JP5281321B2 - Filter element for filtration - Google Patents

Description

  The present invention relates to a filter element for filtration that separates sludge from a liquid containing sludge, and a filtration apparatus using the same. Here, the sludge is an insoluble matter not dissolved in the liquid constituting the liquid material. For example, when the liquid constituting the liquid includes a water-soluble solvent such as water as a main component (including an emulsion including a water-soluble solvent as a main component), solid particles or gels that do not dissolve in the water-soluble solvent such as water And tar-like substances (some contain solid particles and some do not contain). Moreover, when the liquid which comprises a liquid body contains as a main component oil-soluble solvents (non-water-soluble solvent), such as oil which does not melt | dissolve in water, there are solid particles etc. which do not melt | dissolve in oil-soluble solvents, such as oil.

  There are various types of liquids containing sludge, and one example is used coolant. 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 polishing machines. There are various types such as water, oil, and emulsion. The used coolant includes solid particles generated from a workpiece or a processing machine generated during processing. Therefore, when reused, it is necessary to remove the solid particles.

  Conventionally, a backwash filter element used in a filtration device for filtering used coolant is generally manufactured from a wire mesh, a wedge wire, a notch wire, or the like. For example, a wire mesh fixed to a support so that the wire mesh is cylindrical, a wedge wire screen obtained by weaving a wedge wire is fixed to the support so that the screen is cylindrical, a long notch wire There are some which surround and fix the outer periphery of the support so as to form a coil with a gap (slit). For example, Patent Document 1 describes a spiral separator having a separation gap between windings by winding an elastic metal wire in a spiral manner, and a continuous solid-liquid separator provided with the spiral separator.

Japanese Utility Model Publication No. 5-26112

  However, even when these conventional filter elements are used while backwashing, as they are used for a long time, solid particles such as processed chips are sandwiched between meshes or metal wires and metal wires and supports Or, since it is sandwiched between the metal wire and the support, solid particles such as processed chips that cannot be removed by backwashing gradually accumulate in the filter element and clogging occurs. For this reason, it is necessary to periodically replace and disassemble and clean the filter element.

  In addition, while processing in a processing step of processing a workpiece with various processing machines such as a grinding processing machine and a polishing processing machine, solid particles are separated and removed from the used coolant to regenerate the coolant. There is a case where a workpiece is continuously processed while being supplied to various processing machines and recycling the coolant (for example, such a processing apparatus or line). In this case, when the filter element is clogged, the processing in the processing step may be adversely affected (for example, the processing step is stopped). For this reason, there has been an increasing demand for filter elements and filtration devices that do not clog or that do not occur for a longer time.

  In addition, since the coolant is used when processing a workpiece with various processing machines such as a grinding machine and a polishing machine, machine oil may be mixed into the used coolant. In this case, when the coolant is water-soluble, an adhesive gel-like substance is generated. Further, solid particles such as chips and dirt contained in the used water-soluble coolant are entangled with the gel-like substance, and grow into a more sticky tar-like substance. These gel-like or tar-like substances are formed into a film shape on the filtration surface composed of the wire mesh and the gap between which the used water-soluble coolant in a conventional filter element using a wire mesh or a wire flows, and the wire and the gap ( It is deposited in a layered manner. Even if the gel-like or tar-like substance deposited in the film form is removed by backwashing, it can be removed to some extent, but it is difficult to completely remove it. Therefore, even when it is used while backwashing, as it is used for a long time, a gel-like or tar-like substance is sandwiched between the mesh or the metal wire and the metal wire together with the solid particles such as processed chips, or the wire mesh and the support. Or solid particles such as processed chips that cannot be removed by backwashing and gel-like or tar-like substances gradually accumulate in the filter element, causing clogging. To do. For this reason, it is necessary to periodically replace and disassemble and clean the filter element.

  An object of the present invention is to provide a filter element for filtration that can easily remove sludge adhering during filtration by backwashing, and that does not clog or is less likely to occur for a longer time. In addition, the present invention provides a filtration device that can easily remove sludge adhering during filtration by backwashing, is not clogged or less likely to occur for a long time, and can be continuously filtered. Objective.

According to the present invention, in the first aspect, (a) a primary-side filtration surface into which a liquid material to be filtered flows flows through a smooth surface having openings of the fine through-holes of a porous plate having fine through-holes and a smooth surface. The porous plate has a thickness of 0.3 mm or more and an opening diameter of the primary filtration surface of 200 μm or less, and an end of the porous opening that opens to the primary filtration surface of the porous plate has The smooth surface of the porous plate has an arithmetic average roughness Ra of 0.35 μm or less, a maximum height Ry of 2.4 μm or less, and a ten-point average roughness Rz. A filter element for filtering used coolant having a size of 1.7 μm or less, wherein (b) the filter element is composed of the porous plate with a smooth surface having an opening of the fine through hole of the porous plate as an outer surface. Cylindrical filter element And having the smooth surface as a primary filtration surface into which a liquid material to be filtered flows, and the thickness of the perforated plate is 0.3 to 0.5 mm, and (c) the cylindrical filter element Is a bottomed cylindrical filter element having a smooth surface of the perforated plate as an outer peripheral surface and only one end side being an open end, and the direction of the twist axis of the spiral element is the length direction of the cylindrical filter element. A spiral element is provided in the internal space of the cylindrical filter element so as to substantially match, and the spiral element is obtained by twisting a rectangular metal plate around its long axis, and a rectangular metal plate Spir of any one of spiral elements made of ceramics or resin having a shape obtained by twisting a wire around the long axis Is Le element, can be by filtration filter element used coolant, to achieve the above object.

