JPS6317503B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a rotating joint that is effective for use in a device that separates polymeric liquids using a centrifugal force field.

[Prior Art] Recently, a method called FFF (Field Flow Fractionation) has been proposed, which allows separation of polymer solutions with a molecular weight of 10 ⁴ or more. This FFF is a process in which the liquid to be separated is allowed to flow at a constant flow rate in a thin channel (groove), and an external field is applied from a direction perpendicular to the channel, and the solute is separated by the force of that field. is pressed against the wall of the passageway, and particles (solutes) in the solution are separated by utilizing the fact that the pressing force differs depending on the mass of the solute. Forces, thermal gradients, electric fields, etc. have been proposed. Among these, the most popular type is one that utilizes centrifugal force, the structure of which is shown in Figure 2. That is, the rotating shaft 1
A thin cylindrical separation groove 3 concentric with the center of rotation is formed on the outer periphery of the rotating body 2 fixed to the rotating body 2, and while the front part of the rotating body is rotated at high speed by a motor 4, the sample and developing solution are passed through the pipe 5. If introduced into the separation groove 3 at a relatively slow speed, the introduced liquid will be gradually separated by the centrifugal force caused by the high speed rotation of the rotating body, and will be sent to a detection system (not shown) via the pipe 6. A chromatogram is obtained. In addition, in the figure, 7
Numerals a and 7b are bearings for rotatably attaching the rotating shaft 1 to the housing 8.

[Problems to be Solved by the Invention] In such an apparatus, a rotating joint is required because the sample and developing solution must be introduced into and discharged from the separation groove of the rotating body that rotates at high speed. It's coming. Therefore, conventionally, as shown in the figure, a double tube 11 consisting of an outer tube 9 and an inner tube 10 fixed to a housing 8 is inserted into the rotating shaft 1 through bearings 12a and 12b so as to be concentric with the center of rotation. Place it in
Outer tube 9 is secured by O-ring packing 13a, 13b.
A rotary joint is used in which the pipe 5 is connected to the narrow passage 14 between the inner tube 10 and the inner tube 10, and the pipe 6 is separately connected to the inner tube 10.

However, due to the O-ring packing, 2
In a rotating joint that forms two separation areas (passages), it is not possible to maintain a high sealing pressure, so liquid leakage is likely to occur.
The sealing member wears out relatively quickly, and the rotational speed is limited to a few thousand rpm at most. Therefore, it is not possible to apply a very large centrifugal force field to the sample, making it impossible to increase the flow rate of the liquid.
Analysis time becomes longer.

In view of the above problems, one side is fixed via a flat plate-like wear-resistant seal member with a small coefficient of friction.
The other rotates the metal member by spring pressure.
Recently, a surface-seal type rotary joint has been proposed that is constructed so that surfaces are pressed against each other to obtain high sealing pressure. In this method, by increasing the spring strength and increasing the tightening force, the sealing pressure can be made as high as necessary.

However, wear resistance performance is estimated by the product of seal pressure P and rotational circumferential speed V, so if P is set large, V cannot be set large due to the wear resistance of a given seal member. Furthermore, if V is set large, P cannot be set large. Materials with excellent wear resistance include Teflon and polyimide containing graphite carbon, but the wear resistance of these materials is PV = 2100 (Kg/cm ² )・(m/min), and the coefficient of friction is approximately 0.07. It is. For this reason, in reality, the sealing pressure is kept to a necessary level and the circumferential speed V is set high.

Generally, FFF does not require enough pressure to compensate for the pressure loss in the column system and the pressure loss in the system after exiting the column (i.e., the detector). Therefore, when conducting at a flow rate of about 1 mi/min, a sealing pressure of about several kg/cm ² is sufficient. However, there have been attempts to improve the separation performance by using supercritical fluids as the developing solution. In such a case, it is essential to maintain the pressure inside the column at a constant pressure (critical pressure) or higher. For example, carbon dioxide CO ₂ has a critical temperature of 31.0° C. and a critical pressure of 72.8 atm, and a pressure of 100 Kg/cm ² or more is required to maintain the temperature above the critical temperature.

