JPS6349314Y2 - - Google Patents

Description

[Detailed explanation of the invention] [Industrial application field] The invention is based on S-FFF (Sedimentation Field).
Flow Fractionation (Flow fractionation using centrifugal force field)
The present invention relates to a rotating column for sedimentation field flow fractionation that is lightweight and has good sealing performance.

[Prior Art] When particles in a fluid are placed in a centrifugal force field, they receive a force corresponding to the mass of the particles. If this force is greater than the self-diffusion force of the particles, the particles will settle and separate from the liquid layer, forming a solid layer. However, if the particles are small, they will not settle completely and will form a layer where centrifugal force and self-diffusion force are balanced. Furthermore, when fluid flows through a narrow gap, the flow velocity at the portion in contact with the wall surface is slower than at the center, and takes on a parabolic flow velocity distribution toward the center of the gap. When a centrifugal force field is applied perpendicularly to this gap, particles in the fluid will move through the gap at a specific flow velocity at a position where centrifugal force and self-diffusion force are balanced. S-FFF utilizes these properties to separate and fractionate fine particles in fluids.
(Sedimentation Field Flow Fractionation).

The rotating column for S-FFF must meet the following requirements:

The walls are made of chemically inert materials,
It also has an extremely smooth surface, and the surface roughness is submicron or less.The grooves that make up the centrifugal column have gaps W and B that are highly accurate and uniform in the fluid flow direction. There must be complete isolation between the fluid inlet and outlet, there must be no leakage to the outside, and there must be extremely little dead volume between the fluid inlet and outlet. It must be easy to disassemble and reassemble for internal cleaning. To meet these requirements, several proposals have been made by Kirkland (DuPont Central Research Institute) and others.

FIG. 7 is a diagram showing an example of a conventional rotating column for flow fractionation in a sedimentation field. That is, the rotating column is
A separation groove 25 and a seal groove 27 are provided on the outer wall of the inner ring 21, and a sealing material 28 is provided in the seal groove 27.
FIG. 7b shows a cross section of the inner ring 21 when the inner ring 21 is fitted and inserted inside the outer ring 22. Figure 7c shows this. In the column shown in Figure 7,
Gap 29 generally has a height of 50 μm to 300 μm.
It is a parallel gap with a length of 25 mm and a length of about 58 cm.
A fluid inlet 23 and an outlet 24 are located very close to each other at both ends of the gap 29. As shown in FIG. 7c, a seal groove 27 is provided to surround the separation groove 25 forming the gap 29 to prevent liquid leakage.

[Problem that the invention attempts to solve]

In S-FFF, the column gap 29 (total capacity is about 3 ml) is heated at 1 ml/min as shown in Figure 7.
Flow the fluid. In this case, if there is liquid leakage in the column and a bypass flow path is formed, the separation peak will appear at a position other than the predetermined position, or the peak value will no longer show the correct value. In addition, the sample in the portion where the flow rate lags on the order of several tens of times the average flow rate of the fluid flowing through the column is distributed at a position on the order of microns from the wall surface. Therefore, if the wall surface has irregularities on the order of microns, the accuracy of analysis will be greatly affected. Because of this, S
- For FFF columns, it is especially important to prevent liquid leakage, ensure sealing pressure, and ensure the accuracy of the gap 29 surface machining.

However, as shown in Figure 7, in conventional columns, separating grooves that form the gap are provided on the wall of the ring. The problem is that a number of processing techniques are required. Also, the outer diameter of the inner ring and the outer diameter
Another problem is that assembly is difficult because the difference with the inner diameter of the ring is small.

In order to solve the above problem, the applicant of this application
JP-A No. 62-298466 has been filed as a prior application.
To explain this with reference to FIGS. 5 and 6, this rotating column includes a column base 4 that forms an outer frame, a spacer 3 that has a cutout 13 that extends at a constant width in the center and is narrowed into an arrow shape at both ends. , having a cutting part 9 and a fluid injection pipe 10 near the cutting part 9.
and an outflow pipe 11, and a variable diameter ring 2 having a tapered portion on its inner circumferential surface;
The spacer 3 is attached to the column base 4 by sliding the tapered part of the tightening flange 1 onto the tapered part of the variable diameter ring 2. This is characterized in that a channel groove is formed by the gap between the inner wall of the column base 4 and the variable diameter ring 2 in the cutout of the pressing spacer 3.

