Fans

Fan program

SPÄNEX radial fans have been manufactured for a wide range of industrial applications for over 60 years. Many years of experience and continuous further development form the basis for a mature and comprehensive range of single suction centrifugal fans. A particular focus of development work in recent years has been on the subject of energy efficiency and, in this context, speed control by means of frequency converters.

The performance range of the fan program includes volume flows from 1,000 to 120,000 m³/h and a total pressure increase from 1,000 to 10,000 Pa.

With several series and nominal sizes, the entire spectrum of requirements can be covered and the optimum fan selected for each individual case.

The fans are mainly used in the extraction and dedusting systems manufactured and supplied by SPÄNEX, so that the company's own experience from practical use is incorporated into the continuous further development to improve and optimise the fans.

Energy efficiency

The radial fans are the core component of any extraction system in terms of power-saving operation. The efficiency of the fan determines the power consumption and thus the annual electricity costs, given the required ventilation data (extraction volume flow and total pressure increase).

However, when it comes to "energy efficiency", the performance data of the fan is not the only decisive factor; other factors relevant to consumption must also be included in the analysis:

• the pipework system and 

• the operation of the extraction. 

In accordance with our motto "Everything from a single source", our experienced field staff plan and dimension the piping system for each individual application so that the fan has to overcome as little piping resistance as possible at the required extraction volume flows.

Another important contribution to minimizing power consumption is made by the speed control of the fans via frequency converters. The intelligent control and regulation technology recognizes the respective demand for extraction power at any given time and, by regulating the fan speed, provides only the extraction power required in each case. This demand-adapted operation of the extraction system leads to considerable electricity savings and thus lower operating costs. Based on the electricity consumption data of the many systems already supplied, it can be said with certainty that the annual electricity costs for power-controlled extraction systems can be reduced by up to 50 % compared with conventional extraction systems.

Further advantages of speed control by frequency converters can be seen in the following points::

• Fan start-up without power peaks 

• Lower noise emissions

Conveyable materials

SPÄNEX radial fans are suitable for conveying clean air, dust-laden air and chip/dust/air mixtures with low to high material loading. The following materials can be conveyed in chip/dust/air mixtures:

• wood

• other biomass 

• plastic and 

• paper

Execution

The radial fans manufactured by SPÄNEX are part of the compact dust extractors and filtration plants, i.e. they are installed directly into the housings.

In special applications, the radial fans are also arranged outside the filter units, usually in the direction of flow downstream of the filter units ("vacuum" system). In only a few cases it is advisable to install the radial fans in the piping system upstream of the filter units (overpressure system), since the fan impellers that can be used have lower efficiencies.

Also in the pneumatic conveying systems, the transport fans are mainly placed in the clean air side section of the pipework system.

Different impellers are available for each of these individual applications:

• Closed impellers with backward bent blades: conveying clean air or dust/air mixtures with low material loading.

• Closed impellers with backwards positioned blades: conveying of material-laden air (dust or short-fibered chips with low to medium material loading).

• Open impellers with radial blading: conveying of material-laden air (dust, coarse or long-fibered chips and wood chips with high material loading)

The impeller housings are solid steel plate welded constructions in heavy duty design. The casings are profile steel reinforced and painted as standard. If belt drive is required, the fan casing and motor are mounted on a common base frame. The impellers are carefully balanced statically and dynamically to achieve maximum running smoothness. Three types of drive are used:

• Drive directly via the motor shaft

• Drive via a coupling

• Drive via V-belt

When conveying explosive gas/dust/air mixtures, the fans are equipped in accordance with the ATEX directive, including the inlet nozzles with spark protection.

Standard fans

Up to nominal size 400, standard fans with different impeller configurations are available for different pressure levels. The housings and impellers of these fans are manufactured in large series and can be assembled and delivered at short notice as required. Depending on the nominal size, the installed impellers and the pressure stage, motors of efficiency class IE3 (optionally IE4) with outputs between 2.2 and 18.5 kW are used. These are generally direct drives in which the impeller is mounted on the motor shaft.

Wide range of accessories

• Counter flanges and transitions for suction and pressure side

• Compensators

• Vibration isolators

• Wear protection for impellers and casings

• Sound-absorbing housing or sound-insulating cabins

• Speed control via frequency converter

• Rotation, temperature and vibration monitoring

• Pipe and crank sound damper

• Explosion protection

• etc.