| 摘要 |
The hot, vinyl chloride-containing gases leaving the cracking furnace heat liquid 1,2-dichloroethane in a first container to the boiling point or to its immediate vicinity, and the 1,2-dichloroethane is transferred into a second container in which it is partly evaporated under a lower pressure than in the first container. The evaporated 1,2-dichloroethane is fed into the cracking furnace, and the nonevaporated 1,2-dichloroethane is fed back into the first container. By supplying fresh, optionally prewarmed 1,2-dichloroethane into the second container, the amount of product evaporated therein is replaced, the prewarming advantageously being regulated through the level of the liquid 1,2-dichloroethane in the second container. The prewarming of the 1,2-dichloroethane can take place in the convection zone of the cracking furnace or by means of a temperature-control medium, for example steam, which has been heated in the convection zone of the cracking furnace. Compared to processes according to the prior art, higher cracking conversions and a more favorable energy utilization are achieved. |
