Continuous type rotor for centrifugal separation

Abstract

To provide a continuous type rotor for centrifugal separation which hardly generates air bubbles.SOLUTION: A continuous type rotor 1 for centrifugal separation includes a rotor body 2 rotated by a driving motor, an injection pipe 5 for sending a sample to inside the rotor body 2 during rotation of the rotor body 2, and a liquid discharger 6 and a liquid discharge path 10 for discharging supernatant liquid separated during the rotation of the rotor body 2 to the outside the rotor body 2, wherein the liquid discharger 6 is a disc-shaped member which has a slit-like gap α having a constant width on the peripheral end part, and has a liquid discharge groove β communicating with the slit-like gap α and the liquid discharge path 10 formed in the central part.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a continuous centrifuge rotor used in a continuous centrifugation operation in which a sample is introduced from outside the machine and the centrifuged supernatant is collected outside the machine. [Background technology]

[0002] Continuous centrifugal separation operations are performed using continuous centrifugal rotors (also referred to simply as "continuous rotors" in this specification) as described in, for example, Patent Document 1 and Patent Document 2. A conventional example of such a continuous rotor is shown in Fig. 7, and a cross section of a drainer used in the conventional continuous rotor is shown in Fig. 8.

[0003] 7, continuous rotor 100 mainly comprises rotor body 101, core body 102, drainer 103, shutoff piece 104, and support 105 that supports drainer 103, shutoff piece 104, etc., and this support 105 is fixed to the centrifuge body (not shown), so that parts such as drainer 103 and shutoff piece 104 are fixed to the centrifuge body in a non-rotating state. Meanwhile, rotor body 101 and core body 102 are configured to be integrated by lid 106, and a drive shaft (not shown) rotated by a drive motor provided in the centrifuge body engages with shaft hole 101a provided in the underside of rotor body 101, thereby rotating rotor body 101 and core body 102 and applying centrifugal force to the supplied sample. The lower end of a sample injection pipe 107 connected to the sample tank 200 is inserted in a non-contact state into a hole 102 a provided in the core body 102 , and the sample is supplied into the rotating rotor body 101 .

[0004] Next, a brief description will be given of the centrifugal separation operation of a sample using the continuous rotor 100 described above. The sample is injected from an external sample tank 200 via injection pipe 107 and enters centrifugation space A formed by the rotor body 101 and core body 102. The sample is centrifuged in this centrifugation space A, and as further samples are continuously introduced via injection pipe 107, the small mass substances (supernatant) located radially inward gradually move further radially inward, and finally enter waste liquid reservoir B via passage 102b formed in core body 102. The supernatant liquid that has entered waste liquid reservoir B is pumped up by the pumping action of drainer 103, passes through drainage path 108, which is provided concentrically outside injection pipe 107, and is stored in supernatant liquid tank 300, which is provided externally, via discharge pipe 109. The gap between the non-rotating parts such as the drainer 103 and shutoff piece 104 and the rotating parts such as the rotor body 101 and core body 102 is sealed by the shutoff piece 104 placed in the sealing liquid reservoir C provided on the top of the core body 102 and the sealing liquid poured into the sealing liquid reservoir C, and the internal and external spaces of the continuous rotor are completely sealed.

[0005] The structure of the drainer 103 used in the conventional continuous rotor 100 will be described with reference to Figure 8. The drainer 103 is a disc-shaped member having a plurality of spiral grooves 103b formed therein, each with an opening 103a in its peripheral wall, and an opening 103c in the inner wall of each groove 103b at its center communicates with a drainage channel 108 provided concentrically on the outside of the injection pipe 107. As described above, the supernatant liquid that has entered the drainage reservoir B formed in the core body 102 rotates at high speed around the drainer 103 together with the core body 102. The energy of this rotation causes the supernatant liquid to flow from the openings 103a formed in the peripheral wall of the drainer 103 into the grooves 103b in a state of being sucked in. The supernatant liquid is then discharged outside the continuous rotor via the connected drainage channel 108 and stored in a supernatant tank 300 installed outside the machine. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Jikko No. 45-6375 [Patent Document 2] Japanese Patent Application Publication No. 57-91758 Summary of the Invention [Problem to be solved by the invention]

[0007] In the conventional continuous rotor 100 described above, the supernatant liquid rotating at high speed together with the core body 102 in the drain reservoir B is sucked through the opening 103a formed in the stationary drainer 103. This causes the supernatant liquid to be subjected to sudden and complex changes in kinetic energy, which makes it easy for bubbles to be generated by cavitation at the opening 103a. Depending on the sample being processed, the generated bubbles may clog the discharge path 108, etc., causing problems in continuous operation.

