MXPA96006062A - Device for mixing fluids at great veloci - Google Patents

Abstract

The present invention relates to a device that allows mixing at least two fluids almost instantaneously, and homogeneously. It carries at least two introduction channels, each having shapes and dimensions adapted to form fluid currents in a flat or sheet form, so as to ensure an almost instantaneous and homogeneous mixture in an area or area limited

Description

DEVICE FOR MIXING FLUIDS AT GREAT SPEED FIELD OF THE INVENTION The present invention relates to a device that allows to mix at least a first and a second fluid almost instantaneously. It especially allows to obtain a homogeneous mixture.

BACKGROUND OF THE INVENTION The present invention advantageously finds its application to mix rapidly and almost instantaneously several fluids which are capable of reacting with each other. The reactions susceptible to occur between different fluids when mixed, can generate corrosive and / or fouling actions on an element with which they are put in contact, for example a wall of a conduit in which it circulates. The term "action" is defined in all that follows in the text as the faculty or capacity that a mixture has to cause deposits and / or corrode an element, the latter could be an installation in which the mixture circulates. REF: 23613 It is preferable to see as indispensable and in certain cases have a dimension for the mixing zone and a mixing duration as small as possible so as to confine the reactions that may occur between the fluids, such as the physical reactions possible chemical An advantageous application of the present device consists in using as an associated laboratory apparatus, for example, an apparatus for studying the kinetics of evolution or change of a mixture of incompatible fluids. The invention finds its application especially in the context of oil production where it is usual to find a reservoir water associated with the oil, and one or several injection waters that serve for the auxiliary recovery of the oil effluent. The contact between these two waters can provoke physicochemical reactions, such as nucleation, germination and growth or increase, which lead to the formation of crystals or deposits which, in the long run, can block the channels in which the mixtures circulate. Therefore, it is important to study the kinetics of formation and evolution or change of such crystals in order to know and anticipate the problems that result and which frequently lead to repairs and costly interruptions of the production facilities. In order to overcome or solve the problems of the interaction of the fluids in the appropriate analytical device, the latter must carry a fluid mixing apparatus or a mixer that allows an almost intact mixture to be obtained. It is thus possible to determine in a precise manner the instant in which the physicochemical reactions between the different fluids can begin. The possible errors that come from physicochemical phenomena that occur before the entry of the fluids or the mixture of fluids in the analysis device can be solved or solved. In all that follows from the description, the expression "incompatible fluids or waters" refers to fluids whose mixing or contacting causes physical or chemical reactions, such as nucleation, germination and growth of the crystals. Devices for mixing various fluids are already known which carry a first tube in which a first fluid flows and in second tube that surrounds the first tube, and concentric with the latter, in which a second fluid circulates. The turbulence phenomena generated by the movement of fluid circulation can lead to the formation of grains or germs that go back along the tubes and that are embedded, for example on the inner wall of the outer or outer tube. The deposits caused on the walls finally obstruct the mixer. Mixers called "countercurrent mixers" are also known which operate on the following principle: the fluids to be mixed circulate in the opposite directions and are in an area called the mixing zone. Nevertheless, at the level of the mixing zone, the deposits can form on the walls of the mixing zone and can block the ducts in which the fluids circulate. Such mixers are not suitable for the mixing of incompatible fluids. The device according to the invention makes it possible to remedy the aforementioned drawbacks and especially to avoid and / or minimize the formation of deposits by effecting a rapid and almost instantaneous mixing of the fluids. It also makes it possible to obtain a homogeneous mixing of the fluids by carrying out or carrying out this mixing in a limited or reduced area. The instantaneous and rapid mixing of the two waters allows to know the precise moment of the formation of the mixture and thus to cross or release the chemical, physical or physicochemical reactions that could arise between the fluids previously