JP2006281034A - Centrifuge - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a centrifuge capable of facilitating a cleaning or sterilizing operation with a simple structure and efficiently separating and classifying various particulates. <P>SOLUTION: This centrifuge comprises: a suspended rotary cylinder connected to a rotary drive mechanism; a blade housed inside the suspended rotary cylinder; and a frame which supports the suspended rotary cylinder and is provided with a supply pipe for supplying suspension to the suspended rotary cylinder and a discharge pipe for recovering the suspension which flows out from the suspended rotary cylinder. On the lower end part of the suspended rotary cylinder, a guide cap for guiding the suspension received from the supply pipe to the blade is provided. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a centrifugal separator that separates and classifies liquid or solid fine particles dispersed in a suspension by using a specific gravity difference, and particularly, a suspended rotating cylinder type centrifugal device that can rotate at high speed and has blades provided inside. It relates to a separator.

  The suspended rotating cylinder type centrifuge is of simple structure and can be rotated at high speed. Therefore, it is attracting attention as a means for separating and classifying fine liquid or solid particles in the fields of biotechnology and nanotechnology. Yes.

  The basic structure of a suspended rotary cylinder type centrifuge is disclosed in Patent Document 1, for example. That is, a vertically arranged cylindrical rotor whose upper and lower ends are respectively closed by upper and lower caps, and a core assembly that is arranged in the rotor and partitions a plurality of fan chambers for receiving gradient solution and sample solution therein A continuously operated liquid centrifuge for large-scale separation of viruses in a liquid medium comprising a radially innermost portion of the sector chamber and a radial passage communicating with the sector chamber at an end of a tubular shaft; The rotor has a long shape in the axial direction and is supported at both ends by a tubular shaft, and the radial passage is connected to the tubular shaft through the axial passage passing through the upper and lower caps. Centrifugal separators have been proposed that are in communication to form a continuous flow path through.

  On the other hand, in Patent Document 2, if there is a seal or a screw coupling portion at a portion where the liquid sample (suspension) mixed with the particles to be separated from the centrifuge comes into contact, it is performed before using the centrifuge. In order to prevent this, the weldability of the cylindrical rotor and the end plate that closes the upper and lower ends of the device is reduced. A centrifuge has been proposed.

Patent Document 3 proposes a centrifuge that facilitates the disassembly and assembly of the portion that contacts the suspension of the centrifuge in order to facilitate cleaning or sterilization operations. Specifically, a rotor head having a cylindrical rotor sleeve having a lower end portion and an upper end portion, and a lower portion threadedly engaged with the upper end portion of the rotor sleeve, the rotor comprising means for separating low density material from high density material A rotor assembly for a centrifuge comprising a head and a rotor blade assembly unit having a plurality of radial blades extending from a lower end portion of the rotor sleeve to an upper end portion thereof, wherein the rotor blade assembly unit is a rotor head A rotor assembly for a centrifuge has been proposed that is removed from the rotor sleeve as it is separated from the rotor sleeve.
Japanese Utility Model Publication No. 48-28863 JP 2004-322054 A Special Table 2002-529242

  However, in such a centrifuge, the range of fine particles that can be separated and classified is limited, and the range in which the centrifuge can be applied may be narrowed. Moreover, there is a problem that the structure becomes complicated and the cleaning or sterilization operation cannot always be performed easily.

  In view of such problems, the present invention provides a centrifuge that can be easily cleaned or sterilized with a simple structure, and that can efficiently separate and classify various fine particles. With the goal.

  In the suspended rotary cylinder type centrifuge, the present inventors have suspended the suspension in a space (suspension processing space) partitioned by the suspended rotary cylinder and blades of blades housed therein. The present invention has been completed on the basis of the knowledge that the means for guiding the effect on the separation / classification efficiency of the suspension is large.

  A centrifugal separator according to the present invention includes a suspended rotary cylinder coupled to a rotation drive mechanism, blades housed in the suspended rotary cylinder, and supports the suspended rotary cylinder and the suspended rotary cylinder. A centrifugal separator having a supply pipe for supplying suspension to the frame and a frame having a discharge pipe for collecting the suspension flowing out from the suspended rotary cylinder, the lower end of the suspended rotary cylinder The part is provided with a guide cap for guiding the suspension received from the supply pipe to the blade.