According to the second aspect of the present invention, in the second aspect, (a) a primary-side filtration surface into which a liquid material to be filtered flows flows on a smooth surface having openings of the fine through-holes of a porous plate having fine through-holes and a smooth surface. The porous plate has a thickness of 0.3 mm or more and an opening diameter of the primary filtration surface of 200 μm or less, and an end of the porous opening that opens to the primary filtration surface of the porous plate has The smooth surface of the porous plate has an arithmetic average roughness Ra of 0.35 μm or less, a maximum height Ry of 2.4 μm or less, and a ten-point average roughness Rz. It is a filter element for filtration of a liquid material containing adhesive sludge having a size of 1.7 μm or less, and (b) the filter element has the smooth surface having an opening of the fine through hole of the porous plate as the outer surface. Cylindrical filter made of perforated plate An element, having the smooth surface as a primary filtration surface into which a liquid to be filtered flows, the thickness of the porous plate being 0.3 to 0.5 mm, and (c) the cylindrical filter element Is a bottomed cylindrical filter element having a smooth surface of the perforated plate as an outer peripheral surface and only one end side being an open end, and the direction of the twist axis of the spiral element is the length direction of the cylindrical filter element. A spiral element is provided in the internal space of the cylindrical filter element so as to substantially match, and the spiral element is obtained by twisting a rectangular metal plate around its long axis, and a rectangular metal plate Any one of spiral elements made of ceramics or resin having a shape obtained by twisting a wire around the long axis A spiral element, the filtration filter element of the liquid containing the adhesive sludge, it is possible to achieve the above object.

The filter element for filtration according to the present invention can be configured as follows. The fine through hole can be formed by an electron beam drilling method or a laser drilling method. The smooth surface has an arithmetic average roughness Ra of 0.01 μm or less, a maximum height Ry of 0.08 μm or less, a ten-point average roughness Rz of 0.06 μm or less, and an adhesive sludge. It can be made smooth to such an extent that it can be easily peeled off. The inner diameter of the porous openings of the perforated plate, Ru can be gradually widened toward the secondary-side filtering surface which filtrate flows out. The filter element for filtration of the present invention can be used in the following used coolant filter devices or liquid filter devices containing sticky sludge.

A plurality of filter elements having a smooth surface having an opening of the fine through hole of a porous plate having a fine through hole and a smooth surface as a primary filtration surface into which a liquid material to be filtered flows, and a casing incorporating the filter element A used coolant filtering device comprising: an end of a perforated opening that opens with respect to a primary filtration surface of the perforated plate; and a smooth surface of the perforated plate having an arithmetic average The roughness Ra is 2 μm or less, the maximum height Ry is 10 μm or less, the ten-point average roughness Rz is 5 μm or less, and the filter element is separated from the primary filtration surface of another filter element during backwashing. It is set close to the other filter element to a position where sludge adhering to the primary filtration surface can be removed by the backwash flow that is ejected. Its dependent, filtration equipment of the first spent coolant.

A filter element having a smooth surface having an opening of the fine through-hole of a perforated plate having a fine through-hole and a smooth surface as a primary filtration surface into which a liquid material to be filtered flows, and a casing containing the filter element A used coolant filtering device comprising: an end of a perforated opening that opens with respect to a primary filtration surface of the perforated plate is formed of a smooth curved surface, and the smooth surface of the perforated plate has an arithmetic mean roughness. Ra is 2 μm or less, the maximum height Ry is 10 μm or less, the ten-point average roughness Rz is 5 μm or less, and the filter element is reversely ejected from the primary filtration surface of the filter element during backwashing. The inner surface of the casing or backwash flow to a position where sludge adhering to the primary filtration surface can be removed by the washing flow and its reflected flow. It is provided close to the morphism surface, a second filtration equipment of the used coolant.

A plurality of filter elements having a smooth surface having an opening of the fine through hole of a porous plate having a fine through hole and a smooth surface as a primary filtration surface into which a liquid material to be filtered flows, and a casing incorporating the filter element A liquid material filtering device comprising an adhesive sludge comprising: a smooth opening of an end of a porous opening that opens to a primary filtration surface of the porous plate, and a smooth surface of the porous plate The arithmetic average roughness Ra is 2 μm or less, the maximum height Ry is 10 μm or less, the ten-point average roughness Rz is 5 μm or less, and the filter element is the primary of other filter elements during backwashing The other filter element is moved to a position where the sticky sludge adhering to the primary filtration surface can be removed by the backwash flow ejected from the side filtration surface. It is provided close to, filtration equipment of liquid containing a first adhesiveness sludge.

A filter element having a smooth surface having an opening of the fine through-hole of a perforated plate having a fine through-hole and a smooth surface as a primary filtration surface into which a liquid material to be filtered flows, and a casing containing the filter element An apparatus for filtering a liquid material including an adhesive sludge, wherein an end portion of a porous opening that opens to a primary filtration surface of the porous plate is formed of a smooth curved surface, and the smooth surface of the porous plate is The arithmetic average roughness Ra is 2 μm or less, the maximum height Ry is 10 μm or less, the ten-point average roughness Rz is 5 μm or less, and the filter element is a primary filtration surface of the filter element during backwashing Of the casing to a position where adhesive sludge adhering to the primary filtration surface can be removed by the backwash flow ejected from Or backwashing flow is provided near the reflective surface, filtration equipment of liquid containing a second adhesive sludge.

  The filter element for filtering used coolant according to the first aspect of the present invention has the above-described configuration, and sludge contained in the used coolant (solid particles such as chips) is not easily caught on the filter element. Even if sludge adheres to the opening opening on the primary filtration surface during filtration, the adhering sludge can be easily and completely removed in a short time by backwashing, and clogging due to accumulation of sludge does not occur.

  In addition, when the used coolant is a used water-soluble coolant containing sticky sludge (a gel-like or tar-like substance having stickiness), the sticky sludge adheres to the primary filtration surface (especially a membrane). Adhesive sticky sludge can be easily peeled and removed in a short time by backwashing, and clogging due to the accumulation of sticky sludge does not occur.

