Wear protection for centrifugal fans We make air work for you Venti Oelde

Wear protection – an economically sensible decision Damaged impeller without wear protection Extreme demands Large and special fans are often exposed to the harshest wear attacks. Irrespective of the sector, they have to withstand enormous stresses in the production process. In the cement and steel industries in particular, the fans are subject to extreme demands. Abrasive media that are carried in the air flow (e. g. clinker dust, quartz and also corundum, wood and plastic shavings) assault the material. The particles which enter strike all structural elements of the fan – the impeller blades...

A science in itself Venti Oelde possesses experience, gathered over decades, in the design and construction of industrial centrifugal fans and is a technological leader in wear protection. The company constantly promotes research and development in this sector. Together with a reputable German technical university Venti Oelde has meticulously examined wear on industrial fans. Experience from many field studies - some involving industrial plant manufacturers - has been incorporated into the development of measures to provide wear protection.

Virtual test runs – optimal planning for development and refurbishment Effective protection – right from the start At the beginning of the planning phase, the first question to be asked is: what flow medium is to be handled? If it contains abrasive or corrosive substances then some protection of the fan against wear is highly recommended. Ultimately, this will increase the service life of the fan in a profitable manner. To determine the optimal wear protection and its positioning and design, the fan’s load is digitally simulated using computational fluid dynamics (CFD). Taking into account the specific...

Hard shell -even retrospectively However, this technology is not only used in new constructions. It is also an essential component in the optimisation or reconditioning of fans currently in use. The impellers or fans are dismantled by Venti Oelde on site and transported to Oelde. After cleaning the steel parts, an initial visual inspection is performed, as well as technical fault detection using the ultrasound method and dye penetrant testing. Parallel to fault detection, the fan may also be the subject of a flow simulation - customised to its operation - to determine how the fan may best be...

Robust protective layer – intelligent mix of materials against aggressive dust particles Photomicrograph material chromium carbide Hard surfaces are not the sole solution The statement „A lot helps a lot“ can only be applied to wear protection with reservations. The essential thing is to take the correct measures. 500 µm Photomicrograph material fused tungsten carbide Using harder hardfacing does not necessarily provide the wished-for result, especially as it is usually considerably more expensive and more complicated to apply. Furthermore, wear protection materials such as fused tungsten carbide...

* conditional on base material, as sintered at 1100 °C ** conditional on the bonding For example, when the dust is very fine and abrasive a wear protection system where the carbides are evenly distributed and as close together as possible must be selected. This prevents too great an erosion of the carbides. The structure of a wear protection layer consists generally of hard carbide particles embedded into a binder matrix phase. Offering no room for attacks If the so-called pitch, i. e. the distance between the carbides, is too great, the dust particles directly hit the soft binder matrix; this...

Knowing where – proper positioning Protecting the right places Beside selecting the appropriate anti-wear material, its positioning and the implementation of measures to protect the centrifugal fan against wear are of equal importance. Wear protection helps to increase the service life of a fan, and in particular that of the impeller. But it is also a significant cost factor. For this reason, it is necessary to first define which areas are to be protected and which do not require to be protected against wear. Empirical data combined with flow analysis gives an indication of the areas of an impeller...

Special wear protection on the critical areas of the impeller Specific protection against wear in areas of the impeller blade Wear-resistant cover for flanged connectio

Costs at a glance Alongside the selection of the appropriate material and its positioning, correct designing of the wear protection system is of great importance. Firstly, because it needs to be adjusted precisely to the different process parameters. For example, not every wear protection system can be used at higher temperatures. Secondly, because the design selected will influence costs significantly. It is the combination of different wear protection systems which helps to reduce costs without reducing the life span - a solution which gives an excellent cost-benefit ratio. Welded or bolted....

Impeller with fully welded wear protection Bolted connection impeller – shaft ᕃ Wear protection sleeve for each screw Welded and bolted Wear protection for blades, offered by Venti Oelde, is available in welded and bolted variants. In the welded variant, the wear-resistant coating is applied directly to the blade or, alternatively, wear plates are welded on. This variant can be serviced by means of repair welding. In the bolted version, the wear plates are fastened to the blade with through bolts. In addition, they are welded to the centreplate and impeller shroud with a seal weld. For repairs,...

Protection against wear in a modular format – modular, replaceable, cost-effective Modules for combining Venti Oelde offers, as well as conventional wear protection, a sort of modular system. This includes in particular six modules: 1. Wrap-around edge protection liners for blade inlet edges 2. Wear plates on blade inlet edge 3. Wear strips for the impeller centreplate 4. Wear plates for the blades 5. Wear plates for impeller shroud protection 6. Protective caps and plates for the threaded connections impeller – shaft The Venti Oelde modular system makes it possible to use wear protective materials...