FR2784039A1 - PROCESS AND DEVICE FOR PREPARING A SOLUTION OF AT LEAST ONE POWDER PRODUCT IN A LIQUID FLUID - Google Patents

Abstract

The present invention relates to methods and devices for preparing a solution of at least one powdered product in a liquid fluid. The method and the device according to the invention are essentially characterized by the fact that in a first phase, a determined quantity of powdered product is dissolved in a dissolution volume 13 by means of a dissolution liquid coming from a source 8. to obtain an intermediate solution, in a second phase, a determined quantity of the intermediate solution is introduced into a volume of mixture 1 by means of a positive displacement pump 17, with a given quantity of the liquid fluid by the pump 22 to obtain a mixture primary of the intermediate solution and of the liquid fluid, in a third phase, the primary mixture is circulated in a loop circuit 100 to obtain a final mixture, and in a fourth phase, at least part of the final mixture is diverted to a volume of use 24, this part of the derivative final mixture constituting the solution to be obtained. Application, in particular, to the preparation of solutions for carrying out dialysis.

Description

METHOD AND DEVICE FOR PREPARING A SOLUTION

  AT LEAST ONE POWDERED PRODUCT IN A LIQUID FLUID

  The present invention relates to methods for preparing a solution of at least one powdered product in a liquid fluid, as well as to the arrangements

  Tives making it possible to obtain such a solution which find a particularly advantageous application for the preparation of a medical solution for dialysis.

  It is already known processes for preparing a solution of at least one powdered product in a liquid fluid, as well as devices making it possible to obtain such a solution which find application, in particular, in the medical field for preparing solutions for dialysis.10 However, all the methods and devices of this type currently known are not entirely satisfactory because either they are very complex and therefore of a very high cost price, or else too simple to offer reliability and the precision which is desirable in the medical field, in particular that of dialysis. The aim of the present invention is therefore to implement a process for the preparation of a solution of at least one powdered product in a fluid.

  liquid, and to produce a device making it possible to obtain a solution according to the method, finding an advantageous application in the medical field for preparing a solution for dialysis, which overcomes the drawbacks mentioned above of the methods and devices of the prior art.

  More specifically, the subject of the present invention is a process for preparing a solution of at least one powdered product in a liquid fluid, characterized in that it consists: - in a first phase, in dissolving said product in powder in a volume of dissolution by means of a liquid of dissolution to obtain an intermediate solution, - in a second phase, to send a determined quantity of the intermediate solution in a volume of mixture with a given quantity of the liquid fluid to obtain a primary mixture of the intermediate solution and the liquid fluid, - in a third phase, to circulate in a loop said primary mixture to obtain a final mixture, and - in a fourth phase, to derive at least part of the final mixture to a use volume, this part of the final mixture derived in the use volume constituting the solution to be obtained. The present invention also relates to a device making it possible to prepare a solution of at least one powdered product in a liquid fluid, characterized in that it comprises: - a loop circuit comprising a mixing volume comprising three first, second and third inlet ports, a first conduit connecting the first and second inlet ports, a first controllable valve mounted in series in the first conduit upstream from the first inlet port, and a first positive displacement pump mounted in series in the first conduit, - a circuit for supplying dissolving liquid comprising a source capable of delivering, on a first outlet, dissolving liquid, a second conduit connecting the first outlet to a first point of the first conduit, this first point being located between the first controllable valve and the second inlet mouth, and a second controllable valve mounted in series in the second th conduit, - a powder product supply circuit comprising a source of powder product comprising a second outlet, a third conduit connecting the second outlet to a second point of the first conduit, this second point being located between the first controllable valve and the second inlet mouth, a second positive displacement pump and a third controllable valve mounted in series on the third conduit, a liquid fluid supply circuit comprising a source capable of delivering, on a third outlet, the liquid fluid, a fourth conduit connecting the third outlet to the third inlet mouth of the volume of

  mixture, a third positive displacement pump and a fourth controllable valve connected in series in the fourth conduit, and - a circuit of use comprising a volume of sampling of the solu-

  tion to be obtained comprising a supply inlet, a fifth duct connecting a third point of the first duct to the supply inlet of the

  sampling volume, this third point being located between the first controllable valve and the second inlet mouth, and a fifth valve comprising

  mandable mounted in series in the fifth conduit.