[0008] The present invention has been made in view of the problems inherent in the background art described above, and an object of the present invention is to provide a rotor for continuous centrifugal separation that is less likely to generate bubbles. [Means for solving the problem]

[0009] In order to achieve the above object, the present invention provides a rotor for continuous centrifugal separation as described in the following [1] to [5]. [1] A continuous centrifugal rotor comprising a rotor body rotated by a drive motor, a liquid delivery mechanism for delivering a sample into the rotor body while the rotor body is rotating, and a liquid drainage mechanism for discharging the supernatant liquid separated while the rotor body is rotating to the outside of the rotor body, characterized in that the liquid drainage mechanism comprises a drainage reservoir formed in a core body that rotates together with the rotor body and into which the separated supernatant liquid flows, a drainer disposed in a stationary state in the drainage reservoir, and a drainage path communicating with the drainer, and the drainer is a disc-shaped member having a slit-like gap of a fixed width at its peripheral edge and a drainage groove formed in its center that communicates with the slit-like gap and the drainage path. [2] The continuous centrifugal rotor according to [1], characterized in that the drainer is made by stacking a number of disks via spacers, and forming slit-like gaps of the specified width corresponding to the thickness of the spacers between the disks. [3] The continuous centrifugal rotor according to [1] or [2] above, characterized in that the slit-like gaps of the drainer are formed in multiple stages. [4] A continuous centrifugal rotor according to any one of [1] to [3] above, characterized in that the slit-like gap of the drainer is formed to have a width of 0.2 to 1.5 mm. [5] A continuous centrifugal rotor according to any one of [1] to [4] above, characterized in that the slit-like gap of the drainer is formed at the peripheral end portion extending inward from the peripheral end by 5 mm or more. [Effects of the Invention]

[0010] According to the continuous centrifugal rotor of the present invention described above, the supernatant liquid separated in the rotor body can be discharged outside the machine without causing cavitation, resulting in a continuous centrifugal rotor that is less likely to generate bubbles. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a conceptual vertical cross-sectional view showing one embodiment of a continuous centrifugal separator rotor according to the present invention. [Figure 2] FIG. 1 is a half cross-sectional view showing one embodiment of a drainer used in a continuous centrifugal rotor according to the present invention. [Figure 3] FIG. 3 is an exploded half-sectional view of the drainer shown in FIG. 2. [Figure 4] 3A and 3B are diagrams showing the components of the drainer shown in FIG. 2, in which (a) is a plan view of the upper disc, and (b) is a plan view of the disc disposed between the upper and lower discs. [Figure 5] 3A and 3B are diagrams showing components of the drainer shown in FIG. 2, in which (a) is a plan view of the spacer and (b) is a bottom view of the lower disk. [Figure 6]1 is an enlarged cross-sectional view showing a main part of a drainer according to the present invention. [Figure 7] FIG. 1 is a conceptual vertical cross-sectional view showing a conventional continuous centrifugal rotor. [Figure 8] FIG. 1 is a cross-sectional view of a drainer used in a conventional continuous centrifuge rotor. DETAILED DESCRIPTION OF THE INVENTION

[0012] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A continuous centrifugal separator rotor according to the present invention will be described in detail below with reference to the embodiments shown in the drawings.

[0013] As shown in FIG. 1, the continuous centrifugal rotor 1 according to the present invention has a basic structure similar to that of the conventional continuous rotor described in the Background Art section. Specifically, the rotor body 2 has a shaft hole 2a at the center of its underside that engages with the drive shaft (not shown) of a drive motor, and a centrifugal separation space A around it. The core body 3 is fixed to the rotor body 2 by a lid 4 and rotates together with the rotor body 2, applying centrifugal force to a sample supplied to the centrifugal separation space A. The core body 3 has a waste liquid reservoir B at its center and a seal liquid reservoir C at its top. An injection pipe 5, a drainer 6, and a shutoff piece 7 are arranged by supports 8 without contacting the core body 3. The lower end of the injection pipe 5 opens at the bottom of the core body 3, and supplies the sample from a sample tank (not shown) to the centrifugal separation space A in the rotor body 2. The drainer 6 is disposed in the drain reservoir B of the core body 3, and sucks up the separated supernatant liquid that has flowed into the drain reservoir B through a passage 9, and sends the supernatant liquid to a supernatant liquid tank (not shown) provided outside the machine via a drain path 10 provided concentrically on the outside of the injection pipe 5. The shutoff piece 7 is disposed in the sealing liquid reservoir C provided on the top of the core body 2. The sealing liquid reservoir C is filled with sealing liquid.

