JP5837893B2 - Sanitization filter - Google Patents

Description

  The present invention relates to a sterilization filter that allows a liquid such as a nutrient solution for hydroponics or agricultural water taken from a river to pass through and reduces bacteria in the liquid.

  The applicant has previously reduced the number of bacteria in the liquid through the antibacterial action (sanitizing action) of metals such as silver through the nutrient solution used in circulation for hydroponics and agricultural water taken from rivers. A sterilization filter has been proposed (see, for example, Patent Documents 1 and 2). Among these, the sterilization filter of Patent Document 1 is a ceramic ceramic sintered ceramic powder by applying a heat treatment after attaching a slurry of an inorganic silver antibacterial agent to the surface of a porous ceramic sintered body. It is baked on the surface of the body. Inorganic silver-based antibacterial agents have the advantage of superior chemical resistance and corrosion resistance compared to organic silver-based antibacterial agents. In addition, the amount of silver elution from the coating layer onto which the inorganic silver antibacterial agent is baked into the liquid can be kept lower than that of the organic silver antibacterial agent. In addition, there is an advantage that the load on the environment can be reduced.

Furthermore, Patent Document 2 proposes a sterilization filter in which a porous ceramic sintered body carrying an inorganic antibacterial agent is arranged in multiple stages in a container. Specifically, the sanitized layer molded body, which is a porous ceramic sintered body carrying an inorganic antibacterial agent, is a phosphate antibacterial carrying an antibacterial component made of silver or copper ions by an ion exchange method. An agent, an inorganic binder containing SiO ₂ and Al ₂ O ₃ , and granular ceramics are mixed, formed into a donut shape, and then fired. And, a plurality of such sterilized layer molded bodies are stacked in a multistage in a cylindrical container with a discharge pipe suspended in the center, and between the sterilized layer molded bodies stacked vertically, A baffle plate that disturbs the flow of liquid is arranged. The baffle plate has a large-diameter baffle plate whose outer diameter is equal to the inner diameter of the container and whose inner diameter is larger than the outer diameter of the discharge pipe, and a small-diameter baffle plate whose inner diameter is equal to the outer diameter of the discharge pipe and whose outer diameter is smaller than the inner diameter of the container. Yes, large-diameter baffle plates and small-diameter baffle plates are alternately arranged.

  With this configuration, the flow of the liquid introduced from above the container does not flow linearly toward the bottom of the container, but the flow direction is disturbed by the large-diameter baffle and the small-diameter baffle. Thereby, contact with the flowing-down liquid and the antibacterial agent carried by the sterilization layer molding increases, and the liquid can be sterilized efficiently. Moreover, since a space is formed between the sterilized layer molded bodies due to the presence of the baffle plate, the liquid can move in a free direction in the space. This suppresses the liquid from flowing down the sterilized layer molded body at a position where the liquid is biased, and increases the possibility that the liquid comes into contact with the antibacterial agent, so that the liquid can be sterilized more efficiently.

  However, while the sterilization filter of Patent Document 2 has the advantage of higher sterilization efficiency than the sterilization filter of Patent Document 1, a plurality of large-diameter baffles and small-diameter baffles having different diameters are prepared. Therefore, there is room for improvement in that the structure is complicated and it takes time and effort to manufacture, because it is necessary to arrange them alternately between the sterilized layer molded bodies. In addition, the liquid whose flow is disturbed by the small-diameter baffle may flow along the boundary between the sterilized layer molded body and the inner wall of the container, and the liquid whose flow is disturbed by the large-diameter baffle is There is a possibility of flowing along the boundary between the molded body and the outer wall of the discharge pipe. In such a case, the liquid cannot sufficiently receive the antibacterial action of the antibacterial agent carried on the sterilized layer molded body. For this reason, the sterilization filter of Patent Document 2 employs a configuration in which the inner wall of the container and the outer wall of the discharge pipe are each covered with a sterilization sheet, which further complicates the configuration.

  Accordingly, in view of the above circumstances, the present invention is a sterilization filter in which a porous ceramic sintered body is loaded with an inorganic antibacterial agent, and is a sterilization filter capable of sterilizing a liquid with high efficiency while having a simple configuration. It is an object to provide a fungus filter.