  The present invention also relates to a device making it possible to prepare

  a solution of several powdered salts, namely calcium, potassium, magnesium and sodium salts, in a liquid fluid such as

acetic acid.

  Other characteristics and advantages of the present invention appear

  tront during the following description given with regard to the drawings an-

  set for illustrative purposes, but in no way limiting, in which: FIG. 1 represents the block diagram of a device according to the invention making it possible to prepare a solution of at least one powdered product in a liquid fluid, and FIG. 2 shows the block diagram of a device according to the invention for preparing a solution of several products such as powdered salts in a liquid fluid such as acetic acid, for a

  application to the production of a medical solution for dialysis.

  Although the two figures represent two different embodiments of a device according to the invention, the same references designate the same there

  elements whatever the figure on which they appear.

  The Applicant wishes to specify that the two figures represent two embodiments of the object according to the invention, but that there may be

  other embodiments that meet the definition of this invention.

  It also specifies that, when, according to the definition of the invention, the object of the invention comprises "at least one" element having a given function, the

  described embodiment can include several of these elements.

  It also specifies that, if the embodiment of the object according to the invention as illustrated comprises several elements of identical function and

  that if, in the description, it is not specified that the object according to this invention

  tion must necessarily include a particular number of these elements, the subject of the invention may be defined as comprising "at least one" of

these elements.

  The present invention relates to a method for preparing a solution

  at least one powdered product in a liquid fluid, which comprises the qua-

three next phases.

  In a first phase, the powdered product is dissolved in a dissolution volume by means of a dissolution liquid to obtain an intermediate solution.

  In a second phase, a determined quantity of the inter-

  medium is sent into a mixing volume with a given quantity of the liquid fluid to obtain a primary mixture of the intermediate solution and

liquid fluid.

  In a third phase, the method consists in circulating in a loop the

  primary mixture to obtain a final mixture.

  Finally, in a fourth phase, at least part of the final mixture is derived towards a use volume, this part of the final mixture derived

  in the volume of use constituting the solution sought for a use

  given position, for example in the medical field for carrying out dialysis. The method described above is advantageously implemented by means of a device like that which is shown diagrammatically in FIG. 1. The device schematically illustrated in FIG. 1 comprises a circuit

  loop 100, a dissolving liquid supply circuit 200, a circuit

  baked powder product supply 300, a supply circuit

  liquid fluid 400 and a usage circuit 500.

  The loop circuit 100 comprises a mixing volume 1 comprising

  three first 2, second 3 and third 4 inlet ports, a first con-

  duit 5 connecting the first 2 and second 3 inlet ports, a first controllable valve 6 mounted in series in the first conduit 5 upstream of the first inlet mouth 2, and a first positive displacement pump 7 mounted

in series in this first conduit.

  The dissolving liquid supply circuit 200 comprises a source 8 capable of delivering dissolving liquid to a first outlet 9, a

  second conduit 10 connecting the first outlet 9 to a first point 11 of the first

  mier conduit 5, this first point 1 l being located between the first valve

  mandable 6 and the second inlet mouth 3, and a second control valve

  dable 12 mounted in series in the second conduit 10.

  The powder product supply circuit 300 comprises a source of

  powder product 13 comprising a second outlet 14, a third con

  duit 15 connecting the second outlet 14 to a second point 16 of the first

  duit 5, this second point 16 being located between the first controllable valve 6 and the second inlet mouth 3, a second positive displacement pump 17 and a third controllable valve 18 mounted in series on the third conduit 15. The power supply circuit liquid fluid 400 includes a source 19

  able to deliver the liquid fluid to a third outlet 20, a fourth

  duit 21 connecting this third outlet to the third inlet mouth 4 of the mixer volume 1, a third positive displacement pump 22 and a fourth

  controllable valve 23 mounted in series in the fourth conduit. As for the use circuit 500, it comprises a use volume 24 of the desired solution comprising a supply inlet 25, a cin-

  quieme conduit 26 connecting a third point 27 of the first conduit 5 to the supply inlet 25 of the sampling volume 24, this third point 27 being located between the first controllable valve 6 and the second inlet mouth 3, and a fifth controllable valve 28 fitted in series in the

  fifth conduit 26.10 It is clearly specified that, in the context of this description, the expression

  "positive displacement pump" designates any means which makes it possible, following a determined command order, to circulate, in a conduit, a quantity of fluid with a perfectly determined flow rate. In addition, depending on the order, the fluid can be circulated in the conduit, in one direction or in the other. A special value of this control order is even provided so that the positive displacement pump prevents the circulation of the fluid at the

  less in a way. As for the valves, they can be of all types, for example of the tap, valve, etc. type, all of which can be controlled by any means, for example using

electromagnetic control.

