PATENTS

      18.              ALMQUIST, J. A. (E. I. duPont de Nemours & Co.) Apparatus for Effecting Exothermic Catalytic Gas Reactions Such as Ammonia Synthesis.  United States Patent 1,855,040, Apr. 19, 1932.  Chem. Abs., vol. 26, 1932, p. 3150.

A purifier catalyst chamber and a producer catalyst chamber are surrounded by separate pressure-resisting walls, the pressure-resisting wall around the producer catalyst chamber being spaced from the chamber to form an annular passage to which compressed gases are delivered and from which they are passed to the purifier catalyst chamber and then returned to the producer catalyst chamber.

See also British Patent 344,576 (abs. 19).