JPH0463273B2 - - Google Patents

Description

Detailed Description of the Invention (a) Field of Industrial Application The present invention relates to a fluid flow switching valve in a chromatograph, particularly a gas chromatograph and a liquid chromatograph. The present invention relates to a flow path switching valve used for fluid flow path switching operations such as switching.

(B) Prior Art In high-performance liquid chromatographs, a mobile phase liquid is delivered under high pressure by a pump. The liquid feeding by this pump is performed without being interrupted even when the flow path is changed such as when introducing a sample. Therefore, in conventional flow path switching using a valve, all the flow paths are closed, even temporarily, at the time of switching, so pressure fluctuations at the time of flow path switching cannot be avoided. Moreover, pressure fluctuations during channel switching usually disturb the packing state of the column packing material and accelerate deterioration of the separation column.

For this reason, in conventional flow path switching valves, a bypass flow path was provided between the inlet and outlet of the carrier liquid to alleviate pressure fluctuations when switching the flow path. , the flow of the bypass channel and the flow of the introduced sample merge and are guided to the column, so the flow section of the introduced sample becomes longer compared to the case without the bypass channel,
As a result, the peak width became wider and the resolution decreased. In other words, the more the flow rate in the bypass flow path is increased to suppress pressure fluctuations, the more the peak width becomes wider, and it becomes difficult to distinguish between peaks that appear close to each other, which is a problem.

(c) Purpose The flow path switching valve of the present invention aims to improve a conventional flow path switching valve, such as a six-way switching valve, having a stator portion and a rotor portion. That is, the present invention solves problems such as pressure fluctuations, deterioration of separation columns, and reduction in resolution in conventional flow path switching valves, and is applicable to chromatographs such as gas chromatographs and liquid chromatographs, in particular, The purpose of the present invention is to provide a flow path switching valve that exhibits small pressure fluctuations during flow path switching without reducing the degree of separation of a high performance liquid chromatograph.

(D) Structure The present invention provides a flow path switching valve for a chromatograph having a stator and a rotor, in which a hole connected to a carrier fluid flow path and a hole connected to a flow path to a separation column are connected to the holes, respectively. a stator having arc-shaped grooves extending at a desired length on substantially the same circumference and in the same direction of rotation; and at least two substantially point-symmetric arc-shaped grooves extending in substantially the same circumference as the grooves of the stator. and a rotor having a diametrically extending flow path with a flow path end provided at a position a predetermined distance from the groove end.

In the flow path switching valve of the present invention, for example, in the case of a six-way valve, the holes in the stator are formed on the same circumference at intervals of 60°, passing through the stator from the sliding surface, and the grooves are Formed on the sliding surface.

The holes connecting to the carrier fluid flow path and the holes communicating with the separation column are, for example, provided point-symmetrically on the same circumference. Each of these holes has an arcuate groove of an appropriate length with a center angle of less than 60° extending in the same direction on the same circumference, for example, an arcuate groove with a center angle of 30° and an arcuate length. Connect and set up.

For each of the holes connecting to the carrier fluid flow path and the holes communicating with the separation column, holes that are located next to each other in the same direction of rotation, e.g., holes that are located next to each other in the clockwise direction, have a rotor They communicate with each other through channels formed outside or within the rotor.

In the flow path switching valve of the present invention, the rotor sliding surface has arc-shaped grooves on the same circumference that are point symmetrical with respect to the center so as to overlap the holes and grooves provided in the stator, such as a hexagonal valve. For example, an arc-shaped groove with a center angle of 60° and an arc length is provided. In addition to this groove, the rotor sliding surface also has a groove that passes through the rotor at a position spaced from the groove end by a length equal to the arcuate groove of the stator in the opposite direction to the direction of rotation relative to the stator, for example, at a center angle of 30°. The holes are likewise provided point-symmetrically. These holes communicate with each other by channels formed outside or within the rotor. These holes have a length of a circular arc, for example, with a central angle of 30°, extending in the direction opposite to the direction of rotation with respect to the stator and corresponding to the length of the stator hole spacing minus the length of the stator grooves. The grooves can be connected to each other.

When such holes are not formed in the rotor,
The flow path can be formed by forming a groove passing through the center of the rotor sliding surface.