Now, when attempting to obtain such high pressure with a conventional rotary seal, the rotation speed cannot be increased due to the wear resistance of the seal member.

The object of the present invention is to provide a new rotary joint that can overcome the above-mentioned drawbacks.

[Means for solving the problem] In order to achieve this object, the rotating joint of the present invention includes a pair of magnetic bodies disposed close to each other and a sealing member attached to one of the magnetic bodies. , is provided close to at least one of the magnetic bodies in order to bring the two magnetic bodies into close contact with each other with the sealing member interposed therebetween by the attractive force generated by passing magnetic flux between the pair of magnetic bodies. a container that houses a magnet, the two magnetic bodies and the sealing member therein and fixedly supports one of the magnetic bodies, and an outside of the container for rotating the other magnetic body with respect to the magnetic body fixed to the container. A rotating body that transmits rotational force from the container, and holes provided in the two magnetic bodies and the sealing member to flow fluid between the two magnetic bodies, and supply pressurized fluid into the container. , the pressurized fluid is brought into contact with the boundary between the seal member and the magnetic body.

[Embodiment] FIG. 1 is a sectional view showing an embodiment of the present invention, and 15 is a container of a rotating joint. The container has a cylindrical shape with a bottom, and a cylinder 16 communicating with the inside of the container is fixed at the center of the bottom, and these members are made of a non-magnetic material such as SUS316 or SUS304. This cylinder 16 is attached to the housing 8 shown in FIG. 2, and its center is the rotating shaft 1.
coincides with the center of rotation of 17 is the container 15
A cylindrical permanent magnet, such as samarium cobalt, is fixed to the inner wall of the lid 18, and a cylindrical member 19 made of a high magnetic permeability material is attached to the lower surface of this magnet. Further, a member 21 also made of a high magnetic permeability material is placed on the lower surface of the member so as to face each other with a disc-shaped seal member 20 interposed therebetween. As the high magnetic permeability material constituting these members 19 and 21, SUS430 or pure iron (the surface of this pure iron may be plated with nickel plating or hard chrome plating) is used. The seal member 20 is attached to either member 19 or 21. For example, the seal member 20
is fixed with screws to a cylindrical support 22 fixed to the lid body 18 together with the member 1, and the material for this seal member is a material that has a low coefficient of friction, is not peelable, and has little change in shape. It is necessary to use it. As a seal member satisfying such characteristics, for example, graphite, polyimide containing Teflon, Teflon containing graphite carbon, etc. are used.

Reference numeral 23 denotes a permanent magnet such as samarium cobalt, which is attached to the lower end of the member 21, and the seal member 20 is inserted between the two members 19 and 21 by the attractive force of this magnet and the magnet 17 described above.
It plays the role of bringing the material into close contact with the media. Reference numeral 24 denotes a rotary table for rotating the member 21 and the magnet 23, and a shaft 25 is fixed to the center of the bottom of the rotary table. The shaft 25 is a cylinder 1 provided in the container 15.
The lower end of the rotary shaft 1 is connected to the rotary shaft 1 through a flexible tube 26 made of, for example, nylon. The signal is configured to be transmitted to the shaft 25. Needless to say, a gap is also provided between the lower surface of the rotary table 24 and the bottom of the container 15.

Holes 27a and 27b are respectively formed in the opposing surfaces of the members 19 and 21, and the centers of these holes coincide with the center of rotation of the rotary table 24 (rotary shaft 1).
28 is formed on the opposite surface of the member 21, for example, the width is
A shallow annular groove of about 0.4 mm, which is connected to the hole 27.
It is formed concentrically with b. Reference numeral 29 denotes a hole formed in the opposing surface of the other member 19, and the hole is bent at a position opposite to the annular groove 28 formed in the one member 21. It goes without saying that the sealing member 20 placed between these two members 19 and 21 also has holes at positions corresponding to the holes 27a and 29 formed in the member 19. The holes 27a and 29 of the member 19 have the lid 18, the magnet 17, and the member 1.
Pipes 30 and 31 passing through the member 9 are connected to each other, and the hole 27b and the groove 2 formed in the member 21 are connected to each other.
This member 21, the magnet 23, and the rotary table 2 are placed at one point in 8.
4. Pipes 32 and 33 passing through the shaft 25 are connected to each other. The pipes 32 and 33 are connected through tubes 26 to pipes 5 and 6, respectively, which are connected to separation grooves 3 formed in the rotating body 2 of FIG. 2.

