DFCV-AD

1.0 Heat Exchanger

1.1 General: The finned Coil Heat Exchanger consists of either 1/2” or 5/8” O.D. phosphorus deoxidised copper seamless tubes and aluminium fins. Staggered tube construction provides substantially higher capacity since more tubes are exposed to the air stream. The advanced rippled-corrugated fin design creates a state of continuous turbulence, which effectively reduces the boundary layer formation that could otherwise reduce the rate of heat exchange. Fins have full drawn collars to maintain fin spacing and provide a continuous surface cover over the entire tube. The copper tubes are mechanically expanded into the fin collars to provide a continuous primary to secondary compression bond over the entire finned length for maximum heat transfer rates. Headers are made of seamless copper tubing and the coils are circuited for counterflow heat transfer to provide the maximum mean-effective temperature difference. The headers have steel male screw connections with 1/8” vent and drain. A full coil drain of the heat exchangers is not possible and as such Fluid Coolers operating under ambient temperatures that could drop below freezing point must contain liquid with an antifreeze agent. The entire coil block is pressure tested at 15 bar dry air submerged in warm water.

2.0 Air Movement

2.1 The air movement package: This air movement package combines premium aerodynamic and acoustic performance with innovative design to offer a compact fan and motor as an integrated product.

• Adjustable pitch angle impeller allows the optimum aerodynamic performance to be achieved for the given motor output, therefore minimising running costs.
• Exceptionally compact design with short overall motor length.
• Two speed by delta / star reconnection speed control.
• Minimal moving parts for maximum reliability.
• Motor protection IP55.
• Insulation Class F.
• Fan designed for frequent starting.
• Continuous running from -40ºC to 60ºC.
• Integral Overheat thermal cut-out protection.

2.2 Fan(s): The Fan has superb performance with a steep volume/pressure performance curve, giving greater flexibility in design and making it more “tolerant” of pressure variations which may occur because of, for instance, dirt accumulation on the fins of the heat exchanger. The fan, being an integrated product of impeller and motor, is balanced as a complete unit using dynamic single plane balancing. Balance grade is G6.3. The fan and motor are designed to be totally maintenance free.

2.3 Impeller: The impeller has an aluminium hub and clamp-plate, with six equally spaced, fully adjustable, moulded, black, ultra-violet resistant, glass coupled polypropylene airfoil section blades, designed on the latest aerospace technology. All rotating aluminium components are X-ray examined prior to machining to ensure quality.

2.4 Motor: Suitable for horizontal through to vertical shaft operation. IP55 protection, with removable drain plugs. Bearings lubricated with wide temperature range grease, re-lubricated or sealed for life depending on size. Insulation class F as standard. The motor is designed to give maximum flexibility of control by PWM Frequency Inverter, or Voltage Speed Control and where appropriate can be used to give two speeds by Delta/Star reconnect, where 80% of the full speed can be obtained by this method.

Electrical Supply

380 -420 V / 50 Hz / 3 ph

440- 480 V / 60 Hz / 3 ph

Motor Electrical Details

The motor can be run continuously from -40ºC to +60ºC.

Performance Data

The air and sound performance data has been measured in accordance with the following Standards:

• ISO 5801:1977, type A installation test method for air performance (dual numbered BS 848 Part1: 1997)
• BS 848 Part 2:1985, type A installation, method of noise testing.

3.0 Supporting Frame and Casing

3.1 Frame and Casing: The supporting Frame and Casing is an all-bolted painted galvanised steel construction designed to withstand the most adverse weather conditions. Double brake flanges maximise strength of panels. Full baffles separate individual fan sections.

4.0 Adiabatic Pre-Cooler

4.1 Adiabatic Pre-Cooling Medium: The MUNTERS EPACC™ adiabatic pre-cooling section serves as an adiabatic saturator to cool the incoming air. It consists of specially impregnated and corrugated cellulose paper sheets with different flute angles, one steep and one shallower that have been bonded together. Such a design yields a cooling pad with high evaporation efficiency while still operating with a very low-pressure drop. The impregnation procedure for the cellulose paper ensures a strong self supporting product, with high absorbency, which is protected against decomposition and rotting. The evaporative fluid, such as city water, is supplied to a distribution manifold and the rate of the water flow may be initially regulated by a manual-regulating valve. A distribution pad on the top of the cooling pad ensures an even water distribution and minimises the risk of dry spots. The water flows down the corrugated surface of the evaporative cooling pad. The incoming warm and dry air that passes through the pad evaporates most of the water. Any remaining water assists in washing the pad, and is drained to the gutter. In addition scaling is kept to a minimum and no water carry-over occurs due to the fact that the water is directed to the air inlet side of the pad and this where the evaporation takes place. The air that leaves the pad is therefore cooled and humidified simultaneously without any external energy supply, and without formation of aerosols.

For proper Legionella bacteria control, the system and all its water distribution piping is completely drained and dried after each adiabatic cycle.

4.2 Adiabatic Pre-Cooling Casing: The adiabatic pre-cooling casing is made of stainless steel, designed as a direct water system, without the need for pumps.

5.0 Electrical Panel and Controls

5.1 TrilliumSeries Cooler delivered with factory installed electrical panel with step controller: For TrilliumSeries Coolers delivered with factory installed electrical panel including step controller, the TrilliumSeries Cooler will be delivered with panel of IP65 enclosure, including main isolating power switch with lock provision, main fuses, emergency cut-out switch, thermal contactor with coil for each fan, wired to the fan motor thermostatic cut-out switch, 400/230 transformer, all wiring from the electrical panel to the individual fans, step controller and ambient temperature sensor.

Both process fluid outlet temperature and ambient temperature signals are fed into the step controller. The adiabatic pre-cooling will be activated and stopped on the basis of a pre-programmed logical combination of the two signals in the step controller.

5.2 TrilliumSeries Cooler delivered with factory installed electrical panel with variable frequency drive: For TrilliumSeries Coolers delivered with factory installed electrical panel including variable frequency drive, the TrilliumSeries Cooler will be delivered with panel of IP55 enclosure, including main isolating power switch with lock provision, main fuses, emergency cut-out switch, thermal contactor with coil for each fan wired to the fan motor thermostatic cut-out switch, 400/230 transformer.

Danfoss Variable Frequency Drive with built-in RFI filters protected to 1st environment and EN55011 to 1B, built-in DC Link coils which reduce harmonic distortion. Hand-Off-Auto function - fast and easy commissioning. Local control Panel - clear text display read-out. Inverter by-pass power switch. Digital controller, and ambient temperature sensor.

Both fan speed signal from variable speed drive and ambient temperature signal are fed to the digital controller. The adiabatic pre-cooling will be activated and stopped on the basis of a pre-programmed logical combination of the two signals in the digital controller.