| 摘要 |
<PICT:1089353/C1/1> Ammonia is synthesized from a mixture comprising N2 and H2 in a volume ratio of 1:3 and 1.8% by volume of NH3 using a stationary catalyst maintained at 450 -520 DEG C., the pressure being 300 at., in an apparatus comprising cylindrical reaction chamber 2 containing a plurality of parallel longitudinally arranged catalyst tubes 17 communicating at one end with a heat exchanger 10, means 6 for supplying cool reaction gas to the heat exchanger; and temperature control means T, for example pipes 20 set in insulated tube 19 for delivering cool reaction gas in controllable amounts to portions of the catalyst tubes intermediate their ends. These portions of the tubes may be narrowed and may be enclosed in baffles (14), (15) forming chambers 16 (Fig. 3, not shown). In operation, reaction gas entering at 6 combines in heat exchanger 10 with reaction gas from inlet 5 which has flowed downwardly through the annular space 3 between reaction chamber 2 and outer cylinder 1 and through slit 23, and the combined gas stream then flows upwardly through the heat exchanger in heat exchange with hot reaction gases leaving the catalyst tubes and through gas distribution nipple 18 into the reactor chamber, mixes with cool gas fed into each of chambers 16 and also with preheated gas (at start-up) or cool gas (in normal operation) fed in at 24, flows downwardly in contact with the catalyst in tubes 17 and out at 27. |
