ATEX ventilation and safety in industrial environments: Elektrovent's ESIR and EBACK A solutions

Ventilation of industrial environments where potentially explosive atmospheres may occur requires equipment designed to operate safely, taking into account the presence of flammable gases or dust and the ATEX classification of the affected areas. This is also an important aspect for industrial refrigeration professionals, who must assess the safety requirements of technical environments and installations.

For these needs, Elektrovent offers the ESIR ATEX and EBACK A ATEX series , two ranges of centrifugal fans intended for air movement in ducted systems, with construction configurations compliant with the ATEX Directive 2014/34/EU.

The two series are mainly distinguished by the geometry of the impeller, with forward-curved blades and backward-curved blades respectively, offering different selection possibilities based on the aeraulic characteristics of the system.

Ventilation in environments at risk of explosive atmospheres

The presence of flammable substances in industrial environments requires careful consideration of operating conditions and installed equipment. Ventilation can help manage gas and vapor concentrations, but must be designed based on the risk scenarios and environmental characteristics.

Even in the industrial refrigeration sector, especially in the presence of flammable refrigerants , the design of technical rooms may require specific assessments relating to ventilation and safety.

The choice of an ATEX fan therefore does not depend exclusively on the air flow rate, but also on the category of equipment required, the characteristics of the conveyed fluid and the operating conditions.

The ESIR ATEX and EBACK A ATEX series from Elektrovent are designed for Group II explosive atmospheres, in categories 2G, 2D, 3G and 3D, with different configurations for the presence of flammable gases or dusts.

ESIR ATEX: forward-curved centrifugal fans for ducted systems

The ESIR ATEX series includes single-inlet centrifugal fans featuring a welded impeller with forward-curved blades. The range is designed for industrial ventilation systems requiring high air flow rates and relatively low pressures.

Available in seven sizes, with impeller diameters ranging from 220 to 450 mm, ESIR ATEX provides different motor configurations to meet the airflow requirements of the installation.

The construction includes a sealed auger made of painted sheet steel, flanges compliant with UNI EN ISO 13351 and a balanced impeller according to UNI ISO 21940-11.

Among the main technical features:

• Forward curved blade impeller , single inlet, with welded construction.
• 2 and 4-pole motors, with power from 0.37 to 15 kW in the catalog configurations.
• ATEX asynchronous electric motors with IP55 protection , class F insulation and S1 continuous duty.
• Temperature of the conveyed fluid from -20 °C to +40 °C under standard conditions indicated by the manufacturer.
• Group II configurations , categories 2 and 3, for atmospheres containing flammable gases or dusts.

Particular attention must be paid to operating conditions: ESIR ATEX fans must operate connected to ducts or components capable of guaranteeing sufficient pressure drops to keep the electrical absorption within the limits shown on the motor nameplate.

Documented application areas include battery rooms, laboratories, and chemical industry plants.

EBACK A ATEX: backward curved blade impeller and different aeraulic configurations

The EBACK A ATEX series represents an alternative to the ESIR range, thanks to the use of a welded centrifugal impeller with backward curved blades, directly coupled to the motor shaft.

This solution is also intended for ducted industrial ventilation, in applications characterised by high air flow rates and relatively low pressures.

The range includes six sizes, with impeller diameters from 250 to 450 mm, and is equipped with ATEX-approved three-phase asynchronous motors.

Key specifications include:

• Backward curved blade impeller , single suction.
• 2 and 4 pole motors, with power from 0.25 to 11 kW in the catalogue versions.
• IP55 motors, class F insulation and operation in S1 service.
• Temperature of the conveyed fluid between -20 °C and +40 °C.
• ATEX Group II, category 2 and 3 executions , for explosive atmospheres due to flammable gases or dusts.

As for the ESIR series, the structure includes a sealed painted steel screw and flanges compliant with UNI EN ISO 13351.

Backward-curved fans offer a different characteristic curve than forward-curved fans. Therefore, the selection must be made based on the system's operating point, comparing flow rate, pressure, and power consumption.

ATEX requirements, construction configurations and accessories

The two Elektrovent ranges are developed in accordance with the requirements of the ATEX Directive 2014/34/EU , which regulates equipment intended for use in potentially explosive atmospheres.

The available versions include versions for atmospheres containing gas (G) or dust (D), with different protection categories depending on the classification of the environment.

In the standard version 4, the impeller is directly coupled to the motor shaft, which is mounted on a dedicated support. Version 5, with the motor flanged directly to the fan volute, is also available upon request.

Both series can also be requested in stainless steel and with different orientations of the delivery mouth, to facilitate integration into duct networks.

The standard orientation is LG 270°, while 180° and 225° configurations require special construction.

The equipment can be completed with suction and pressure counterflanges and protective nets, necessary in cases of free-blow use.

How to choose the right ATEX fan for your installation

For designers and technicians operating in industrial plants, the correct selection of an ATEX fan requires a joint evaluation of safety conditions and aeraulic performance.

It is necessary to consider the classification of the area, the nature of the substances potentially present, the required flow rate, the pressure drops of the network and the operating conditions.

The performance declared by Elektrovent refers to air at 15°C, an altitude of 0 metres above sea level and type D installations, without accessories or protective nets.

It is also important to comply with the limitations relating to the fluid conveyed: the product specifications require non-dusty, non-abrasive, and non-corrosive gases. ATEX compliance of the equipment does not therefore automatically imply its suitability for handling any flammable substance.

With ESIR ATEX and EBACK A ATEX, Elektrovent offers two ranges of centrifugal fans for industrial ventilation in potentially explosive atmospheres , with different impeller geometries and construction configurations, to be selected in relation to the technical and safety requirements of the installation.