However, in the rotating column, screw holes are provided in the column base 4 and the flange 5 of the tightening flange 1, and the column base 4 and the tightening flange 1 are fixed with bolts 7. 1 must be provided with a predetermined thickness, and if the radius of the rotating column is increased, that is, the column length is increased, the weight increases, making it difficult to control the power of the drive unit, control the rotational speed, or take measures to prevent vibrations. There is a problem. In addition, if titanium is used instead of SUS304 or 316 to reduce the weight of the material,
This has the problem of significantly increasing material costs.

Furthermore, a variable diameter ring 2 is attached to the tightening flange 1.
In order to insert the inflow pipe 10 and the outflow pipe 11 attached to the
Since it is provided over the entire radial length of the lower end surface, there is a problem in that the sealing performance of this part is weak and leaks easily. In this case, if this part is filled with elastic polymer, it will penetrate into the gap due to centrifugal force and sealing will be possible. However, when used under high pressure, the sealing performance is insufficient, and the sealing performance is insufficient when rotation is stopped. The problem is that it is no longer possible to obtain

The present invention solves the above-mentioned problems, and aims to provide a rotating column for sedimentation field fluid fractionation that can be made lightweight even when the diameter of the column is increased, and that can improve sealing performance. The purpose is

[Means for solving problems]

Therefore, the rotating column for sedimentation field flow fractionation of the present invention has a column base constituting an outer frame, a spacer for forming a channel groove, and a cut section, and a fluid injection pipe and a fluid outflow tube near the cut section. a variable diameter ring having a pipe and a tapered portion on the inner circumferential surface; and a tightening ring inserted inside the variable diameter ring and having a tapered portion on the outer circumferential surface, and the tightening ring and the column base are connected to each other. The bottom surface is fixed with bolts, and the spacer is fixed to the column by the action of the tapered part of the tightening ring and the tapered part of the variable diameter ring.
This is characterized in that a channel groove is formed by the gap between the inner wall of the column base and the variable diameter ring at the cutout portion of the spacer when pressed against the base.

[Effect]

In the present invention, for example, as shown in FIGS. 2 and 3, the variable diameter ring 3 is
By expanding the spacer 2 and pressing the spacer 33 against the inner wall of the column base 34, a sealing effect can be achieved independently of centrifugal force. 4
5 on the bottom side of the column base 34, the thickness of the side wall of the heavy column base 34 can be reduced. Since the cutout portion 35a of the ring 31 is thinner than the thickness of the tightening ring 31, the spacer 33 in this portion is firmly fixed, thereby improving sealing performance.

〔Example〕

The following describes the embodiments with reference to the drawings.

Fig. 1 is an assembly diagram showing one embodiment of the rotary column for sedimentation field flow fractionation of the present invention, Figs. 2 and 3 are partial vertical cross-sectional views of the embodiment shown in Fig. 1, and Fig. 4 is the main FIG. 7 is a longitudinal sectional view showing another embodiment of the invention.

1 to 3, the rotating column of the present invention is composed of a tightening ring 31, a variable diameter ring 32, a spacer 33 and a column base 34.

The tightening ring 31 is made of a lightweight metal such as aluminum alloy and is formed into a cylindrical shape, and its outer peripheral surface is tapered so that the cross section decreases from the top to the bottom. Further, two insertion holes 35, 35 are formed in the radial direction of the tightening ring 31, and a plurality of screw holes 36, 36, . . . are formed passing through the tightening ring 31. Furthermore, the third
As shown in the figure, a notch 35a is provided on the outer peripheral surface of the tightening ring 31 so as to communicate with the insertion hole 31 and allow passage of a fluid injection pipe 38 and a fluid outflow pipe 39, which will be described later. The notch 35a is the tightening ring 3
The notch is thinner than the thickness of 1, and its depth is slightly larger than the protruding length of the fluid inlet pipe 38 and the fluid outlet pipe 39.

The variable diameter ring 32 is made of SUS-316 or SUS-
304 material is used and is processed into a ring shape and has a cutting part 37 cut at one place, and a fluid injection pipe 38 protruding toward the inner circumference side of the variable diameter ring 32 near both ends of the variable diameter ring 32. and fluid outflow pipe 3
9 is installed. The protruding lengths of the fluid injection pipe 38 and the fluid outflow pipe 39 are formed to be smaller than the thickness of the tightening ring 31. In addition, spacer mounting recesses 4 are provided at both ends of the outer surface of the variable diameter ring 32.
0,40 are formed, and the variable diameter ring 32
The inner circumferential surface of the tightening ring 31 is tapered in a direction opposite to the taper of the outer surface of the tightening ring 31, and is formed so that its cross section increases from the top to the bottom.
The tapered surfaces of the tightening ring 31 and the variable diameter ring 32 are made of different metals to minimize friction, but both tapered surfaces may be coated with a friction reducer, fine particles of Teflon. Alternatively, a friction-reducing gasket made of a polyimide material containing graphite Teflon (registered trademark) may be inserted into the tapered portion of the tightening ring 31.