  The filter element for filtering a liquid material containing sticky sludge according to the second aspect of the present invention has the above-described configuration, and the sticky sludge adheres to the primary filtration surface (particularly as a film-like deposit). ), The attached sticky sludge can be easily peeled and removed in a short time by backwashing, and clogging due to the accumulation of sticky sludge does not occur.

Filter elementary DOO in the 1-2 aspect of the present invention, only the outer peripheral surface and to one side a smooth surface of the perforated plate is a cylindrical filter element having a bottom which is an open end, said smooth surface, be filtered In the inner space of the cylindrical filter element, the direction of the twist axis of the spiral element substantially coincides with the length direction of the cylindrical filter element. since is provided with a spiral element, since the it is possible to reinforce the cylindrical filter element by a spiral element, during the filtration, it can be used in the pressure of the liquid filtration target high pressure. Further, at the time of filtration, the flow of the filtered liquid flowing through the internal space of the cylindrical filter element becomes a turbulent flow by the spiral element. Therefore, in the internal space of the cylindrical filter element, said even perforated plate sludge of solid particles or the like passing through the porous openings of the flows, it accumulates in the internal space or attached sludge on the inner surface of the cylindrical filter element Can be prevented. Furthermore, at the time of backwashing, the flow of backwashing liquid flowing through the internal space of the cylindrical filter element is vortexed by the spiral element. Therefore, when using as a filter element in the said filtration apparatus, the inside of a casing is further stirred and backwashing property can be improved.

Each of the first and second used coolant filtering devices has the above-described configuration, and sludge (solid particles such as chips) contained in the used coolant is not easily caught on the filter element. Even if sludge adheres to the opening that opens on the side filtration surface during filtration, the adhering sludge can be easily and completely removed in a short time by backwashing, and the filter element is clogged due to accumulation of sludge. Does not happen.

In the case where the used coolant is a used water-soluble coolant containing sticky sludge (a gel-like or tar-like substance having stickiness), the first used coolant filtration device has a sticky sludge Even if it adheres to the primary filtration surface (especially as a film-like deposit), the adhering sticky sludge is backwashed (especially by the backwash flow ejected from the primary filtration surface of other filter elements). It can be easily removed completely in a short time, and clogging due to accumulation of sticky sludge does not occur.

When the used coolant is a used water-soluble coolant containing sticky sludge (a gel-like or tar-like substance having a sticky property), the second used coolant filtration device has a sticky sludge Even if it adheres to the primary filtration surface (especially as a film-like deposit), the adhered sticky sludge is backwashed (especially backwash flow ejected from the primary filtration surface of the filter element and its reflection). It can be easily removed completely in a short time (by flow), and clogging due to the accumulation of sticky sludge does not occur.

Therefore, the first and second used coolant filtration devices can repeatedly perform filtration in an efficient state in which the filtration performance before filtration is restored by repeating filtration and backwashing. It becomes possible, and the used coolant can be filtered efficiently and continuously, so that the filtered coolant can be obtained efficiently and continuously. Therefore, the first and second used coolant filtering devices are configured to remove sludge from used coolant while processing in a processing step of processing a workpiece by various processing machines such as a grinding machine and a polishing machine. The coolant is regenerated by separating and removing the coolant, and the regenerated coolant is supplied to the various processing machines, and it is suitable as a used coolant filtering device used when continuously processing a workpiece while recycling the coolant. .

The liquid filtration apparatus including the first sticky sludge has the above-described configuration, and adheres even if the sticky sludge adheres to the primary filtration surface (particularly, adheres as a film-like deposit). Adhesive sludge that has been removed can be easily removed completely in a short time by backwashing (especially by backwashing flow ejected from the primary filtration surface of another filter element), and clogging due to accumulation of sticky sludge Does not happen.

The liquid filtration device including the second sticky sludge has the above-described configuration, and adheres even if the sticky sludge adheres to the primary filtration surface (particularly, adheres as a film-like deposit). The sticky sludge that has been removed can be easily and completely removed in a short time by backwashing (especially by the backwashing flow ejected from the primary filtration surface of the filter element and its reflected flow). No clogging will occur.

Therefore, the liquid filtration apparatus including the first and second sticky sludges repeatedly repeats filtration in an efficient state in which the filtration ability before filtration is restored by repeating filtration and backwashing. Since the liquid material containing the sticky sludge can be efficiently and continuously filtered, the filtered liquid can be obtained efficiently and continuously.

[Filter element]
The filter element of the present invention has a smooth surface of a porous plate having a smooth surface as a primary filtration surface into which a liquid material to be filtered flows. Examples of the porous plate having a smooth surface include a porous plate having a flat smooth surface and a porous plate having a curved smooth surface. Examples of the perforated plate having a curved smooth surface include a cylindrical perforated plate having a smooth surface on part or all of the outer peripheral surface, and a cylindrical perforated plate having a smooth surface on part or all of the inner peripheral surface. A porous plate constituting a part of any one of the cylindrical porous plates and having a smooth surface is available. The filter element of the present invention comprises a single porous plate, or a combination of two or more porous plates ( however, a porous plate having eight rectangular smooth surfaces is formed at the open end. ( Excluding a polygonal cylindrical filter element such as a cylinder having an octagonal shape and a combination in which the outer peripheral surface is a smooth surface).