  In the above-mentioned centrifuge, the induction cap is preferably provided with an opening and a skirt that gradually increases in diameter from the opening, and preferably can be detachably attached to the blade. In addition, the induction cap may be such that the maximum diameter of the skirt portion is slightly smaller than the inner diameter of the suspended rotary cylinder.

  Further, in the above centrifugal separator, the suspended rotating cylinder is preferably provided with a bag-like portion on the outer periphery of the upper end, and the blades are provided with three or more blades arranged at equal intervals around the blade shaft. It should be a thing.

  The centrifuge according to the present invention can efficiently perform separation and classification with a simple structure, and can easily perform washing or sterilization operations. In addition, by attaching an introduction cap optimal for the suspension to be separated and classified to the blades, it is possible to efficiently separate and classify various fine particles.

  Embodiments of a centrifuge according to the present invention will be described with reference to the drawings. 1-4 show an embodiment of a centrifuge 100 according to the present invention. 1 is a front view of the centrifuge 100, FIG. 2 is a partial cross-sectional view of a suspended rotary cylinder portion of the centrifuge 100, FIG. 3 is a partial cross-sectional view of a suspended rotary cylinder lower portion, and FIG. 3 is a perspective view of a blade 15 and a guide cap 30 that are accommodated in a lower rotating cylinder 10. FIG.

  As shown in FIG. 1, a centrifuge 100 has a bowl-shaped frame 40 in which a cylindrical outer cylinder 42 standing upright is held by a stand 41, and a suspension rotating cylinder 10 described below has a suspension. Supply pipe 55 and a discharge pipe 56 for recovering the suspension flowing out from the suspended rotary cylinder 10. As shown in FIG. 2, a suspended rotary cylinder 10 is rotatably supported inside the outer cylinder 42. Further, the blade 15 is accommodated inside the suspended rotary cylinder 10, and a guide cap 30 is attached to the lower end of the blade 15. The suspended rotary cylinder 10 is rotated at a high speed by the rotation drive mechanism 60 shown in FIG.

  As shown in FIG. 2, the suspended rotary cylinder 10 includes a cylinder portion 11, a bottom portion 12, and a head portion 13, and the head portion 13 is connected to a spindle 65 described below via a coupling nut 66. Is driven to rotate by a sub pulley 63. As shown in FIG. 3, the cylindrical portion 11 and the bottom portion 12 are screw-coupled via a seal 19, and the cylindrical portion 11 and the head portion 13 are similarly screw-coupled. As a result, the suspended rotary cylinder 10 can be easily disassembled and assembled, and the blade 15 and the induction cap 30 can be detached and the collected coarse particles in the suspension can be easily discharged.

  Further, as shown in FIG. 3, the lower part of the suspended rotary cylinder 10 is supported by the outer cylinder 42 so that the rotation center of the suspended rotary cylinder 10 coincides with the central axis ZZ of the outer cylinder 42. That is, the drag 43 is fitted into the outer cylinder 42 so that the center axis thereof coincides with the center axis ZZ of the outer cylinder, and the drag 43 is fixed to the outer cylinder 42 by the nut 46 after alignment. A bearing 48 is held on the drag 43, and the bearing 48 is aligned to such an extent that it contacts the bush 18 provided on the bottom 12 of the suspended rotary cylinder 10. As a result, the suspended rotating cylinder 10 is held so as to rotate at high speed around the central axis ZZ of the outer cylinder 42. In this example, the drag 43 is provided with a greasing hole 43a and a greasing bearing 48 is used, but an oil-free bearing can also be used.

  A nozzle 45 connected to the supply pipe 55 is provided at the center of the drag 43, and the tip of the nozzle 45 projects into the introduction hole 12a provided in the bottom 12 of the suspended rotary cylinder 10. The introduction hole 12a has a conical shape, and a labyrinth effect is exerted between the end of the introduction hole 12a and the nozzle 45. Therefore, the supply hole 55a passes from the supply port 45a of the nozzle 45 to the suspended rotating cylinder 10. The supplied suspension is prevented from leaking.