In the flow path switching valve of the present invention, the hole connecting to the carrier fluid flow path on the stator side and the hole connecting to the flow path to the separation column each have a rotating groove or the like of a rotor engaged with the stator. Arc-shaped grooves of appropriate length extending in the direction of movement are connected, and grooves of appropriate length are also formed on the rotor side to cooperate with the grooves, making it easy to switch the flow path. Even when the rotor is rotated, the grooves in the stator and the grooves on the rotor side are always connected, so the carrier fluid flow path is either a fluid flow path on the stator side or a fluid flow path formed on the rotor side. This allows constant connection to the separation column, thereby avoiding pressure fluctuations. Moreover, since the sample can be introduced at the stage when the carrier fluid flow is flowing through the fluid flow path formed by communicating the holes on the stator side, there is no difference from normal sample introduction, and the band broadening. will not occur. Therefore, the peak width does not widen.

The flow path switching valve of the present invention forms two flow paths by the fluid flow path formed on the stator side and the fluid flow path formed on the rotor side.
For example, it can be used for column switching.

Further, the flow path switching valve of the present invention can of course be used alone as an injector, but at the same time, it can also be used in connection with a pretreatment column.

Furthermore, the sliding surfaces of the stator and rotor are generally circular and planar, but a hollow cylindrical or hollow conical stator may be combined with a cylindrical or conical rotor. The fluid flow paths formed in the stator and rotor may be formed by drilling grooves on the sliding surface, but it is preferable to form them outside the sliding surface by, for example, passing holes through them from leakage etc. .

It is preferable that the size of the hole and the width of the groove are small.

Further, it is preferable that the fluid flow path formed outside the rotor has a low resistance to the liquid.

(E) Examples Hereinafter, embodiments of the fluid flow path switching valve of the present invention will be described with reference to the attached drawings, but the present invention is not limited to the following description. .

For convenience of explanation, all the figures show six-way valves; however, the present invention is not limited to six-way valves, and can be applied to other appropriate valves such as four-way valves, eight-way valves, and others. Not even.

FIGS. 1 and 2 are explanatory diagrams of an embodiment of the fluid flow path switching valve of the present invention, in which the maximum rotation angle of the rotor operation during flow path switching is 60°. FIG. 1 shows its stator section, and FIG. 2 shows its rotor section. 3 to 5 show the sliding surfaces of the stator part and the rotor part during the flow path switching process of the fluid flow path switching valve which is an embodiment of the present invention shown in FIGS. 1 and 2. It is a figure explaining the engagement relationship of the hole and groove of a surface, and the flow condition of the fluid.

In the sliding surface 2 of the stator 1 shown in FIG. 1, the through holes 5, 6, 7, 8, 9 and 10 are formed on the same circumference at intervals of circular arcs with a center angle of about 60°. Among these holes, hole 5 connects to the carrier fluid flow path 20 and hole 8 connects to the carrier fluid flow path 20.
2 to a separation column (not shown). These holes 5 and 8 have arcuate grooves 11 formed on the same circumference as those holes and having an arcuate length with a central angle of about 30° in the forward rotational direction of the rotor.
12 are connected to each other. Also, hole 6 and hole 9
are communicated with each other by, for example, a fluid flow path 21 formed on the outside of the stator.

As the rotor 3 rotates, the sliding surface 4 of the rotor 3 shown in FIG. 17 and 18 are provided.

The through holes 13 and 14 and the grooves 15 and 17 connected to these holes are respectively formed symmetrically with respect to the center point. They are communicated by a fluid flow path 19. Furthermore, the grooves 16 and 18 are formed symmetrically with respect to the center point.

Figures 3 to 5 show the positional relationships and mutual connection relationships of holes, grooves, and flow paths in the stator and rotor, respectively, when the stator shown in Figure 1 and the rotor shown in Figure 2 are combined. In this figure, small circles indicate holes formed in the stator and rotor sliding surfaces, inner arcs indicate grooves in the rotor, and outer arcs indicate grooves in the stator. FIG. 3 shows the positions of the holes and grooves on the sliding surface of the stator and the holes and grooves on the sliding surface of the rotor in the first state of the fluid flow path switching valve of the present invention, for example, the state at the time of sample introduction. , are shown simultaneously and overlappingly.