<Smooth surface>
The smooth surface of the porous plate having a smooth surface is preferably smooth to such an extent that the adhesive sludge can be easily peeled off by backwashing. The smoothness of the smooth surface of the porous plate having a smooth surface can be set to the following level according to the surface roughness standard (JIS B0601-1994) . The arithmetic average roughness Ra can be 2 μm or less (preferably 1.5 μm or less, more preferably 1 μm or less, further preferably 0.6 μm or less, particularly preferably 0.4 μm or less). The maximum height Ry can be 10 μm or less (preferably 8 μm or less, more preferably 5 μm or less, and even more preferably 3 μm or less). The ten-point average roughness Rz can be 5 μm or less (preferably 4 μm or less, more preferably 3 μm or less, and further preferably 2 μm or less). The smooth surface of the porous plate having a smooth surface is particularly preferably a mirror surface (for example, Ra 0.01 μm or less, Ry 0.08 μm or less, Rz 0.06 μm or less). The smooth surface of the porous plate having a smooth surface can be obtained, for example, by performing one or both of electrolytic polishing and buff polishing on the surface of a metal porous plate such as a stainless steel plate. The surface of the metal porous plate can be made into a mirror surface by buffing, for example.

  The easy releasability (high releasability) of adhesive sludge by backwashing is a special effect obtained because the surface of the porous plate is smooth, and the surface of a conventional filter element manufactured with a wire mesh or wire Even if the electrode is electropolished, it is not possible to easily remove the adhesive sludge. That is, as shown in FIG. 8, the surface of a conventional filter element manufactured with a wire mesh or a wire has large unevenness and steps that are not comparable to a plate-like body. And the steps are basically gone. FIG. 8 shows a surface portion of a conventional filter element (after electrolytic polishing) in which one long wire 81 having a triangular cross section in the radial direction is fixed to a support 82 in a coil shape with a gap (slit). It is a partial expanded sectional view of the direction (diameter direction of a wire) which crosses a wire, and the big level | step difference 83 exists between the wires wound around the support body. Therefore, sticky sludge (especially film-like sticky sludge) adhering to the surface after electrolytic polishing of a conventional filter element made of wire mesh or wire cannot be removed sufficiently even after backwashing. It will remain on the surface.

<Perforated plate>
In the porous plate having a smooth surface, the diameter of the opening of the primary filtration surface into which the liquid material to be filtered flows is set to a diameter that can remove sludge contained in the liquid material to be filtered. For example, it can be 800 μm or less (preferably 500 μm or less, more preferably 300 μm or less, further preferably 200 μm or less, particularly preferably 100 μm or less), but in the present invention, it is 200 μm or less (preferably 100 μm or less). The thickness of the perforated plate can be 0.3 mm to 5 mm, for example, but is 0.3 to 0.5 mm in the present invention.

When the liquid material to be filtered is used coolant, the diameter of the opening on the primary side filtration surface of the porous plate is 500 μm or less (preferably 450 μm or less, more preferably 300 μm or less, further preferably 200 μm or less, particularly preferably 100 μm). Hereinafter, it can be most preferably 80 μm or less, particularly 70 μm or less if necessary, but in the present invention, it is 200 μm or less (particularly preferably 100 μm or less, most preferably 80 μm or less, particularly 70 μm or less if necessary). is there.

The aperture ratio in the primary filtration surface into which the liquid material to be filtered of the perforated plate having a smooth surface flows can be 5% or more (for example, 10%). Here, the aperture ratio in the primary filtration surface is calculated by S ₁ / S ₂ × 100 (%), where S ₁ is the total area of the opening and S ₂ is the total area of the primary filtration surface including the opening. Is the value to be Note that the aperture ratio in the case where the porous plate having a smooth surface has a non-porous region that does not become a filtration surface because the porous formation region is biased is calculated without including the area of the non-porous region in the total area of the primary-side filtration surface. Is the value to be

  The inner diameter of the opening of the perforated plate having a smooth surface is preferably an opening (penetration) that gradually expands from the primary filtration surface into which the liquid to be filtered flows into the secondary filtration surface through which the filtrate flows out. Hole). More specifically, the shape of the internal space of the opening of the perforated plate having a smooth surface is such that the opening area of the primary side filtration surface is smaller than the opening area of the secondary side filtration surface and the opening side of the primary side filtration surface is It is the taper shape which is gradually expanded toward the opening end of the secondary filtration surface.

  In addition, any one or both of the edge part of the opening with respect to the primary side filtration surface of the said perforated plate and the edge part of the opening with respect to a secondary side filtration surface can be comprised from a smooth curved surface. When the end of the opening with respect to the primary filtration surface of the perforated plate is formed of a smooth curved surface, the portion with the smallest inner diameter of the opening exists inside the opening than the opening end of the primary filtration surface. Become.

The perforated plate can be obtained by forming through holes in various plate bodies of a resin such as metal, ceramics, and synthetic resin by a drilling method such as an electron beam drilling method or a laser drilling method. Examples of the metal include stainless steel, nickel-based alloy (Haynes International, Inc. Hastelloy, etc.), titanium, aluminum, and the like. The perforated plate can be preferably obtained by forming fine through holes in a plate-like body with an electron beam drilling machine. The thickness of the perforated plate can be 0.3 mm to 5 mm, for example, but is 0.3 to 0.5 mm in the present invention.

<Spiral element>
Filter elements of the present invention is a cylindrical, inside the columnar internal space of the cylindrical filter element, which only set the spiral element. Preferably, it is a cylindrical filter element having a cylindrical shape with a bottom having an open end only at one end side, and has a smooth surface at least on the outer peripheral surface, and an inner side (especially an inner peripheral surface) and an outer side (especially an outer peripheral surface). A spiral element is provided in a columnar internal space inside a plurality of fine through holes that communicate with the outer peripheral surface. As a spiral element, there is one obtained by twisting a rectangular metal plate around a long axis, or one made of ceramics or resin having such a shape.

[Filtering equipment]
The filtration device may include a plurality of filter elements of the present invention and a casing containing the filter element. Each of the filter elements is positioned so that sludge (especially adhesive sludge) adhering to the primary filtration surface can be removed by backwash flow ejected from the primary filtration surface of another filter element during backwashing. Up to the other filter elements.