to the measurement cell and makes the results of measuring erroneous or inaccurate. One such device or mixer is particularly well adapted to be placed at the entrance of a cell of study of the kinetics of formation of the deposits or of the problems of corrosion that result from the mixing of two incompatible waters. The device intended to mix at least a first and second incompatible fluids, carries an internal part comprising at least a first channel for introducing said first fluid, this first channel communicates with a hole or window located in the lower part of the piece internal, this gap or window has a passage section SI chosen so that the first fluid leaves the hole or window in the form of a first vein or fluid stream in the form of a sheet, the internal part also has a throat located on its wall external or external, this throat has a depth p and a length? g, an outer envelope around the internal part, the outer envelope is provided with at least one introduction hole of the second fluid and the outer envelope is located with respect to the internal part so that the internal wall of the external envelope delimits with the throat a lateral channel of circulation that generates a second vein or current and fluid in the form of a sheet, the two veins or streams of fluids are in an area that allows the confinement of the mixture delimited by the passage section SI, the circulation channel and the internal wall of the outer envelope to form an almost instantaneous and homogeneous mixture. Advantageously, in order to optimize the mixing performance, the exit direction of the first fluid sheet made at an angle O with the exit direction of the second fluid sheet, comprises between 60 and 90 °, and preferably substantially the same at 90 °. The passage section SI is defined by a length L and a height h, the ratio L / h is chosen preferably at least greater than 10. In order to ensure almost instantaneous and homogeneous mixing, the sheets of said first fluid and second fluids preferably have speeds between 0.1 and 5 m / sec. According to one embodiment of the invention, the first channel can be located substantially in the center of the internal part, and in the internal part bring to the level of its lower end an area located between the lower end of the central channel and the recess or window, the shape of the zone is chosen so that the pressure of the sheet of the first fluid is distributed in a substantially homogeneous manner over the passage section SI and so that its speed is substantially homogeneous over the section SI. The lateral channel may have a helical or spiral shape so as to communicate a helical movement to the second fluid, which makes it possible in particular to draw the first fluid. Advantageously, the external part can carry an extension of the shape adapted to maintain or conserve the helical or spiral movement that the mixture of the fluids has at the exit from the mixing zone. The mixer according to the present invention finds particularly its application at the entrance of a device for controlling the kinetics of formation of deposits for a mixture of two incompatible fluids. It especially allows to generate an emulsion from non-miscible fluids. A) Yes, one of the important originalities of the device consists in generating veins or streams of fluids each having a sheet form and mixing these sheets of fluid with a fast enough speed to obtain an almost instantaneous and homogeneous mixture. The arrangement of the circulation channels of two fluids that are to be mixed is chosen so as to obtain sheets of fluid whose directions form an angle that allows an almost instantaneous mixing and optimizes the mixture. The directions of these veins or fluid streams are preferably substantially orthogonal. The second fluid comes out in the form of a helical sheet that drags, after having found it, the sheet of the first fluid in its helical movement in the course of which a vortex effect is created, allowing to concentrate the mixture of the fluids capable of generating deposits towards the center of the spiral and thus, by the acceleration of the fluid and the crystals in the course of the formation, minimize the germination phenomena that lead to the incrustation on the outer elements in the vicinity of the mixing chamber. The invention and its characteristics will be better understood with the reading of the following description, not limiting and illustrated by the figures representing respectively; - Figure 1 shows an overview of the mixing device according to the invention, Figures 2A and 2B respectively show variants of embodiment allowing to obtain several sheets of fluid, Figure 3 shows the use of the device associated with a study cell and for measuring the kinetics of deposit formation, and Figure 4 schematizes another variant of the device of Figure 2 carrying an extension piece.

