JP2019109079A - Liquid mixing apparatus - Google Patents

Abstract

To provide a mixing apparatus in which a part of high density liquid does not remain in the mixing apparatus, air bubble in the liquid is difficult to remain inside, and a pressure drop is small while suppressing production costs.SOLUTION: A mixing apparatus comprises: a first member having a cylindrical concave portion in which an inflow port of liquid is arranged on a side of the concave portion so that an inflow direction is along a bottom surface and a side surface of the concave portion; and a second member having a conical concave portion in which the outflow port of liquid is arranged at the apex of the cone. The first member and the second member are joined so that respective concave portions of them faces each other.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a mixing device for mixing different liquids and a liquid delivery system for a liquid chromatograph in which the mixing device is incorporated in a flow path.

  In liquid chromatographs, mixing devices for uniformly mixing different liquids are used in various situations. For example, mixing eluents of different concentrations or compositions in a controlled ratio and supplying them to a column, mixing concentrated eluents with diluted water online and supplying a prepared eluent to a column, columns The mixing device plays an important role, for example, in a situation where a reaction reagent is mixed with the eluate from the column to cause a post-column reaction. This mixing apparatus includes a dynamic mixer having a movable part such as a stirrer and a static mixer having no movable part. Static mixers are less expensive than dynamic mixers, and have a mixing device (see Patent Document 1, for example) of a type in which the large diameter portion is jetted after reducing the inner diameter of the flow path tube, and a complicated flow path. There is a mixing device (see, for example, Patent Document 2) and the like which imparts a rotational motion to and mixes them.

  However, in the mixing device in which the inner diameter is changed coaxially as described in Patent Document 1, when the large diameter portion is jetted, a part of the liquid having a high density is accumulated at the end portion inside the mixing device When it did not mix, the air bubbles contained in the liquid might be stuck at the end and remain. In addition, in the mixing device as described in Patent Document 2, although the possibility of a part of the dense liquid accumulating in order to impart rotational movement to the liquid is low, the pressure loss is due to the extremely complicated flow path. In some cases, bubbles contained in the liquid may be caught and left in the middle of a complicated flow path.

JP, 2005-69818, A JP 2008-12453 A

  An object of the present invention is to provide a mixing device with a small pressure loss, since a part of the liquid with high density is not accumulated inside the mixing device while the manufacturing cost is suppressed, air bubbles in the liquid are less likely to remain inside. It is.

  In order to solve the above problems, the present inventors focused on the inflow direction and the outflow direction of the liquid, and came to complete the present invention.

That is, the present invention
A first member having a cylindrical recess, and an inflow port provided on the side surface of the recess such that the inflow direction of the liquid is a direction along the bottom surface and the side surface of the recess;
A second member having a conical recess and the liquid outlet provided at the apex of the cone;
The first member and the second member are joined such that their respective concave portions face each other.

  The mixing apparatus of the present invention may be joined between the edge of the recess of the first member and the edge of the recess of the second member via an O-ring. Further, as a bonding mode of the first member and the second member, it is possible to provide a fitting portion for making the concave portions opposite to each other, and a mode of bonding by screwing or clamping.

  In addition, a plurality of mixing devices of the present invention may be used and connected in series in a manner such that the flow inlets of other mixing devices are connected to the flow outlets of the one mixing device.

  Furthermore, an eluent tank is connected to the inflow port in the mixing apparatus of the present invention via a switching valve and / or a flow path, and a liquid transfer pump is connected to the output port to provide a liquid transfer system for liquid chromatograph. Even if a plurality of mixing devices are used as described above, an eluent tank is connected to the inlet of the mixing device at one end via a switching valve and / or a flow path, and the other end is at the other end. A liquid feed pump may be connected to the outlet of the mixing device via a flow path to provide a liquid feed system for liquid chromatograph.

  According to the mixing apparatus of the present invention, the liquid can be efficiently mixed, a part of the liquid with high density is not easily accumulated inside the mixing apparatus, and air bubbles are also less likely to be caught. In addition, the structure is very simple as compared with the conventional mixing apparatus which imparts rotational movement to a liquid, and the manufacturing cost can also be suppressed. Furthermore, the pressure loss is small because a portion with a small flow path diameter and a complicated flow path are not used.

