Explosion Safety in Recycling Plants – Immark is Exploring New Horizons

The careful handling of resources and their preparation for multiple uses is an objective for many companies across a number of industries. For several years the “paperless office” has also been a recurring topic. For various reasons this concept can’t be implemented in a vast number of companies. Therefore, there is still a great demand for printer toner. Anyone who has ever changed such a toner, and maybe even held the toner the wrong way, or even dropped it will remember: even if the toner cartridge is supposedly empty, there is still colour residue left inside it.

In the past, the accruing empty toner cartridges were either, refilled by the manufacturers in Switzerland (which will continue to be maintained in the future), burned, or separated in a complex process in order to enable the recycling of individual components. It was already foreseeable some time ago that the latter is not economically viable in the long term. For this reason, Immark AG developed a new recycling plant, which was recently awarded the 2017 Swiss Recycling Award. By using this system, it is possible to avoid the incineration of the complete cartridges, if the toner cartridges are delivered to Immark AG.

The new Immark AG (Switzerland) toner recycling plant has a processing capacity of 1500 tonnes per year, and is therefore capable of recycling the toner cartridges of the entire Swiss market. The biggest challenge in the development of the new system was managing the potential for dust explosions, caused by airborne dust particles. In order to avoid an explosion, an inert agent has been used which is constantly introduced into the shredder of the system. In addition, a device for a flameless venting (Q-Box) was installed below the shredder, in order to enhance the holistic and sustainable protection concept.

If, therefore, an ignition source is created despite the inert agent, the explosion vent of the Q-Box will open and the stainless-steel mesh filter will absorb the flame and pressure of the explosion, so that both the system, its environment, and above all the employees, are protected in the best possible manner. In this situation, a simple explosion vent was not sufficient, since the system is installed in a building of the Immark AG, and therefore neither the flames nor the pressure of a possible explosion can be relieved into the environment.

After shredding, the toner cartridges are transported into a screen through a screw conveyor. There, the toner-intermediate mixture is sieved off and filled into BigBags. The other components are then passed on to other systems, e.g. metal recycling.

The goal of Immark AG was “recycling instead of incineration”, which was made possible with this system. With a view on profitability and the safety of employees, everything could be realised at the same time, thanks to the innovative Explosion Safety concept.