Iron and steel industry

Highly efficient extraction of process dust in electric steelworks, blast furnaces, sintering plants, and rolling mills. This not only ensures compliance with strict emission limits, but also a clean and safe workplace. The fans must be able to withstand abrasive media and high temperatures.

Transport of flue gases and other emissions through downstream cleaning systems such as filters, scrubbers, and catalytic converters. Reliability and corrosion resistance are crucial here to ensure continuous operation of the environmental protection systems.

Circulation of cooling air for cooling system components, assemblies, and products. Precise and reliable airflow is essential to prevent overheating and ensure product quality.

Supplying the necessary air volumes and temperatures for drying processes in various production steps. Energy efficiency and uniform air distribution are crucial for productivity.

Transport of process gases within production facilities, for example in coke production or in by-product recovery plants. Gas-tight designs and compliance with specific safety standards are essential here.

The dust released in the various production processes of the iron and steel industry is generally highly abrasive. These particles, consisting of iron oxide, metallic iron, coke dust, slag components, and additives, are extremely hard and have sharp edges. As they flow through the fans in dedusting systems, these particles constantly impact the surfaces of the impellers (blades, hub, cover plate) and the housing (inlet nozzle, spiral housing).

This continuous abrasive wear leads to progressive material removal. On the impeller blades, this results in a reduction in blade thickness and a change in the aerodynamic contour. This has serious consequences for the performance of the fan:

• Reduction in delivery pressure and volume flow:
  The changed blade geometry leads to less efficient energy transfer to the conveying medium.
• Increased energy consumption:
  In order to deliver the required performance, the drive motor must expend more energy.
• Vibrations and noise:
  Uneven material removal can lead to an imbalance in the impeller, resulting in vibrations and increased noise emissions.
• Premature fan failure:
  Progressive material loss weakens the structural integrity of the impeller and housing, which can lead to cracks, deformation, and ultimately fan failure.

The service life of the fans is significantly reduced by the abrasiveness of the media, resulting in frequent and costly maintenance and repair work as well as production downtime. The selection of suitable materials with high hardness and wear resistance as well as design measures to reduce impact speeds and optimize flow are therefore essential.

High process temperatures occur in many areas of iron and steel production, particularly in pig iron production, steel production, and downstream processes such as continuous casting and rolling. The exhaust gases that must be removed from these processes can reach temperatures of several hundred degrees Celsius.

These high temperatures place considerable demands on the fans used in exhaust gas cleaning systems:

• Material strength:
  The materials used in the fans must maintain their mechanical strength and creep resistance even at high temperatures over long operating periods. A loss of strength can lead to deformation or failure of components.
• Thermal expansion:
• The thermal expansion of the materials must be taken into account in the design to avoid stresses and warping. Different expansion coefficients of different components can lead to problems at the connection points.
• Storage and lubrication:
  The bearings of the fans must be designed for high operating temperatures. Special high-temperature greases and, if necessary, cooling systems for the bearings are required to ensure reliable operation.
• Sealing systems:
  The seals must remain functional even at high temperatures and must not become brittle or lose their sealing effect.
• Insulation:
  In some cases, thermal insulation of the fan housing is necessary to minimize heat loss and limit ambient temperatures.

The wrong choice of materials or inadequate design for high temperatures can lead to premature wear, leaks, and fan failure, which impairs the efficiency of exhaust gas cleaning systems and can potentially cause environmental damage.

Aggressive gases and vapors can be released during various production steps in the iron and steel industry, such as during coke production or in certain by-product recovery plants. These media can contain a variety of corrosive substances, including sulfur compounds (e.g., hydrogen sulfide, sulfur dioxide), chlorine compounds, nitrogen oxides, and acidic or basic aerosols.

The effect of these corrosive media on the fans leads to chemical reactions with the material surfaces:

• Surface corrosion:
  Uniform material removal over the entire surface.
• Pitting corrosion:
  Localized, intense material removal that can lead to holes and a weakening of the structure.
• Crevice corrosion:
  Corrosion in narrow crevices and under seals, which is difficult to detect and can lead to unexpected failures.
• Intergranular corrosion:
  Corrosion along the grain boundaries of the material, which significantly reduces its strength.
• Stress corrosion cracking:
  The interaction of tensile stresses and corrosive media, which can lead to cracks in the material.

Corrosion can significantly impair the mechanical strength of fans, lead to leaks, and drastically reduce service life. The selection of materials with high chemical resistance to the specific process media (e.g., stainless steels, special alloys) and the use of suitable corrosion protection measures (e.g., special coatings, cathodic protection) are essential to ensure reliable and safe operation.

The iron and steel industry is under increasing global pressure to significantly reduce its environmental impact. This is the result of increasingly stringent national and international legislation aimed at limiting emissions of pollutants into the air and water. Relevant emissions include, among others:

• Particulate matter (PM10, PM2.5):
  These are produced in various production processes and can have a significant impact on air quality and human health.
• Sulfur dioxide (SO2):
  This is released during the combustion of sulfur-containing fuels and the processing of sulfide ores and contributes to the formation of acid rain.
• Nitrogen oxides (NOx):
  These are produced during high-temperature processes and contribute to smog formation and the acidification of ecosystems.
• Carbon monoxide (CO):
  A toxic gas produced by incomplete combustion.
• Carbon dioxide (CO2):
  The most significant greenhouse gas, whose emissions contribute to global warming.

