Evaluation of the Impact Made by the Hydrodynamic Regime of the Granulation Equipment Operation on the Nanoporous Structure of N4HNO3 Granules.

The article deals with the impact of the hydrodynamic feature of the vortex granulator operation and intensity of the heat transfer agent’s directional vortex motion on the structure and quality of the porous surface layer and internal nanoporous structure in the ammonium nitrate granules. The analysis results of the porous ammonium nitrate quality indices, obtained in different hydrodynamic regimes, were demonstrated. The structure of a granule, obtained in the vortex gas flow with different twisting intensity, was studied. The received data make the base to create the engineering calculation method of granulators as a part of the unit to obtain 3D nanostructured porous surface layer on the ammonium nitrate granule. The obtained porous ammonium nitrate (PAN) samples were tested to define the explosive features of the industrial explosive “Ammonium Nitrate/Fuel Oil” (ANFO). The detonation velocity of ANFO was determined by the Dotrish method (it is based on the comparison of the known detonation velocity of the detonating chord with the unknown velocity of ANFO detonation). The industrial explosive (ANFO) charges based on the 95 % of PAN and 5 % of the diesel fuel distillate reliably detonate from the intermediate charge – trotyl block, which is initiated by the electric detonator. The ANFO detonation velocity was 2.2- 2.3 km/s. It is possible to regulate the process regarding the nanostructured porous layer formation with the specified properties owing to the selection of the optimal hydrodynamic regime to lay the humidifier’s film and granules heat treatment. The results of the theoretical and experimental research carried out by authors enable to perform the optimization projection of the main equipment in the unit to obtain PAN, i.e. the vortex granulator. [ABSTRACT FROM AUTHOR]