  In order to solve the above-mentioned problems, the sterilization filter according to the present invention includes a columnar filter base in which an inorganic antibacterial agent is supported on a porous ceramic sintered body, and a side peripheral surface of the filter base is coated with a resin. A plurality of single layer filters each having a side peripheral surface resin layer and a pair of end surface peripheral edge resin layers each having a peripheral edge portion of the filter base coated with resin. The side peripheral surface resin layer and the pair of end surface peripheral portion resin layers are integrally formed of a heat-shrinkable resin tube, and the end surface peripheral portion resin layer is formed between adjacent filter bases. A gap having a distance twice the thickness is formed ".

  The kind of “ceramics” of the “porous ceramic sintered body” is not particularly limited, and examples thereof include alumina, mullite, zirconia, magnesia, silicon carbide, and silicon nitride ceramics. .

  The “inorganic antibacterial agent” is not particularly limited as long as it contains metal ions having antibacterial properties such as silver ions and copper ions, but the antibacterial obtained by ion exchange of such metal ions with cations of glass or zeolite. An antibacterial agent obtained by immersing a calcium salt such as an agent, hydroxyapatite, calcium phosphate, or calcium carbonate in a water-soluble metal salt such as silver nitrate, followed by baking, and a phosphate compound such as zirconium phosphate or titanium phosphate as a water-soluble metal Antibacterial agents obtained by washing and filtering after salt and wet stirring can be used.

As a method of “supporting” the inorganic antibacterial agent on the porous ceramic sintered body, an inorganic antibacterial agent and a slurry containing a glass component are adhered to the porous ceramic sintered body, and then heat treated to perform inorganic treatment. A method for coating amorphous glass containing an antibacterial agent on the surface of a porous ceramic sintered body, molding a mixture of ceramic raw material powder, an inorganic antibacterial agent, and an inorganic binder containing a glass component, and firing the mixture And a method of obtaining a porous ceramic sintered body containing an inorganic antibacterial agent. In the above method, SiO ₂ , sodium silicate, glass frit, feldspar and the like can be used as the glass component.

  The “heat-shrinkable resin” constituting the “heat-shrinkable resin tube” is not particularly limited as long as it is a resin having heat-shrinkability, but polypropylene, polyethylene, polyethylene terephthalate, polystyrene, vinyl chloride, etc. are used. Is possible.

  The single-layer filter of the sterilization filter with this configuration is such that the filter base is placed in a heat-shrinkable resin tube longer than its thickness so that both ends of the heat-shrinkable resin tube are redundant, and the heat-shrinkable resin tube is heated. Then, it can be formed by shrinking. More specifically, a portion of the heat-shrinkable resin tube that surrounds the side peripheral surface of the filter base is in close contact with the side peripheral surface of the filter base by heat contraction to form a side peripheral surface resin layer. Further, the excess portions at both ends of the heat-shrinkable resin tube are heat-shrinked while being folded inward along the periphery of the end surface of the filter base, thereby closely contacting the peripheral portion of the end surface of the filter base. Part resin layer.

  In the sterilization filter of this configuration, in each of the single-layer filters arranged in multiple stages, an end surface peripheral portion resin layer covering the peripheral portion of one end surface and an end surface peripheral portion resin layer covering the peripheral portion of the other end surface And exerts the action of disturbing the flow direction of the liquid. And in the sterilization filter of the present invention, the end face peripheral resin layer that disturbs the liquid flow direction on one end face side of the single-layer filter, and the end face peripheral resin layer that disturbs the liquid flow direction on the other end face side. The heat shrinkable resin tube is integrally formed. Therefore, compared with a conventional sterilization filter (Patent Document 2) in which baffle plates are separately provided on one end face side and the other end face side of a single-layer filter, it has a simple configuration that is easy to manufacture. Nevertheless, the liquid can be sterilized with high efficiency by disturbing the flow direction of the liquid.

