JP4714055B2 - centrifuge - Google Patents

Description

  The present invention relates to a liquid material to be centrifuged, which is a mixture of a substance having a large specific gravity (usually a solid such as solid particles, but may be a liquid; the same shall apply hereinafter) and a liquid having a specific gravity smaller than that of the substance. In addition, the present invention relates to a centrifuge that separates a substance having a large specific gravity and a liquid having a specific gravity smaller than that of the substance by centrifugal force.

  A centrifugal separator separates a substance having a large specific gravity from a liquid to be centrifuged and a liquid having a specific gravity smaller than that of the substance. However, depending on the type of the liquid having a small specific gravity, the liquid collected by centrifugation may be foamed, and it may not be preferable that the separated and recovered liquid is foamed. For example, the solid particles are separated and removed from the used coolant, the liquid coolant containing no solid particles is recovered, and the coolant is repeatedly used.

  Coolant is a liquid that is supplied for cooling, lubrication, cleaning, etc. when processing workpieces (metal, glass, ceramics, etc.) with various processing machines such as grinding machines and cutting machines. There are various types such as water, oil, and emulsion. The used coolant contains solid particles generated from a workpiece or a processing machine generated during processing, and therefore it is necessary to remove the solid particles. However, if the separated and recovered coolant is foamed, the action as the coolant (cooling, lubrication and washing actions) is impaired, so there is a problem in using the separated and collected coolant even if the solid particles are removed. (Especially when used repeatedly and repeatedly) Therefore, conventionally, the bubble suppression centrifuge described in Patent Document 1 has been known.

Japanese Patent Laid-Open No. 62-114671

  However, even with the bubble suppression centrifuge described in Patent Document 1, foaming of the separated and recovered coolant may not be sufficiently suppressed.

  An object of this invention is to provide the centrifuge which can fully suppress the foaming of the liquid collect | recovered by centrifugation.

According to the present invention, a rotating container for centrifugal scattering outflow light liquid than the material separating larger material specific gravity by centrifugal force from a liquid material to be separated, the separation liquid scattered flowing out of the rotary vessel The separation liquid is formed between the outer periphery of the rotating container and the outer peripheral surface of the rotating container and the inner peripheral surface of the surrounding part so as not to leak to the outside of the centrifuge. The above object can be achieved by a centrifuge having a lead-out flow path for guiding, wherein the centrifuge is provided with a mesh portion on the inner peripheral wall surface of the surrounding portion.

Upper Kito heart separator is the separation liquid scattered outflow from rotating container collide surface, can to include a foam control unit configured for suppressing the inclined surfaces foaming suppressing inclined surfaces said foaming The inclined surface may be inclined so that the incident angle when the separated liquid collides with the inclined surface is 30 to 60 °, and the mesh portion is provided in a region closer to the gravitational direction than the inclined surface. be able to. Further, the upper Kito heart separator is the outlet to the upstream side of the outlet passage, can be at least partially formed by a porous wall provided with perforated chamber can pass said separation liquid. In the present invention, the substance having a large specific gravity may be not only a solid such as a solid particle but also a liquid. In the present invention, the description of the numerical value range includes not only both end values but also any arbitrary intermediate value included therein.

Centrifugal separator of the present invention are those having the above SL configuration may be liquid having a foaming even if a separation and recovery target, to sufficiently suppress foaming of liquid recovered was centrifuged Therefore, it is possible to solve the problems caused by foaming of the liquid to be separated and recovered. For example, when the liquid to be separated and recovered is a coolant, it is possible to separate and recover the coolant while preventing the coolant operation (cooling, lubrication, and cleaning operations) from being impaired.

[Rotating container]
The rotating container is a container that separates a substance having a large specific gravity from a liquid material to be centrifuged by centrifugal force and scatters and flows a liquid having a specific gravity smaller than that of the substance. The liquid to be centrifuged is a mixture of a substance having a large specific gravity and a liquid having a specific gravity smaller than that of the substance. The substance having a large specific gravity may be not only a solid such as a solid particle but also a liquid. The shape of the rotating container can be, for example, cylindrical or substantially cylindrical.