In this state, the carrier liquid flows through the flow path 2.
0 into the stator hole 5, from the hole 5 via the stator groove 11 and the rotor groove 16, and from the stator hole 6 into a fluid channel filled with a sample, which is used as a sample loop or a precolumn. 21
The sample in the fluid flow path 21 is pushed out through the stator hole 9, through the rotor groove 18 and the stator groove 12, and from the stator hole 8 through the flow path 22 into a separation column (not shown). ) will be introduced.

On the other hand, another liquid, for example, a pre-column mobile phase, enters the stator hole 7 from the flow path 23, passes through the rotor groove 17, hole 14, flow path 19, hole 13, and groove 15 in order, and then enters the stator. It flows out from the hole 10.
However, when the liquid channel 21 is used as a sample loop and a sample introduction section is provided, the hole 23 is sealed.

FIG. 4 shows a state rotated by 30 degrees from the state shown in FIG. It shows the state of engagement between the groove, the hole in the rotor, and the groove.

First, between FIGS. 3 and 4, a groove 1 is connected to a hole 5 in the stator into which the carrier liquid enters.
1 and the groove 16 of the rotor, and connect the hole 5 to the hole 6.
Similarly, the connection between grooves 12 and grooves 18 in the rotor, which connect to holes 8 in the stator that communicate with separation columns (not shown), is maintained regardless of rotation of the rotor, so that the holes 8 is communicated with hole 9, so that the carrier fluid is not blocked. Then, the rotor is rotated to the state shown in FIG. 4, and the rotor hole 13 overlaps the stator hole 5 through which new carrier liquid flows, and similarly, the rotor hole 13 overlaps the stator hole 8 communicating with the separation column. The holes 14 overlap to form the fluid flow path 19 of the rotor.
, which communicates stator holes 5 and 8 such that the carrier liquid entering from channel 20 flows continuously uninterrupted from channel 22 to the separation column.

If the rotor is further rotated by 30 degrees from FIG. 4, the connection state at the stage of injecting the sample in FIG. 5 is reached, but the rotor does not rotate any further.

The grooves 11 connecting to the stator holes 5 into which the carrier liquid enters between FIGS. 4 and 5 are disconnected from the rotor grooves 16 and likewise the separation columns (not shown). ), the connection between the groove 12 of the rotor and the groove 18 of the rotor connected to the hole 8 of the stator, which communicates with the hole 8 of the stator, is broken, but the groove that connects the groove of the rotor with the groove 11 of the stator, which connects to the hole 5 of the stator into which the carrier liquid flows, is removed. 15 continues to connect, and
Since the groove 12 connecting to the hole 8 communicating with the separation column (not shown) remains in contact with the groove 17 of the rotor, the carrier liquid entering from the carrier liquid flow path 20 during this time is transferred from the flow path 22 to the separation column ( (not shown), the sample can be reliably injected into the liquid channel 21 without interrupting the carrier liquid even at the stage of FIG.

6 and 7 are explanatory diagrams of another embodiment of the fluid flow path switching valve of the present invention,
Maximum rotation angle of 60° for rotor operation when switching channels
belongs to. FIG. 6 shows its stator section, and FIG. 7 shows its rotor section.
FIGS. 8 to 10 show the relationship between the stator part, the sliding surface, and the rotor part during the flow path switching process of the fluid flow path switching valve which is an embodiment of the present invention shown in FIGS. 6 and 7. It is a diagram illustrating the engagement relationship between holes and grooves on the moving surfaces and the fluid flow conditions, with small circles indicating holes formed in the stator and rotor sliding surfaces, inner arcs indicating grooves on the rotor, and outer arcs indicating the stator. This shows the groove of the

In the sliding surface 32 of the stator 31 shown in FIG.
0 are formed on the same circumference at intervals of circular arcs with a central angle of about 60°, and among these holes, the hole 35 is connected to the carrier fluid flow path 48,
Bore 38 communicates with a separation column (not shown) via fluid flow path 50. These holes 3
5 and hole 38, on the same circumference as those holes,
Arc-shaped grooves 41 and 42, which are formed to have an arcuate length with a center angle of approximately 30° in the forward rotational direction of the rotor, are connected to each other. The holes 36 and 39 also communicate with each other, for example, by a fluid flow path 49 formed on the outside of the stator.

