FR2595264A1 - DEVICE FOR MIXING TWO LIQUIDS, PARTICULARLY OF DIFFERENT DENSITIES - Google Patents

Abstract

THIS DEVICE IS CHARACTERIZED IN THAT IT CONTAINS A TUBE 10 HAS SENSITIVELY VERTICALLY, A SHAFT 12 SUITABLE TO ROTATE COAXIALLY IN TUBE 10 AND SUCCESSIVELY INCLUDING FROM BOTTOM TO TOP A LOWER HELICAL PART 14 WHICH IS SHAPED BY A FIRST SENSE, AT LEAST ONE PALLET 16 LOCATED IN A RADIAL PLANE OF SHAFT 12 AND OF EXTERNAL DIAMETER SLIGHTLY LESS THAN THE INTERNAL DIAMETER OF TUBE 10, AN UPPER HELICAL PART 18 OF WHICH THE PROPELLER IS SHAPED IN A SECOND DIRECTION CONTRARY TO THE FIRST SENSE , OF THE HOLES 20 BEING FORMED IN THE TUBE 10 FACING THE PALLET 16, A LIQUID INLET 6 IS PROVIDED SO THAT LIQUID 6 FLOWS DOWN TO THE UPPER HELICOIDAL PART 18, L 'SHAFT 12 TURNS ACCORDING TO THE FIRST SENSE SO THAT LIQUIDS 4, 6 ARE SUCKED OUT THROUGH THE LOWER OPEN END OF TUBE 10 AND THROUGH ITS INLET AND EXHAUSTED HOLES 20.

Description

1. Device for mixing two liquids, in particular with different densities

  The subject of the present invention is a provision

  sitive mixing two Liquids, especially with different densities.

  In some industries, notably the

  chemical industry, it is interesting to be able to mix

  manage two liquids or solutions of different densities and / or phases without too rapid separation

  of the two phases present and while having a dis-

  fine and fairly long persion. When the two liquids

  consist of two solvents, one in the aqueous phase

  se and the other in the organic phase, mineral salts can pass from the organic solution to the aqueous solution if the two liquids are mixed very finely and for a relatively long time. It is then possible to collect the salts from the aqueous solution and then to purify them with a view to subsequent re-use. As conventional mixing devices, magnetic rod agitators or motorized propellers are known. In both cases, the bar or the propeller creates in the two liquids a vortex mixing the two phases in contact. In the case where the two phases have very different densities, the separation of the two phases is too fast and the salt exchanges

  between the two solutions are then weak. The return

  ment of such devices is therefore insufficient.

  Other devices are also known

  conventional mixers such as decan mixers

  pulsed columns. They consist in forcing one into the other two flows each formed by one of the liquids to be mixed. The mixture can be improved by

  sending pulses into the streams. As before

  ment, this type of device does not work well for

  very different densities of liquids.

  The invention therefore relates to a device for mixing two liquids which overcomes the drawbacks mentioned above. For this purpose, the mixing device comprises a tube arranged so

  substantially vertical, a shaft capable of rotating coaxia-

  LEMENT in the tube and successively comprising from bottom to top a helical lower part whose propeller is formed in a first direction, at least one pallet located in a radial plane of the shaft and of outside diameter slightly less than the inside diameter of the tube , a helical upper part whose helix is formed in a second direction opposite to the first direction, holes being formed in the tube facing the pallet, a liquid inlet orifice being provided for

  so that liquid flows down to

  that at the helical upper part, the shaft rotating in the first direction so that the liquids are sucked through the open lower end of the tube

  and through said inlet port and expelled through the holes.

  Advantageously, said inlet orifice is

  constituted by windows formed in the light tube-

  above the helical top or

  through the open upper end of the tube.

  Advantageously, the helical parts

  each have a helix pitch, the pitch of the lower part being larger than the pitch of the

the top part.

  In any case, the invention will be better understood.

  taken with reference to the following description of a

  example of implementation given by way of illustration and not limitation, with reference to the single appended figure, representing, in longitudinal section, the device

  mixer according to a preferred embodiment of the invention

vention.

