Centrifugal separator

Abstract

Even with a smaller pump, high precision in removing fine particles can be achieved. [Solution] The separation section 10 has a fluid outlet at the axis and a fluid inlet 14 at a position offset from the axis, and supplies a fluid containing fine particles from the fluid inlet 14 at a predetermined flow velocity to generate a vortex, moves the fine particles outward in a centrifugal state, discharges the fluid separated from the fine particles from the fluid outlet 13, and decelerates the vortex to allow the separated fine particles to settle, and a settling section 20 settles the fine particles that have settled in the separation section 10, and the separation section 10 has a cylindrical part 11 and a bottom part 12 below the cylindrical part 11 that is tapered and narrows as it goes downward, and the vertical length of the cylindrical part 11 is approximately twice the inner diameter of the cylindrical part 11.

Description

Technical Field

[0001] The present invention relates to a centrifugal separator for separating and removing fine substances such as fine powder scraps contained in a fluid.

Background Art

[0002] For example, in a machining apparatus, machining is performed while supplying cutting fluid from a supply tank, and the cutting fluid contains fine powder-shaped cutting scraps. The cutting fluid containing this fine powder-shaped cutting scraps is supplied to a filter device, and the cutting scraps are removed by this filter device and the cutting fluid is returned to the supply tank (for example, Patent Document 1).

[0003] As such a filter device, for example, there are those that remove cutting scraps by a filter membrane or by precipitation, but in any case, there are problems such as being unable to surely remove fine powder-shaped cutting scraps contained in a large amount in the cutting fluid with a small-sized device in a short time.

[0004] Therefore, there is a centrifugal separator that supplies a fluid containing fine substances at a predetermined flow rate to generate a vortex, moves the fine substances outward in a centrifugal state, discharges the fluid from which the fine substances have been separated, and decelerates the vortex to precipitate the separated fine substances (for example, Patent Document 2).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, in such centrifugal separators, in order to separate and reliably remove a large amount of fine particles in a short time, it is necessary to supply the fluid containing the fine particles at a predetermined flow rate. This requires a larger pump to supply the fluid containing the fine particles, which leads to the problem of increased power consumption.

[0007] This invention has been made in view of the above-mentioned problems, and aims to provide a centrifugal separator that can achieve high accuracy in removing fine particles even when the pump is miniaturized. [Means for solving the problem]

[0008] To solve the above objective, the first feature of the centrifugal separator according to the present invention is: A separation unit having a fluid outlet at the axis and a fluid inlet at a position offset from the axis, supplying a fluid containing fine particles from the fluid inlet at a predetermined flow velocity to generate a vortex, moving the fine particles outward in a centrifugal state, discharging the fluid from which the fine particles have been separated from the fluid outlet, and slowing down the vortex to allow the separated fine particles to settle, It has a sedimentation section for settling the fine particles that settle in the separation section, The separation portion has a cylindrical portion and a tapered bottom portion below the cylindrical portion that narrows as it goes downwards, and the vertical length of the cylindrical portion is approximately twice the inner diameter of the cylindrical portion. A second feature of the centrifugal separator according to the present invention is, The separation portion is characterized by having a length in the vertical direction of the bottom portion that is four times or more the inner diameter of the cylindrical portion. The third feature of the centrifugal separator according to the present invention is The volume of the sedimentation section is eight times or more the volume of the separation section. The fourth feature of the centrifugal separator according to the present invention is, The aforementioned fluid inlet is The separation section has a flow path that supplies the fluid in the same direction as the vortex generated in the separation section. The fifth feature of the centrifugal separator according to the present invention is, Multiple separation units are arranged in series. The separation unit located at the top has a configuration that includes the fluid outlet and the fluid inlet. The sixth feature of the centrifugal separator according to the present invention is, In the fluid outlet of the separation section located at the uppermost level, or in the communication hole of the separation section, The key is that an obstacle is placed on at least one of the lower sides to restrict the lifting of microscopic particles. [Effects of the Invention]

[0009] According to the centrifugal separator of the present invention, high accuracy in removing fine particles can be achieved even when the pump is miniaturized. [Brief explanation of the drawing]