[Envelopment]
The surrounding portion surrounds the outside of the rotating container so that the separated liquid splashed and flown out of the rotating container does not leak to the outside of the centrifuge. The shape of the surrounding portion can be appropriately set according to the shape of the rotating container. When the shape of the rotating container is a cylindrical shape such as a cylindrical shape or a substantially cylindrical shape, for example, a diameter larger than the diameter of the rotating container. A cylindrical shape such as a cylindrical shape or a substantially cylindrical shape can be used.

[Delivery channel]
The outlet channel is a channel that is formed between the outer peripheral surface of the rotating container and the inner peripheral surface of the surrounding portion, and guides the separated liquid that has flown out of the rotating container to the outside of the centrifuge. Normally, the outlet channel can be formed by the outer peripheral surface of the rotating container and the inner peripheral surface of the surrounding part, but is provided separately between the outer peripheral surface of the rotating container and the inner peripheral surface of the surrounding part. A flow path that joins the separated liquid and that guides the joined separated liquid to the outside of the centrifuge may be used as an outlet flow path.

[Mesh part]
As the mesh portion, a metal net, a plate (preferably a metal plate) having a slit (rectangular elongated opening), and a plate having a slit (preferably a metal plate) stacked two or more. (The slits may be parallel or intersect).

Mesh portion is provided on the inner peripheral wall surface of the surrounding portion. When the separated liquid splashed and flown out of the rotating container is foamed, the foamed separated liquid is defoamed by flowing in contact with the mesh portion. In the case of providing a mesh portion to the derived channel, provided on the inner peripheral wall surface of the packaging surrounding portion (more preferably, provided in close contact with the inner peripheral wall surface). For example, the mesh portion can be provided in a collision surface where the separated liquid splashed and flown out of the rotating container collides with the inner peripheral wall surface of the surrounding portion or a region where the separated liquid flows down on the gravity direction side of the collision surface. In the case where the centrifuge is provided with a foam suppression part, preferably, a mesh part is provided on the gravitational direction side (preferably the region on the gravitational direction side adjacent to the inclined face) with respect to the inclined surface of the foam suppression part. Provide.

  The mesh portion is preferably provided as a continuous annular and belt-shaped mesh portion so as to surround the rotating container in a rotational direction of 360 ° in a position separated from the rotating container (more preferably, on the inner peripheral wall surface of the surrounding portion). It is provided so that the belt-like surface of the mesh part is in close contact). If sufficient defoaming is possible, the mesh portion does not necessarily have to be continuously provided so as to surround the rotating container in the rotation direction by 360 °, but is a discontinuous annular and belt-like mesh portion. (For example, 50% or more with respect to the entire circumference). Such a mesh part is possible, for example, by arranging a plurality of plate-like or belt-like mesh members in a discontinuous annular shape.

[Porous chamber]
The porous chamber is provided at the outlet portion of the outlet channel or at the upstream side thereof, and at least a part thereof is formed of a porous wall so that the separation liquid can pass therethrough. The foaming separation liquid is defoamed by passing through the porous chamber. The porous chamber can be filled with a filler having a defoaming action. Examples of the filler having a defoaming action include glass or ceramic spherical bodies. The porous chamber is preferably formed separately from the outlet channel and is detachably disposed in the outlet channel.

  The porous chamber is preferably arranged in a separation liquid retaining portion provided in the outlet channel. The separation liquid retention portion is a region where the entire cross section of the outlet channel (the channel cross section perpendicular to the direction in which the separation liquid flows) is filled with the separation liquid. That is, for example, the outlet portion of the outlet channel is bent into a U-shape, a V-shape, an L-shape, or the like so that the separation liquid outlet at the outlet portion of the outlet channel is filled with the separation liquid. In the case where a part of the outlet channel is provided in a region lower than the outlet separation liquid outlet surface, the outlet channel part existing in the region lower than the outlet surface stores the separated liquid scattered and discharged from the rotating container. It becomes the retention part of the separation liquid which can be formed. Therefore, when the separation liquid flows into the staying part from the upstream side of the staying part, the staying part is completely filled with the separation liquid. When the separation liquid further flows in, the same amount of the separation liquid as the inflowing separation liquid flows out from the separation liquid outlet in an overflow state. Since the liquid flowing out from the outlet passes through the staying portion filled with the separation liquid, when a porous chamber is provided in the staying portion, in addition to the defoaming action by the porous chamber, the defoaming action by the staying portion. Thus, bubbles can be removed more sufficiently.