DETAILED DESCRIPTION OF THE INVENTION The description given hereinafter by way of illustration and in no way limiting, refers to a device adapted to perform a homogeneous mixture of at least two incompatible fluids in a rapid, almost instantaneous manner. For reasons of simplicity, the device is hereinafter referred to as a mixer. Placed, for example, at the entrance of a cell for the study of the kinetics of deposit formation or of the appearance of corrosion phenomena, one of such mixers makes it possible especially to fix in a precise manner the instant in which the mixing is carried out and in this way the instant where the interactions between incom-patible fluids can be initiated.

The mixer of FIG. 1 comprises, for example, an internal part 1 located inside an external envelope or enclosure 2. The internal part 1 can be composed of a first part the substantially cylindrical part comprising a first circulation channel 3 of the first fluid and extended by a second part Ib preferably conical or truncated cone shaped carrying a second flow channel 6 of the second fluid, detailed as described below. The first channel 3 is preferably located along the central axis A of the part of the internal part 1. The second part Ib preferably has a conical shape or a truncated cone shape that will be enlarged when it moves away from the lower end of the mixer to the top of the mixer. It has in its lower part a recess or window 4 communicating with the first channel 3. The opening or recess 4 preferably has a rectangular shape, with a height h and a length L (FIG. 2A), which defines a surface or a step section SI of selected dimension so that the first fluid circulating in the channel 3, ends through the gap or window 4 in the form of a fluid stream having a sheet form. This sheet of fluid arrives on the passage section SI and passes through it with a substantially perpendicular direction. The second part or secondary part Ib also carries on its outer side wall 5 a groove 6 or channel, which preferably has a helical or helical shape, a depth p and a width (FIG. 2B). The throat or throttle 6 extends for example along the entire length of the second part or secondary part Ib. The internal diameter of the outer shell 2 is chosen so that the space confined or delimited by the throat or throttle 6 and the inner wall of the shell or shell, and more particularly the space located in the vicinity of the hole or window 4, called here after the mixing region or zone, is of a limited extent or of reduced dimensions and preferably substantially equal to the three-dimensional space or volume defined by the depth and width of the throat or throttle and the surface of the gap or window. The size or size of the area for effecting or carrying out the mixing thus defined, makes it possible to optimize the mixing of the sheets of the fluids that come respectively from the central channel 3 and from the lateral channel 6, as described immediately after the description . Advantageously, in the lower part of the second part Ib, between the lower end of the flow channel 3 and the opening 4 there is an area 7 whose shape is adapted so that the first fluid leaving the channel 3 passes through this zone 7 and is distributed with a substantially homogeneous pressure on the passage section SI, in the most uniform manner possible. The outer casing 2 is provided with at least one hole 8i for introducing a second fluid to be mixed with the first fluid. The second fluid for the mixer is introduced through an orifice 8i, passes immediately into an annular space 9 formed by the inner wall 10 of the outer shell 2 and the outer wall of the first part la. At the exit from this annular space 9 it penetrates into the channel 11 formed by the groove 6 and the internal wall 10 of the casing 2 located with the remainder of the second part Ib. The shape of the inner wall 10, preferably, it is adapted so that the channel 11 has a substantially constant depth over its entire length and preferably equal to the depth of the throat 6. The channel 11 thus formed has a width and a depth chosen to generate a fluid flow. which has a sheet form of reduced thickness.

The sheet of the second fluid thus formed, or the second sheet circulating in this channel, acquires a helical movement circulating in the throat 6. The second fluid stream thus has an exit direction substantially close to or in the direction of the longitudinal axis of the fluid. the throat as it is specified here later. The longitudinal axis of the throat forms an angle O with a perpendicular to the passage section SI. The value of this angle is chosen so that the first sheet of fluid that opens into the passage section SI or recess 4 and the second sheet of fluid that opens from the side channel, are under an incidence that allows obtaining an almost instantaneous mixture and homogeneous. At the exit of the gap or window 4, the first fluid sheet thus finds the second sheet of fluid in an area called the mixing zone 12 delimited, for example, by the surface of the gap or window 4 and the inner wall of the envelope 2 and that can be extended in the vicinity and preferably below this area. The particular shape of the sheet of the two fluids, the chosen angle QC and the small dimensions of the mixing zone 12 favor the rapidity of mixing of the two fluids and their homogenization. The mixture leaves the mixing space or zone 12 in a helical or spiral form.