  Further, by simply stacking single layer filters having end face peripheral resin layers on both end faces, the thickness of the end face peripheral resin layer is naturally doubled between adjacent filter bases, in other words, heat shrinkability. A gap having a distance twice the thickness of the resin tube is formed. Here, if the distance between the filter bases is too small, the effect of freely moving the liquid in the gap is not sufficiently exerted. On the other hand, if the distance is too large, the size of the entire sterilization filter Will be unnecessarily increased. In contrast, in the sterilization filter of the present invention, the distance between the single-layer filters is twice the thickness of the heat-shrinkable resin tube, and the thickness of a commercially available general heat-shrinkable resin tube is 0. Since the thickness is about 5 m to 3 mm, it is possible to easily form a gap having an appropriate distance that is neither too small nor too large.

  Further, in each of the plurality of single-layer filters constituting the sterilization filter, it is a resin having elasticity that covers the peripheral portions of the side peripheral surfaces and both end surfaces. Therefore, since these resin layers (side peripheral surface resin layer and end surface peripheral portion resin layer) serve as cushions that absorb external force, the mechanical strength of the sterilization filter can be increased. That is, in the present invention, the resin layer that enhances the mechanical strength of the sterilization filter has both an effect of disturbing the flow direction of the liquid and an effect of forming a gap between the single-layer filters.

  In addition, in the sterilization filter of this configuration, since the single-layer filters having the end surface peripheral resin layer are stacked on both end surfaces, the liquid is guided to the end surface peripheral resin layer and carries the inorganic antibacterial agent. There is a reduced risk that the liquid flows through the inside of the filter base and the liquid flows along the boundary between the side peripheral surface of the filter base and the side peripheral surface resin layer. Thereby, unlike the conventional sterilization filter (patent document 2), the liquid can be sterilized with high efficiency without requiring the antibacterial sheet to be disposed on the side peripheral surface of the filter base.

  The sterilization filter according to the present invention has the above-described configuration, and “the plurality of stacked single-layer filters are integrated by a resin tape wound from the outside of the side peripheral surface resin layer”. It can be.

  In the sterilization filter of this configuration, since the single-layer filters stacked in multiple stages are integrated, the introduction pipe for introducing the liquid to be sterilized and the discharge for discharging the liquid after passing through the sterilization filter It is easy to accommodate the sterilization filter in a state where the single layer filters are stacked in multiple stages in the casing of the filter device to which the pipe is connected. In addition, since a plurality of single-layer filters are integrated, the single-layer filters are prevented from being rattled or damaged by collision between the single-layer filters. In addition, it is a resin tape that has elasticity that integrates multiple single-layer filters, and the wound resin tape layer serves as a cushion to absorb external force. Can be increased.

  In addition to the above configuration, the sterilization filter according to the present invention may be “the distance of the gap is 2 mm to 4 mm”.

  By setting the distance of the gap to 2 mm to 4 mm, as described later, it is possible to eliminate the waste of space due to making the gap unnecessarily large and to disinfect the liquid with high efficiency.

  As described above, as an effect of the present invention, a sterilization filter in which an inorganic antibacterial agent is supported on a porous ceramic sintered body, which has a simple configuration and can sterilize a liquid with high efficiency. A filter can be provided.

It is the (a) perspective view and b) sectional drawing of the single layer filter which comprises the bacteria elimination filter of one Embodiment of this invention. It is sectional drawing which decomposed | disassembled some disinfection filters which piled up the single layer filter of FIG. It is sectional drawing of the filter apparatus which uses the sanitization filter of FIG.

  Hereinafter, a sterilization filter 1 according to an embodiment of the present invention will be described with reference to FIGS. 1 to 3. Here, the case where this invention is applied to the sterilization filter which sterilizes the nutrient solution used by the circulation type for hydroponics is illustrated.

  The sterilization filter 1 of this embodiment includes a columnar filter base 11 in which an inorganic antibacterial agent is supported on a porous ceramic sintered body, and a side peripheral surface resin layer in which the side peripheral surface 11a of the filter base 11 is coated with a resin. 12a and a plurality of single-layer filters 10 each having a pair of end surface peripheral portion resin layers 12b each of which is coated with a resin at the peripheral portions of both end surfaces 11b of the filter base 11 are stacked. The side peripheral surface resin layer 12a and the pair of end surface peripheral portion resin layers 12b are integrally formed by the heat-shrinkable resin tube 12, and the thickness of the end surface peripheral portion resin layer 12b is between adjacent filter bases 11. A space S having a distance twice as long as this is formed. In the sterilization filter 1, the plurality of stacked single-layer filters 10 are integrated by a resin tape 15 wound from the outside of the side peripheral surface resin layer 12a.