  These means are well known in themselves and, for the sole purpose of simplifying the present description, they will therefore not be more fully

  described here. In a preferred embodiment, the device further comprises means 30 capable of delivering a first signal whose value is representative of the concentration of the product dissolved in the intermediate solution

  flowing in the third conduit 15. These means 30 comprise for example a conductivity sensor, for example an electrical Wheatstone bridge, one of the four branches of which is mounted in the conduit 15 in contact with the fluid which can circulate there.

  For use in automatic mode, the device further comprises means 31 for delivering a second signal representative of the temperature

  dissolving liquid, for example a temperature sensor such as a thermistor or the like situated in contact with the dissolving liquid in the source 8 or in the second conduit 10.

  As mentioned above, the device can operate almost automatically. To this end, it comprises a processing member 40 of the microprocessor type or the like which includes outputs 41, respectively for controlling the first, second and third positive displacement pumps and the first, second, third, fourth and fifth controllable valves, and inputs 42 for receiving and processing the first and second signals defined above. 05 This processing member 40 is programmed to develop command signals for controlling the positive displacement pumps and the controllable valves.

  according to a process determined according to the needs of the users of the solution obtained in the use volume 24, as described below. A person skilled in the art will easily know how to program this processing member 40 according to the structural description given above and the functional description given below.

  The device described above works and is used in the following way: It is first of all assumed that all of the controllable valves are in their closed state and that the positive displacement pumps are stopped. The dissolution volume 13 contains a determined quantity of powdered product, such as a salt or the like, soluble in the dissolution liquid, such as water, which is capable of being delivered to the outlet 9 of the source 8. The control unit 40 can be programmed to carry out the following orders: Firstly, the controllable valves 12 and 18 are open and the positive displacement pump 17 is controlled to draw up a determined quantity of dissolution liquid, from the source 8 in the dissolution volume 13 via the conduits 10, 5 (in part) and 15. As soon as the entire quantity of powdered product is dissolved, that is to say

  as soon as the intermediate solution defined above in the process is obtained, the controllable valve 12 is closed and the controllable valve 6 is open.

  At this instant, the positive displacement pump 17 is controlled to send, into the mixing volume 1, a determined quantity of this inter-solution.

  medial via conduits 15 and 5 (in part) .30 Then, the controllable valve 23 is open and the positive displacement pump 22 is controlled to send, in the mixing volume 1, an amount of

  liquid fluid determined in correlation with the quantity of intermediate solution which was sent into this volume of mixture by the positive displacement pump 17, to obtain in this volume of mixture, the primary mixture defined above

before in the process.

  In fact, knowing the concentration Cs of the powdered product dissolved in the intermediate solution and the volume V of the quantity of this solution introduced into the mixing volume, the processing member 40 determines the actual quantity Qr of powdered product present in this volume of mixing,

  according to the relationship Qr = V.Cs. Knowing this quantity Qr of product in

  dre and the concentration of the liquid fluid delivered to the outlet 20, the processing member

  40 can control the positive displacement pump 22 to introduce into the mixing volume 1, a quantity of liquid fluid correlated with the quantity Qr of powder product defined above, to obtain the mixture

primary desired.

  When this primary mixture is obtained, all the controllable valves

  except the valve 6 and the positive displacement pump 7 are closed

  o commissioned to obtain a loop circulation in circuit 100.

  The positive displacement pump 7 is controlled until the concentration of the mixture in the loop circuit 100 is constant. This concentration can be controlled by a concentration detector placed on the conduit 5 to

  the outlet 3 of the mixing volume, as shown at 70 in FIG. 2.

  When the concentration of the mixture is constant, the mixture obtained is the

final mixture defined above.

