RAA
EVAPORATIVE COOLERS

The axial version of evaporative coolers replaces evaporative towers where it is necessary to separate the process fluid from the atmosphere and recirculating water. The units are similar to cooling towers, although they have a reinforced structure to support the weight of the coils and have an onboard recirculation pump.

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EVAPORATIVE COOLERS

They differ from evaporative towers in the use of a heat exchange battery for the primary process fluid.

Having a machine with the process fluid inside a heat exchange coil allows the primary fluid not to be “dirtied” by sediments or microparticles present in the water. The presence of the heat exchange coil also makes it possible to use glycolised process water where the system requires it.

Key points for choosing an evaporative cooler instead of an evaporative tower:

The process fluid flows through a heat exchanger coil: the fluid is not contaminated by particles in the water or by atmospheric agents.

Glycolated fluids can be used safely thanks to the use of the heat exchange coil

The units can operate in dry mode in sub-zero winter conditions, without recirculating water and only with the fans running.

PRODUCT DATA SHEET

CONSTRUCTION FEATURES

W-Tech RAA series, axial type evaporative coolers, are manufactured and assembled in accordance to our Quality System certified by ISO 9001.

MAGNELIS

All our machines are built as standard in Magnelis®, it is an eco-sustainable alloy made up of 93.5% zinc, 3.5% aluminum and 3% magnesium. The percentage of magnesium allows the self-repair process after cutting and punching operations and protects deformed surfaces. Another characteristic is the corrosion resistance, superior even in environments rich in chloride and ammonia. The maximum workability and greater resistance, compared to other materials, allows the use of a smaller quantity of metal coating and therefore a greater lightness of the machines.

STRUCTURE & ASSEMBLY

The standard unit is built with Magnelis® (steel, zinc, aluminium, magnesium) ZM310 type sheet metal panels to ensure maximum surface protection empirically comparable to a galvanized sheet metal with over 1000 g/m2 of zinc. The individual panels, following the cutting and folding phase, are assembled with AISI 304 (A2-70) or on request AISI 316 (A4-80) stainless steel small parts and highly adhesive butyl mastic gasket reinforced with polyester mesh inside to guarantee great shape stability and resistance to temperature variations. No welding is required in the various stages of assembly of the structure (self-supporting). The color of the sheet metal type Magnelis® is RAL 9006.

AIR INTAKE GRILLES

Louvers are in PVC with special dual flow design in order to eliminate the sun light into the water basin, possible residue/leafage or accidental water leakage. Positioned on the four sides of the unit, louvers can be completely removed to allow an easy access to the basin during maintenance.

WATER COLLECTION BASIN

The basin section is built with a thick Magnelis® ZM310 sheet metal structure and is equipped with of removable anti-cavitation type filter in AISI 304L (to protect the primary circuit pump) and water make-up valve with brass/stainless steel body and floating sphere in stainless steel or polypropylene. The configuration of the basin is such as to allow the reduction of the volume of water and therefore a lower weight during operation. The surface of the basin is inclined to allow complete drainage and emptying in case of maintenance, avoiding water stagnation and preventing bacteriological development. All machine connections are made of galvanized steel (AISI 304L on request).

THERMAL EXCHANGE COIL

The standard heat exchange coil is made of smooth (optionally finned) carbon steel tubes (AISI 304L on request) of suitable diameter and thickness and bent following our proprietary geometry. Everything is hot-dipped galvanized in accordance with the UNI EN ISO 1461:2009 standard to guarantee perfect resistance to corrosion. Subsequently the coil is tested in compliance with the PED-CE regulation.
The machines are supplied with the coil pre-charged with nitrogen at a pressure of 3 bar.

WATER DISTRIBUTION SYSTEM

The water is uniformly distributed by a piping system inside the machine made of PVC with a Magnelis® sheet metal distribution box . The spray nozzles are of the non-clogging type, of medium and large diameter, in ABS and easily replaceable in case of maintenance.

VENTILATION SYSTEM

(MOTORS + FANS)

The axial fans are made with high efficiency glass fiber reinforced polypropylene (PPG) blades, aluminum hub, galvanized steel bush and bolts. The fan protection net is made of galvanized steel. The motors, efficiency class IE3, with tropicalised IP56 mechanical protection, specifically designed for operation in a humid atmosphere, insulation class F, continuous service S1, shape V6 and automatic condensate drain, are keyed directly to the axial fans (direct coupling). The electric motors undergo a class C5 painting cycle to guarantee maximum protection against corrosion and humidity. The motors are suitable for being coupled to frequency variators (VSD-Inverters) 30-50Hz.
The engines comply with CE 2019/1781 regulation.
The connection cable coming out directly from the electric motor casing is taken outside the structure and wired directly to the terminals in a special IP56 junction box.

DROP SEPARATOR

Drift eliminators are made in PVC (PP on request) and divided in various sections to facilitate their removal in case of replacement or inspection of ventilation and water distribution system. The used drift eliminators allow a passage of drops equal to 0.001% of the droplets present at the entrance, removing water loss, potential aerosols drift that might contain Legionella bacteria.

TEST

All components are supplied assembled. Each unit, before delivery, is subjected to hydraulic testing, to ensure that there are no water leaks in the tank, and electrical to check that the electric motors have an absorption in line with the plate data.

CATALOGS AND TECHNICAL DATA

Catalog list.

CERTIFICATIONS

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