Apparatus for producing a gaseous hydrocarbon/air mixture and for the catalytic oxidation of this mixture

Apparatus for forming a gaseous hydrocarbon/air mixture and for subsequently catalytically oxidizing said mixture, said apparatus comprising an evaporator having an air inlet pipe on the inflow side of said evaporator, an outlet pipe for said mixture on the outflow side of said evaporator and at least one injection nozzle positioned between said inlet and outlet pipes suitable for injecting hydrocarbon into said evaporator, and a shell-and-tube reactor comprising a plurality of parallel, externally cooled, catalyst-filled tubes, a hood on the upstream side of the tubes and a hood on the downstream side of the tubes, said hood on the downstream side being substantially convex-shaped as viewed from the exterior of said reactor and said hood on the upstream side being substantially concave-shaped as viewed from the exterior of said reactor such that the volume of the upstream hood is substantially reduced compared with the volume of an outwardly curved hood, said upstream hood being in communication with the outlet pipe of said evaporator.