  As shown in FIG. 4, the blade 15 has six (three or more) blades 15b around the blade shaft 15a. Each blade is provided with a rivet 16, and a spring 17 is provided on the rivet 16. It can be attached.

  The blade 15 is held and fixed inside the suspended rotary cylinder 10 by a spring 17. That is, as shown in FIG. 2, the spring 17 presses the inner wall of the cylindrical portion 11 of the suspended rotary cylinder 10, and the blade 15 rotates in a suspended manner by the frictional force acting between the spring 17 and the cylindrical portion 11. It is held and fixed inside the cylinder 10. In order to prevent the coarse particles in the suspension from flowing out from the suspended rotary cylinder 10 toward the discharge pipe 56, the blade 15 has its upper end in contact with the head 13 of the suspended rotary cylinder 10. Is attached.

  As shown in FIG. 4, the guide cap 30 includes an opening 32 and a skirt portion 31, and is provided with a groove 33 for detachably attaching the guide cap 30 to the blade 15. The skirt portion 31 gradually increases in diameter from the opening 32, and the guide cap 30 has a conical shape as a whole.

  As shown in FIG. 1, the rotational drive mechanism 60 includes a motor 61, a main pulley 62, a belt 68, a secondary pulley 63, and a spindle 65. The slave pulley 63 has a clutch therein, and the pindle 65 is rotated at high speed by the motor 61 via the main pulley 62, the belt 68, and the slave pulley 63. The rotation of the pindle 65 is transmitted to the suspended rotary cylinder 10 via a coupling nut 66 as shown in FIG. 2, and the suspended rotary cylinder 10 is rotated at high speed. The clutch provided in the slave pulley 63 also has a function of preventing abnormal rotation of the suspended rotary cylinder 10.

  As described above, the frame 40 includes the outer cylinder 42, the stand 41 that holds the outer cylinder vertically, the supply pipe 55 that supplies the suspension, and the discharge pipe 56 that collects the suspension (FIG. 1). The outer cylinder 42 is provided with a mechanism for holding the suspended rotary cylinder 10 so as to be rotatable at a high speed, and a mechanism for supplying the suspension from the supply pipe 55 to the suspended rotary cylinder 10 (FIG. 2). The frame 40 includes a water collection chamber 58 that collects the suspension discharged from the discharge port 13b provided in the head 13 of the suspended rotary cylinder 10 and guides it to the discharge pipe 56 as shown in FIG. Yes. Thereby, the suspension containing fine particles from which coarse particles are removed from the suspended rotating cylinder 10 rotating at high speed can be efficiently recovered from the discharge pipe 56. Note that the opening area and the number of the discharge ports 13b, the size of the water collecting chamber 58, and the like are appropriately determined by the capacity of the centrifuge, the number of rotations of the suspended rotating cylinder 10, and the like.

  The water collection chamber 58 is formed in a space surrounded by the cover 50 and the labyrinth 51, and leakage of the suspension to the outside is prevented by the labyrinth 51 and the gasket 57 provided on the top of the cover 50. ing. The number of stages of the labyrinth 51 is provided as necessary, and in this example, it is provided in two stages.

  Separation / classification of liquid or solid fine particles in suspension using such a centrifuge 100 is performed as follows. That is, the suspension supplied from the supply pipe 55 is sprayed from the supply port 45a by the nozzle 45 to the introduction hole 12a in the bottom 12 of the suspended rotary cylinder 10. The jetted suspension flows into the opening 32 of the induction cap 30 that rotates at high speed together with the blades 15 through the inflow chamber 14. The suspension flowing into the induction cap 30 is in a vortex state. Therefore, the suspension containing a large amount of coarse particles having a large specific gravity is guided along the inner wall of the skirt portion 31 of the guide cap 30 toward the outer periphery of the blade 15 and flows into the suspension processing space. On the other hand, the suspension containing a large amount of fine particles having a small specific gravity in the suspension flows into the suspension processing space around the blade shaft 15a through the central portion of the induction cap 30. In this way, the suspension is first roughly separated and classified by the induction cap 30.