[0014] 1, a sample tank (not shown) and an injection pipe 5 connected to the sample tank constitute a liquid delivery mechanism for delivering the sample to the inside of the rotor body. Also, a passage 9 formed in the core body 3, a waste liquid reservoir B, a drainer 6, a drainage path 10, and a supernatant liquid tank (not shown) constitute a liquid drainage mechanism for discharging the separated supernatant liquid to the outside of the rotor body.

[0015] 2 to 6 show one embodiment of the drainer 6 used in the continuous rotor 1 according to the present invention. The drainer 6 according to this embodiment is formed as a disk-shaped member having a slit-like gap α of a constant width at its peripheral edge and a drain groove β in its central portion that communicates with the slit-like gap α and the drainage path 10 (see FIGS. 2 and 6). Specifically, the drainer 6 is formed by stacking a large number of disks 20a to 20e via spacers 21a to 21d, with the slit-like gaps α of a constant width corresponding to the thickness of the spacers 21a to 21d formed between the disks 20a and 20b, between the disks 20b and 20c, between the disks 20c and 20d, and between the disks 20d and 20e, respectively, and the drain groove β is formed by holes 22b, 22c, and 22d formed in the centers of the disks 20b, 20c, and 20d.

[0016] As shown in Figures 3 and 4(a), upper disk 20a is thick, with spacer 21a integrally formed as a protrusion in the center of the lower surface. The peripheral edge of the upper surface of upper disk 20a is formed with sloped surface 23a that gradually becomes thinner as it extends outward. A through-hole 24a for inserting injection pipe 5 is formed in the center of upper disk 20a, and three equally spaced female screw holes 25a are formed around the portion where spacer 21a is formed, taking advantage of the thickness of the upper disk.

[0017] 3 and 4(b), the disks 20b, 20c, and 20d arranged between the upper disk 20a and the lower disk 20e (described later in detail) are thin plates having holes 22b, 22c, and 22d at their centers, respectively, which form the drainage groove β and also serve as through holes 24b, 24c, and 24d for inserting the injection pipe 5. The holes 22b, 22c, and 22d are formed with six arm-shaped hole portions 26b, 26c, and 26d extending radially at equal intervals from the center, and screw insertion holes 25b, 25c, and 25d are formed at three equally spaced locations between the six arm-shaped hole portions.

[0018] As shown in Figures 3 and 5(b), lower disk 20e is thick and has spacer 21d integrally formed as a protrusion in the center of its upper surface. The peripheral edge of the lower surface of lower disk 20e is formed with sloped surface 23e that gradually becomes thinner as it extends outward. Mounting portion 27 for fixing the tip of injection pipe 5 in an open state is provided in the center of lower disk 20e, and three screw insertion holes 25e are formed at equal intervals around the portion where spacer 21d is formed.

[0019] The spacers 21b, 21c to be interposed between the above-mentioned disks 20b, 20c, 20d are formed as circular plates with an outer diameter approximately half that of the above-mentioned disks, as shown in Figures 3 and 5(a), and have through holes 28b, 28c in the center for inserting the injection pipe 5, and screw insertion holes 29b, 29c formed at three equally spaced locations around the periphery.

[0020] The above-mentioned disks 20a to 20e and spacers 21a to 21d are stacked as shown in Fig. 3, and screws 30 are inserted into screw insertion holes 25b to 25e, 29b, and 29c formed in each member and screwed into female screw hole 25a formed in the upper disk, thereby forming disk-shaped drainer 6 as shown in Fig. 2. As shown in Fig. 6, drainer 6 has slit-like gaps α of a constant width at the peripheral edge between each disk, and is stacked in a state where the tips of arm-like hole portions 26b, 26c, and 26d of holes 22b, 22c, and 22d formed in the disks protrude from the outer edge of the spacers, and a drainage groove β communicating with slit-like gap α and drainage channel 10 is formed in the center.

