FR2740051A1 - Device for distributing, mixing, injecting and/or extracting fluids - Google Patents

Abstract

Device for distributing, mixing, injecting and/or extracting a number of fluids where there is a principal fluid A and at least one first secondary fluid B1 and a second secondary fluid B2. The device contains means to collect the principal fluid A which are connected to at least one mixing chamber, at least one primary injection and/or extraction circuit for the first secondary fluid B1 and a second injection and/or extraction circuit for the second secondary fluid B2. These circuits connect to the mixing chamber through one or more openings allowing the (B1 and B2) fluids to pass into or out of the chamber. The mixing chamber has at least one inlet for the principal fluid and at least one outlet. The device also contains means of redistributing the fluid from the mixing chamber. The injection and/or extraction circuits are distinct and placed near the mixing chamber at at least one of the chamber walls with a direction parallel to the axis of the device. Column allowing the separation of a fluid containing several separable components, comprising at least a first and second bed of solid granules separated by at least one of the above devices.

Description

 The present invention relates to a device for distributing, mixing, adding and withdrawing several fluids, one of which is considered as the main fluid and the others as secondary fluids.

 It applies particularly well to fluids in the gaseous, liquid or supercritical state in the field of chromatography.

 It finds applications in a column comprising at least two beds of granular solids separated from each other by at least one device of this type called hereinafter abbreviated DME.

 In the field of the distribution of a fluid at the entry of a zone and in particular at the entry of a bed of granular solids and, more particularly in the field of liquid chromatography, it is important to '' obtain a distribution or collection of the fluid (s) as homogeneous as possible.

In particular, in the case of simulated moving bed chromatography, most often operated in simulated counter current, which most often combines large diameters and numerous separation stages with injection or withdrawal of products between two stages, this DME must ensure the radial collection of a main fluid (A) as uniformly as possible while inducing in the chromatography column the minimum of dead volumes. This EMR must be designed so as to avoid back mixing as much as possible, which could hinder the separation of bodies already carried out in the area located upstream of this
DME. It must also be designed so that the pressure drop DP which it induces in the column is as low as possible.

 This EMR must also ensure during the injection of at least one secondary fluid (B) a mixture as uniform as possible of this fluid (B) with the fluid (A) and this, under the same conditions as above, that is to say by minimizing as much as possible the dead volumes, the back-mixing and the induced DP. It is the same in the case of the withdrawal of a fluid from this DME.

 Finally, this DME must ensure the radial redistribution of the fluid obtained after addition or withdrawal towards the inlet of the chromatography zone located immediately downstream of said DME. This redistribution must be as uniform as possible, entail the minimum of dead volumes and back-mixing so as not to affect the separation of the bodies already carried out in the zone located upstream of this DME and also imply the lowest possible pressure drop DP .

 Among the dispenser or EMR systems described in previous publications and used at the industrial stage for fine chemistry, the laboratory or large industry, mention may be made of the dispenser offered by the company AMICON which comprises a central deflector-dispenser system. This distributor makes it possible to obtain a relatively correct distribution of the main fluid with small dead volumes, but it does not include any means making it possible to perform a function of adding or withdrawing a secondary fluid, nor any means ensuring a mixing function. of a secondary fluid with the main fluid. In addition, the central deflector system causes some disturbances in the radial distribution of the main fluid and the pressure drop is relatively large due to high speeds at the level of the relatively punctual central collection. in the dispenser.

 It is recalled that the terms upstream and downstream are to be considered with respect to the direction of circulation of the main fluid (A1).

 US-A-3,948,775 describes a DME used in a chromatographic column comprising two beds in which the main fluid (A) is collected downstream of a grid located at the outlet of the first bed by a pipe and returned upstream of the second bed and of a collection grid by a pipe, before being redistributed in the second bed laterally. The secondary fluid (B) can be introduced via an additional line and mixed in line with the main fluid, the mixing being carried out relatively punctually. The collection and redistribution zones are separated by an inclined waterproof baffle. This DME makes it possible to obtain a conical collection with a low dead volume. However, the way to mix the two fluids is not optimal. In addition, the existence of an external line induces an additional dead volume which can cause a back-mixing phenomenon and additional pressure drops. The lateral distribution of fluids due to its lack of symmetry can lead to imperfect homogenization for large diameters.