[0010] [Figure 1] This figure shows an example of the arrangement of a centrifugal separator. [Figure 2] This is a cross-sectional view of a centrifugal separator according to Example 1 of the present invention. [Figure 3] (A) is an example of test data showing the relationship between the ratio of the vertical length of the cylindrical part to the inner diameter of the cylindrical part and the separation and removal rate in a centrifugal separator according to Example 1 of the present invention. (B) is an example of test data showing the relationship between the ratio of the vertical length of the bottom part to the inner diameter of the cylindrical part and the separation and removal rate in a centrifugal separator according to Example 1 of the present invention. (C) is an example of test data showing the relationship between the ratio of the volume of the sediment section to the volume of the separation section and the separation and removal rate in a centrifugal separator according to Example 1 of the present invention. [Figure 4] (A) is an explanatory diagram illustrating the structure of the inlet path and fluid inlet of the centrifugal separator according to Embodiment 1 of the present invention, and (B) is an explanatory diagram illustrating the fluid flow in the inlet path and fluid inlet of the centrifugal separator according to Embodiment 1 of the present invention. [Figure 5] This is a cross-sectional view of a centrifugal separator according to Embodiment 2 of the present invention. [Modes for carrying out the invention]

[0011] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The same or equivalent parts and components throughout the drawings are denoted by the same or equivalent reference numerals. However, it should be noted that the drawings are schematic and different from the actual ones. Also, there are parts where the dimensional relationships and ratios are different between the drawings.

[0012] Moreover, the embodiments shown below exemplify devices and the like for embodying the technical idea of this invention, and the technical idea of this invention does not specify the arrangement of each component part as follows. The technical idea of this invention can be variously modified within the scope of the claims.

[0013] The centrifugal separator of the present invention is used for filtering fine substances such as raw materials in pharmaceuticals, chemicals, foods, and beverages, recovering fine substances such as cutting powders in automobiles, machine tools, and the processing industry, filtering circulating water and wastewater in each factory, water treatment, etc., removing fine substances such as impurities in semiconductors, bio, etc., and removing fine substances such as foreign matters in washing water, solvents, etc., and is widely used for separating and removing fine substances contained in fluids of liquids and gases.

[0014] An example of the arrangement of the centrifugal separator of the present invention is shown in FIG. 1. The example shown in FIG. 1(A) is arranged in the path for supplying raw materials and others from a raw material and other tank to each device by a pump, and removing fine substances contained in the raw materials and others by the centrifugal separator. The example shown in FIG. 1(B) is the same as the example in FIG. 1(A), but the fine substances separated in the centrifugal separator are discharged to a discharger. The example shown in FIG. 1(C) separates fine substances in the centrifugal separator and returns the raw materials and others to the raw material and other tank. The example shown in FIG. 1(D) is the same as the example in FIG. 1(C), but the fine substances separated in the centrifugal separator are discharged to a discharger.

[0015] Hereinafter, in this embodiment, the case of using the present invention for collecting fine objects such as cutting powder of a machine tool or a processing industry will be described. In this embodiment, it is used for the case of removing fine powder-shaped scraps contained in a liquid, which is a cutting fluid, as the fluid, but it can also be used in the same manner for removing fine objects contained in a gas. Further, any fine objects can be used, and it is not limited to fine powder-shaped scraps.

[0016] <Example 1> First, the centrifugal separator 1 according to Example 1 of the present invention will be described with reference to FIG. 2. FIG. 2 is a cross-sectional view of the centrifugal separator according to Example 1 of the present invention.

[0017] (Configuration of the centrifugal separator) The centrifugal separator 1 according to Example 1 of the present invention includes a separation unit 10 and a precipitation unit 20. The separation unit 10 and the precipitation unit 20 are integrally provided, improving the airtightness between the separation unit 10 and the precipitation unit 20, and are formed of a metal such as aluminum, for example, being lightweight and having strength.

[0018] The separation unit 10 has a fluid outlet 13 at its axis center and a fluid inlet 14 at a position offset from the axis center. The fluid containing fine objects is supplied into the separation unit 10 from the fluid inlet 14 through the inflow path 15. The inflow path 15 becomes narrower as it approaches the fluid inlet 14 and is provided such that the cross-sectional area of the fluid inlet 14 is the smallest. Thereby, the fluid containing fine objects is vigorously supplied from the fluid inlet 14 to generate a vortex. Then, the fine objects are moved outward in a centrifugal state, and the fluid separated from the fine objects is discharged from the fluid outlet 13, and the vortex is decelerated to sediment the separated fine objects.

[0019] The separation unit 10 has a cylindrical portion 11 having a hollow cylindrical shape and a bottom portion 12 having a tapered shape that narrows downward as it goes downward. The cylindrical portion 11 and the bottom portion 12 are integrally provided.

[0020] The vertical length F of the cylindrical portion 11 is approximately twice the inner diameter Dc of the cylindrical portion 11. The vertical length I of the bottom portion 12 is at least four times the inner diameter of the cylindrical portion 11.

