| 摘要 |
<p>This falling-film apparatus for the equicurrent evaporation of a solution is used for purification of solutions resulting from urea synthesis. The apparatus consists of a tuba-bundle heat-exchanger in which a feed distributor lets the solution fall onto an uppermost tube sheet. The tubebundle also comprises falling-film pipes jutting out of this uppermost sheet. The jutting out portions, or inlet sleeves are closed at their uppermost end and are supplied with tangential distribution slots. The apparatus is also provided with means for the recycle of vapours released from the bottom of the exchanger to a level higher than the uppermost end of the sleeves.</p> |
