Patent GB-827550-A (GB)
Title: Improved method of and apparatus for continuously contacting liquids
Inventor: HABICHT LOJO
IPC: B01D11/04
Filed: 1956-12-13
Abstract: Two immiscible liquids of different specific gravities are mixed together by rotation and then separated in one or more stages, characterized in that in the region of the boundary surface of the rotating liquids controlled fractions of both liquids are jointly withdrawn; separated and at least one of said liquids is recirculated in a stage.  The liquids are passed in counter-currents through the stages, preferentially disposed one above the other and the lighter liquid after separation is usually returned to the same stage and its discharge from its separated phase is effected by overflow.  The withdrawal of the liquid may be effected independently of the recirculation.  Reaction chambers 1, 2, 3, 4, are accommodated one above the other in an upright closed cylindrical body 5.  Through the centre of the cylindrical body passes a stirrer shaft 6 having four stirring wings 7 in each chamber, adapted to the dimensions of the chamber in order to render possible turbulence-free rotation of the liquids.  The lighter liquid is introduced into the jacketed chamber 1 by pump 8 through pipe 9 and is set in rotation but, in consequence of its lower mass, remains nearer the centre in the inner zone of the chamber.  The lighter liquid passes through the <PICT:0827550/III/1> <PICT:0827550/III/2> <PICT:0827550/III/3> passages 11 into setting chamber 12, in which any entrained particles of the heavier liquid are separated and flow back to the chamber 1.  The lighter liquid overflows settling chamber 12 and passes beneath conical hood 13 to the base of the chamber 2.  In chamber 2 and also in the succeeding chambers 3 and 4 the same processes take place as in chamber 1, until finally the lighter liquid emerges through the overflow 14 and leaves the installation through a float valve 15.  The heavier liquid introduced into chamber 4 by pump 16 through the pipe 17, two sector-shaped supply and separation chambers 18 and through the perforated branch 10 flows through the inner zone holding the lighter liquid towards the outer zone of the chamber in consequence of the centrifugal acceleration imparted to it.  Its greater fraction is then returned to the ligher liquid again by the acceleration imparted to the liquid, through two return pipes 19 connected at the lower part of the chamber, two sector-shaped supply chambers 20 and the perforated branch 10, whereupon the cycle described begins again. The smaller fraction of the heavier liquid is withdrawn by two peeling devices 21 and introduced through two pipes 22, two supply chambers 18 and a branch 10 into the chamber 3.  The peeling devices 21 serve simultaneously to regulate the level of the two liquids in each chamber, since at high level of heavier liquid more, and at low level less, of heavier liquid is withdrawn. Fractions of the lighter liquid simultaneously absorbed by the peeling devices 21 and passing to the supply chambers 18, which are constructed as separating chambers by installation of sheets supporting better separation, are separated in said chambers at the top, pass through the apertures 23 into the settling chamber 12 and are returned through the latter back to the chamber.  The peeling device 21 together with the magnetic valve 28 controlled by the photo-electric cell 26 and the relay 27 serves to regulate the state of the level of the two liquids in the chamber 1. The fraction of lighter liquid which has passed into the separator is returned to the chamber 1 through the pipe 29.  In starting up the installation, while venting by means of the valve 30 the heavier liquid is first introduced into chamber 4, that is the top chamber, in the manner described.  It fills said chamber up to the level of the settling chamber 12 and then overflows into chamber 3.  A partial filling of the latter end of the chamber 2 occurs in corresponding manner.  After the overflowing into the chamber 1, the heavier liquid passes during the filling, in consequence of communicating connection, through the pipe 24 into the separator 25 from which it is separated out as soon as level governed by the arrangement of the separator has been reached.  The supply pipe for the heavier liquid is now shut off, the pipe to the separator blocked, the stirrer shaft set in rotation and the lighter liquid introduced into the chamber 1 as described.  Its exit from the overflow 14 indicates complete filling of the installation.  After recommencing the supply of heavier liquid and opening the connection to the separator 25, the installation is in continuous operation.