[0021] Conventional centrifugal separators have a set of ratios that serve as design guidelines. It is possible to manufacture a centrifugal separator by using existing ratios, with the inner diameter of the cylindrical section of the separation unit set to "1". For example, in the aforementioned Patent Documents 1 and 2, the vertical length of the cylindrical section is equal to the inner diameter of the cylindrical section, or the vertical length of the cylindrical section is shorter than the inner diameter of the cylindrical section. When a centrifugal separator is manufactured using such a configuration ratio, in order to achieve appropriate fine particle removal accuracy, it is necessary to increase the pump capacity so that the fluid flows in at an operating pressure of 0.1 (MPa) or higher at the fluid inlet, and to increase the size of the pump itself.

[0022] In the centrifugal separator 1 according to Embodiment 1 of the present invention, the vertical length F of the cylindrical portion 11 is approximately twice the inner diameter Dc of the cylindrical portion 11. However, it is not necessarily required that the vertical length F of the cylindrical portion 11 be twice Dc; for example, it may be allowed to have a certain range, such as from 1.9 to 2.1 times.

[0023] Figure 3(A) shows an example of test data illustrating the relationship between the ratio of the vertical length F of the cylindrical portion 11 to the inner diameter Dc of the cylindrical portion 11 and the separation and removal rate in a centrifugal separator 1 according to Embodiment 1 of the present invention. Here, ceramic particles are used as the fine material.

[0024] As shown in Figure 3(A), assuming the inner diameter Dc of the cylindrical portion 11 is x (mm), the separation and removal rate is highest at 62 (%) when the vertical length F of the cylindrical portion 11 is 2x (mm), and it can be seen that the separation and removal rate decreases under the conditions F=x and F=3x.

[0025] When the vertical length F of the cylindrical section 11 is approximately twice Dc, the reason why the separation and removal rate increases is related to the movement of particles inside the centrifugal separator. As described above, the inflow path 15 narrows as it approaches the fluid inlet 14, and the cross-sectional area of ​​the fluid inlet 14 is set to be the smallest. Therefore, when the fluid passes through the fluid inlet 14, it is rectified, the inflow velocity increases, and centrifugal force is generated, creating a vortex. If the vertical length F of the cylindrical section 11 at this time is less than twice Dc, a sufficient vortex is not formed, and the particles cannot move sufficiently to the inner wall of the separation section 10 and flow out from the fluid outlet 13. In addition, because a sufficient vortex is not formed, turbulence becomes strong at the bottom 12, leading to a decrease in the removal rate.

[0026] Therefore, in the centrifugal separator 1 according to Embodiment 1 of the present invention, the vertical length F of the cylindrical portion 11 is made approximately twice the inner diameter Dc of the cylindrical portion 11.

[0027] Furthermore, as described above, the length I in the vertical direction of the bottom portion 12 is at least four times the inner diameter of the cylindrical portion 11.

[0028] Figure 3(B) shows an example of test data illustrating the relationship between the ratio of the vertical length I of the bottom portion 12 to the inner diameter Dc of the cylindrical portion 11 and the separation and removal rate in a centrifugal separator 1 according to Embodiment 1 of the present invention. Here, ceramic particles are used as the fine material.

[0029] As shown in Figure 3(B), the longer the vertical length I of the bottom portion 12, the higher the separation and removal rate. It was found that even when the vertical length I of the bottom portion 12 exceeds four times the inner diameter of the cylindrical portion 11, it has almost no effect on the separation and removal rate.

[0030] The reason why the separation and removal rate increases when the vertical length I of the bottom 12 is four times or more the inner diameter Dc of the cylindrical part 11 is related to the flow velocity of the liquid inside the bottom 12. If the vertical length I of the bottom 12 is less than four times the inner diameter Dc of the cylindrical part 11, it becomes difficult for vortices to form, and the fluid does not centrifuge along the inner wall of the bottom 12 but flows out from the fluid outlet 13. The longer the vertical length I of the bottom 12, the easier it becomes for vortices to form, leading to an improvement in the separation and removal rate of fine particles.

[0031] The sedimentation section 20 settles the fine particles that settle in the separation section 10. As described above, the bottom 12 of the separation section 10 is tapered downwards and communicates with the sedimentation section 20 through a communication hole 12a located on the axial center.

[0032] The sedimentation section 20 has an outlet 21 for discharging the settled fine matter, and this outlet 21 is equipped with a discharge valve 22, allowing the settled fine matter to be easily discharged from the outlet 21 by manually operating the discharge valve 22.