 The DME described in patent US-A-3,214,247 is used in a chromatographic column. The main fluid is collected entirely downstream of a collection grid positioned at the outlet of a first bed and redistributed downstream of a grid located near a second bed. The secondary fluid is introduced through holes positioned in the central zone of the DME where it mixes directly with the main fluid. This DME has the advantage of having low dead volumes and of inducing a relatively moderate pressure drop due to its transverse collection. However, the mixing function is not fully mastered and can induce back-mixing phenomena throughout the conical collection and / or redistribution section. In addition, the mixing zone is not confined to the central zone according to a diameter.

 The DME described in application WO-95 / 03.867 of the applicant partially overcomes the drawbacks presented by the devices of the prior art, in particular it makes it possible to optimize the mixing of the main and secondary fluids.

 However, due to its mechanical design, in particular the arrangement of the chambers on or through a baffle, it leads in practice to limit to two the number of fluids other than the main fluid.

 In addition, the injection and / or withdrawal chambers and the conduits communicating with them, see the circulation of fluids which may differ in their nature and composition. In fact, at each change of fluid, there is in the conduit a plug of a first fluid having circulated before the second fluid and which is pushed into the column or withdrawn from the column. This has the effect, in particular of polluting the spaces (conduits and / or rooms) of circulation and therefore of reducing the production yields and the purity of the products. To avoid these drawbacks, one way of proceeding consists in rinsing, which increases the complexity of the operations and decreases their yield.

 In addition, in the case of columns of large diameters, such a DME requires a branching of the specific tubes so that the fronts of the fluids arrive simultaneously at each point of the section.

 These two constraints are very penalizing for the process and lead to devices having complex structures.

 It has been discovered, and this is one of the objects of the present invention, that the abovementioned drawbacks can be remedied by means of a specific arrangement of the mixing and / or injection chambers.

By associating a chamber with a fluid, all the time that the process lasts, for example, by injecting and / or withdrawing from this chamber a first fluid
F1 while another chamber will be used for a second fluid F2, this avoids problems of plugs created by the remainder of the first fluid injected into the conduit connected to the chamber.

 In addition, such an arrangement makes it possible to overcome the problems of length of travel of the various fluids in the devices of the prior art.

 Advantageously, the mixing chambers have dimensions chosen to obtain, at each outlet point of the secondary fluids, substantially identical fluid flow rates.

Thus, the present invention relates to a device for distributing, mixing and extracting several fluids, at least one of the fluids being a main fluid A1, at least one first auxiliary fluid B1 and at least one second auxiliary fluid
B2, said device comprising at least one means for collecting said main fluid A, said means for collecting being connected with at least one mixing chamber by means of, for example, a calibrated orifice, at least one means of introduction and / or extracting the first auxiliary fluid B1 connected to at least one injection and / or withdrawal chamber, at least one means for introducing and / or leaving the second auxiliary fluid B2 connected to at least one d injection and / or withdrawal, said injection and / or withdrawal chambers being in communication with said mixing chamber by means of one or more openings allowing the passage of said auxiliary fluids (B1, B2) in the mixing chamber, said mixing chamber comprising at least one orifice calibrated to allow a mixture to pass through resulting from the interaction between the different fluids in the mixing chamber towards a redistribution space. It is characterized in that each of said conduits connected to said injection and / or withdrawal chambers is connected to a source and / or an enclosure for recovering a single auxiliary fluid.

 In this way, an introduction and / or withdrawal conduit sees the passage of a single fluid during the operation of the process.

 According to one embodiment of the device according to the invention, the dimensions of the injection and / or withdrawal chambers are chosen to ensure a flow rate of the fluids which are substantially identical over all the outlet orifices. For example, the ratio of the developed length of said chambers to the average or equivalent width is preferably less than 30, preferably less than 20 and preferably less than 10.

 The invention also relates to a column comprising, for example, at least a first bed and at least a second bed of granular solids separated from each other by at least one device according to one of claims 1 or 2 in which the collecting means comprises at least one grid substantially in contact with the first bed and the redistribution space is limited by at least one second grid substantially in contact with the second bed.

