Patent GB-719109-A (GB)
Title: Process for carrying out rapid chemical reactions
IPC: B01F3/08
Filed: 1952-04-08
Abstract: <PICT:0719109/IV (b)/1> <PICT:0719109/IV (b)/2> Cyclopentanone, cyclohexanone or cycloheptanone oximes are converted to lactams in the presence of a liquid catalyst such as sulphuric, phosphoric or perchloric acid by feeding the oxime axially into the core of a vortex formed by a circulating stream of lactam sulphate and sulphuric acid.  In Fig. 1, molten cyclohexanone oxime is fed from vessel 6 through pipe 4 which discharges axially into the centre of a radially symmetrical chamber 2 at 34 (Fig. 2).  A mixture of caprolactam and sulphuric acid is circulated through pipe 14, pump 18, heat exchanger 19 and pipe 3 to enter the chamber 2 tangentially to form a vortex therein.  The mixture of the axially-fed oxime and the liquid of the vortex discharges from chamber 2 into vessel 1 and is recirculated.  Make-up sulphuric acid containing 2 per cent free sulphur trioxide is added to the circuit by pipe 8 from vessel 10. In an example, caprolactam and sulphuric acid in a ratio of 2 : 3 by weight are circulated at 110 DEG  C. to form a vortex in chamber 2, the pressure on the feed-pipe 3 being 2 1/2 atmospheres (gauge) and the flow rate 1000 kg./hour.  Molten cyclohexanone oxime is fed axially to the vortex at a rate of 10 kg. per hour whilst sulphuric acid is fed from vessel 10 at 1 1/2 times the oxime feed rate.  The reaction product is recovered from vessel 1 by pipe 11, neutralized with ammonia and after separating, distilled to yield 98 per cent lactam calculated on the oxime.  In a similar manner monobromophenol containing some dibromophenol but free from tribromophenol is prepared by feeding bromine water (containing 7.5 grams Br2/litre) to a vortex formed by feeding phenol water (50 grams/litre phenol) to chamber 2.  The liquid obtained is extracted with ether and the extract dried by evaporation.ALSO:<PICT:0719109/III/1> <PICT:0719109/III/2> Chemical reactions between two miscible liquids or components thereof, which reactions are liable to undesired side reactions consequent upon fluctuations, in reaction conditions, are carried out by continuously supplying one of the liquids under pressure to a radially symmetrical chamber having an axial outlet, in such a manner that a vortex is formed, and continuously introducing the other liquid into the rotating liquid by supplying it axially to the core of the vortex.  In Fig. 1, a vessel 1, provided with overflow 11 contains a chamber 2 (Fig. 2) to which the pipe 3 delivers liquid tangentially to the chamber wall to form a vortex therein and a pipe 4 delivers the other component from a heated vessel 6 axially to the chamber at 34.  The mixture leaves the chamber through discharge 33.  A pipe 14 from the base of vessel 1 leads to the suction side of pump 15 which delivers liquid through a heat exchanger 19 back to pipe 3.  A bye-pass pipe 26 is provided and a vessel 10 is connected by line 8 to the circuit formed by pipes 14, 18 and 3.  If desired the tangential injection may be at a point midway between two opposed discharge orifices, thus forming two vortices into each of which the other component is axially fed.  The heat exchanger 19 removes or supplies heat by means of a boiling liquid, the boiling point of which can be adjusted by varying the pressure in the heat exchanger 19. According to examples (1) cyclopentanone, cyclohexanone or cycloheptanone oximes are converted into lactams by feeding the oxime axially to a rotating body of sulphuric acid and lactams sulphate.  (2) Monobromophenol containing some dibromophenol but free from tribromophenol is prepared by feeding bromine water (containing 7.5 grams Br2/litre) to a vortex formed by feeding phenol water (50 grams phenol/litre) to the chamber 2. The liquid obtained is extracted with ether and the extract dried by evaporation.