[0033] In the separation section 10, the fine particles are moved outward in a centrifugal state, and the fluid from which the fine particles have been separated is discharged from the fluid outlet 13. The vortex is then slowed down, causing the separated fine particles to settle. The volume of the settling section 20 is made larger than the volume of the separation section 10. Specifically, the volume of the settling section 20 is set to be at least eight times the volume of the separation section 10.

[0034] Figure 3(C) shows an example of test data illustrating the relationship between the ratio of the volume of the sedimentation section 20 to the volume of the separation section 10 and the separation and removal rate in a centrifugal separator 1 according to Example 1 of the present invention. Here, ceramic particles are used as the fine material.

[0035] As shown in Figure 3(C), it was found that as the ratio of the volume of the sedimentation section 20 to the volume of the separation section 10 is increased, the separation and removal rate improves until the volume of the sedimentation section 20 becomes eight times the volume of the separation section 10. However, once the volume of the sedimentation section 20 exceeds eight times the volume of the separation section 10, it has almost no effect on the separation and removal rate.

[0036] Therefore, in the centrifugal separator 1 according to Embodiment 1 of the present invention, the volume of the sedimentation section 20 is set to be eight times or more the volume of the separation section 10.

[0037] (Processing using a centrifugal separator) In the centrifugal separator 1 according to Embodiment 1 of the present invention, a fluid containing fine particles is supplied at a predetermined flow rate from the fluid inlet 14 of the separation unit 10 to generate a vortex, the fine particles are moved outward in a centrifugal state, the fluid from which the fine particles have been separated is discharged from the fluid outlet 13, the separated fine particles are discharged from the communication hole 12a and recovered in the sedimentation unit 20.

[0038] As shown in Figures 4(A) and 4(B), a fluid containing fine particles is supplied from the fluid inlet 14 to the inside of the separation unit 10 via the inlet path 15. At this time, the inlet path 15 supplies the fluid in the same direction as the vortex generated in the separation unit 10. As the fluid containing fine particles flows through the inlet path 15, the inlet path 15 creates a flow in the same direction as the vortex. Therefore, the collision pressure between the fluid containing fine particles supplied from the fluid inlet 14 and the fluid in the separation unit 10 is reduced, the flow loss of the fluid containing fine particles is reduced, and it can be supplied at high speed, so a predetermined flow velocity can be maintained, and the pump supplying the fluid containing fine particles can be made smaller and power consumption can be reduced.

[0039] In the separation unit 10, the fine particles are moved outward in a centrifugal state, and the fluid from which the fine particles have been separated is discharged from the fluid outlet 13, and the vortex is slowed down to allow the separated fine particles to settle.

[0040] The settled fine particles settle within the sedimentation section 20, and when the discharge valve 22 is manually opened, the fine particles that have settled within the sedimentation section 20 are discharged to the outside through the discharge port 21.

[0041] As described above, the volume of the sedimentation section 20 is set to be at least eight times the volume of the separation section 10. Therefore, the volume of the sedimentation section 20 is sufficiently large relative to the volume of the separation section 10, and even if the separated fine particles settle in the sedimentation section 20, the increase in the internal pressure of the sedimentation section 20 can be reduced. Consequently, the separated fine particles can smoothly enter the sedimentation section 20 from the separation section 10, resulting in a decrease in the internal pressure of the separation section 10. This allows the fluid containing the fine particles to be supplied from the fluid inlet 14 at a predetermined flow rate, enabling a smaller pump to supply the fluid containing the fine particles and reducing power consumption.

[0042] <Example 2> Figure 5 is a cross-sectional view of a centrifugal separator according to Example 2 of the present invention.

[0043] As shown in Figure 5, the centrifugal separator 1A according to Embodiment 2 of the present invention has two separation units 10 arranged in series in the vertical direction. Here, the separation unit 10 located at the top is referred to as separation unit 10A, and the separation unit 10 located at the bottom is referred to as separation unit 10B. The separation unit 10A located at the top has a fluid outlet 13 and a fluid inlet 14.

[0044] A fluid containing fine particles is supplied at a predetermined flow rate from the fluid inlet 14 of the separation unit 10A to generate a vortex, which moves the fine particles outward in a centrifugal state, and the fluid from which the fine particles have been separated is discharged from the fluid outlet 13. The fluid containing the fine particles, which have moved outward in a centrifugal state, is then discharged from the communication hole 12b to the separation unit 10B. Furthermore, within the separation unit 10B, the fluid containing the fine particles, which have moved outward in a centrifugal state, is discharged from the communication hole 12a, and the fine particles are settled in the sedimentation unit 20.