The present invention also relates to a method for distributing, mixing and extracting several fluids, one of the fluids being a main fluid A1, at least a first auxiliary fluid B1 and at least a second auxiliary fluid
B2, said device comprising at least one means for collecting said main fluid A, said collecting means being in relation to at least one mixing chamber, at least one means for introducing and / or extracting the first auxiliary fluid B1 connected at least one injection and / or withdrawal chamber, at least one means for introducing and / or extracting the second auxiliary fluid
B2 connected to at least one injection and / or withdrawal chamber, said injection and / or withdrawal chambers being in communication with said mixing chamber by means of one or more openings allowing passage said auxiliary fluids (B1, B2) in the mixing chamber, said mixing chamber comprising at least one orifice calibrated to allow a mixture resulting from the interaction between the different fluids in the mixing chamber to pass to a redistribution space.

 It is characterized in that one uses for distributing and / or withdrawing fluids of a different nature from the different means (conduits and / or chambers) affected.

 During the process in a conduit and a distribution and / or withdrawal chamber circulates only one fluid, that is to say that there is no mixture of fluids having different natures.

 This eliminates any risk of pollution due to the presence of plugs and eliminates the preliminary rinsing and or purging of fluid residues.

The present invention thus offers the following advantages - by avoiding injecting fluids of different types into conduits and
in mixing and / or racking chambers, the problems of
plugs existing in the prior art, and thus optimizes the yields of the
process according to the invention, - it is no longer necessary to rinse the lines or conduits to
eliminate plugs, - the isochronicity being perfect, this avoids tubing devices
complex inside the column.

Other advantages and characteristics of the device according to the invention will appear on reading the description given below by way of indication and in no way limitative in relation to the appended drawings in which - FIGS. 1 and 1A show a section along yy a mode of
realization of the device according to the invention and in particular the arrangement of
different chambers in a column, and a section along a plane xx of the
Figure 1, - Figure 2 is a section of another embodiment along a plane xx, and - Figures 3 and 4 show alternative embodiments of the different
injection and / or withdrawal chambers.

 The DME constituted in the figures described below of elements referenced 3, 4, 5, 6, 7, 8 and 9 described in FIG. 1, comprises at least two chambers 5, 6 for injecting and / or withdrawing fluids secondary (B1, B2 ...) placed, for example, on either side of a mixing chamber 7 having, for example, a substantially elongated shape according to a diameter or the largest dimension of the DME.

 The injection and / or withdrawal chambers 5, 6 are provided with one or more orifices 15, 16 allowing the passage of the fluids (withdrawal or injection into the mixing chamber). These orifices are preferably calibrated orifices.

The size and distribution of the orifices 14 for introducing the main fluid A, the orifices 17 for leaving a fluid from the mixing chamber, orifices 15 and 16 are preferably chosen to obtain a pressure drop or loss of pressure and a sufficient speed to generate turbulence in the mixing chamber 7 corresponding to a strong back-mixing and thus obtain better efficiency of the mixing of the main A1 and secondary B1 fluids,
B2. Such an arrangement makes it possible to isolate the mixing chamber 7 from the collection and redistribution spaces.

 Thus, the inlet orifices 14 are series of holes or slots, preferably, regularly spaced to achieve a collection as uniform as possible of the main fluid A1 towards the mixing chamber 7.

 The size and the geometry of these orifices are chosen so that the fluid at the inlet of the mixing chamber has a favorable speed for the creation of turbulence inside the mixing chamber and at the same time to generate a loss of charge to confine turbulence inside the mixing chamber.

 Thus, the spacing between inlet orifices 14 of the fluid A1 is, for example, between 30 and 100 mm and preferably between 40 and 60 mm. The speed of the fluid through the orifices obtained with such a spacing varies for example between 0.3 and 3 m / s, preferably between 0.5 and 2 m / s and preferably between 0.7 and 1.2 m / s. The pressure drop thus generated at the outlet of the orifices is between 10 and 100 g / cm2 and preferably between 30 and 60 g / cm2.

 The outlet orifices 17 for a fluid from the mixing chamber are for example formed by a series of holes or slots, preferably, regularly spaced so as to redistribute the fluid coming from the mixing chamber and, resulting in most cases of mixing at least one main fluid with at least one secondary fluid, as uniformly as possible towards the redistribution space Ed.

