) to 12 dB(A) (depending on water loading and louver height) measured 1,5 m from the side or end of the unit when water is circulated with fans off. The water silencers are constructed of lightweight PVC sections and can be easily removed for access to the basin area. The water silencer will have no impact on unit thermal performance.