  Further, in the case of a filtration device in which only one filter element of the present invention is built in the casing, the filter element is subjected to the backwash flow ejected from the primary filtration surface of the filter element at the time of backwashing and the reflected flow thereof. It is provided close to the inner surface of the casing or the backwashing reflective surface to a position where sludge (particularly sticky sludge) adhering to the primary filtration surface can be removed. The backwash flow reflecting surface reflects sludge (particularly sticky sludge) adhering to the primary filtration surface by reflecting the backwash flow ejected from the primary filtration surface of the filter element and colliding with the primary filtration surface. What is necessary is just to remove.

  When the primary-side filtration surface is a flat surface, the backwash flow reflecting surface can be provided to face the primary-side filtration surface. Further, when the outer peripheral surface of the cylindrical or polygonal cylindrical filter element is the primary filtration surface, the backwash flow reflecting surface is provided concentrically with the central axis of the cylindrical filter element as the center. The inner peripheral surface of a cylindrical or polygonal cylindrical body (at least one of both ends is an open end) can be used. That is, the cylindrical or polygonal cylindrical body incorporates the filter element in its columnar internal space. The cylindrical or polygonal cylindrical body can be detachably provided on the filter element.

  In addition, even in the case of a filtration apparatus in which a plurality of filter elements of the present invention are built in a casing, the influence of backwash flow ejected from the primary filtration surface of another filter element due to the presence of obstacles apart from each other When there is a filter element that does not receive, such a filter element adheres to the primary filtration surface by backwash flow ejected from the primary filtration surface of the filter element during backwashing and its reflected flow. It can be provided close to the inner surface of the casing or the backwashing reflective surface up to a position where sludge can be removed.

According to the filter element of the present invention (particularly, the filtration device using the filter element of the present invention), the sticky sludge adhering to the primary filtration surface during the filtration of the liquid material containing the sticky sludge adheres in the form of a film. Even in this case, it can be removed and removed easily and easily in a short time by backwashing. Therefore, the filter element of the present invention (particularly, the filtration device using the filter element of the present invention) is attached to the filter element by a filtration step of filtering a liquid material containing sticky sludge through the filter element, and in the filtration step. It has a backwashing process which backwashes and removes sticky sludge, and can be used suitably for the filtration method of the liquid substance containing adhesive sludge which filters continuously the liquid substance containing sticky sludge.

An embodiment of a filtration device using the filter element of the present invention will be described with reference to the drawings. In addition, the following Examples 1-3 are reference examples, respectively. FIG. 1 is a schematic cross-sectional view in the length direction (perpendicular to the radial direction of the cylinder) of a substantially cylindrical filtration device 10 according to an embodiment of the present invention. The substantially cylindrical filtration device 10 is provided with a filter element 14 according to an embodiment of the present invention. FIG. 2 is a view of the bottomed cylindrical filter element 14 attached to the substantially cylindrical filtration device of FIG. 1 and having an open end on one end side as viewed from the radial direction of the cylinder. First, the filter element 14 will be described.

[Example 1 (filter element)]
As shown in FIG. 2, the filter element 14 has a cylindrical shape having an open end 14a on one end side and a bottom 14b on the other end side. Further, the filter element 14 has a plurality of fine through holes in the cylindrical surface that allow communication between the inner space inside the cylinder and the outer space. The outer peripheral surface of the cylinder is a primary filtration surface into which a liquid material to be filtered flows during filtration, and is a smooth surface. The shape of the internal space of the fine through-hole is such that the opening area of the primary filtration surface is smaller than the opening area of the secondary filtration surface through which the filtered liquid flows out and the opening end on the primary filtration surface side It is a taper shape which is gradually expanded toward the opening end on the secondary filtration surface side. The shape of each opening of a primary side filtration surface and a secondary side filtration surface is circular. In addition, the edge part of both opening can also be comprised from a smooth curved surface.

<Filtration of liquid without sticky sludge>
The filtration and backwashing in the case where the liquid to be filtered is used coolant that does not contain sticky sludge will be described. FIG. 3A is a schematic enlarged partial cross-sectional view in the thickness direction of the wall 30 of the cylindrical portion of the cylindrical filter element of FIG. 2 and is a view for explaining a situation during the filtration operation. FIG. 3B is a schematic enlarged partial cross-sectional view in the thickness direction of the wall 30 of the cylindrical portion of the cylindrical filter element of FIG. 2 and is a view for explaining the situation during the backwash operation.

  A minute through hole 31 is provided in the wall 30 of the cylindrical portion. One opening end of the fine through-hole 31 opens to the primary filtration surface 30a into which the liquid material to be filtered flows, and the other opening end opens to the secondary filtration surface 30b from which the filtered liquid flows out. To do. The shape of the internal space of the fine through hole 31 is such that the opening area of the primary filtration surface 30a is smaller than the opening area of the secondary filtration surface 30b and the opening end of the secondary filtration surface from the opening end of the primary filtration surface It is a taper shape which is expanding gradually toward. Therefore, at the time of filtration, the solid particles 32 contained in the used coolant are captured by the small-diameter opening end 31a of the fine through-hole 31 and separated from the coolant. Therefore, from the opening end on the inflow side of the liquid material to be filtered The solid particles 32 to be separated are less likely to be clogged than in the case of a tapered shape in which the inner diameter gradually decreases toward the opening end on the filtrate outflow side.

  On the other hand, at the time of backwashing, as shown in FIG. 3B, the backwashing liquid flows from the large diameter opening end 31b side of the fine through hole 31 toward the small diameter opening end 31a. Since the flow rate gradually increases and the backwashing liquid is ejected more vigorously from the small-diameter opening end 31a to remove the solid particles trapped in the small-diameter opening end 31a, the backwashing liquid has a small-diameter opening end of the fine through hole Backwashing can be performed more effectively than when flowing from the side toward a large-diameter opening end or when the inner diameter of the fine through hole is uniform.

