公开(公告)号：DE2631834A1

公开(公告)日：1978-01-19

申请号：DE2631834

申请日：1976-07-15

Applicant: BASF AG

Inventor： BECKER ROLF DIPL ING DR ,  BORHO KLAUS DIPL ING DR ,  BUECHNER OSKAR DIPL CHEM DR ,  GROPPER HANS DIPL CHEM DR ,  HARTIG ULRICH DIPL CHEM DR

IPC: B01J3/00 ,  C08F2/00 ,  C08F2/34 ,  C08F10/00 ,  C08F10/02

Abstract: The invention relates to a process for rapidly letting-down the pressure in continuous high pressure polymerization systems for the polymerization of ethylene. In this process, the let-down hot reaction mixture is passed into an expansion vessel in such a way that the jet of let-down hot reaction mixture issuing from the let-down line is led into the partially water-filled expansion vessel at an angle of from 0 DEG to 45 DEG to the water surface, so that the jet does not enter below the surface but must touch or strike it. The method described makes it possible to let the mixture down partially and thus to slow down the decomposition in the case of explosive decomposition reactions occurring in the polymerization system.

公开(公告)号：DE3031124A1

公开(公告)日：1982-04-08

申请号：DE3031124

申请日：1980-08-18

Applicant: BASF AG

Inventor： BORHO KLAUS DIPL ING DR ,  FROMM DIETER DIPL CHEM DR ,  SCHIER ERNST-JUERGEN DIPL CHEM ,  SCHNEEHAGE HANS HENNING DIPL C ,  WIDMANN ALFRED DIPL ING DR

IPC: C07C273/10 ,  C07C67/00 ,  C07C239/00 ,  C07C273/12 ,  C07C273/16 ,  C07D251/62 ,  C07D251/60

Abstract: A process for isolating liquid urea and its thermal decomposition products from the off-gas of melamine synthesis, which gas has been freed from melamine by fractional condensation and then been washed with molten urea, wherein the off-gas, containing 2-10 kg of melt per kg of pure gas, is passed at 8-30 m/sec tangentially into the upper part of an axially symmetrical separation zone. As a result of the rotation imparted to the gas/liquid mixture, the two phases are separated from one another, and both pass downward through the separation zone. The gas and liquid are separately taken off at the bottom end of the separation zone. The residence time of the gas mixture in the separation zone is not less than 0.5 second.