  More specifically, the porous ceramic sintered body is an alumina ceramic sintered body obtained by firing a foamed resin (polyurethane sponge) immersed in an alumina slurry and making the foam porous by burning out the foamed resin. Is a cylindrical shape having a diameter of 95 mm and a thickness of 30 mm.

  A slurry obtained by mixing and pulverizing an inorganic silver antibacterial agent and a glass component with water is attached to this porous ceramic sintered body, and fired at 1200 ° C. to 1300 ° C. to sinter the inorganic silver antibacterial agent into the porous ceramic sintered body. Coated on the body surface.

  The filter base 11, which is a porous ceramic sintered body coated with an inorganic silver-based antibacterial agent, is placed in a heat-shrinkable resin tube 12 having an inner diameter of 95 mm and a length of 50 mm, and both ends of the heat-shrinkable resin tube 12 become redundant. The heat-shrinkable resin tube 12 was heated. A portion of the heat-shrinkable resin tube 12 surrounding the side peripheral surface 11a of the filter base 11 was brought into close contact with the side peripheral surface 11a of the filter base 11 by heat shrinkage to form a side peripheral surface resin layer 12a. Further, the excess portions at both ends of the heat-shrinkable resin tube 12 are thermally contracted while being folded inward along the peripheral edge of the end surface 11b of the filter base 11, and are closely contacted with the peripheral edge portion of the end surface 11b to be end peripheral edge portions. Resin layer 12b was formed. Thus, as shown in FIG. 1, the side peripheral surface 11a of the filter base 11 is covered with the side peripheral surface resin layer 12a, and the peripheral portions of the both end surfaces 11b are respectively covered with the end surface peripheral portion resin layer 12b. A single-layer filter 10 was formed. In addition, as the heat-shrinkable resin tube 12, a polyolefin resin tube having a thickness of 0.5 mm to 2 mm was used.

  Seven of the single-layer filters 10 are stacked, and in that state, the resin tape 15 is wound from the outside of the side peripheral surface resin layer 12a, and the seven single-layer filters 10 are integrated as shown in FIG. Disinfection filter 1 was obtained. As the resin tape 15, a polyvinyl chloride resin tape having an adhesive layer on one side was used.

  In the sterilization filter 1 having the above configuration, the gap S having a distance between the adjacent filter bases 11 is twice the thickness of the end face peripheral resin layer 12b, that is, twice the thickness of the heat-shrinkable resin tube 12. Is formed.

  The sterilization filter 1 having the above configuration can be used in the filter device 20 illustrated in FIG. The casing 21 of the filter device 20 has a cylindrical shape with both ends closed, and an introduction pipe 22 for introducing liquid is connected to one end side, and a discharge pipe 23 for discharging liquid is connected to the other end side. Yes. The sterilization filter 1 is accommodated in the casing 21 between the introduction pipe 22 and the discharge pipe 23. Since the sterilization filter 1 is one in which the seven single-layer filters 10 are integrated with the resin tape 15, it is easy to accommodate the seven single-layer filters 10 in the casing 21 in a state where the seven single-layer filters 10 are stacked.

  In the filter device 20 having such a configuration, the liquid introduced into the filter device 20 from the outside through the introduction pipe 22 is carried on the filter base 11 of each single-layer filter 10 when passing through the sterilization filter 1. The liquid sterilized by the inorganic silver antibacterial agent and sterilized is discharged out of the filter device 20 through the discharge pipe 23. Therefore, the nutrient solution for hydroponics can be circulated and used by sterilizing with the filter device 20.

  The filter device 20 illustrated in FIG. 3 is used so that the stacking direction of the single-layer filters 10 is the vertical direction, and the introduction pipe 22 is positioned upward and the discharge pipe 23 is positioned downward in the casing 21. The introduction pipe 22 extends to the inside of the casing 21, and an elbow pipe 22b that is curved in an L shape is connected to the tip thereof. Since the elbow-type pipe 22b is connected to the introduction pipe 22 with the opening end facing upward, the liquid introduced from the introduction pipe 22 is elbow-type pipe 22b as shown by a one-dot chain line in the figure. The sterilization filter is made to flow down from the open end and spread in the casing 21 before flowing down the sterilization filter. Thereby, the liquid can be passed through the filter substrate 11 carrying the inorganic silver antibacterial agent without any deviation.