Through the rotation of the sliding surface 34 of the rotor 33 shown in FIG. 7, through holes 43 and 44 and grooves 45 and 46 are formed on the same circumference so as to overlap the holes and grooves on the stator sliding surface. It is being

The through holes 43 and 44 are formed symmetrically with respect to the center point, and the through holes 43 and 44 are formed symmetrically with respect to the center point.
Both are in communication via a fluid flow path 47 provided outside the rotor. Further, the grooves 45 and 46 are formed symmetrically with respect to the center point.

FIG. 8 shows the positions of the holes and grooves on the sliding surface of the stator and the holes and grooves on the sliding surface of the rotor in the first state of the fluid flow path switching valve of the present invention, for example, the state at the time of sample introduction. , are shown simultaneously and overlappingly.

In this state, the carrier liquid flows through the flow path 4.
8 into the stator hole 35, and from the hole 35 via the stator groove 41 and the rotor groove 45,
From the stator hole 36 enters a fluid channel 49 which is used as a sample loop and is filled with sample;
The sample in this fluid flow path 49 is pushed out, and the sample is passed through the hole 39 of the stator, through the groove 46 of the rotor and the groove 42 of the stator, and from the hole 38 of the stator.
It is introduced into a separation column (not shown) via a flow path 50.

FIG. 9 shows a state rotated by 30 degrees from the state shown in FIG. This shows the engaged state.

First, between FIG. 8 and FIG. 9, the grooves 41 and 45 in the rotor, which connect to the holes 35 in the stator through which the carrier liquid flows, remain connected, making the holes 35 communicate with the holes 36, but again. Similarly, the connection between grooves 42 and grooves 46 in the rotor connecting to holes 38 in the stator communicating with a separation column (not shown) is maintained regardless of rotation of the rotor, connecting holes 38 to holes 39. Since it is communicated, the carrier fluid will not be blocked. Then, the rotor is rotated to the state shown in FIG. 9, and the rotor hole 43 newly overlaps the stator hole 35 into which the carrier liquid flows, and at the same time, the rotor hole 43 overlaps the stator hole 38 communicating with the separation column. The holes 44 of the rotor overlap, and the fluid flow path 47 of the rotor overlaps the hole 35 of the stator.
and 38, so that the carrier liquid entering from channel 48 will continuously flow uninterrupted from channel 50 to the separation column.

If the rotor is further rotated by 30 degrees from FIG. 9, the connected state of FIG. 10 for injecting the sample into the fluid flow path 49 is reached, but the rotor does not rotate any further.

Groove 41 connecting to stator hole 35 into which carrier liquid enters between FIGS. 9 and 10
is disconnected from the rotor groove 45, and the rotor groove 46 is also disconnected from the groove 42, which connects to the stator hole 38 which communicates with the separation column (not shown), but the carrier A groove 4 in the stator that connects to a hole 35 in the stator into which the liquid flows
1 and the rotor flow path continue to be connected, and the groove 42 that connects to the hole 38 communicating with the separation column (not shown) continues to connect to the rotor hole 4.
4, the carrier liquid entering from the carrier liquid flow path 48 continuously flows uninterrupted from the flow path 50 to the separation column (not shown), even during the stage of FIG. Transfer the sample to the liquid flow path 4 without blocking the liquid.
9 can be reliably injected.

FIG. 11 shows another embodiment of the rotor of the fluid valve of the present invention.

In the sliding surface 61 of the rotor 60, through holes 62 and 63 are formed point-symmetrically on the same circumference as the through holes 64 and 65. Through holes 62 and 64 and 63 and 6
5 has a central angle of 60°. The holes 64 and 6
5, in the same direction as the rotational direction of the rotor, respectively.
Arc-shaped grooves 66 and 67 connected to the holes 64 and 65 and having a center angle of 30 degrees are provided on the same circumference. These holes, for example 62 and 64, are communicated with centrally opposed holes 63 and 65, for example, by channels 70 and 71 formed on the outside. Further, an arcuate groove with a center angle of 60° is formed on the same circumference, spaced apart by a center angle of 30° from the grooves and holes.

