Open circuit - PMM

PMM series is suggested in big size plants. Every unit is designed according to the technical data of the relevant project. All models are made of factory pre-assembled modules and components.
The particular design of PMM series grants a quick and inexpensive installation, besides the possibility of adjusting/designing the unit to fit the existing basins or structures.

Capacity from 2,6 to 14 MW

Motor-fan (axial) group with gearbox reducer, low installed power, possibility of low noise levels

IP56 motors

Casing made of FRP sandwich panels, thickness 22 mm. Metal frame in hot dip galvanized steel after fabrication (galvanization process in accordance with UNI EN ISO 1461-99 regulation, thickness not inferior to 80 micron)

Water distribution system in PVC, PP or PE equipped with non-clogging PP spray nozzles

Fill pack with different kinds of air/water channels, suitable for the use with different water types

Certified PP drift eliminators (entrainment 0,01%)

Every unit is equipped with 2 big man-sized access doors for an easy access to the internal components

For every order a static and dynamic structural analysis is carried out, considering seismic factors, wind thrust, snow load, etc.

Technical specifications

LOAD BEARING STRUCTURE in high thickness, hot dip galvanised steel (galvanisation process in accordance with UNI EN ISO 1461-99 standard, thickness not inferior to 80 micron).

CASING consisting of 22 mm thick polyester resin sandwich panels reinforced with fibreglass with isophthalic gelcoat for UV-protection.
Sealing between the load bearing structure and the panels is guaranteed by a special bituminous sealing gasket.
The tower casing is equipped as standard with n. 2 FRP big man-sized access doors in hot-dip galvanised steel after fabrication frame to allow easy inspection and quick and safe access to the inside of the tower.

PERIMETER FRAME with FILL PACK SUPPORT in high thickness, hot dip galvanised steel (galvanisation process in accordance with UNI EN ISO 1461-99 standard, thickness not inferior to 80 micron). It is located and fixed to the base of the tower body to form a strong structure.
Hot dip galvanized steel after fabrication metal supports are fixed to the frame to support the fill pack.

FAN DECK entirely in non-slip stretched metal sheet, in accordance with the safety regulations in force, hot dip galvanized after fabrication. The fan deck is walkable and cage ladder/s with handrail/s are available as optional items.

NUTS AND BOLTS in stainless steel AISI 304.

AXIAL FAN SYSTEM with TRANSMISSION shaft made of:

  • Motor three-phase, 4 poles, IEC2, IP56 electric motor, class F/B insulation, with tropicalized winding, multi-voltage (400/690 V) and multi-frequency (50-60 Hertz), located outside the fan stack
  • No-reverse gear system
  • Flexible drive shaft
  • Right angle gearbox reducer in special execution for cooling towers
  • Axial fan with aluminium blades, pitch angle adjustable when at rest, jointed by a central hub directly coupled to the gearbox output shaft, operating at low rpm, characterized by low sound level

FRP segments fan stack, designed to optimize the fan performances reducing the power consumption
Hot dip galvanized (after fabrication) steel frame to support the whole fan group, the motor, the transmission shaft and the gearbox

DRIFT ELIMINATORS, high efficient, certified by EUROVENT, consisting of three folds PP sheets, thermoformed under vacuum and welded together to form panels of such shape and size as to guarantee maximum efficiency of droplet separation from the airflow drawn by the fan.

WATER DISTRIBUTION SYSTEM made of PN 10 pipes and connectors complete with flanged connection, entirely made of plastic material, consisting in a main header and branches with non-clogging, static type, spray nozzles.
This system grants a perfect and even perfusion of the fill pack, and therefore an optimal performance.
The non-clogging nozzles are made of isotactic polypropylene with full cone (120° angle) spraying

FILL PACK (or heat exchange surface) consisting of PVC or PP sheets, thermoformed under vacuum and welded together (air/water channels of different kinds suitable for the cooling of different water types).
The shape and the size of the fill pack optimise the contact between air and water, and therefore the heat transfer process.

LOWER SUPPORT STRUCTURE made of steel profiles, hot-dip galvanized after fabrication, designed to be installed on a concrete water basin.

AIR INLET LOUVERS made of FRP, designed to be fitted into the above mentioned lower structure.

Special versions

All models are available in the following special versions:

  • ATT – for high temperature water (max. peaks of 80 °C)
  • N – for moderately dirty water with small quantities of suspended solids
  • N-ATT – for moderately dirty water with small quantities of suspended solids at high temperature (max. peaks of 80 °C)
  • GS/GSL – for very dirty water containing high quantities of suspended solids
  • SILENT– different technical solutions to reduce the noise

Several solutions can be designed from time to time according to the customers’ demands and the various critical issues of the systems:

  • Adaptation to existing tanks or structures (replacement of other cooling towers)
  • Limited available space
  • Short plant shutdown for the replacement of existing towers
  • Short erection time with limited use of workforce for the final installation
  • Short time from the order confirmation to the start-up
  • Easy, fast and safe access to internal parts: the operations for ordinary and extraordinary maintenance are greatly simplified
  • Transportability of pre-assembled modules and components on standard vehicles
  • Limited use of cranes or forklifts for final assembly
  • Energy savings (axial fans, low rpm)
  • Multiple solutions to curb the sound levels
  • Cooling of different types of water
  • Maximum operating flexibility to optimize the system according to the different loads and environmental conditions.