Gas mixer and distributor with heat exchange between incoming gases

A gas mixer and distributor for mixing and feeding a gaseous reaction mixture to the inlet of a reactor, the gas mixer and distributor comprising:

• means forming a first chamber with a first inlet for receiving a first gaseous reactant;
• means forming a second chamber downstream of said first chamber with respect to the direction of flow of said first gaseous reactant with a second inlet for receiving a second gaseous reactant;
• means forming a third chamber downstream of said second chamber with respect to the direction of flow of said first and second gaseous reactants and positioned to discharge the effluent therefrom into the inlet of said reactor;
• said second chamber being interposed between the first and third chambers;
• an array of a plurality of parallel elongated tubes communicating at first ends thereof with the first chamber, and extending from the first chamber through the second and third chambers to the inlet of said reactor;
• heat exchange means in said second chamber comprising a plurality of tubular sections coaxially positioned over the tubes to form annular flow passages around the plurality of tubes between said first and second chambers for receiving and directing flow of said second gaseous reactant through said annular passages in heat transfer interaction with said first gaseous reactant;
• and
• a plurality of openings in the walls of the tubes and communicating with the third chamber for passing streams of the second gaseous reactant into the tubes for mixing with the first gaseous reactant, whereby said gaseous reactants are mixed in said third chamber after heat transfer interaction therebetween in said second chamber;
• each of said tubes including a section of gradually increasing cross-section opening toward the second ends of the tubes at the entrance of said reaction chamber to distribute the flow of the mixture uniformaly across the entrance of said reaction chamber;
• said openings being spaced from the second ends of the tubes to insure substantially complete mixing of the first and second gaseous reactants within the tubes prior to entering the said reaction chamber.