Charakterisierung von mechanischen Abfallbehandlungsanlagen hinsichtlich der Entstehung von Staubexplosionen
Research output: Thesis › Doctoral Thesis
During the treatment of waste material in order to recycle, the solid passes through the reprocessing units, crushing and milling. This is necessary to seperate the recyclable fraction out of the waste massflow. At each treatment step and transfer station a fine-grained fraction occurs. In order to classify the risk potential of the combustible dusts occurring in mechanical waste treatment facilities and to identify the influencing factors on the explosion behaviour, dusts from different waste treatment facilities of different industrial partners were investigated and their explosion characteristics were studied. Besides the general safety relevant indices the influences of particle size, particle shape and inert fraction were examined in detail. The particle shape has an influence on the dispersion of dusts. Due to the necessary minimum explosion concentration bad dispersion qualities can decrease or neglect the explosion hazard. This is why it is important to know the affinity to disperse dusts from deposits. In the case of dusts from mechanical waste treatment facilities risk reduction due to solid inertants is an interesting approach, because of the fact, that the dusts itself contain a huge amount of inert fraction. The inert fraction is on average about 40 mass percent and higher. Furthermore the influence of the particle shape and particle size of solid inertants in the dust mixture was investigated. These investigations showed that the explosion behavior of dusts from mechanical waste treatment facilities is strongly influenced by the presence of inert material. A considerable influence of particle size could be observed clearly. It could be found that for the reduction of severity of dust explosions the particle size of the inertants is more important than particle shape of them. The identification of the influencing factors and their importance for the dust explosion reactions enables an estimation of the explosion behavior of dusts from certain mechanical waste treatment facilities. For paper reprocessing, metal recycling and substitute fuel preparation plants the dust quality is constant over time and explosion behavior can be predicted with respect to the inert fraction and other influencing factors. But residue treatment facilities are extremely unsteady in material quality, why predictions of the explosion behavior are impossible in these cases. Anyway within the estimation of dust explosion risks in mechanical waste treatment facilities the bad dispersion behaviour of the occurring dusts has to be taken into account. The aim of further investigations should be the construction of a model to calculate the explosion characteristics of dusts with simultaneous consideration of all influencing factors.
|Translated title of the contribution||Characterization of Mechanical Waste Treatment Facilities Regarding the Formation of Dust Explosions|
|Publication status||Published - 2014|