PATENT

3387. ----- [SOCIÉTÉ CHIMIQUE DE LA GRANDE PAROISSE, AZOTE ET PRODUITS CHIMIQUES.]   French Patent 652,574, Apr. 11, 1928.  Chem. Abs., vol. 23, 1929, p.3523.

In exothermic catalytic reactions carried out under pressure, the fresh gas is caused to arrive between the wall supporting the pressure and an inner tube containing the catalytic material, to protect the wall against the temperature.  The gas is mixed with the residual gas from the reaction chamber from which the product of the reaction has been removed, and the mixture enters a heat exchanger before passing to the reaction chamber. 

See also French Patent 644,266 (abs. 3386).