In addition, the spiral movement of the second fluid sheet creates a vortex or swirl phenomenon that draws the mixture of fluids and possible crystals into formation path towards the center of the spiral thus created. The acceleration due to the vortex or swirl and the concentration of this mixture, allows minimizing the germination phenomena that could lead to incrustation phenomena on the walls at which contact the mixture can be found. The walls can be those of the devices located after the mixer. The value of the angle, for example, belongs to the range of 60 to 90 ° and, preferably, the angle F 1 is substantially equal to 90 °. The dimensions of the groove 6, that is to say its depth p and its width X-, define with the outer envelope 2 the second lateral outlet channel. They are preferably chosen so that the width / depth ratio J / p varies from 10 to 50, for example by choosing a width between 20 and 40 mm and a depth comprised between 1.5 and 0.3 mm. The choice of these dimensions associated with the arrangement of the outer casing 2 and the part Ib of the internal part allows to generate sheets of fluid, the shape of the sheet allows to optimize the operation of the mixture. The values of the height h of the gap or window 4 and its length L are preferably chosen so that the ratio L / h is at least equal to 10, so that a first fluid stream having a sheet form is obtained. or first sheet. They are chosen in particular so that the first fluid sheet passes through the passage section SI corresponding to the surface of the gap or window 4 with a speed comprised, for example, between 0.1 and 5 m / sec. The high values of the speed, as well as the small dimensions of the passage section SI allow, advantageously to benefit from a self-cleaning phenomenon of the openings. Indeed, any deposits that could have the tendency to form by the contact of the fluids on the walls of the device, are detached by the sheets of fluid, both the first sheet of fluid and the second, thus creating a kind of phenomenon known as "extraction" or "erosion cleaning". The passage section SI of the gap or window 4 is for example substantially equal to 1.2 mi1. Thus for a first and a second fluid introduced in the proportions of 50 cmVmin each, whose total expenditure of 100 cm3 / min., Of such dimensions, leads to a linear velocity for each of the sheets of fluid of approximately 0.7 m / sec. The two sheets of fluid enter the confined mixing space in which they are mixed quickly and almost instantaneously. This procedure improves the homogeneity of the mixture thus formed. For a step section SI of the order of 0.5 mmJ, and for the fluids introduced in proportions identical to those mentioned below, the velocity of the fluid sheets when they penetrate into the mixing zone is substantially equal to 5 m / sec. The gap or window 4 as well as the throat 6 are preferably of reduced dimensions, so as to ensure an instantaneous and as homogeneous mixture as possible of the two fluids. They are carried out, for example, by electroerosion or by any other technique known to the man skilled in the art, which makes it possible to accurately make the openings of the parts of reduced dimensions with edges free of roughness. Advantageously, the sheets of fluid to be mixed are subdivided into several elementary sheets. An example of embodiment of the hollow or window and the throat that allows such a result to be obtained, is given by way of indication and never limiting in Figures 2A and 2B. The first sheet of fluid that comes from the passage section SI can be subdivided into several elementary sheets by placing, for example just before the gap or window 4, an element having a grid or crenellated shape that subdivides the first sheet of fluid into several sections. first elementary sheets of fluid (Figure 2A). According to another variant embodiment, the throat 6 (FIG. 2B) is preferably adapted to also generate several elementary fluid sheets. Thus, it can have walls that allow creating several second elementary plates. The fact of subdividing the sheets and effecting the mixing between several first elementary sheets and second elementary sheets optimizes the mixing of the sheets of fluid and their homogeneity. The zone 7 specially designed to allow a distribution of the fluid pressure over the passage section SI preferably has a substantially trapezoidal shape whose first side corresponds at least to the hollow or window 4. This shape also makes it possible to obtain a speed linear for the first substantially identical sheet of fluid over the entire SI surface. The number of the insertion holes 8i may be greater than two so as to obtain a better distribution of the fluid in the lateral channel. These introduction holes can take various forms such as circular, triangular shapes, ... and be evenly distributed, for example, on the outer envelope. It is also possible to introduce miscible or immiscible fluids, to constitute the second fluid. In the case where the fluids to be mixed are introduced into the mixer in different proportions, the fluid having the smallest expense is preferably sent in the central channel 3 and that of the strongest waste is introduced through the openings 8i. to pass towards the helical channel 11. The helical movement and the important value of the fluid flow that circulates in the lateral channel allows the latter to drag the first fluid that leaves the central channel 3. The different elements of the mixer are made of resistant steel to fluids under pressure that can be aggressive, or even Hastelloy or Uranus as is well known to the person skilled in the art. The conical part Ib of the outer shell 2 can be made separately from Teflon, for example, or from a non-polar material which due to its nature prevents and / or minimizes the formation of fouling deposits in the mixer. One of the advantageous applications of the device consists of placing at the entrance of a study cell the evolution kinetics of the formation of the crystals resulting from the contacting of two incompatible fluids, for example a reservoir water and one or several injection waters, or even a reservoir water with a product, such as a reservoir ihnibidor, or even a reservoir water with an