[Foam suppression part]
The foaming suppression unit is configured such that the surface on which the separated liquid splashed out of the rotating container collides is formed as an inclined surface that suppresses foaming, and the inclined surface that suppresses foaming causes the separated liquid to collide with the inclined surface. The inclined surface is inclined so that the incident angle is 30 to 60 ° (preferably 35 to 55 °, more preferably 40 to 50 °). The incident angle when the separated liquid collides with the inclined surface is a line perpendicular to the inclined surface at the collision point of the inclined surface and the traveling direction of the separated liquid when the separated liquid collides with the inclined surface. It means the angle between

  The separated liquid that scatters and flows out of the rotating container generally foams when it scatters from the rotating container. And when the said inclined surface does not exist, the separation liquid which scattered and flowed out from the rotation container collides directly with convex parts, such as a reinforcing bar which comprises the frame | skeleton of an enclosure part, its edge part, or an inner peripheral wall surface, and it foams further. On the other hand, when the foaming suppression unit is provided, the separated liquid splashing and flowing out of the rotating container collides with the inclined surface, and thus foaming can be remarkably suppressed.

  The inclined surface that suppresses foaming is preferably provided as a continuous annular inclined surface so as to surround the rotating container by 360 ° in the rotation direction at a position separated from the rotating container. As the foam suppression portion having such an inclined surface, there is a continuous annular (ring-shaped) foam suppression plate surrounding the rotary container in the rotational direction at a position separated from the rotary container, but a part of the enclosure portion Can also be used as a foam suppression part. In other words, the surface on the inner peripheral surface of the surrounding portion where the separated liquid that has scattered and collided collides can be configured as an inclined surface that suppresses foaming of the present invention.

  If it is possible to sufficiently suppress foaming, the inclined surface that suppresses foaming does not necessarily have to be continuously provided so as to surround the rotating container in the rotational direction by 360 °. , 50% or more of the entire circumference). Such a foam suppression portion is possible by arranging a plurality of plate-like members in a discontinuous ring shape and tilting so as to correspond to the inclined surface that suppresses the foaming, and the inner peripheral surface of the surrounding portion In addition, it is possible to configure a part of the surface on which the separated liquid splashed and collided collides as an inclined surface for suppressing foaming of the present invention.

  Embodiments of the centrifuge of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view in a direction in which a rotary shaft 1a of a rotary container of a centrifuge according to an embodiment of the present invention is longitudinally cut.

  The rotating container 1 has a substantially cylindrical shape, has a rotating shaft 1a coupled to a motor (not shown), and rotates around the rotating shaft at a speed capable of being centrifuged. A coolant supply pipe 1b protrudes from the bottom of the rotating container. The coolant supply pipe 1b exists on the extension of the central axis of the rotating shaft 1a, and supplies a separation target coolant containing solid particles to the inside of the rotating container. More specifically, the separation target coolant is continuously injected into the inside of the rotary container from the opening of the injection portion at the tip of the coolant supply pipe. The separation target coolant continuously injected from the opening of the injection unit into the rotating rotating container is pressed against the inner peripheral wall surface outside the rotating container by a centrifugal force to form a ring shape. Since the separation target coolant is continuously injected from the opening of the injection portion, the ring thickness is gradually increased from the inner peripheral wall surface toward the rotation axis direction and accumulated.

  Since the solid particles in the coolant to be separated thus accumulated in the ring shape move and accumulate on the inner peripheral wall side of the rotating container by centrifugal force, the liquid layer of the coolant from which the solid particles are separated on the rotating shaft side. Is formed.

  The rotary container is provided with an upper lid 1c. The upper lid 1c is provided with a plurality of holes 1d so as to surround an extension line of the central axis of rotation of the rotary shaft 1a. The hole 1d is a hole through which the coolant from which the solid particles are separated is scattered and flows out of the rotating container. That is, since the coolant to be separated is continuously injected from the opening of the injection portion, as described above, the ring thickness is gradually increased from the inner peripheral wall side toward the rotation axis direction, so that the ring is accumulated. The inner peripheral surface S reaches the position of the hole 1d, and excess coolant (coolant (clean liquid) from which solid particles are separated and removed) is scattered and flows out from the hole to the periphery of the rotating container. The direction in which the coolant scatters is a direction substantially perpendicular to the rotation axis 1a.