  In the sterilization filter 1 of the present embodiment having the above-described configuration, when the liquid passes, it is guided by the end surface peripheral portion resin layer 12b covering the peripheral portion with the both end surfaces 11b of the single-layer filter 10, and the flow direction is disturbed. As a result, the liquid flows through the inside of the filter base 11 carrying the inorganic antibacterial agent, and the risk of the liquid flowing along the boundary between the side peripheral surface 11a of the filter base 11 and the side peripheral surface resin layer 12a is reduced. Has been. Thereby, since the liquid which distribute | circulates can fully receive the effect | action of an inorganic type antibacterial agent, a liquid can be disinfected with high efficiency.

  In each of the single-layer filters 10 arranged in multiple stages, an end face peripheral resin layer 12b that disturbs the liquid flow direction on one end face 11b side, and an end face peripheral part that disturbs the liquid flow direction on the other end face 11b side The resin layer 12 b is integrally formed with one heat-shrinkable resin tube 12. Thereby, compared with the case where a configuration for disturbing the flow direction of the liquid is separately provided on one end surface side and the other end surface side of the single-layer filter, the flow direction of the liquid is extremely simple. By disturbing the liquid, the liquid can be sterilized with high efficiency.

  In addition, by simply stacking the single-layer filters 10, a gap S is naturally formed between adjacent filter bases 11. The distance of the gap S is twice the thickness of the heat-shrinkable resin tube 12 ( In this embodiment, it is 1 mm to 4 mm). Accordingly, the liquid is freely moved in the gap S between the filter bases 11, so that the liquid is sufficiently large to exhibit the action of suppressing the deviation of the position where the liquid circulates. It is possible to easily form an appropriately sized gap S that does not unnecessarily increase the size. Actually, the sterilization filter 1 used for one month for the treatment to pass through the hydroponics nutrient solution was observed by cutting each single-layer filter 10, and dust was uniformly attached to the cross section. Was. From this, it was confirmed that the effect | action which suppresses the bias | inclination of the distribution position of a liquid was fully exhibited by the space | gap S of the magnitude | size of this embodiment.

  Furthermore, in each of the plurality of single-layer filters 10 constituting the sterilization filter 1, the side peripheral surface resin layer 12a and the end surface peripheral edge resin layer 12b serve as cushions that absorb external force. Has been enhanced. In addition, since the layer of the resin tape 15 in which the plurality of single-layer filters 10 are integrated also serves as a cushion that absorbs external force, the mechanical strength of the sterilization filter 1 is further increased.

The sterilization filters of Examples 1 to 3 were manufactured in the same manner as in the above-described embodiment except that the distance of the gap S between the filter bases 11 (interval between adjacent filter bases) was different.
Example 1: Air gap 1 mm (heat shrinkable resin tube thickness 0.5 mm)
Example 2: Air gap 2 mm (heat shrink resin tube thickness 1.0 mm)
Example 3: Air gap 4 mm (thickness of heat-shrinkable resin tube 2.0 mm)

For comparison, the following sterilization filters of Control Examples 1 and 2 were produced.
Control Example 1: Seven filter substrates identical to those in the example were stacked (no voids)
Control example 2: Seven filter substrates identical to those in the example were stacked with a spacer having a height of 2 mm in between (7 mm gap).
That is, the control example 1 is an example in which there is no gap between the filter bases, and the control example 2 has a gap of 2 mm between the filter bases but does not have a configuration corresponding to the end face peripheral resin layer. In addition, as the spacer of Control Example 2, a spacer having the surface coated with the above inorganic antibacterial agent was used.

