Improvements in or relating to the treatment of gases with solids and especially to a continuous purification of coal gas and continuous revivification of spent oxide

摘要

553,414. Contacting gases with solids. APPLEBY-FRODINGHAM STEEL CO., Ltd., STEPHENSON, H. P., and CURTIS, A. L. Nov. 17, 1941, No. 14771. [Class 1 (i)] [Also in Group XII] In a process for treating gases by contacting large volumes of gas with a small quantity of solids, especially for the removal of sulphuretted hydrogen from coal gas, the gas travels continuously in one direction and small quantities of solid are repeatedly circulated through the gas in a counter current direction at a plurality of points along its path. Coal gas containing sulphuretted hydrogen passes from right to left in turn through each of three rotating cylinders 1 from an inlet 2 to an outlet 3. Iron oxide is introduced at the lefthand end and passes in turn through each cylinder from left to right, being re-circulated by a path a into contact with air, to oxidize the sulphide, and return to each cylinder. A part of the oxide is bled off at d from one cylinder, and passed into the circuit a of the next cylinder on the right until the spent oxide passes at b to a recovery plant 7 in which it is treated with carbon disulphide for removal of free sulphur. The solution is distilled in stills 10, the carbon disulphide being passed through a condenser 11 to a tank 8 from which it is pumped at 9 to the plant 7. The oxide is passed through a centrifuge 13, dried in a drier 14, and returned at c to the circuit. The rotating cylinders are provided with baffles which shower the oxide through the gas.