 The size of the holes or slots 17 is chosen, for example to generate a certain pressure drop making it possible to confine the turbulence inside the mixing chamber 7, for example a pressure drop of between 10 and 100 g / cm2 and preferably between 30 and 60 g / cm2. This pressure drop value corresponds in particular to a spacing of the holes or slots from 30 to 100 mm and preferably from 40 to 60 mm and to a speed value for the fluid leaving the mixing chamber of between 0.3 and 3 m / s, preferably between 0.5 and 2.0 m / s and preferably between 0.7 and 1.5 m / s.

 In this way, the collection and good distribution of the fluid coming from the mixing chamber and passing into the redistribution space at the grid 9 is optimized.

 The orifices 15, 16 for introducing or withdrawing the secondary fluid are, for example formed by a series of holes, preferably, regularly spaced to inject and / or withdraw the secondary fluid 81, B2 as uniformly as possible towards and / or of the mixing chamber 7. These orifices are, for example, dimensioned so that the linear speed of the fluid injected at the inlet of the mixing chamber is large enough to promote the creation of turbulence in the mixing chamber and to obtain a significant pressure drop enabling the secondary fluid B to be distributed and / or withdrawn as uniformly as possible all along the injection and / or withdrawal chamber.

 The speed of the fluid through the outlet orifices 15, 16 is, for example, between 1 and 15 m / s, preferably between 2 and 10 m / s and preferably between 3 and 4 m / s. The spacing between the holes is chosen, for example between 30 and 100 mm and preferably between 40 and 60 mm. The corresponding pressure drop varies between 100 and 2000 g / cm2 and preferably between 200 and 1000 g / cm2.

 The collection space Ec located under the collection grid 3 has a shape adapted to minimize the dead volumes and the residence times of the fluids. It has a height varying for example from 5 to 50 mm, preferably from 5 to 30 mm and a substantially rectangular or conical shape.

 The Ed redistribution space is, for example, identically designed to minimize dead volumes and turbulence. It has for example a height varying between 5 and 50 mm, preferably between 5 and 30 mm and preferably between 15 and 20 mm and can have any shape, for example rectangular or conical.

 A mixing chamber 7 has for example a substantially elongated shape and preferably rectangular.

 The geometry and dimensions of the injection and / or withdrawal chambers are chosen to ensure a substantially identical flow of fluids over all the outlet orifices. For example, the ratio of the developed length of said chambers to the average or equivalent width being lower to 30 and preferably less than 20, and preferably less than 10.

 Advantageously, the width of the mixing chamber is chosen for example as a function of the value of the speed of one of the auxiliary fluids opening into the mixing chamber so that the auxiliary fluid meets the wall of the mixing chamber situated opposite the wall from which the auxiliary fluid comes. This optimizes the mixing efficiency.

 The collecting means consist for example of a grid 3 delimiting with the mixing chamber and / or the injection and / or withdrawal chambers, a collecting space 4 for the main fluid A1.

 Similarly, the redistribution means comprise for example a grid 9 which delimits with the mixing chamber and / or the injection and / or withdrawal chambers a redistribution space 8 which communicates with the calibrated orifice 17.

 The device is placed in a column of the chromatographic column type 1 consisting of at least two beds 2, 10 separated by the DME.

The two upper and lower beds respectively are made of granular solids.

 According to one embodiment, the assembly constituted by the injection (and / or withdrawal) chambers are preferably attached to either side of the mixing chamber constituting a mechanical assembly of box type of substantially flat shape.

 This box separates for example in whole and practically over the entire section of the column an upper collection space 4, with a redistribution space 8 located at the bottom.

The operation of such a device is for example the following
The main fluid Al circulating in the upper bed 2 is collected as uniformly as possible in the collection space 4 thanks to the grid 3 of substantially planar shape arranged over the entire section of the chromatographic column.

 This fluid is then introduced into the mixing chamber 7 through the calibrated orifices 14, arranged over the entire length of the upper part of the chamber. This arrangement allows uniform introduction into the mixing chamber, while generating turbulence in the mixing chamber, which is beneficial to the efficiency of the mixing.