  Next, since the suspension flowing into the suspension treatment space is rotated at high speed and the centrifugal force acts on the fine particles in the suspension, the suspension is moved from the lower end to the upper end of the suspension treatment space. Coarse particles are collected on the inner peripheral surface of the cylindrical portion 11 of the suspended rotary cylinder 10 in accordance with the length of time during the flow and the magnitude of the centrifugal force (arrow L in FIG. 2). On the other hand, the suspension containing fine particles that have not been collected flows out from the outlet 13b to the water collecting chamber 58 through the outlet hole 13a of the head 13 as shown by the arrow S in FIG. Then, the suspension is discharged from the discharge pipe 56, and necessary fine particles are collected from the discharged suspension, and the suspension is separated and classified. The coarse particles collected in the suspended rotary cylinder 10 are discharged batchwise by stopping the operation of the centrifuge 100 and disassembling the suspended rotary cylinder 10.

  In this way, the centrifugal separator 100 separates and classifies the suspension. In this centrifuge 100, as described above, the induction cap 30 is provided at the lower end of the blade 15, and rough separation and classification are performed in advance by the induction cap 30, so that separation and classification can be performed with high efficiency. it can.

  FIG. 5 is a graph showing the results of examining the difference in classification efficiency depending on the presence or absence of the induction cap 30. In FIG. 5, the horizontal axis represents the particle diameter Dp, and the vertical axis represents the partial classification efficiency Δη. Further, D in FIG. 5 indicates the maximum outer diameter of the skirt portion 31 of the guide cap 30 when the inner diameter of the cylindrical portion 11 of the suspended rotating cylinder 10 is 45 mm (the thickness of the skirt portion 31 is 0.5 mm). ). According to FIG. 5, when there is no induction cap 30 indicated by ●, almost no classification is performed. On the other hand, in the case of D = 37, 39 and 41 provided with the induction cap 30, the classification is advanced, and the classification is advanced as the maximum outer diameter D of the skirt portion 31 is increased from 37 mm to 41 mm. I understand.

Note that FIG. 5 shows a case where silica particles having a median diameter of 0.7 μm and a density of 2300 kg / m ³ having the particle size distribution shown in FIG. It is the result of performing a classification test at a rotation speed of 6000 rpm of the suspended rotary cylinder 10 using the suspension. The test apparatus used for this classification test is shown in FIG. The test equipment consists of a water tank 101 with a capacity of 4 liters, a pump 102, a flow meter 103, and the centrifugal separator 100. The temperature of the suspension and the dispersion state of the silica particles are controlled by the temperature control device 107, ultrasonic dispersion. The measurement was performed using an apparatus 105 and a stirring bar 106. Silica fine particles manufactured by Denki Kagaku Kogyo Co., Ltd. were used. The average particle size was measured by a laser diffraction method using a particle size distribution analyzer LA920 manufactured by Horiba.

  Thus, since the present centrifuge 100 is provided with the induction cap 30, it is possible to perform separation and classification efficiently. However, the centrifuge according to the present invention is not limited to the above embodiment. For example, a cylindrical partition member 25 shown in FIG. 8A is disposed between the blade 15 and the head 13 of the suspended rotating cylinder 10 as shown in FIG. By configuring the bag-like portion 28 between the blades 15, the classification efficiency can be improved.

  Further, the guide cap 30 can be formed into a lid shape as shown in FIG. That is, the guide cap 30 includes a skirt portion 31, a groove 33, and a top plate 35. The top plate 35 guides the suspension received from the nozzle 45 to the outer periphery of the suspended rotary cylinder 10 and the blade 15. A guide groove 36 is provided. The shape and depth of the guide groove 36 are formed in accordance with the characteristics of the fine particles to be separated and classified. Thereby, various fine particles can be classified.

  Using the test apparatus shown in FIG. 7, a test was performed to determine how the number of blades 15b of the blade 15 used in the centrifugal separator 100 and the rotational speed of the suspended rotating cylinder 10 affect the classification efficiency. . Both tests were performed using a suspension in which silica particles shown in FIG. 6 were dispersed in pure water, at a flow rate of 0.3 l / min, and the rotation speed of the suspended rotating cylinder 10 was 6000 rpm.