The spacer 33 is made of polyimide or a polyimide sheet coated with Teflon (registered trademark), and is tapered into an arrow shape toward the position corresponding to the fluid injection pipe 38 and the outflow pipe 39, and is cut to a constant width over the other area. A cutout 40 is formed, and attachment holes 41, 41 are formed at both ends of the spacer 33.

Column base 34 is SUS-316 or SUS
-304 material is used, and is formed into a cylindrical container that accommodates the tightening ring 31, variable diameter ring 32, and spacer 33, and its inner peripheral surface is mirror polished. Furthermore, screw holes 42, 42, . A sealing O-ring 44 is disposed within the sealing groove 43, as shown in FIG.

Next, the assembly method will be explained. First, the spacer 33 is attached to the spacer attachment recesses 40, 40 of the variable diameter ring 32 with one end fixed and the other end semi-fixed using screws. Next, after compressing the variable diameter ring 32 to reduce its diameter and inserting and disposing the variable diameter ring 32 in the column base 34,
When the tightening ring 31 is inserted into the variable diameter ring 32, as the tapered surface of the tightening ring 31 moves down the tapered surface of the variable diameter ring 32, the variable diameter ring 32 is forcibly moved by the action of the wedge. It is expanded and firmly pressed against the inner wall of the column base 34 via the spacer 33. At this time, as shown in FIG. 3, the fluid injection pipe 38 and the outflow pipe 39 of the variable diameter ring 32 pass through the notches 35a, 35a of the tightening ring 31, and the insertion hole 35,
35. Then, by inserting the bolts 45 into the screw holes 36 and 42, the tightening ring 31 and the column base 34 are tightened and fixed, and the swage type connector 46 is connected to the injection pipe 38 and the outflow pipe 39.

Therefore, as shown in FIG.
A spacer 33 is sandwiched between the column base 34 and the column base 34, and the thickness of the spacer 3 is the width W of the channel groove. The width W of this channel groove is 50 μm ~
Selected within the range of 300 μm. Therefore, the opposing surfaces of the variable diameter ring 32 and column base 34 are mirror-finished. Selection of W can be easily achieved by replacing spacers 33 with different thicknesses and variable diameter rings adapted to the spacers 33. Further, since the spacer 33 is fixed to the variable diameter ring 32, the fluid introduction/outlet can be accurately set at the narrowest position of the gap of the arrow-shaped cutout 40. As a result, the variable diameter ring 32
The positional relationship between the cutting part 9, the fluid injection pipe 38, and the outflow pipe 39 can be provided as close as possible, so that the column length L can be as long as possible. Furthermore, since the tightening ring 31 and the column base 34 are fixed by the bolts 45 on the bottom side of the column base 34, the fixation shown in FIGS.
Compared to the illustrated example, the sidewall thickness of the heavier column base can be reduced.

Further, as shown in FIG. 3, a variable diameter ring 32
The fluid inlet pipe 38 and the outflow pipe 39 of the clamping ring 3
1 through the notches 35a, 35a of the insertion hole 3.
5 and 35, but since the notch 35a is cut thinner than the thickness of the tightening ring 31, the tightening ring 31 is fixed as shown in the example of FIGS. Compared to the case where a notch is provided in the entire radial direction of the lower end surface of the spacer 33, the spacer 33 in this portion is firmly fixed and the sealing performance can be improved.

FIG. 4 shows another embodiment of the rotating column for sedimentation field flow fractionation of the present invention. In the above embodiment, sealing between the spacer 33 and the column base 34 is performed via the O-ring 44, but in this embodiment, a polyimide or Teflon (registered trademark) coated material is used instead of the O-ring. A sheet member 47 made of polyimide is provided. The phenomenon of the interface between a fluid and a solid flowing in a channel groove is
Since it is affected by the critical surface tension between the solid and the fluid, it has a large impact on the measurement results. It has been found that by using the sheet member 47 described above, the peak appears sharply and in a short time in the measurement results. Therefore, the seat member can be selected according to the fluid flowing in the channel groove, and a lightweight aluminum alloy can be used for the column base 34, making it possible to further reduce the weight. Also, since there is no O-ring, variable diameter ring 3
2 can be inserted smoothly.