Compliance with these strict environmental regulations requires the use of efficient exhaust gas cleaning technologies, in which fans play a central role. They must reliably convey the process gases to the various cleaning components (e.g., cyclones, filters, scrubbers, catalysts) while ensuring the required pressure conditions.

The challenges in this context are manifold:

• High separation efficiency:
  The fans must be integrated into systems that achieve very high separation efficiencies for the various pollutants.
• Variability of emissions:
  The composition and concentration of emissions can vary depending on the production phase, which requires flexible and controllable fan systems.
• Space restrictions:
  In existing plants, there is often limited space available for the installation of new or improved exhaust gas cleaning systems.
• Energy efficiency of the entire plant:
  The gas purification itself must also be energy-efficient in order to minimize operating costs and indirect CO2 emissions.

Selecting the right fans, tailored to the specific requirements of the gas purification processes and the applicable environmental regulations, is therefore crucial for the sustainable operation of iron and steel plants.

The iron and steel industry is an energy-intensive sector. High energy costs represent a significant competitive disadvantage and have a considerable impact on the profitability of companies. In this context, the energy consumption of the fans used plays a not insignificant role, especially in systems with a large number of fans or those that run continuously.

Inefficient fan operation can lead to unnecessarily high energy costs. This can be caused by:

• Use of outdated or incorrectly dimensioned fans:
  Fans that are not optimally designed for the operating point of the system operate with low efficiency.
• High system resistance:
  Clogged filters, long or poorly designed piping systems increase system resistance and require more energy to move the medium.
• Lack of or inefficient speed control:
  When load requirements fluctuate, operating fans at a constant speed leads to unnecessary energy losses.
• Wear and deposits:
  Contaminated or damaged impellers and housings impair the aerodynamic efficiency of the fans.

Reducing the energy consumption of fans is therefore an important goal for lowering operating costs and improving competitiveness. This can be achieved through various measures:

Selection of highly efficient fans: Modern centrifugal fans with optimized impeller geometries and aerodynamic designs achieve high efficiencies over a wide operating range.

• Optimization of system design:
  Reduction of pressure losses in pipes and other components.
• Use of speed control systems:
  Adjusting the fan speed to the actual demand to avoid oversizing and idle losses.
• Regular maintenance and cleaning:
  Ensuring that the fans are in optimal operating condition.
• Energy monitoring and management:
  Recording and analyzing energy consumption to identify potential savings.

Investing in energy-efficient fan systems usually pays off through significantly reduced operating costs and a faster return on investment.

Iron and steel production is often a continuous process that runs 24 hours a day, 7 days a week. Unplanned downtime of production equipment can result in significant financial losses due to production losses, quality defects, and contractual penalties. Fans are an integral part of these production processes in many critical applications. The failure of an important fan can therefore bring the entire production line to a standstill.

Minimizing downtime is therefore a key concern in the iron and steel industry. This requires:

• High reliability of the fans:
  Robust design, high-quality materials, and careful manufacturing processes are crucial for a long service life and trouble-free operation.
• Redundant systems:
  In particularly critical applications, the use of redundant fans or fan systems can ensure the availability of the plant. In the event of a fan failure, a backup unit automatically takes over its function.
• Predictive maintenance:
  The use of sensor and analysis technologies enables condition monitoring of the fans and early detection of potential problems before a failure occurs. This allows timely maintenance and replacement of wear parts.
• Fast availability of spare parts and service:
  In the event of an unexpected failure, fast delivery of spare parts and competent support from the service partner are crucial to keep downtimes as short as possible.
• Easy maintenance and accessibility:
  The fans are designed to make maintenance work easy, which also helps reduce downtime.

Investing in reliable fan systems and preventive maintenance strategies is therefore an essential factor in ensuring continuous and economical operation in the iron and steel industry.

For use in blast furnaces, we recommend our high-temperature centrifugal fans, which are specially designed for operation at extremely high temperatures. These fans are made of heat-resistant materials and ensure a reliable air supply to the blast furnace.

POLLRICH centrifugal fans for sintering plants are particularly robust and resistant to dust loads. They are made of wear-resistant materials and have special filters and separators that ensure reliable operation even with high dust concentrations.

Yes, we offer ATEX-compliant centrifugal fans for use in potentially explosive areas. These fans meet the strict safety requirements of Directive 2014/34/EU and ensure safe operation in explosive atmospheres.

POLLRICH centrifugal fans ensure efficient cooling of the rolls in rolling mills, thereby contributing to high product quality and a long service life for the rolls.  Our fans can be individually adapted to the requirements of the rolling process and are characterized by high reliability and energy efficiency.

POLLRICH centrifugal fans contribute to reducing emissions in the iron and steel industry by:

• increasing the energy efficiency of the plants
• improving the separation of dust and pollutants
• supporting the use of environmentally friendly technologies

Of course! We tailor our centrifugal fans precisely to the individual requirements of our customers in the iron and steel industry. This includes, for example:

• Special coatings for increased corrosion protection
• Adaptation of motor power and speed
• Integration of silencers
• Special designs according to customer requirements

All POLLRICH centrifugal fans for the iron and steel industry are individually designed according to customer specifications and precisely tailored to their operating points.

POLLRICH centrifugal fans are robust and low-maintenance. However, regular inspections and maintenance work help to extend the service life of the fans and ensure optimum operation. Our service team will be happy to advise you on the recommended maintenance intervals and assist you in carrying out maintenance work.