It is the (a) perspective view which represented the internal structure of the mixing apparatus which is one Example of this invention, (b) Top view, (c) It is a side view. BRIEF DESCRIPTION OF THE DRAWINGS In one Example of this invention, the (a) perspective view, the (b) top view, and the (c) side view which represented the internal structure of the mixing apparatus which has two inflow ports. It is a disassembled perspective view of the mixing apparatus which is one Example of this invention. It is the figure which showed the joining aspect of the 1st member and the 2nd member. It is a figure for demonstrating an example of the ion chromatograph system provided with the mixing apparatus of this invention. It is the (a) perspective view which represented the internal structure of the mixing apparatus before reaching this invention, (b) Top view, (c) It is a side view. In the ion chromatograph system provided with the mixing apparatus, it is a comparison figure of the baseline by the difference in the mixing apparatus used.

  Hereinafter, although the ion chromatograph system provided with the mixing apparatus of this invention is demonstrated in detail based on the form represented to drawing, these do not limit this invention.

  Fig.1 (a) is an internal structure perspective view of the mixing apparatus of this invention, FIG.1 (b) is a top view, FIG.1 (c) is a side view. It has an inlet 41 at the side, an outlet 43 at the apex of the cone and an interior space 44 in the shape of a cone. The inflow port 41 is connected such that the inflow direction of the liquid is along the bottom and the side of the internal space 44, whereby the liquid can be given rotational motion. Furthermore, since the liquid comes out from the upper part of the conical shape, it has a structure in which a part of the liquid having a large density is less likely to be accumulated in the internal space.

  Fig.2 (a) is an internal structure perspective view of the mixing apparatus which has two inflow ports in the mixing apparatus of this invention, FIG.2 (b) is a top view, FIG.2 (c) is a side view. The inlets 41 and 42 are both connected in such a way that the inflow direction of the liquid is along the bottom and the side of the internal space 44, and can similarly impart rotational motion to the liquid, thereby Suitable for mixing. Also when mixing three or more types of liquids, three inlets may be similarly provided. It goes without saying that it is possible to mix two or more liquids via the switching valve even if there is only one inlet.

  FIG. 3 is an exploded perspective view of the mixing apparatus of the present invention. The mixing apparatus of the present invention is simply constituted of two parts (a first member and a second member) as shown in the figure, and there is no problem if they are joined in such a manner that their respective recesses face each other. For example, in the embodiment of FIG. 3, the first member is formed with a fitting recess, the second member is formed with a fitting protrusion, and the recess for forming the internal space is the fitting recess, It forms in the convex part, respectively. As described above, since the fitting concave and the convex for each member are formed and fitted into one mixing device, high processing accuracy is not necessary, and the flow path is not complicated. Therefore, it can be understood that the manufacturing cost is not high and the pressure loss is also small.

  As described above, as a bonding mode of the first member and the second member, a concave portion for fitting, a convex portion are formed at a place where there is a concave portion for forming an internal space (see FIG. 4A), etc. In addition, to form a recess and a protrusion for fitting other than the place where there is a recess for forming an internal space (refer to FIG. 4 (b)), provide two or more through holes at a position other than one recess. The other member has a non-through hole aligned with the through hole, and screwing the through hole and the non-through hole (see FIG. 4C), etc. No problem. In addition, as a bonding mode of the first member and the second member, there is no problem even if it is stopped using a screw or a clamp via an O-ring (see FIG. 4D).

  The material of the member is not particularly limited, such as metal or resin, but a chemically inert material is required, and in ion chromatograph using a part of organic solvents such as acetonitrile, polytetrafluoroethylene or poly Chemically inert and highly solvent resistant resins such as ether ether ketones are preferred. The volume of the concave portion is not particularly limited, but in the case where different liquids are repeatedly switched and fed at regular intervals, the volume is preferably about 2 to 3 times the volume of the repetitive volume. The shape of the member is not particularly limited, such as a cylinder, a triangular prism, a quadrangular prism, etc. However, in the case of a shape where the side surface of the member is a curved surface, the vicinity of the inflow port is flat to prevent positional deviation of the liquid inlet during processing. It is preferable to cut it out into a shape.