  The controllable valve 28 is then open and the controllable valve 6 is closed, the positive displacement pump 7 being kept in operation. In this way, the final mixture circulating in the conduit 5 is diverted to the use volume 24, to fill it with a quantity determined according to a

  order received by the positive displacement pump 7.

  When the operating volume 24 contains the desired quantity of final mixture, the device is reset to its initial state as defined above in order to be able to operate again as described above, it being understood that the filling of the operating volume 24 can be performed several times until

  exhaustion of the quantity of final mixture contained in the volume of mixture 1.

  The device described above finds a particularly advantageous application for the preparation of solutions for dialysis. A more suitable system

  particularly intended for use in this application is schematically illustrated in FIG. 2.

  This device comprises, like that illustrated in FIG. 1, a loop circuit 100, a circuit for supplying dissolving liquid 200, a circuit

  powder product supply 300, a liquid fluid supply circuit 400 and a use circuit 500.

  However, in the application defined above, the dissolving liquid supply circuit 200 comprises a source 8 capable of delivering, on the

  first outlet 9, pure water and at PH 7.

  The powder product supply circuit 300 comprises four primary supply circuits 300 / 1-4 mounted in parallel and all connected to the conduit 5, for example at the same point 16 defined above. These four primary supply circuits each comprise a dissolution volume 13 each containing a powdered product, respectively a calcium salt (Ca), a magnesium salt (Mg), a potassium salt

(K) and a sodium salt (Na).

  In a possibility due to the particular nature of the sodium salts, the dissolution volume 13 which is associated with them can be connected, at its upper level 10, by another second conduit 10 ′, to another outlet 99 from the source 8 of dissolving liquid, to be able to introduce water according to a

  specific process. In addition, the liquid fluid supply circuit 400 is a supply circuit for acetic acid, for example from the so-called "25%" trade.

  Advantageously, the device according to the invention may also include means 50 for purging at least the five conduits 5, 10, 15, 21, 26. This

  embodiment illustrated in FIG. 2 shows the possibilities of purging the lines 5, 10, 15, 21 and 26, but also volumes 1 and 24, valves 30, etc. These purge means possibly comprise a buffer volume 51 per-20 putting, if necessary, to store the residues of the purges and their evacuation by the outlet 52 towards the regulatory elimination means.

  The device may also include means 60 for detecting the minimum level of security of the solution in the use volume 24 so as to

  ability to re-order filling.

Claims (6)