The sterilization filters of Examples 1 to 3 and Control Examples 1 and 2 are accommodated in the filter device 20 illustrated in FIG. 3, and the stacking direction of the single-layer filters is in the vertical direction from the introduction pipe 22. A predetermined amount of the bacterial solution was supplied. The bacterial solution that naturally flowed through the sterilization filter was collected without being circulated, and the sterilization rate was calculated by the following formula.
Bactericidal rate (%) = (N−M) / N × 100
N: Number of bacteria per unit volume of bacterial solution before passing through sterilization filter M: Number of bacteria per unit volume of bacterial solution after passing through sterilization filter

As a result, the sterilization rates of Examples 1 to 3 and Control Examples 1 and 2 were as follows.
Example 1: 91%
Example 2: 100%
Example 3: 100%
Control Example 1: 85%
Control Example 2: 88%

  As described above, the sterilization rate was higher in Examples 1 to 3 having gaps between the filter substrates than in Control Example 1 having no gaps between the filter substrates. In particular, Example 2 in which the gap between the filter bases was 2 mm had a higher sterilization rate than Example 1 in which the gap was 1 mm, and the sterilization rate in Example 2 was an extremely high rate of 100%. Further, the sterilization rate of Example 3 having a larger 4 mm gap was 100% as in Example 2. Therefore, it is desirable that the gap between the filter bases is 2 mm or more from the viewpoint of the sterilization rate, and even if it is too large, the space is only wasted without contributing to the sterilization rate. It can be said that it is desirable.

  Moreover, even if it has a 2 mm space | gap desirable as a space | gap between filter base | substrates, the disinfection rate of the comparative example 2 without the structure corresponded to an end surface peripheral part resin layer was a low thing. From this, it was confirmed that the above-mentioned action which improves the disinfection efficiency of a disinfection filter has the end face peripheral part resin layer.

  The present invention has been described with reference to the preferred embodiments. However, the present invention is not limited to the above-described embodiments, and various improvements can be made without departing from the scope of the present invention as described below. And design changes are possible.

  For example, although the case where the shape of the filter base | substrate 11 was a column shape was illustrated above, it is not limited to this, A cross section can be made into the column shape of an ellipse or a polygon. Even in such a shape, by thermally shrinking the heat-shrinkable resin tube 12 along the shape of the filter base 11, the side peripheral surface resin layer 12a in close contact with the side peripheral face 11a of the filter base 11, and The end surface peripheral portion resin layer 12b can be formed in close contact with the end surface 11b.

  Moreover, although the case where the circulation type nutrient solution was sterilized was illustrated above, the use of the sterilization filter 1 is not limited to this, water for agriculture taken from a river, water to be purified at a water purification plant, It can be used as a filter for sterilizing water used in fish farms, hot spring water used in circulation, and the like.

  Furthermore, although the case where seven single-layer filters are stacked in one sterilization filter is illustrated above, the number of stacked single-layer filters is not limited to this.

  In addition, in the above, the case where a plurality of single-layer filters are stacked up and down is illustrated, but the direction in which the single-layer filters are stacked, in other words, the direction in which the liquid flows is not particularly limited. .

DESCRIPTION OF SYMBOLS 1 Disinfection filter 10 Single layer filter 11 Filter base | substrate 11a Side peripheral surface 11b of filter base | substrate End surface 12 of a filter base | substrate 12 Heat shrinkable resin tube 12a Side peripheral surface resin layer 12b End surface peripheral part resin layer 15 Resin tape S Cavity 20 Filter apparatus 21 Casing 22 Introduction pipe 23 Discharge pipe

Japanese Patent No. 3619355 JP 2010-263843 A

Claims (3)

A columnar filter base in which an inorganic antibacterial agent is supported on a porous ceramic sintered body, a side peripheral surface resin layer in which a side peripheral surface of the filter base is coated with a resin, and peripheral edges of both end surfaces of the filter base are A plurality of single-layer filters each having a pair of end face peripheral resin layers coated with resin are stacked,
In each of the single-layer filters, the side peripheral surface resin layer and the pair of end surface peripheral portion resin layers are integrally formed by a heat-shrinkable resin tube,
An antibacterial filter characterized in that a gap having a distance twice as large as the thickness of the resin layer on the edge surface is formed between the adjacent filter bases. The sterilizing filter according to claim 1, wherein the plurality of stacked single-layer filters are integrated by a resin tape wound from the outside of the side peripheral surface resin layer. The sterilization filter according to claim 1 or 2, wherein a distance between the gaps is 2 mm to 4 mm.

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