<Filtration of liquid containing sticky sludge>
FIG. 7 illustrates filtration and backwashing when the liquid to be filtered is a used water-soluble coolant containing an adhesive gel substance (adhesive sludge) and solid particles such as chips. In FIG. 7, the same reference numerals as those in FIG. 3 are the same as those shown in FIG.

  Fig.7 (a) is a general | schematic expanded partial sectional view of the thickness direction of the wall 30 of the cylindrical part of the cylindrical filter element of FIG. 2, Comprising: It is a figure for demonstrating the condition at the time of filtration driving | operation. FIG.7 (b) is a general | schematic expanded partial sectional view of the thickness direction of the wall 30 of the cylindrical part of the cylindrical filter element of FIG. 2, Comprising: It is a figure for demonstrating the condition at the time of a backwash operation.

  During filtration, the solid particles 32 contained in the used water-soluble coolant and the gel-like substance having adhesiveness are captured by the primary filtration surface 30a and separated from the coolant. Accumulated as sticky sludge 71.

  On the other hand, at the time of backwashing, as shown in FIG. 7B, the backwashing liquid flows from the large-diameter opening end 31b side of the fine through hole 31 toward the small-diameter opening end 31a. And the backwash liquid is ejected more vigorously from the small-diameter opening end 31a. In addition to this, the primary-side filtration surface 30a is a smooth surface, and the film-like sticky sludge 71 is only attached in a state of being easily peeled off from the primary-side filtration surface 30a. Therefore, the film-like sticky sludge 71 adhering to the primary filtration surface can be easily peeled and removed by backwashing.

  The filter element 14 is, for example, a fine through hole in which a hole diameter of a small diameter opening end 31a is approximately 70 μm and a diameter of a large diameter opening end 31b is approximately 200 μm by electron beam drilling on a flat stainless steel plate having a thickness of 0.5 mm. It can be manufactured by opening 31 and bending it into a cylindrical shape, providing a bottom at one open end, and providing a ring-shaped flange at the other open end. The primary filtration surface of the filter element 14 is electropolished. According to the surface roughness standard (JIS B 0601-1994), the arithmetic average roughness Ra is about 0.35 μm, and the maximum height Ry is about 2. 4 μm and Rz are approximately 1.7 μm.

[Example 2 (filtering device)]
The substantially cylindrical filtration device 10 includes a substantially cylindrical casing 13 having an inflow port 11 for allowing used coolant to be filtered and an outflow port 12 for allowing the filtered coolant to flow out, and is incorporated in the casing. Filter element 14 for filtering used spent coolant. The used coolant which is the object of filtration is supplied to the inflow port 11 by a pump (not shown).

  A total of seven filter elements are arranged in the substantially cylindrical casing 13 such that six filter elements are separated from and surrounded by the center of one filter element (see FIG. 4 described later). reference). The substantially cylindrical casing 13 is provided with a disk-shaped partition wall 13b having seven openings for arranging the seven filter elements as described above. The partition wall 13b divides (divides) the internal space of the substantially cylindrical casing 13 into a used coolant inflow chamber 13a and a filtered coolant inflow chamber 13c into which the filtered coolant flows, and seven filter element mounting plates. But there is. The seven openings of the partition wall 13b are provided so that six openings are separated from each other and surround the outer periphery with the one opening as a center. Each of the seven filter elements is detachably fixed by a fixing member (not shown) so that the opening end side is connected to the seven openings of the partition wall (mounting plate) 13b.

  The used coolant (primary liquid) flowing in from the inflow port 11 flows into the used coolant inflow chamber 13a. A cylindrical filter element 14 is provided in the used coolant inflow chamber 13a. The used coolant is filtered when flowing from the outside to the inside of the cylindrical filter element 14, and the filtered coolant flows into the inside of the cylindrical filter element 14. The filtered coolant (secondary liquid) flows into the filtered coolant inflow chamber 13 c from the opening end of the cylindrical filter element 14 and flows out from the outflow port 12.

  Backwashing can be performed by blowing backwash air from the backwash air blowing port 15. By blowing backwash air from the backwash air blowing port 15, the filtered coolant (backwash liquid) is ejected from the inside to the outside of the cylindrical filter element 14, so that backwashing can be performed. More specifically, each of the seven filter elements has a backwash flow of filtered coolant ejected from its own outer peripheral surface and a backwash flow of filtered coolant ejected from the outer peripheral surface of another filter element. Sludge adhering to the outer peripheral surface of the filter element can be completely removed by the flow (in addition, the backwash flow is reflected by the outer peripheral surface of another filter element or the inner peripheral surface of the casing 13).

  In particular, when the liquid to be filtered is a used water-soluble coolant containing sticky sludge (a gel-like or tar-like substance having stickiness), the filtration device of Example 2 has a sticky sludge. Even if the adhering sticky sludge adheres to the primary filtration surface, the adhering sticky sludge can be completely peeled and removed in a short time by backwashing, and clogging due to sticky sludge accumulation does not occur. Absent. Sludge such as solid particles removed from the outside of the cylindrical filter element 14 and the backwash liquid are discharged from the discharge port 16 to the outside of the substantially cylindrical casing 13 as a drain. When backwashing is performed, the outlet 12 is closed. Moreover, when filtering, the backwash air blowing port 15 and the discharge port 16 are closed.

[Evaluation of peelability of gel-like substances]
The test liquid containing the sticky sludge was filtered using the filtration device of Example 2, and the same evaluation test filter element as the filter element 14 (however, the diameter of the opening end on the small diameter side was 70 μm and the opening ratio on the small diameter side) 5%), a gel-like substance (adhesive sludge) was adhered to the film and backwashed, and the peelability of the gel-like substance adhered to the film was evaluated. At that time, the distance L between the filter elements was changed to 1 / 2D, D, 2D, and 3D (where D is the diameter of the filter). This relationship is shown in FIG. FIG. 4 is a schematic cross-sectional view in the radial direction of the cylinder of the substantially cylindrical casing 41 of the substantially cylindrical filtration device according to an embodiment of the present invention, in which seven cylindrical filter elements 40 are incorporated. It is a figure for demonstrating the arrangement | positioning relationship of a cylindrical filter element. As the test liquid, a water-soluble coolant (emulsion type) mixed with 0.5% machine oil and sludge having an average particle diameter of 100 μm (the concentration of solid particles was adjusted to 400 mg / L) was used. In addition, backwashing was started at a filtration pressure of 0.2 MPa, and the backwashing time was 10 seconds.