  1- Method for preparing a solution of at least one powdered product in a liquid fluid, characterized by the fact that it consists: - in a first phase, of dissolving said powdered product in a volume of dissolution (13) by means of a dissolution liquid to obtain an intermediate solution, - in a second phase, to send a determined quantity of the intermediate solution in a volume of mixture (1) with a given quantity of liquid fluid to obtain a primary mixture of the intermediate solution and the liquid fluid, in a third phase, circulating in loop (100) said primary mixture to obtain a final mixture, and   - in a fourth phase, to divert at least part of the final mixture to a use volume (24), this part of the final mixture   vee in the volume of use constituting the solution to be obtained. 15 2Device making it possible to prepare a solution of at least one powdered product in a liquid fluid, characterized by the fact that it comprises: * a loop circuit (100) comprising: - a mixing volume (1) comprising three first (2), second (3) and third (4) inlet openings, - a first conduit (5) connecting the first (2) and second (3) inlet openings , - a first controllable valve (6) mounted in series in the first duct (5) upstream of the first inlet mouth (2), and - a first positive displacement pump (7) mounted in series in the first duct (5 ), * a dissolving liquid supply circuit (200) comprising: - a source (8) capable of delivering dissolving liquid to a first outlet (9), - a second conduit (10) connecting the first outlet ( 9) at a first point (11) of the first conduit (5), this first point (11) being located between the first re controllable valve (6) and the second inlet mouth (3), and - a second controllable valve (12) mounted in series in the second conduit (10), * a powder product supply circuit (300) comprising: - a source of powdered product (13) comprising a second outlet (14), - a third conduit (15) connecting the second outlet (14) to a second point (16) of the first conduit (5), this second point (16) being located between the   first controllable valve (6) and second inlet mouth (3), and a second positive displacement pump (17) and a third control valve   dable (18) mounted in series on the third conduit (15), * a liquid fluid supply circuit (400) comprising: - a source (19) capable of delivering the liquid fluid to a third outlet (20), - a fourth conduit (21) connecting the third outlet (20) to the third inlet mouth (4) of the mixture volume (1), and - a third positive displacement pump (22) and a fourth controllable valve (23) connected in series in the fourth conduit, and * a use circuit (500) comprising: - a use volume (24) capable of containing the solution to be obtained, comprising a supply inlet (25),   a fifth conduit (26) connecting a third point (27) of the first conduit (5) to the supply inlet (25) of the use volume (24), this third   the fifth point (27) being located between the first controllable valve (6) and the second inlet mouth (3), and   - a fifth controllable valve (28) mounted in series in the fifth conduit (26).   3- Device according to claim 2, characterized in that it further comprises means (30) capable of delivering a first representative signal   the concentration of the product dissolved in the solution flowing in the third conduit (15).   4- Device according to claim 3, characterized in that the means (30) capable of delivering a first signal representative of the concentra-   tion of the product dissolved in the solution flowing in the third conduit30 (15) comprise at least one conductivity sensor.   - Device according to one of claims 2 to 4, characterized by the fact that it comprises means (31) for delivering a second signal representative of   the temperature of the dissolution liquid. 6- Device according to claims 4 and 5, characterized in that it   comprises a processing member (40) comprising outputs (41), respectively for controlling the first (7), second (17) and third (22) positive displacement pumps and the first (6), second (12), third (18), fourth (23) and fifth (28) controllable valves, and inputs (42) to receive I! and processing the first and second signals, said processing member (40) being   able to develop command signals for controlling according to a determined process said positive displacement pumps and controllable valves for preparing said solution. 05 7- Device according to one of claims 2 to 6, characterized by the fact that it comprises means (50 ) to purge at least the five conduits (5, 10, , 21, 26).   8- Device according to one of claims 2 to 7, characterized in that it comprises means (60) for detecting a level of fluid in the volume of use (24).   9- Device according to one of claims 2 to 8, characterized in that it further comprises means (70) for determining the concentration of   the solution flowing in the first conduit (5). 10- Device for preparing a medical solution for dialysis, characterized in that it comprises: * a loop circuit (100) comprising: - a volume of mixture (1) comprising three first (2), second (3) and third (4) inlet ports, - a first conduit (5) connecting the first (2) and second (3) inlet ports, - a first controllable valve (6) mounted in series in the first conduit (5 ) upstream of the first inlet mouth (2), and - a first positive displacement pump (7) mounted in series in the first conduit (5), * a circuit for supplying dissolving liquid (200) comprising: - a source (8) capable of delivering water to a first outlet (9), - a second conduit (10) connecting the first outlet (9) to a first point (11) of the first conduit (5), this first point (11) being located between the first controllable valve (6) and the second inlet mouth (3), and - a second controllable valve (12) mounted in series in the second conduit (10), * supply circuits for four powder products (300), respectively a calcium salt, a magnesium salt, a potassium salt and a sodium salt, each supply circuit including: 35 - a source of one of the four powdered products (13), said source comprising a second outlet (14), - a third conduit (15) connecting the second outlet (14) to a second point (16) of the first conduit (5), this second point (16) being located between the first controllable valve (6) and the second inlet mouth (3), and - a second positive displacement pump (17) and a third controllable valve (18) mounted in series on the third conduit (15), * an acetic acid supply circuit (400) comprising: - a source (19) capable of delivering acetic acid to a third outlet (20), a fourth conduit (21) connecting the third outlet (20) to the third inlet mouth (4) of the mixing volume (1), and   - a third positive displacement pump (22) and a fourth control valve   lo dable (23) mounted in series in the fourth conduit (21), and * a use circuit (500) comprising: - a use volume (24) capable of containing the dialysis solution, comprising an inlet for supply (25), - a fifth conduit (26) connecting a third point (27) of the first pipe (5) to the supply inlet (25) of the use volume (24), this third   point (27) being located between the first controllable valve (6) and the second inlet mouth (3), and - a fifth controllable valve (28) mounted in series in the cin- quième conduit (26).