 The secondary fluid B1 is brought and introduced into the chamber 5 through the tubing 12, then injected into the mixing chamber 7 through the calibrated orifices 15. These calibrated orifices distributed uniformly over the entire length of the chamber allow uniform injection of the fluid B1 in this chamber, the holes being dimensioned to obtain a high injection speed favorable to the efficiency of the mixing with the main fluid A1 by the creation of strong turbulence in a confined space.

 Conversely, the fluid B1 can be withdrawn through the same uniform sampling device in the mixing chamber 7 thanks to the calibrated orifices 15, collection in the chamber 5, then withdrawal of all of the fluid B1 by the tube 12.

 The same description applies for injecting or withdrawing the other secondary fluid B2 by means of the tube 13, the chamber 6 and the orifices 16.

 According to one embodiment, the device of the present invention is, for example, in the form of a substantially flat "pancake" and arranged, for example horizontally, preferably of reduced thickness. The shape can be circular.

 It consists of a box providing both a mechanical support function and a collection and distribution function and / or mixing and / or withdrawal of fluids. This box. can itself be covered over almost its entire upper part by an inlet grid delimiting a collection space on the box, and also covered over its entire lower part by an outlet grid delimiting a redistribution space under the box.

The box comprises for example - a mixing chamber arranged substantially vertically over the entire
height of the box, and arranged horizontally according to a diameter or a
transverse line (Figures 1, 2 and 3). This room divides the box in two
parts substantially equal or not.

- at least two injection and / or withdrawal chambers arranged
horizontally on either side of the mixing chamber, - if there are more than two injection and / or withdrawal chambers, we can
horizontally superimpose several chambers on each side of the
mixing chamber (Figures 3 and 4).

Claims (4)

 1 - Device for distributing, mixing and extracting several fluids, one of the fluids being a main fluid A1, at least a first auxiliary fluid B1 and at least a second auxiliary fluid B2, said device comprising at least one collecting means (3, 4 ) of said main fluid A, said collecting means being in relation to at least one mixing chamber (7), at least one means (12) for introducing and / or extracting the first auxiliary fluid B1 connected to at least one injection and / or withdrawal chamber (5), at least one means (13) for introducing and / or extracting the second auxiliary fluid 82 connected to at least one injection and / or withdrawal chamber ( 6), said injection and / or withdrawal chambers (5, 6) being in communication with said mixing chamber (7) by means of one or more openings allowing the passage of said auxiliary fluids (B1, B2) in the mixing chamber, said mixing chamber (7) comprising at least one orifice this calibrated (17) to allow a mixture resulting from the interaction between the different fluids in the mixing chamber to pass to a redistribution space, characterized in that each of said conduits connected to said injection and / or withdrawal chambers is connected to a source and / or an enclosure for recovering a single auxiliary fluid so as to avoid mixing of fluids having different natures.  2 - Device according to claim 1, characterized in that the dimensions of the injection and / or withdrawal chambers are chosen to ensure a flow of substantially identical fluids on all the outlet orifices, the ratio of the developed length of said chambers to the average or equivalent width being less than 30 and preferably less than 20.  3 - Column comprising at least a first bed and at least a second bed of granular solids separated from each other by at least one device according to one of claims 1 or 2 in which the collecting means comprises at least one grid substantially in contact with the first bed, and the redistribution space is limited by at least one second grid substantially in contact with the second bed.  4 - Method for distributing, mixing and extracting several fluids, one of the fluids being a main fluid Al, at least a first auxiliary fluid B1 and at least a second auxiliary fluid 82, said device comprising at least one collecting means (3, 4 ) of said main fluid A, said collecting means being in relation to at least one mixing chamber (7), at least one means (12) for introducing and / or extracting the first auxiliary fluid B1 connected to at least one injection and / or withdrawal chamber (5), at least one means (13) for introducing and / or extracting the second auxiliary fluid B2 connected to at least one injection and / or withdrawal chamber ( 6), said injection and / or withdrawal chambers (5, 6) being in communication with said mixing chamber (7) by means of one or more openings allowing the passage of said auxiliary fluids (81, 82) in the mixing chamber, said mixing chamber (7) comprising at least one orifice this calibrated (17) to allow a mixture resulting from the interaction between the different fluids in the mixing chamber to pass to a redistribution space, characterized in that it is used to distribute and / or withdraw fluids of a different nature from the means, such said conduits and / or said different injection and / or withdrawal chambers.