An apparatus for the continuous reaction of liquids with gases, in particular for the preparation of toluenediamine by hydrogenation of dinitrotoluene, which comprises - a vertically elongated reactor in which there is a reaction space, - at least one heat exchanger which is arranged within the reactor, - at least one inlet for introducing the cooling medium into the heat exchanger, - at least one outlet for taking the cooling medium off from the heat exchanger, - at least one inlet for introducing the gaseous reactant into the reaction space, - at least one inlet for introducing the liquid reactant into the reaction space, - at least one mixing chamber, - at least one downward-directed driving jet nozzle for introducing the reaction medium, the outlet of which is arranged above the at least one mixing chamber and which is in fluid communication with the reaction space, - at least one outlet for taking the reaction medium off from the reactor and - at least one means arranged below the heat exchanger and below the mixing chamber for diverting the reaction medium flowing downward through the mixing chamber in such a way that the reaction medium once again flows upward through the heat exchanger, and - where an external circuit having a pump arranged therein provides fluid communication between the outlet for taking off the reaction medium from the reactor and the at least one driving jet nozzle for introduction of the reaction medium into the reactor, - wherein the means for diverting the reaction medium flowing downward through the mixing chamber is a diversion pan which has a surface which is aligned in the transverse direction of the reactor and extends over a major part of the area occupied by the underside of the heat exchanger in the cross section of the reactor but not over the entire cross section of the heat exchanger and also a lateral border which extends in the longitudinal direction of the reactor and points upward, i.e. in the direction of the ejector, and extends to the underside of the heat exchanger, where the ejector is formed by a driving jet nozzle, a mixing chamber, optionally a diffuser and optionally further cylindrical sections. - a vertically elongated reactor in which there is a reaction space, - at least one heat exchanger which is arranged within the reactor, - at least one inlet for introducing the cooling medium into the heat exchanger, - at least one outlet for taking the cooling medium off from the heat exchanger, - at least one inlet for introducing the gaseous reactant into the reaction space, - at least one inlet for introducing the liquid reactant into the reaction space, - at least one mixing chamber, - at least one downward-directed driving jet nozzle for introducing the reaction medium, the outlet of which is arranged above the at least one mixing chamber and which is in fluid communication with the reaction space, - at least one outlet for taking the reaction medium off from the reactor and - at least one means arranged below the heat exchanger and below the mixing chamber for diverting the reaction medium flowing downward through the mixing chamber in such a way that the reaction medium once again flows upward through the heat exchanger, and - where an external circuit having a pump arranged therein provides fluid communication between the outlet for taking off the reaction medium from the reactor and the at least one driving jet nozzle for introduction of the reaction medium into the reactor, - wherein the means for diverting the reaction medium flowing downward through the mixing chamber is a diversion pan which has a surface which is aligned in the transverse direction of the reactor and extends over a major part of the area occupied by the underside of the heat exchanger in the cross section of the reactor but not over the entire cross section of the heat exchanger and also a lateral border which extends in the longitudinal direction of the reactor and points upward, i.e. in the direction of the ejector, and extends to the underside of the heat exchanger, where the ejector is formed by a driving jet nozzle, a mixing chamber, optionally a diffuser and optionally further cylindrical sections.