GB191317690A - Improvements in and Apparatus for the Production of Hydrogen. - Google Patents

Abstract

17,690. Messerschmitt, A. Aug. 1. Hydrogen - producing furnaces.-Relates to the production of hydrogen by the alternate reduction and oxidation of iron ores &c. and iron by means of reducing-gases and steam, the heating being effected by a gas of low calorific power, and the reduction by a gas of high calorific power. A gas of low calorific value generated in a producer 1, Fig. 1, having an air-pipe 6 is led through a pipe 3 to heat directly the iron reaction mass in the hydrogen producer 4, a blast of air being supplied by a pipe 10; the hot gases escape by a passage 13 into a superheater 15. In the reduction phase that follows, steam is blown under pressure into the same producer 1 through a pipe 8 so as to produce a water gas or Dowson gas of high calorific value, which reduces the iron mass in the producer 4 and can be burnt in the superheater 15 by an air blast. In the subsequent oxidation phase, the producer 1 is shut off by the register 2, and steam from a pipe 16 passes through the superheater 15 and passage 13 into the producer 4, the hydrogen evolved being conducted by a pipe 12 to a seal tank 11. For indirect heating of the iron mass it may be placed in a decomposer 19, Fig. 2, communicating at the bottom with the heating-space of the producer 18, which is constructed as a superheater 27. The producer gas from the chamber 1 is, during the heating- phase, introduced at the bottom of the heating- chamber of the hydrogen producer 18, and an air blast is admitted by a pipe 26, the hot gases escaping through a chimney 29. In the reduction phase, the reducing-gas is introduced along the same path and flows upwards through the decomposer 19, and then by a pipe 24 to the furnace of the steam boiler. Alternatively, the reducing gas may be caused to flow downwards through the decomposer 19, and, by admitting air through the pipe 26, the reduction exhaust gases from the decomposer 19 may be burnt in the heating-space of the producer 18. The oxidation is effected with the registers 20, 28 and the chimney damper 30 closed by introducing steam through a pipe 25 into the heating-space, the hydrogen passing by a pipe 22 into the tank 11. In a modification, Figs. 3 and 4, two or more decomposers 31, 33 are combined in the manner shown, so that the contents of one decomposer are. reduced by a reduction gas of high calorific value admitted by a pipe 36 or 48, while at the same time the contents of the second decomposer are heated by the reduction exhaust gases escaping from the first decomposer by way of the passage 32, while the escaping gases receive from a pipe 39 a blast of air for combustion, the mixture passing tangentially into a combustion chamber 49 arranged above the reduction shaft. Steam is then admitted to the second decomposer by one of the pipes 43, where it is superheated, and is conducted by the passage 32 to the first decomposer where it is decomposed in the known manner. The operations are then repeated in the reverse direction. For heating at the start &c., an auxiliary gas-pipe may be arranged behind the air-pipe 39 to introduce gas simultaneously with an air blast into the passage 32. In a further modification, Fig. 5, the various zones of a shaft furnace charged with a suitable iron reaction mass are reduced successively, and are so heated that the gases from the lowest zone are burnt in the upper zone by air from an air blast. The shaft furnace 51 is provided with a refractory lining and passages 52 into which open tangentially nozzles arranged at various heights a, b, c, d and supplied with gas by a pipe 53 and with an air blast bv a pipe 54. The heating-nozzles a, b are first opened, and, when the reaction mass has been heated. The heating-gases are cut off and reduction gases of high calorific value are introduced at a while the blast air nozzles c. d are opened. After a time the nozzle c is closed, and lastly the nozzle d. When the whole contents of the shaft have been successively reduced in this manner, the valve 60 is closed and steam admitted through a pipe 57. The steam is superheated by contact with the chequer-work 56 and flows downwards through the reaction mass, the hydrogen escaping through a pipe 59. The gas and air mixture required for the starting-heat &c. may be produced in separate chambers out of contact with the reaction mass.