  The said test result is shown to FIGS. FIG. 10 is a graph showing the effect of the number of blades 15b of the blade 15 on the classification efficiency. The graph shows the particle diameter Dp on the horizontal axis and the partial classification efficiency Δη on the vertical axis with the number of blades 15b as a parameter. It is. As shown in FIG. 10, when there is no blade 15b, the classification does not proceed at all, and when the number of blades 15b is 3, 4 or 6, the classification proceeds, and although the number of blades 15b is small, the number of blades 15b is small. It can be seen that classification increases as the number increases.

  FIG. 11 is a graph showing the influence of the number of rotations of the suspended rotating cylinder 10 and the number of blades 15b of the blades 15 on the classification efficiency. The number of blades 15b is used as a parameter, and the horizontal axis indicates the suspended rotating cylinder 10 5 is a graph showing the number n of rotations and the completely collected particle diameter Dpmax on the vertical axis. In addition, the continuous line in a figure shows the theoretical formula of centrifugation. The flow rate of the suspension was 0.3 l / min.

  As shown in FIG. 11, when the number of blades 15b of the blade 15 is 3, 4, or 6, the higher the rotational speed n, the smaller the complete collection particle size, and the rotational speed n is 9000- It can be seen that at 10,000 rpm, the completely collected particle size remains almost unchanged. Further, it can be seen that when the number of blades 15b is small, the variation of the completely collected particle size from the theoretical value is large, and when the number of blades 15b is 6, the theoretical value is well matched.

It is a front view of the centrifuge which concerns on this invention. It is a partial cross section figure of the suspension rotation cylinder part of FIG. FIG. 2 is a partial cross-sectional view of a lower part of a suspended rotating cylinder in FIG. 1. It is a perspective view of the blade | wing and guide cap part of FIG. It is a graph which shows the effect which it has on the classification efficiency of an induction cap. It is a graph which shows the particle size distribution of the silica particle used when the graph of FIG. 3 was calculated | required. It is a layout figure which shows the outline | summary of the testing apparatus used when calculating | requiring the graph of FIG. It is the front view and attachment figure of a partition member. It is the front and side view showing other examples of a guidance cap. It is a graph showing the influence which the number of blades of a blade | wing has on classification efficiency. It is a graph showing the influence which the rotation speed of a suspension rotation cylinder and the number of blades of a blade | wing have on classification efficiency.

Explanation of symbols

10 Hanging rotating cylinder
11 Tube
12 Bottom
13 head
14 Inflow chamber
15 feathers
16 rivets
17 Spring
18 Bush
19 Seal
25 Partition member
28 Bag-shaped part
30 induction cap
31 Skirt
32 opening
33 groove
35 Top plate
36 Guide groove
40 frames
41 Stand
42 outer cylinder
43 Drag
45 nozzles
46 Nut
48 Bearing
50 cover
51 Labyrinth
55 Supply pipe
56 Discharge pipe
57 Gasket
58 Catchment room
60 Rotation drive mechanism
61 motor
62 Main pulley
63 Secondary pulley
65 spindle
66 Coupling nut
68 belts
100 centrifuge

Claims (6)

A suspended rotating cylinder connected to a rotation drive mechanism, a blade accommodated in the suspended rotating cylinder, a supply pipe that supports the suspended rotating cylinder and supplies suspension to the suspended rotating cylinder And a frame having a discharge pipe for collecting the suspension that has flowed out of the suspended rotary cylinder,
A centrifuge in which a lower end portion of the suspended rotary cylinder is provided with an induction cap for guiding the suspension received from the supply pipe to the blades.   The centrifuge according to claim 1, wherein the guide cap includes an opening and a skirt that gradually increases in diameter from the opening.   The centrifuge according to claim 1 or 2, wherein the induction cap can be detachably attached to the blade.   The centrifuge according to any one of claims 1 to 3, wherein the induction cap has a skirt portion whose maximum diameter is slightly smaller than the inner diameter of the suspended rotary cylinder.   The centrifugal separator according to any one of claims 1 to 4, wherein the suspended rotating cylinder has a bag-like portion on an outer peripheral portion at an upper end thereof.   6. The centrifugal separator according to claim 1, wherein the blade includes three or more blades arranged at equal intervals around the blade shaft.

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