  The surrounding part 2 surrounds the outside of the rotating container so that the separated liquid splashed out of the rotating container does not leak to the outside of the centrifuge and has a substantially cylindrical shape. On the inner peripheral surface of the surrounding portion, an annular foaming suppression portion 3 whose diameter gradually increases in the direction of gravity is provided. The foaming suppression unit 3 is configured such that the surface on which the separated liquid splashing and flowing out of the rotating container collides is an inclined surface that suppresses foaming. The inclined surface that suppresses the foaming is an inclined surface that is inclined so that an incident angle θ is 45 ° when the separated liquid collides with the inclined surface.

  Here, the incident angle θ when the separated liquid collides with the inclined surface in the cross-sectional view in the longitudinal direction of the rotating shaft 1a will be described as follows. FIG. 2 is a cross-sectional view in a direction in which the rotary shaft 1a of FIG. 1 is longitudinally cut, and only the cross section of the foam suppression unit 3 is shown. In addition, 2a is a metal reinforcing member of the surrounding portion 2. The incident angle θ when the separated liquid collides with the inclined surface is formed by the traveling direction d1 of the separated liquid and a line d2 perpendicular to the inclined surface 3a at the collision point of the inclined surface 3a of the foam suppression unit 3. It is a horn. Since the separated liquid splashing and flowing out of the rotating container collides with the inclined surface 3a of the foaming suppression unit 3, foaming can be remarkably suppressed.

  An annular conveyor mesh 4 having a substantially constant diameter is provided on the inner peripheral wall surface of the surrounding portion on the gravity direction side of the inclined surface. As shown in FIG. 3, the conveyor mesh 4 is a metallic mesh (a mesh in which a plurality of metal wires having a thickness of 1 mm are intersected at 90 ° to form a square opening (4 mm × 4 mm)). Since the separated liquid flows in contact with the conveyor mesh 4, it is defoamed. Thereafter, the separation liquid flows out of the centrifuge from the outlet 2b through the outlet channel. On the other hand, a part of the coolant (drain) and solid particles are discharged from the lower part of the rotating container.

  As shown in FIG. 4, the separation liquid can also flow out of the centrifuge after passing through a porous chamber disposed in a staying portion upstream of the outlet portion of the outlet channel. FIG. 4 is a cross-sectional view in the gravity direction of the outlet channel near the outlet of the outlet channel. In FIG. 4, reference numeral 41 denotes a liquid level of the separation liquid at the separation liquid outlet, and a lower part of the liquid level is a retention part 42 for the separation liquid. The entire porous chamber 43 exists in the staying portion 42. The porous chamber 43 is filled with spherical glass. The separation liquid that flows into the staying part 42 from the outlet flow channel part 44 upstream of the staying part 42 and passes through the staying part 42 is more fully affected by the defoaming action by the staying part in addition to the defoaming action by the porous chamber. Bubbles can be removed.

  As the porous chamber 43, there is an antifoaming cartridge as shown in FIG. The defoaming cartridge is formed of a metal plate (punch metal) having holes with a diameter of 1 mm on the entire surface and a small pitch between the holes, and a lid 51b is provided at the opening of a cylindrical container 51 having a bottom surface 51a. It is detachable. Therefore, the lid 51b can be removed and the interior space of the container 51 can be filled with a filler having a defoaming action (for example, a plurality of glass spheres). Since the pipe 46 having the internal space as the outlet channel is detachably connected to the pipe 45 having the inner space as the outlet channel, the pipe 46 is removed from the pipe 45 so that the inner space of the pipe 45 is removed. A defoaming cartridge as shown in FIG. Therefore, since the filler to be filled in the defoaming cartridge can be easily changed, when the liquid to be separated changes, it can be easily changed to the optimum filler according to the type of liquid to be separated. . The inner diameter of the tube 45 is slightly larger than the outer diameter of the defoaming cartridge.

[Measurement of foaming rate and defoaming rate]
Various used coolant liquids containing solid particles were centrifuged by the same centrifuge as in the above example to obtain a coolant liquid from which the solid particles were removed. As the coolant, NAC (Synthetic), NK-88 (Solution), SEC800P (Synthetic), and CG50P (Solution) (all manufactured by Noritake) were each diluted 50 times with water. More details are as follows.