injection water and a reservoir inhibitor. Figure 3 schematizes a mixer 31 substantially identical to that of figure 2 located at the entrance of a device 32 for studying the phenomena of nucleation and germination of crystals that comes from the interaction of a first fluid Fl and a second fluid F2. The mixer 31 for example, is connected to a first source 33 of fluid Fl by a conduit 34 communicating with the central channel 3 of the mixer (figure 1) and a second source 35 of fluid F2 by a line 36 connected to at least one of the holes 8i (figure 1). The second source of fluid can be fed by itself by different sources of fluid Si and of the associated conduits Ci. The conduits 34 and 36 are advantageously provided with the device for regulating and controlling the expense, such as the valves or keys V .., V ~ intended to regulate the quantity of the injected fluids. The mixer 31 is positioned so that it penetrates the study device 32 and communicates in this position with a circulation duct 37 that allows the mixture made in the mixer 31 to pass to the study device 32. The mixture passes through the circulation conduit 37 and leaves the device 32 through an evacuation conduit 38. The device 32 can also be equipped with means 39 for controlling and adjusting the pressure and the temperature., to determine and control the thermodynamic parameters of the study of crystal formation. It can also carry any other device necessary to study the evolution of the mixture over time. These means can be placed in several places of the device, which are chosen according to the analysis that is desired. An example of operation for one of such devices consists in sending the first fluid to channel 3 under a flow rate of 50 cm3 / min and in a ratio of 50/50 and the second fluid to the lateral heli-coidal channel shown on the figure 2 through an orifice 8i with an expenditure of the order of 50 cm3 / min and a ratio of 50/50. According to the description given in relation to Figure 1 and under such conditions, the mixture obtained in the mixing zone 12 of the mixer 31 leaves the latter in the form of a spiral with a speed of approximately 0.7 m / sec to penetrate in the conduit 37. Due to the vortex or swirl, the mixture of the two fluids is concentrated in the center of the spiral as indicated above. This concentration decreases the likelihood of the mixture meeting the wall of the circulation conduit 37 and prevents crystalline germination on the walls before or at the entrance of the study device. In this way, the initial moment of study of the formation of the crystals can be precisely determined and the measurement errors generated by the phenomena that may arise prior to the device are minimized. The instantaneous or almost instantaneous mixing speed contributes to improve the precision of the measurements, especially delimiting the moment of the beginning of the possible reactions. Furthermore, the mixing speed at the outlet of the mixer has a speed at least higher than the speed it acquires circulating in the duct 37. The existing speed difference helps to prevent the formation of germs at the level of the walls of the circulation duct 37 and the rise of possible germs at the level of the hole or window 4 of the mixer (figure 1). Advantageously, the values of the flow rate and the quantity of each of the fluids introduced at the inlet of the mixer and fixed by the valves V .., V "are found to be substantially identical to the output of the mixer. One such mixer can be advantageously placed at the entrance of an inhibitor study device such as that described in the patent application EP 033,557. According to a preferred mode of the mixer described in FIG. 4, the part 2 carries an extension 41. It is placed, for example, after the mixing zone 12 (FIG. 1) at the level of the lower end of the mixer. The inner wall 42 of the extension 41 has a shape adapted to preserve the helical movement of the mixture at the exit of the mixer, especially the vortex or swirl effect that allows to concentrate the mixture of the fluids in the center of the spiral or propeller so as to minimize the probability of contact of the mixture reacting on the walls of the conduit 37 (Figure 3) with which it is in communication as described above. This shape is to be enlarged, for example, from the lower extremity of the mixer. The expression "reaction mixture" contemplates or encompasses a mixture of fluid that can introduce corrosion and / or fouling actions. An interesting application of the invention consists in mixing at least one inhibitor that comes from a Si source with a fluid that plays the role of carrier vector that comes from another source Si. By carrier vector it is understood that the carrier fluid to which the inhibitor is mixed, does not interact by itself. The inhibitor must react only with the first fluid exiting the first source which is injected, for example, through the central channel of the mixer. One such way of proceeding allows to optimize the mixing of the fluids and to ensure that the action of the inhibitor starts in the device for studying the kinetics and passes to the outside of the study device. The instant of the formation of the mixture is thus known precisely, this instant of the mixture corresponds especially to the moment where the inhibitor begins to react. The precision of the measurements is thus increased since the inhibitor does not act on the mixture only when the latter is inside the device 32. In the context of oil production, for example, the use of one of such mixers allows introduce an inhibitor at the moment where organic crystals, minerals or even hydrates, begin to form for example. Without going outside the scope of the invention, it is also possible to use this type of device in the framework of treatment of industrial and domestic water, for example in the most particular domain of geothermal energy. Advantageously, the device is used to produce an emulsion in the defined proportions, especially an emulsion made from non-miscible fluids. In fact, the fact that the mixture in the mixer is effected almost instantaneously and at high speeds "creates" the emulsion. It is also possible to easily make a water-in-oil or oil-in-water emulsion.