Reference numeral 34 denotes a tube penetrated through the side wall of the container 15, through which a pressurized liquid such as water or a developing solution for transporting a sample, or a supercritical liquid 35 is passed through the space partitioned off by the sealing member 20 inside the container 15. 36, that is, for continuously injecting into the space on the side where the member 21 that rotates in close contact with the seal member 20 is placed. The liquid injected into this space 36 flows through the gap between the cylinder 16 and the shaft 25, collects in a saucer 37, and is collected by a collection device (not shown). Reference numeral 38 denotes an umbrella-shaped draining body attached to the inner portion of the tray 37 of the shaft 25, and is used to prevent the liquid 35 from leaking to the tube 26 side.

In addition, the lid body 18, the support body 22, the rotary table 24,
Shaft 2, pipes 30, 31, 32, 33 and pipe 34
are each made of a non-magnetic material such as SUS316 or SUS304.

As a result, the magnetic flux from the permanent magnets 17 and 23 is constricted by the members 19 and 21 with high magnetic permeability, and as a result, strong magnetization of different polarities occurs on each end face, and as a result, a strong attractive force is generated. is pressed against the sealing member 20 with strong sealing pressure. While one member 21 rotates in this state, the hole 27
The sample and developing solution are supplied from a and 27b to the separation groove 3 of the rotating body 2, and the separated liquid is supplied to the annular groove 2.
8. It is led to a detection system (not shown) through the hole 29.

Incidentally, in the above embodiment, the annular groove 28 was formed on the sealing surface of the rotating member 21, but the sealing member 2
It goes without saying that the annular groove may be formed on the lower surface of the seal member by processing the seal member 0 thicker.
In addition, the member 1 is
Although the members 9 and 21 are attracted, it goes without saying that the members 19 and 21 can be attracted by only one of the permanent magnets.

[Effects of the Invention] As described in detail above, according to the present invention, it is possible to obtain a rotating joint that is capable of high speed rotation and has a long sealing member life. In order to prevent liquid leakage, the sealing pressure is set to be sufficiently higher than the pressure difference between the liquid pressure of the liquid to be separated and the pressure outside the sealing surface, but in the present invention, the pressurized liquid is Since the pressure difference between the two is very small, the sealing pressure can also be lowered accordingly. As a result, the rotation speed can be increased and the life of the seal member can be increased. In addition, the heat generated by frictional heat in the seal part due to rotation can be cooled by the pressurized liquid, and furthermore, since the pressurized liquid is made to pass through the bearing part of the rotating member of the seal part, It has effects such as acting as a lubricant.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing one embodiment of the present invention, and FIG.
The figure shows a conventional example device. 15: Container, 16: Cylinder, 17, 23: Permanent magnet, 19, 21: Member, 20: Seal member, 2
4: Turntable, 25: Axis, 26: Tube, 27
a, 27b, 29: hole, 28: groove, 30, 31,
32, 33: pipe, 34: pipe, 35: pressurized liquid,
36: Space, 37: Saucer, 38: Drainer body.

Claims (1)

[Claims] 1 A pair of magnetic bodies disposed close to each other, a sealing member attached to one of the magnetic bodies, and an attractive force generated by passing a magnetic flux between the pair of magnetic bodies, A magnet provided close to at least one of the magnetic bodies in order to bring the two magnetic bodies into close contact with each other with a sealing member interposed therebetween; and a magnet that accommodates the two magnetic bodies and the sealing member inside and fixes one of the magnetic bodies. a rotating body that transmits rotational force from outside the container in order to rotate the other magnetic body relative to the magnetic body fixed to the container, and a rotating body that transmits rotational force from the outside of the container in order to rotate the other magnetic body relative to the magnetic body fixed to the container; A magnetic body and a hole provided in the sealing member are provided, and a pressurized fluid is supplied into the container, and the pressurized fluid is brought into contact with the boundary between the sealing member and the magnetic body. A rotating joint featuring