Fluidized bed reactor for exothermic reactions

A reactor provided at the bottom with one or more pipes for gaseous reaction media and at the top with one or more outlet pipes for reaction product, which reactor is provided with a number of bundles of parallel axial tubes for a coolant to be passed through the reactor concurrently with the reaction media, means maintaining said tubes for the greater part of their length substantially uniformly distributed over the cross-section of the reactor, the tubes of each bundle being connected to a header and manifold space located within the reactor, said header and manifold, which being regularly arranged around an axial supply pipe for the coolant, are provided with flat tube sheets toward which the tubes of a bundle converge and to which they are connected, said manifold spaces are connected to the supply pipe by means of radial pipes and the header spaces are also connected by means of radial pipes with a coolant discharge pipe arranged concentrically around the supply pipe, said concentrically arranged axial supply pipe and said coolant discharge pipe passing through a wall of said reactor, said inlet pipe or pipes are branched in a stellate configuration so that the branches are between or just downstream of the manifold spaces and said branches are each provided with a number of gas outflow openings which are suitable to keep in the fluidized state during operation a finely grained mass of catalyst particles present in the reactor, wherein said axial supply pipe is surrounded by a second concentric pipe one extremity of which is connected to the lower extremity of the coolant discharge pipe, the other extremity debouching with the supply pipe into a space to which the radial pipes leading to the manifold spaces are connected.