| 摘要 |
Gases from an exothermic catalytic synthesis process are cooled by indirect heat exchange with a volatile organic liquid which is under pressure, and the resulting organic vapour is expanded through a turbine, then cooled, condensed, and recycled. Suitable organic liquids are CFCl3, CCl2F2, propane and butane. With reference to the figure (not shown), gases at 400-450 DEG F. from NH3 synthesis in converter (2) are cooled to 200-250 DEG F. in tubular heat exchanger (3) by contact with organic liquid admitted at 150-250 psia. from (4). The gases may be further cooled to below 150 DEG F. in heater exchanger (6) using, e.g. water. Condensed NH3 is separated from H2 and N2 in (10), the latter gases being returned to converter (2). The organic vapour from (3) passes via liquid separator (18) to turbine (20, which may be connected to a compressor or generator. The vapour, at 20-50 psia., is then liquefied in cold-water condenser (24) and pumped back to exchanger (3). |
