As part of a joint research project with the Management Center Innsbruck (MCI), MANN+HUMMEL’s Industrial Filters Business Unit has invented a new and improved cyclone pre-cleaner technology solution. By making certain changes to the geometry of the cyclone cell its performance has been increased, while the energy consumption has been reduced.

MANN+HUMMEL cyclone technology is used in high-performance air filter systems. In simple terms you could say its job is to pre-separate the coarse particles in the intake air of air filter systems. This is particularly important when dust levels are extremely high or service intervals are long as in the case of railway traffic or commercial vehicles. Pre-separation improves the actual separation function (particle absorption) provided by the air filter and thereby extends the lifetime of the main filter.

The cyclone pre-cleaner gets its name from its whirlwind-like functionality. Air flows into the cell and is rotated using slanting ‘guide vanes’. This rotation produces centrifugal forces, which press the ‘heavy’ (i.e. coarse) dust particles  on to the inner wall of the cyclone cell. From here, the dust  is carried into a dust collector, which is emptied continuously. Here, it is a case of the faster the rotation in the cyclone cell, the higher the number of particles separated.

The following direct correlation was always assumed in the past: The more dust particles filtered from the air,  the greater the pressure drop in the cyclone cell and the greater the energy (electricity or fuel) consumption needed  in order to keep the speed of the rotation. The joint research project carried out by the Industrial Filters Business Unit and the Management Center Innsbruck (MCI) between April 2013 and April 2014 was aimed at improving  the cost-benefit ratio of this process.

During this relatively short period (for a research project), we managed to resolve a technological paradox by developing a completely new cyclone pre-cleaner which has a greater separation efficiency and lower pressure drop than previous models. We are achieving very high separation efficiency with a pressure drop of just a few millibars. The production of the new cyclone pre-cleaner has already begun for railway vehicles and other applications.

How did we achieve this breakthrough? Well, we gradually changed the geometry of the cyclone cell to optimise the flow conditions further and further. The speed of the air intake flow through the cyclone cell does of course depend on a number of variables, such as the length and outer diameter of the cell, the inner diameter of the distributor, the position and the diameter of the guide vanes, and so on. Through our trials with the different variables, we ended up with the ideal flow conditions. The components were made in the MCI laboratory by using a 3D printer and tested on their test bench.

Developing a new cyclone pre-cleaner wasn’t the first joint research project we have worked on with the MCI. We have been working together with the Management Center Innsbruck for many years now and the collaboration with the college has come to be very unbureaucratic and friendly. Apart from the excellent knowledge of the employees and students, the team spirit and efficiency were also key factors in enabling the success of the project.