  FIG. 5 is a diagram in which a plurality of the mixing apparatuses of the present invention shown in FIG. 1 are connected in series and incorporated in an eluent suction channel of an ion chromatograph pump. Because of the low pressure drop, it can be incorporated into the suction channel of the pump.

  Hereinafter, although it demonstrates using an Example, this invention is not limited to this.

  An ion chromatograph system was produced in which two mixing devices according to the present invention shown in FIG. 1 and the mixing device shown in FIG. 6 were respectively incorporated in series into a plunger-type pump suction flow path. The mixing apparatus shown in FIG. 6 has an inlet 41 at the side, an outlet 43 at the top, and an internal space 44 combining three cylindrical shapes. The inlet 41 is connected in the direction of the lowermost cylinder center, so that it is difficult to impart rotational movement to the liquid. The diameter of the bottom of the internal space of the mixing device shown in FIG. 1 is 15 mm, the height is 86 mm, and the internal space volume is 710 μL, and the diameters of the lowermost and uppermost cylinders of the mixing device shown in FIG. Is 6 mm, the central cylinder diameter is 12 mm, the overall height is 11 mm, and the internal space volume is 680 μL.

  FIG. 7 shows the detection of electric conductivity when the 10-fold concentrated eluent and pure water for dilution are alternately switched and sent at a ratio of 1 to 9 for the two solutions at the stroke unit of the plunger pump. Baseline comparison. Specifically, using a plunger-type pump with a volume of 9.4 μL per stroke, the eluent concentrated for 10 strokes for three strokes is pumped to make the liquid pure water for dilution. After switching, 27 strokes of liquid were repeatedly delivered. The 10-fold concentrated eluent used was a mixed aqueous solution of 38 mM sodium bicarbonate and 30 mM sodium carbonate, and the measurement was performed at a flow rate of 1.5 mL / min. The baseline a using the mixing apparatus shown in FIG. 6 clearly shows periodic fluctuation resulting from switching between the 10-fold concentrated eluent and pure water for dilution, and thus mixing is not possible. It is enough. On the other hand, in the baseline b using the mixing apparatus of the present invention shown in FIG. 1, periodic fluctuations due to switching of the 10-fold concentrated eluent and pure water for dilution are almost visible. It turns out that it is gone and it is high mixing efficiency.

10 tank 1 (10 times concentrated eluent)
20 tank 2 (pure water for dilution)
31 Solenoid valve for liquid switching 1
32 Liquid Switching Solenoid Valve 2
40 mixing device 41 inlet 42 separate inlet 43 outlet 44 mixing device internal space 45 fitting part 46 screwing part 47 O ring 50 plunger type pump 60 sampler 70 analysis column 80 suppressor 90 conductivity detector

Claims (7)

A first member having a cylindrical recess, and an inflow port provided on the side surface of the recess such that the inflow direction of the liquid is a direction along the bottom surface and the side surface of the recess;
A second member having a conical recess and the liquid outlet provided at the apex of the cone;
A mixing apparatus characterized in that the first member and the second member are joined such that their respective recesses face each other. The mixing device according to claim 1, wherein an O-ring is joined between an edge of the recess of the first member and an edge of the recess of the second member. The mixing device according to claim 1 or 2, wherein the first member and the second member each have a fitting portion for causing the concave portions to face each other. The mixing apparatus according to any one of claims 1 to 3, wherein the first member and the second member are joined by screwing or clamping. A plurality of mixing devices according to any one of claims 1 to 4, and the mixing devices are connected in series in such a manner that the flow inlets of other mixing devices are connected to the outlet of one mixing device via a flow path. Mixing equipment group. An eluent tank is connected to the inflow port of the mixing apparatus according to any one of claims 1 to 4 through a switching valve and / or a flow path, and a liquid feed pump is connected to the outflow port through the flow path Delivery system for liquid chromatograph. An eluent tank is connected to the inlet of the mixer at one end of the mixer group according to claim 5 via the switching valve and / or the channel, and the outlet of the mixer at the other end is a channel A liquid delivery system for liquid chromatographs, in which a fluid delivery pump is connected via.

Images