  As a comparative test, the seven filter elements for evaluation test were the same in size and shape as the filter element for evaluation test, a filter element using a wedge wire, a filter element using a notch wire (hole diameter 50 μm, opening ratio 20 %) And the filter element using a wire mesh (hole diameter # 200 (77 μm), wire diameter 0.05 mm, opening ratio 37%), the peelability of the gel-like substance was evaluated in the same manner as described above. .

  These evaluation results are shown in Table 1. The peelability was evaluated visually with the naked eye. Evaluation result 5 is “completely peeled”, 4 is “substantially peeled”, 3 is “attached to the surface”, 2 is “remains inside the element”, and 1 is “clogged”.

  The relative ratio of the distance L between the filter elements to the diameter D of the filter is 0.2 ≦ L / D ≦ 3 (preferably L / D ≦ 2, more preferably L / D ≦ 1, more preferably L / D ≦ 0.5).

[Example 3 (filtration device)]
In the filtration device of Example 2, seven filter elements are arranged, but in the filtration device of Example 3, only one filter element is arranged. Therefore, an opening is provided only at the center of the partition wall (mounting plate).

The same evaluation as the peelability evaluation of the gel-like substance was performed using a filtration apparatus using the single filter element for evaluation test.
At that time, the distance L between the outer peripheral surface of the filter element 50 and the inner peripheral surface of the cylindrical casing 51 is changed to 1 / 2D, D, 3 / 2D, and 2D (where D is the diameter of the filter). It was. This relationship is shown in FIG. FIG. 5 is a schematic cross-sectional view in the radial direction of the cylinder of the substantially cylindrical casing 51 of the substantially cylindrical filtration device according to one embodiment of the present invention, in which one cylindrical filter element 50 is incorporated. It is a figure for demonstrating the arrangement | positioning relationship between an element and a cylindrical casing. The obtained results are shown in Table 2.

  The relative ratio of the distance L between the outer peripheral surface of the filter element 50 and the inner peripheral surface of the cylindrical casing 51 with respect to the filter diameter D is 0.2 ≦ L / D ≦ 2 (preferably L / D ≦ 1. 5, more preferably L / D ≦ 1, and even more preferably L / D ≦ 0.5.

[Example 4 (filter element)]
A filter element according to Example 4 of the present invention is shown in FIG. FIG. 6A is a diagram of a bottomed cylindrical filter element 60 and a spiral element 61 whose one end side is an open end according to an embodiment of the present invention when viewed from the radial direction (perpendicular to the length direction). It is. The spiral element 61 is a spiral element having a shape obtained by twisting both ends in the longitudinal direction of a rectangular metal plate in opposite directions (the twist direction is the same in all directions, and there is no inversion portion). . FIG. 6B shows a longitudinal direction of a cylindrical filter element with a bottom having an open end on one end side of the embodiment of the present invention incorporating the spiral element 61 shown in FIG. It is a schematic sectional drawing of a direction perpendicular to the radial direction.

  The filter element 60 is the same as the filter element of the first embodiment. The spiral element 61 is provided in the cylindrical inner space of the filter element 60 so that the direction of the twist axis of the spiral element 61 coincides with the length direction of the filter element 60. The spiral element 61 is provided such that the outer peripheral end thereof is almost in contact with the inner peripheral surface of the wall of the cylindrical portion of the filter element 60. According to the filter element of the fourth embodiment of the present invention, the filter element 60 can be reinforced by the spiral element 61, so that the pressure of the liquid material to be filtered (for example, used coolant) is increased during filtration. can do. Further, during filtration, the flow of the filtered liquid flowing in the internal space of the filter element 60 becomes turbulent by the spiral element 61. Therefore, in the internal space of the cylindrical filter element 60, sludge such as solid particles that have passed through the fine through hole is smaller than the diameter of the small diameter opening end of the fine through hole provided on the wall of the cylindrical portion. Even if it flows in, it is possible to prevent sludge from adhering to the inner surface of the filter element 60 or accumulating in the internal space. Furthermore, at the time of backwashing, the flow of backwashing liquid flowing in the internal space of the filter element 60 becomes a vortex by the spiral element 61. Therefore, when using the filter element of Example 4 instead of the filter element in the filtration apparatus of Examples 2-3, the inside of a casing is further stirred and backwashing property can be improved.

[Evaluation of peelability of gel-like substances]
Using the filter element of this Example 4, the peelability of the gel-like substance as described above was evaluated. The arrangement inside the filtration apparatus was performed in the case of a multi-tube type in which seven pieces were arranged as in FIG. 4 and in the case of a single tube type in which one piece was arranged as in FIG. Table 3 shows the results obtained in the case of the multitubular type. Table 4 shows the results obtained in the case of the single tube type.

