Optimized introduction of the starting materials for a process for preparing aromatic amines by hydrogenation of nitroaromatics

An apparatus, comprising:

• a reactor,
• a driving jet nozzle at one end of the reactor, adapted for injecting a reaction mixture from a bottom region of the reactor via an external loop into the bottom region of the reactor,
• an inlet adapted for a nitroaromatic at one end of the reactor,
• an inlet adapted for hydrogen, and
• a measuring device adapted to detect partial or complete blocking of the inlet adapted for the nitroaromatic after improper contact between the inlet adapted for the nitroaromatic and a liquid phase in the reactor,
• wherein the inlet adapted for the nitroaromatic is distinct from the driving jet nozzle,
• wherein the apparatus is adapted such that, at a correct fill height of the reactor, direct physical contact between the inlet adapted for the nitroaromatic and the liquid phase occurs neither in the reactor nor in a pumped circuit, either in an operating state or on shutting down, and
• wherein the apparatus is adapted to hydrogenate the nitroaromatic with the hydrogen in the reactor in the presence of a suspended catalyst in the liquid phase, thereby obtaining an aromatic amine.