[0045] As described above, in the centrifugal separator 1A according to Embodiment 2 of the present invention, since the two separation units 10 are arranged in series in the vertical direction, the fluid containing fine particles is discharged from the separation unit 10A to the separation unit 10B, and the fine particles are moved outward in a centrifugal state within the separation unit 10B, and the fluid from which the fine particles have been separated flows into the separation unit 10A. This makes it easier to separate the fluid from which the fine particles have been separated from the fluid containing the fine particles, and a higher separation and removal rate can be obtained.

[0046] Alternatively, as shown in Figure 5, an obstacle 51 may be placed below the fluid outlet 13 of the uppermost separation unit 10A, and an obstacle 52 may be placed below the communication hole 12b of the lower separation unit 10B. Obstacles 51 and 52 are fixed by fixing members (not shown).

[0047] A fluid containing fine particles is supplied at a predetermined flow rate from the fluid inlet 14 of the separation unit 10A to create a vortex, which moves the fine particles outward in a centrifugal state, and the fluid from which the fine particles have been separated is discharged from the fluid outlet 13. At this time, the obstacle 51 prevents the fine particles from floating up.

[0048] Furthermore, within the separation section 10B, the fluid containing the fine particles that have moved outward in a centrifugal state is discharged from the communication hole 12a, and the fine particles are recovered in the sedimentation section 20. At this time, the obstacle 52 prevents the fine particles from floating up.

[0049] In this manner, an obstacle 51 is placed at the fluid outlet 13 of the separation unit 10A located at the top, and an obstacle 52 is placed at the communication hole 12b with the separation unit 10B. This prevents fine particles from floating up, allowing them to settle efficiently and improving the separation efficiency.

[0050] In the centrifugal separator 1A according to Embodiment 2 of the present invention, obstacles 51 and 52 are arranged, but either one of them may be arranged.

[0051] Furthermore, in the centrifugal separator 1A according to Embodiment 2 of the present invention, the separation unit 10 is configured to include two separation units 10, namely separation unit 10A and separation unit 10B. However, the invention is not limited to this configuration, and the separation units 10 may be arranged in series in the vertical direction in three or more stages. [Industrial applicability]

[0052] This invention is applied to a centrifugal separator that separates and removes fine particles such as fine powder debris contained in a fluid. It can efficiently supply the fluid containing the fine particles at a predetermined flow rate to generate a vortex, enabling miniaturization of the pump that supplies the fluid containing the fine particles and reducing power consumption. [Explanation of Symbols]

[0053] 1.1A Centrifugal Separator 10 Separation part 11 Cylindrical section 12 Bottom 12a,12b communication hole 13 Fluid outlet 14 Fluid inlet 15. Inflow Routes 20 Sedimentation section 21 Outlet 22 Exhaust valve

Claims

1. A separation unit having a fluid outlet at the axis and a fluid inlet at a position offset from the axis, supplying a fluid containing fine particles from the fluid inlet at a predetermined flow velocity to generate a vortex, moving the fine particles outward in a centrifugal state, discharging the fluid from which the fine particles have been separated from the fluid outlet, and slowing down the vortex to allow the separated fine particles to settle, It has a sedimentation section for settling the fine particles that settle in the separation section, The separation portion has a cylindrical portion and a tapered bottom portion below the cylindrical portion that narrows as it goes downwards, and the vertical length of the cylindrical portion is approximately twice the inner diameter of the cylindrical portion. A centrifugal separator characterized by the following features.

2. The separation portion has a length in the vertical direction of the bottom that is four times or more the inner diameter of the cylindrical portion. The centrifugal separator according to claim 1, characterized in that it is a centrifuge.

3. The volume of the sedimentation section is eight times or more the volume of the separation section. The centrifugal separator according to claim 1, characterized in that it is a centrifuge.

4. The aforementioned fluid inlet is The separation section has a channel that supplies the fluid in the same direction as the vortex generated therein. The centrifugal separator according to claim 1, characterized in that it is a centrifuge.

5. Multiple separation units are arranged in series. The separation unit located at the top has a configuration that includes the fluid outlet and the fluid inlet. The centrifugal separator according to claim 1, characterized in that it is a centrifuge.

6. In the fluid outlet of the separation section located at the uppermost level, or in the communication hole of the separation section, An obstacle was placed on at least one of the undersides to restrict the lifting of microscopic particles. The centrifugal separator according to claim 5, characterized in that it is a centrifuge.

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