FIG. 1 is a schematic cross-sectional view in the length direction (perpendicular to the radial direction of the cylinder) of a substantially cylindrical filtration device according to an embodiment of the present invention. FIG. 2 is a view of a bottomed cylindrical filter element according to an embodiment of the present invention attached to the substantially cylindrical filtration device of FIG. 1 as viewed from the radial direction of the cylinder. . Fig.3 (a) is a general | schematic expanded partial sectional view of the thickness direction of the wall of the cylindrical part of the cylindrical filter element of FIG. 2, Comprising: It is a figure for demonstrating the condition at the time of filtration driving | operation. FIG.3 (b) is a general | schematic expanded partial sectional view of the thickness direction of the wall of the cylindrical part of the cylindrical filter element of FIG. 2, Comprising: It is a figure for demonstrating the condition at the time of a backwash operation. FIG. 4 is a schematic cross-sectional view in the radial direction of a cylinder of a substantially cylindrical filtration device according to an embodiment of the present invention that incorporates seven cylindrical filter elements, and shows the positional relationship of the seven cylindrical filter elements. It is a figure for demonstrating. FIG. 5 is a schematic sectional view in the radial direction of the cylinder of the substantially cylindrical filtration device of one embodiment of the present invention incorporating one cylindrical filter element, and the positional relationship between the cylindrical filter element and the cylindrical casing It is a figure for demonstrating. FIG. 6A is a diagram of a bottomed cylindrical filter element and a spiral element, in which one end side of one embodiment of the present invention is an open end, viewed from the radial direction (perpendicular to the length direction). . FIG. 6B shows the length direction (cylinder diameter) of a bottomed cylindrical filter element having an open end on one end side of the embodiment of the present invention incorporating the spiral element shown in FIG. It is a schematic sectional drawing of a direction perpendicular to the direction. Fig.7 (a) is a general | schematic expanded partial sectional view of the thickness direction of the wall 30 of the cylindrical part of the cylindrical filter element of FIG. 2, Comprising: It is a figure for demonstrating the condition at the time of filtration driving | operation. FIG.7 (b) is a general | schematic expanded partial sectional view of the thickness direction of the wall 30 of the cylindrical part of the cylindrical filter element of FIG. 2, Comprising: It is a figure for demonstrating the condition at the time of a backwash operation. FIG. 8 shows a surface of a conventional filter element (after electrolytic polishing) in which a long wire having a triangular cross section in the radial direction is fixed to a support in a coil shape with a gap (slit). It is a partial expanded sectional view of the direction (diameter direction of a wire) to cross.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Substantially cylindrical filtration apparatus 13 Substantially cylindrical casing 14 Cylindrical filter element 14a Open end 14b Bottom 30a Primary side filtration surface 30b Secondary side filtration surface 31 Fine through-hole 32 Solid particle 71 Film-like adhesive sludge

Claims (5)

A smooth surface having an opening of the fine through hole of a porous plate having a fine through hole and a smooth surface is provided as a primary-side filtration surface into which a liquid material to be filtered flows,
The porous plate has a thickness of 0.3 mm or more and an opening diameter of the primary filtration surface is 200 μm or less,
The end of the perforated opening that opens to the primary filtration surface of the perforated plate is composed of a smooth curved surface,
The smooth surface of the perforated plate has an arithmetic average roughness Ra of 0.35 μm or less, a maximum height Ry of 2.4 μm or less, and a ten-point average roughness Rz of 1.7 μm or less. Filter element for filtration,
The filter element is a cylindrical filter element made of the porous plate with a smooth surface having an opening of the fine through hole of the porous plate as an outer surface, and the primary side filtration into which a liquid material to be filtered flows is passed through the smooth surface. Having a surface, the thickness of the perforated plate is 0.3-0.5 mm,
The cylindrical filter element is a bottomed cylindrical filter element in which the smooth surface of the porous plate is an outer peripheral surface and only one end side is an open end,
A spiral element is provided in the internal space of the cylindrical filter element so that the direction of the twist axis of the spiral element substantially coincides with the length direction of the cylindrical filter element,
The spiral element is a spiral element obtained by twisting a rectangular metal plate around the major axis, and a spiral element made of ceramic or resin having a shape obtained by twisting a rectangular metal plate around the major axis A filter element for filtering used coolant, characterized by being a spiral element of any of the above. A smooth surface having an opening of the fine through hole of a porous plate having a fine through hole and a smooth surface is provided as a primary-side filtration surface into which a liquid material to be filtered flows,
The porous plate has a thickness of 0.3 mm or more and an opening diameter of the primary filtration surface is 200 μm or less,
The end of the perforated opening that opens to the primary filtration surface of the perforated plate is composed of a smooth curved surface,
The smooth surface of the perforated plate has an arithmetic average roughness Ra of 0.35 μm or less, a maximum height Ry of 2.4 μm or less, and a ten-point average roughness Rz of 1.7 μm or less. A filter element for filtration of a liquid material containing
The filter element is a cylindrical filter element made of the porous plate with a smooth surface having an opening of the fine through hole of the porous plate as an outer surface, and the primary side filtration into which a liquid material to be filtered flows is passed through the smooth surface. Having a surface, the thickness of the perforated plate is 0.3-0.5 mm,
The cylindrical filter element is a bottomed cylindrical filter element in which the smooth surface of the porous plate is an outer peripheral surface and only one end side is an open end,
A spiral element is provided in the internal space of the cylindrical filter element so that the direction of the twist axis of the spiral element substantially coincides with the length direction of the cylindrical filter element,
The spiral element is a spiral element obtained by twisting a rectangular metal plate around the major axis, and a spiral element made of ceramic or resin having a shape obtained by twisting a rectangular metal plate around the major axis The filter element for filtration of the liquid substance containing the sticky sludge characterized by being the spiral element in any one of these.   The filter element according to claim 1, wherein the fine through hole is formed by an electron beam drilling method or a laser drilling method. The smooth surface has an arithmetic average roughness Ra of 0.01 μm or less, a maximum height Ry of 0.08 μm or less, a ten-point average roughness Rz of 0.06 μm or less, and an adhesive sludge. The filter element according to any one of claims 1 to 3, wherein the filter element is smooth to such an extent that can be easily peeled off.   5. The filter element according to claim 1, wherein an inner diameter of the porous opening of the porous plate gradually increases toward a secondary filtration surface through which the filtrate flows.

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