3960.  WOODALL-DUCKHAM, LTD. Continuously-operating Vertical Retort for the Production of Synthetic Gas. British Patent 531,289, Jan. 1, 1941. Chem. Abs., vol. 35, 1941, p. 8,262.

Retort is provided at the region of transition to the preheating zone to where the temperature is in the region of 300° with a gas-collecting space into which surplus gases flow. The gases generated in the preheating zone and in the carbonizing zone are led down through the reaction zone. The term "synthetic" gas refers to a gas consisting essentially of H₂ and CO in such proportions as to make it suitable for production of hydrocarbons, alcohols or NH₃ by catalytic synthesis processes, the gas having been freed from hydrocarbons.