Freon

The 3C concept has been extended to the Dricon range, which works on the same principle but applied to condensing refrigerants like freon and ammonia. Muller Dricon units offer far superior energy efficiency over equivalent air-cooled systems because the performance is dependent on ambient wet bulb temperature, not dry bulb temperature as is the case with air cooled condensers.

Muller 3C units comprise: -

• Two vertical finned tube heat exchanger coils
• Two sets of evaporative precooling pads
• Bank of low noise axial flow fans
• Water distribution system for air precooling consisting of:
  • water circulation pump
  • water make-up solenoid
  • motorised dump valve (with spring return)
• Programmable Logic Controller (PLC)

1. Heat Exchanger Coils

Standard coils are manufactured from copper tubes/aluminium fins. The tubes are mechanically expanded into collared holes in the fins to ensure proper mechanical and thermal bonding for effective heat transfer. The coils are a floating tube design. An alternative tube/fin combination is galvanised steel tubes / aluminium fins.

2. Evaporative Precooling

CeLPad Type 5090 evaporative cooling pads are designed to pre-cool the incoming air.

The Celpads cover the entire air inlet faces on both sides of the unit, supported by water distribution trays on top and drain troughs at the bottom.

Precooling is only activated only when ambient air temperature exceeds the designated preset set-point (for lower ambient air temperature pre-cooling is not necessary). Water is pumped over the pads to saturate the pad. The system includes a dump valve, which opens daily or when pre-cooling is not required to drain all the water from the unit to eliminate any potential.

3. Axial Flow Fans

A bank of fans on top deck of the unit draws air through precooling media and the heat exchangers. The fans are low speed axial flow fans with either winglet/bionic blade design (for SH08) or wide chord blades (for H07) to provide optimum performance and low noise.

4. PLC Controller

The PLC controller is used to control fan speed (to match cooling demand) and activate precooling function.

Following are some of the features of the controller:

• Full microprocessor control with real time clock
• Memory backup in case of power failure
• Multi-line LCD display of vital parameters and alarms
• User interface for set-point adjustments
• Analogue output for fan speed control
• Digital outputs include: CelPad pump, water dump valve and water makeup valve
• Water dump and auto dry control
• Password protection of all set-points