It is noted that in relation to this date the best method known by the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Having described the invention as above, property is claimed as contained in the following

Claims (9)

R E I V I N D I C A C I O N S

1. A device designed to mix at least a first and a second incompatible fluid, characterized in that it carries an internal part comprising at least a first channel for introducing said first fluid, the first channel communicates with a hole or window located in the lower part of the internal part, the gap or window has a passage section SI chosen so that the first fluid leaves this hole or window in the form of a first fluid stream in the form of a sheet, the inner part bears also a throat located on its outer wall, the throat has a depth p and a length%, an outer envelope around the internal part, the outer shell is provided with at least one introduction hole of the second fluid and the outer shell is located with respect to the internal part so that the internal wall of the external envelope delimits with the throat a lateral channel of circulation that generates a sec In the case of a fluid stream in the form of a sheet, the two fluid streams are in a mixing zone delimited by the passage section SI, the circulation channel and the inner wall of the external envelope to form an almost instantaneous mixture and homogeneous

2. The device according to claim 1, characterized in that the outlet direction of the first fluid sheet forms an angle O with the outlet direction of the second fluid sheet, comprised between 60 and 90 °, and preferably substantially equal to 90 °.

3. The mixing device according to claims 1 and 2, characterized in that the passage section SI is defined by a length L and a height h and the ratio L / h is at least greater than 10.

4. The device according to one of the preceding claims, characterized in that the sheets of the first and second fluids have speeds between 0.1 and 5 m / sec.

5. The mixing device according to claim 1, characterized in that the first channel is located substantially in the center of the internal part, and in that the internal part brings to the level of its lower end an area located between the lower end of the central channel and the gap or window, the shape of the zone is chosen so that the pressure of the sheet of the first fluid is distributed in a substantially homogeneous manner over the passage section SI and so that its speed is substantially homogeneous over the section SI.

6. The mixing device according to claim 1, characterized in that the side channel has a helical or spiral shape, so as to communicate a helical movement to the second fluid.

7. The device according to one of the preceding claims, characterized in that the external part has an extension of shape adapted to preserve the helical or spiral movement that has the mixture of the fluids at the exit of the mixing zone.

8. The mixing device according to one of the preceding claims, characterized in that it is placed at the entrance of a device for controlling the kinetics of formation of deposits for a mixing of the two incompatible fluids.

9. The use of a device according to one of the preceding claims, for generating an emulsion from the immiscible fluids.