GB268722A - Improvements in or relating to processes for carrying out exothermic chemical reactions - Google Patents

Abstract

268,722. Soc. l'Air Liquide, Soc. Anon. pour l'Etude et l'Exploitation des ProcÚdÚs G. Claude, (Assignees of Soc. Chimique de la Grande Paroisse Azote et Produits Chimiques). April 1, 1926, [Convention date]. Catalytic processes and apparatus.-In exothermic reactions such as the synthesis of ammonia, heat is conveyed from hotter to cooler parts of the catalytic mass by means of the reaction gases before they come into direct contact with the catalyst. In one arrangement, the reaction gases entering a pressure vessel are led through a central tube B to the hotter end of the catalytic mass, then by tubes C to the cooler end again, and finally by tubes C<1> back to the hotter end, where they pass into the surrounding catalyst. The tubes C may be partly heat-insulated, and may be arranged coaxially inside the tubes C<1>, so as to minimize loss of heat in transit from the hotter to the cooler regions. A number of separated parallel tubes may replace the central tube B. The tubes C, C<1> may be coiled, and may be pointed at their ends, to facilitate their expansion within the catalytic mass. A part of the fresh gases may be led between the heat-insulated catalyst container J and the pressure tube H, in order to cool the latter, before entering the upper end of the catalyst container J. In another arrangement, the reaction gas entering the pressure vessel is distributed to an outer series of tubes embedded in the catalyst, and after passing up through these tubes is conveyed downwards through an inner series and finally up through a central tube and into contact with the catalyst. An independent current of gas is conveyed between the catalyst container and pressure tube and is discharged to the outside of the pressure vessel, as described in Specification 268,721. Specification 150,744 also is referred to.