FIG. 12 shows yet another embodiment of the rotor of the fluid valve of the present invention.

In this embodiment, the sliding surface 7 of the rotor 72
No holes are formed in the rotor 72, and the flow paths of the rotor 72 are all formed by grooves. The sliding surface 73 has a central angle
30° arcuate grooves 74 and 75 are formed on the same circumference in point symmetry with respect to the center, and a groove 78 is formed that connects the ends 79 and 80 of the grooves facing each other on the center line to form a flow path. ing.

Moreover, on the same circumference of the same sliding surface 73, grooves 76 and 77 with a center angle of 60 degrees are formed point-symmetrically with respect to the center, separated by a center angle of 30 degrees from the groove end.

Similarly, the rotors of the embodiments shown in FIGS. 11 and 12 can be combined with the stator to switch the flow paths without causing pressure fluctuations, and can perform sample introduction as usual. There is no such thing as widening.

(f) Effect The present invention provides a hole connecting to the carrier fluid flow path of the stator and a hole connecting to the fluid flow path to the separation column, each of which has a circular arc groove with a center angle of less than 60°, which is identical to the hole. On the other hand, the rotor has a central angle of 60°, for example, to cooperate with this.
Because the arc groove is provided, even if the rotor is rotated during fluid switching, the fluid flows continuously without interruption in the flow path from the carrier fluid flow path inlet to the fluid flow path outlet to the separation column. Therefore, pressure fluctuations caused by blockage of the flow path, etc. do not occur. Therefore, since the packing state of the packing material in the separation column is not changed, deterioration in performance of the separation column can be prevented. Moreover, for example, a loop formed on the outside of the stator can be used as a sample loop or a precolumn. The samples in these loops can be easily guided into the flow paths by switching the flow paths of the valves. Moreover, since the sample does not mix with a branch flow such as a bypass flow, the sample in the flow path is not diluted and the width of the sample band does not become longer. Therefore, the broadening of the peak width that occurs when a branched flow is formed is prevented, and the separation of peaks that occur close to each other is clear. In this way, compared to conventional fluid flow path switching valves, it has many advantages, and in addition, it
Because liquid chromatography and its uses are large,
The impact is huge.

[Brief explanation of drawings]

FIGS. 1 and 2 show one embodiment of the fluid flow path switching valve of the present invention, and FIGS. 3 to 5 are diagrams for explaining the flow path switching process of the valve. FIG. 6 and FIG. 7 show another example of the embodiment of the fluid flow path switching valve of the present invention, and FIGS. 8 to 10 are diagrams for explaining the flow path switching process of the valve. Figures 11 and 12 are
2A and 2B each illustrate another example of a rotor in one of the other embodiments of the present invention. In these figures, 1 and 31
is a stator, and 3, 33, 60 and 72 are rotors. 5 to 10 and 35 to 40
are holes provided in the stator sliding surfaces 2 and 32, and 11, 12, 41, and 42 are grooves similarly formed in the stator sliding surfaces. 13,14,4
3, 44, 62, 63, 64 and 65 are through holes formed in the rotor sliding surface;
7, 18, 45, 46, 66, 67, 68, 6
9, 74, 75, 76, 77 and 78 are grooves formed on the rotor sliding surface. Also, the flow paths 20 and 48 connected to the stator
is a carrier fluid flow path, and similarly, flow path 2
2 and 50 are fluid flow paths connecting to the separation column.

Claims (1)

[Claims] 1. In a flow path switching valve for a chromatograph having a stator and a rotor, from the hole connecting to the carrier fluid flow path and the hole connecting to the flow path to the separation column, the holes are located on approximately the same circumference, respectively. and a stator having arc-shaped grooves that both extend in the same rotational direction and a desired length, at least two substantially point-symmetric arc-shaped grooves that extend around the same circumference as the grooves of the stator, and from the ends of the grooves. 1. A flow path switching valve for a chromatograph, comprising: a rotor having a flow path extending in a diametrical direction and having flow path ends provided at positions separated by a certain length.