  An apparatus was used in which the coolant liquid continuously removed from the processing machine through a centrifuge to remove solid particles and circulate again to the processing machine. The sample liquid is 1 pass (until the coolant liquid is obtained by separating the solid particles through a centrifuge using an unused coolant liquid in the processing machine), and 1 minute after the liquid is collected in 1 pass, Samples were collected after 2 minutes and 3 minutes, and the respective densities were measured. The average value of these four values was taken as the density after separation. The collection location of the liquid to be measured is the separation liquid outlet at the end of the outlet flow path for the separated separation liquid. The liquid to be measured was collected with a graduated cylinder at the separation liquid outlet, and the volume was read immediately, and then the weight was measured to calculate the density.

As the centrifuge, (1) an inclined plate (annular foam suppression unit 3, the same applies hereinafter) is disposed, and a conveyor mesh (annular conveyor mesh 4, the same applies hereinafter) and an antifoam cartridge (shown in FIG. 5). (Reference Example 1) , (2) Inclined plate and conveyor mesh, and in the absence of defoaming cartridge, (3) Inclined plate and conveyor When the mesh and the defoaming cartridge were disposed, (4) the density after separation was determined separately in the case where the defoaming cartridge was disposed in the staying portion and the inclined plate and the conveyor mesh were not disposed (Reference Example 2) . In addition, as a comparative example, (5) the density after separation when the inclined plate, the conveyor mesh, and the defoaming cartridge were not provided was obtained. In addition, the retention part was provided only in the case of said (4).

And the foaming rate and defoaming rate in each case of said (1)-(5) were calculated | required. The obtained values are shown in Tables 1-5. Here, it is assumed that the foaming rate = (stock solution density−separation density) / stock solution density, and the smaller the density after separation, the smaller the foam, the better the foaming rate. Further, the defoaming rate = the foaming rate according to the examples or the reference examples (in the cases (1) to (4) above) / the foaming rate according to the comparative example (in the case (5) above). Since the defoaming rate is lower as the rate is closer to the foaming rate according to the comparative example, the smaller the value, the better. As shown in the following Tables 1 to 5, when the centrifuge of the present invention is used, the foaming rate and the defoaming rate are small and excellent.

FIG. 1 is a schematic cross-sectional view in a direction in which a rotary shaft 1a of a rotary container of a centrifuge according to one embodiment of the present invention is longitudinally cut. FIG. 2 is a partial cross-sectional view in the direction of longitudinally cutting the rotating shaft 1a of FIG. FIG. 3 is a schematic enlarged view of the conveyor mesh. FIG. 4 is a schematic cross-sectional view showing the porous chamber disposed in the retention portion of the outlet channel. FIG. 5 is a view showing a substantially cylindrical antifoam cartridge, FIG. 5-A is a view showing a surface where a lid attached to the opening of the antifoam cartridge is present, and FIG. 5-B is an antifoam FIG. 5C is a diagram illustrating a side surface of the cartridge, and FIG. 5-C is a diagram illustrating a bottom surface of the defoaming cartridge.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rotating container 2 Surrounding part 3 Foaming suppression part 3a Inclined surface 4 Conveyor mesh 42 Retention part 43 Porous chamber

Claims (2)

A rotating container that separates a substance having a large specific gravity from the liquid to be centrifuged by centrifugal force and scatters and flows out a liquid having a specific gravity smaller than that of the substance, and the separated liquid that scatters and flows out from the rotating container does not leak outside the centrifuge. In this way, there is a surrounding portion that surrounds the outside of the rotating container, and an outlet channel that is formed between the outer peripheral surface of the rotating container and the inner peripheral surface of the surrounding portion and guides the separation liquid to the outside of the centrifuge. A centrifuge,
A centrifuge having a mesh portion provided on an inner peripheral wall surface of the surrounding portion. A surface on which the separated liquid splashed and spilled from the rotating container collides is provided as a foam suppression portion configured as an inclined surface that suppresses foaming, and the inclined surface that suppresses foaming collides with the inclined surface. Is an inclined surface inclined so that the incident angle is 30 to 60 °,
The centrifuge according to claim 1, wherein a mesh portion is provided in a region closer to the gravitational direction than the inclined surface.

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