[0021] The width W of the slit-shaped gap α of a constant width formed at the peripheral edge of the drainer 6 and the length L of the peripheral edge (see FIG. 6 ) are designed to gently decelerate the supernatant liquid drawn by the drainer 6 through the slit-shaped gap α to a speed at which cavitation is unlikely to occur, taking into consideration the physical properties of the sample being processed, the processing volume, and the size of the continuous rotor. From this perspective, the width W of the slit-shaped gap α of the drainer 6 is preferably 0.2 to 1.5 mm, more preferably 0.3 to 1.0 mm, and particularly preferably 0.4 to 0.7 mm. From the same perspective, the length L of the slit-shaped gap α of the drainer 6 is preferably 5 mm or more from the peripheral edge, more preferably 7 mm or more from the peripheral edge, and particularly preferably 10 mm or more from the peripheral edge. The upper limit of the length L of the slit-shaped gap α of the drainer 6 is 30 mm or less, given the upper limit of the size of the drainer.

[0022] The continuous centrifugal rotor 1 according to the present invention uses the drainer 6 described above, and therefore the supernatant liquid that is supplied to the centrifugal separation space A in the rotor body 2, centrifuged, reaches the drainage reservoir B through the passage 9 of the core body 3, and rotates at high speed together with the core body 3 in the drainage reservoir B can be sucked into the slit-like gap α of a fixed width formed at the peripheral end of the drainer 6, and its speed can be gradually reduced, allowing the supernatant liquid to be discharged outside the machine without causing cavitation. This results in a continuous centrifugal rotor that is less likely to generate bubbles.

[0023] The continuous centrifuge rotor according to the present invention has been described above, but it goes without saying that the technical scope of the present invention is not limited to the scope described in the above embodiment. It will be apparent to those skilled in the art that various modifications and improvements can be made to the above embodiment. Furthermore, it is clear from the claims that embodiments incorporating such modifications and improvements are also included within the technical scope of the present invention. [Industrial Applicability]

[0024] According to the present invention, a continuous centrifugal rotor that is less likely to generate bubbles can be provided, and therefore can be used for continuous centrifugal separation of a wide variety of samples. [Explanation of symbols]

[0025] 1. Continuous centrifugal rotor (continuous rotor) 2 Rotor body 2a Rotor body shaft hole 3 Core Body 4 Lid 5 Injection pipe 6 Drainer 7 Breaking Piece 8 Supports 9 Passages formed in the core body 10 Drainage channel 20a Upper disc 21a Spacer integrally formed on the upper disc 23a Slope formed on the upper disc 24a A through hole formed in the upper disc through which the injection pipe is inserted 25a Female screw hole formed in the upper disc 20b, 20c, 20d Disks disposed between the upper and lower disks 22b, 22c, 22d Holes forming drainage grooves formed on each disk 24b, 24c, 24d: Through holes formed in each disk for inserting injection pipes 25b, 25c, 25d Screw insertion holes formed on each disk 26b, 26c, 26d Arm-shaped holes formed radially around the holes of each disk 20e Lower disc 21d Spacer integrally formed on the lower disc 23e Slope formed on the lower disc 25e Screw insertion holes formed in the lower disc 27 Water injection pipe attachment part provided on the lower disc 21b, 21c Spacers interposed between each disk 28b, 28c: Through holes formed in each spacer for inserting injection pipes 29b, 29c Screw insertion holes formed in each spacer 30 screws A. Centrifugal space B. Drainage reservoir C Sealing fluid reservoir α Slit-shaped gap β Drainage groove

Claims

1. a rotor for continuous centrifugation comprising a rotor body rotated by a drive motor, a liquid delivery mechanism for delivering a sample into the rotor body while the rotor body is rotating, and a liquid drainage mechanism for discharging supernatant liquid separated while the rotor body is rotating to the outside of the rotor body, wherein the liquid drainage mechanism comprises a drainage reservoir formed in a core body that rotates together with the rotor body and into which the separated supernatant liquid flows, a drainer disposed in a stationary state in the drainage reservoir, and a drainage path communicating with the drainer, and the drainer is a disc-shaped member having a slit-like gap of a fixed width at its peripheral edge and a drainage groove formed in its center that communicates with the slit-like gap and the drainage path.

2. 2. The continuous centrifugal rotor according to claim 1, wherein the drainer is formed by stacking a number of disks with spacers interposed therebetween, and forming slit-like gaps of the specified width corresponding to the thickness of the spacers between the disks.

3. 3. The continuous centrifugal rotor according to claim 1, wherein the slit-like gaps of the drainer are formed in multiple stages.

4. 3. The continuous centrifugal rotor according to claim 1, wherein the slit-shaped gap of the drainer is formed to have a width of 0.2 to 1.5 mm.

5. 3. A continuous centrifugal separator rotor according to claim 1, wherein the slit-like gap of the drainer is formed at the peripheral edge portion extending inward from the peripheral edge by 5 mm or more.

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