If the above-described rotating column for sedimentation field fluid fractionation of the present invention is used at a rotation speed of about 3000 rpm, the centrifugal force will be about 1007 G. Therefore, 1G
is equal to the pressure of 1Kg/cm ² per unit mass, so G = (2πf/60) ²・r・m m=ρ・d・w・h S=W(h−B)...by the seal area per unit , frame length r=10cm, rotation speed f=
3000rpm, variable diameter ring material density ρ = 4.5g/
cm ³ (titanium), the flesh pressure of the variable diameter ring d = 0.2 cm, and the width B of the variable diameter ring = 2.5 cm, the sealing pressure will be approximately 1800 Kg/cm ² . The polyimide sheet has a test result showing that it deforms by 13% at 2360 kg/cm ² , so it is sufficiently durable for use. However, if polyimide sheets are used under higher G's, the sealing pressure may become too high and plastic deformation may occur. In that case, the problem can be solved by replacing the polyimide sheet with a metal sheet to create a spacer, or by making the variable diameter ring thinner.

[Effect of idea]

As is clear from the above explanation, according to the present invention, the reference surface of the channel groove has a flat structure, so it can be manufactured with high precision even by lathe processing, and the surface can be easily mirror-finished. It can be realized. Moreover, since the structure is simple, handling becomes easy and the cost can be reduced.

Also, the force of the tightening ring 31 causes the variable diameter ring 32 to
By expanding the spacer 33 and pressing the spacer 33 against the inner wall of the column base 34, a sealing effect can be achieved independently of centrifugal force.

In addition, since the spacer 33 is fixed to the variable diameter ring 32, the fluid inlet and outlet of the channel groove can be precisely set, and there is no direct leakage phenomenon from the inlet to the outlet. 33 and variable diameter ring 32 adapted to it
This can be easily achieved by replacing.

Furthermore, a tightening ring 31 and a column base 34
is fixed to the column base 34 with bolts 45.
Since this is carried out on the bottom side of the rotating column, the thickness of the side wall of the column base 34, which is heavy, can be made thinner, and the weight can be reduced even when the radius of the rotating column is increased. In addition, the fluid injection pipe 3 of the variable diameter ring 32
8 and the outflow pipe 39 are connected to the notch 35 of the tightening ring 31.
Since the notch a is thinner than the thickness of the tightening ring 31, the spacer 33 in this part is firmly fixed, and the sealing performance can be improved.

[Brief explanation of drawings]

Fig. 1 is an assembly diagram showing one embodiment of the rotary column for sedimentation field flow fractionation of the present invention, Figs. 2 and 3 are partial vertical cross-sectional views of the embodiment shown in Fig. 1, and Fig. 4 is the main A vertical cross-sectional view showing another embodiment of the invention, FIG.
The partial cross-sectional view in the figure, FIG. 7, is a diagram for explaining a conventional rotating column for flow fractionation in a sedimentation field. 31...Tightening ring, 32...Variable diameter ring, 33
... Spacer, 34... Column base, 35... Insertion hole, 35a... Notch, 36... Screw hole, 37... Cutting part, 38... Fluid injection pipe, 39... Fluid outflow pipe, 40
...Spacer mounting recess, 41...Mounting hole, 42...Screw hole, 43...Seal groove, 44...O ring, 45...
Bolt, 46... Swage type connector, 47... Sheet member.

Claims (1)

[Claims for Utility Model Registration] (1) A column base constituting an outer frame, a spacer for forming a channel groove, and a cutting part, with a fluid injection pipe and a fluid outflow pipe in the vicinity of the cutting part. a variable diameter ring having a tapered portion on its inner peripheral surface; and a tightening ring inserted inside the variable diameter ring and having a tapered portion on its outer peripheral surface,
The tightening ring and the bottom of the column base are fixed with bolts, and the spacer is pressed against the column base by the action of the tapered part of the tightening ring and the tapered part of the variable diameter ring. - A rotating column for sedimentation field fluid fractionation, characterized by a channel groove formed by a gap between the inner wall of the base and the variable diameter ring. (2) The protruding length of the fluid inlet pipe and the fluid outflow pipe from the inner circumferential surface of the variable diameter ring is set to be smaller than the thickness of the tightening ring, and the tightening ring is provided with a wall facing the fluid inlet pipe and the fluid outflow pipe. A rotating column for sedimentation field flow fractionation according to claim 1, characterized in that a notch is formed as a cutout.