| 摘要 |
Bromine- and/or chlorine-containing di-halides of normally gaseous olefines are prepared by continuously passing the halogen and olefine cocurrently downwardly through a vertical elongated reactor provided interiorly with heat exchange means which present a large expanse of cooling surface per volume of free reactor space, withdrawing heat through the surface of the heat exchange means to maintain the interior of the reactor at a temperature below the boiling point of the product dihalide whilst also maintaining an entirely fluid phase, the olefine and halogen being contacted together in the presence of liquid product dihalide while the latter flows downwardly, as a discontinuous liquid phase, over the surface of said heat exchange means, withdrawing a liquid stream containing product dihalide from a lower portion of the reactor, and recovering substantially halogen-free olefine dihalide. When the halogen is bromine or bromine and chlorine, the interior of the reactor is preferably maintained at 10-150 DEG C., and when the halogen is chlorine, it is preferably maintained at from -10 to 50 DEG C. Preferred heat exchange means are superimposed flat spirally-wound tubular coils, the convolutions in adjacent coils being out of register. The column may contain intermediate zones containing solid packing pieces disposed between two sets of adjacent tubular heat exchange means. Examples prepare ethylene dibromide and ethylene dichloride. Specifications 804,996 also is referred to.ALSO:<PICT:0875561/III/1> Apparatus suitable for the preparation of olefine dihalides (see Group IV(b)) comprises a verticular tubular column (1), inlet means (9) for admitting reactants into an upper portion of the column, tubular heat exchange means (2-5) disposed within the column and providing in effect a packed section extending vertically throughout a major portion of the column and also occupying a major proportion of the cross-sectional area of the column while being spaced from the wall of the column, said heat exchange means being constituted to a substantial extent by surfaces extending generally transversely across the column and providing a discontinuous liquid flow path over substantially the whole crosssectional area of the column; and outlet means (11) for withdrawing liquid product from a lower portion of the column. The numerals relate to Fig. 1 of the Figures accompanying the second Provisional Specification. Preferably the heat exchange means are each constituted at least in part by a number of superimposed flat spirally-wound tubular coils, the convolutions in adjacent coils being out of register. As shown, the column may be provided with an intermediate zone 6 containing solid packing pieces. Specification 804,996 also is referred to. |