  A device for mixing two liquids is

shown in the single figure.

  The mixing device referenced 2 is used to mix two liquids 4, 6 of different densities, the liquid 6 being for example the heaviest and resting

at the bottom of a container 8.

  The mixing device 2 has everything

  first a tube 10 arranged in a substantially vertical

  wedge. A shaft 12 is housed in the tube 10 so as to be able to rotate coaxially in the tube 10. This shaft 12 successively comprises from bottom to top a helical lower part 14 whose helix is formed in a first direction, at least one pallet 16 whose outer diameter is slightly less than the diameter

  inside of the tube 10 and a helical upper part

  dale 18 whose propeller is formed in a second direction

contrary to said first sense.

  When the shaft 12 is in the operating position

  operation in tube 10, the lower end of

  the helical lower part 14 is close to the former

  open lower end of the tube 10, the latter being at

near the bottom of the container 8.

  Holes 20 are formed in the wall of the

tube 10 opposite the pallet 16.

  Windows 22 are also formed in the wall of the tube 10 slightly above the part

helical upper 18.

  The helical lower part 14 is des-

  intended to suck the liquid 6 of density greater than

  across the lower end of the tube 10 and the

  helical upper tie 18 is intended to suck the

  liquid 4 of lower density through windows

  very 22, the propeller pitch being determined in function

  tion of the density of each of the liquids and the flow rates

  respective desired for said liquids.

  When the shaft 12 rotates in said first direction of the helix of the helical lower part 14 / The liquid 6 is sucked by the lower part 14

  and the liquid 4 is sucked up through the upper part 18.

  These two liquids are then laminated between the pallet 16 and the inner face of the corresponding tube 10. The two mixed liquids are then expelled by the

holes 20.

  IL then creates flows of liquid penetrated

  trant by the lower end of the tube 10 and by the

  windows 22 and emerging through the holes 20, this

  contributing to create an emulsion promoting exchanges

  between the two phases of the two corresponding liquids.

  The mixing device according to the invention therefore allows mixing of liquids of very different densities while having a slow separation, a fine and fairly long dispersion and an effective exchange of salts. Such a device makes it possible to pass the

  almost all of the salts in a solution in the other

  Lution. He is able to work as well in

  continuous operation than in discontective operation

bare.

  Of course, the above description has not

  has been given as an example, all modifications in the embodiments that can be envisaged

  without modifying the fundamental principle of the invention.

  We could for example remove the windows

  very 22 and let the liquid of lower density penetrate

  4 by the open upper end of the tube 10.

  The device would therefore essentially serve to suck up the liquid 6 of higher density, bring it up and mix it with the liquid 4 which would descend into the tube 10. The mixture produced would always be expelled

through holes 20.

Claims (4)

  1. Mixing device (2) of two liquids (4, 6) in particular of different densities, characterized   in that it comprises a tube (10) arranged in a sense   so vertically vertical, a shaft (12) capable of turning coa-   xially in the tube (10) and comprising successively-   from bottom to top a helical lower part (14) whose helix is formed in a first direction, at least one pallet (16) located in a radial plane of   the shaft (12) and slightly smaller outside diameter   laughing at the inside diameter of the tube (10), a helical upper part (18) whose helix is formed in a second direction opposite to the first direction, holes (20) being formed in the tube (10) facing the pallet ( 16), a liquid inlet port (6) being provided so that liquid (6) flows down to the helical upper part (18), the shaft (12) rotating according to the first sense of such   so that the liquids (4, 6) are drawn in through the   open lower part of the tube (10) and through said ori-   inlet and expelled through the holes (20).   2. Mixing device according to the claim   tion 1, characterized in that the liquid inlet orifice (6) consists of windows (22) formed in the tube (10) slightly above the part helical upper (18).   3. Mixing device according to the claim   tion 1, characterized in that the liquid inlet orifice (6) is constituted by the upper end open tube (10).   4. Mixing device according to the claim   tion 1, characterized in that the helical parts (14, 18) each have a helix pitch defined so as to impose a ratio between the flows of liquids   (4, 6) as a function of the respective densities.