Honeycomb filter for removing pathogenic bacteria and filter device for removing pathogenic bacteria

Abstract

To provide a honeycomb filter for removing pathogenic bacteria which can collect and reproduce pathogenic bacteria, and can reduce replacement frequency.SOLUTION: A honeycomb filter 1 for removing pathogenic bacteria includes: a ceramic honeycomb structure 10 having an outer peripheral wall 100, an inflow side cell 101 which is arranged inside the outer peripheral wall, is opened on an inlet side end face 10a and is sealed with an outlet side end face 10b, an outflow side cell 102 which is arranged inside the outer peripheral wall 100, is opened on the outlet side end face 10b and is sealed with the inlet side end face 10a, and a porous partition wall 103 which is arranged between the inflow side cell 101 and the outflow side cell 102; and a ceramic porous gas permeable film 11 which is provided on the partition wall 103, wherein in a step of making fluid flowing in from the inflow side cell 101 and making the fluid flowing out of the outflow side cell 102, the partition wall 103 and the gas permeable film 11 are structured to collect 99.97% or more particles of 0.3 μm, and to burn off the collected particles by heating.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a honeycomb filter for removing pathogens and a pathogen removal filter device for removing pathogens from an atmosphere. [Background technology]

[0002] It is generally known that high-efficiency air filters (HEPA filters) are used to remove pathogens from the atmosphere. Due to the recent increase in infectious diseases, the scope of application of such filters has expanded from specific areas such as infectious disease control rooms to more general areas such as offices.

[0003] Because HEPA filters have high collection efficiency, their gas permeability (transmission loss) easily increases due to the trapped material. Furthermore, because HEPA filters are difficult to reuse, they must be replaced with unused filters after a certain period of time. The frequency of filter replacement depends on the air quality of the environment (amount of viruses, dust, dirt, etc.), so unless a certain level of contamination is expected, filters should be replaced periodically, with a margin for filter transmission loss, even if they are still usable.

[0004] When changing filters, viruses can no longer be removed and cleanliness cannot be maintained, so depending on the application location, it was necessary to shut down the room or equipment using the filters. As a result, when changing filters, it was necessary to consider the impact of equipment shutdown. In addition, when changing filters, it was necessary to handle filters contaminated with viruses, which raised concerns about secondary contamination of the workers changing them and the area around the filters.

[0005] Patent Document 1 listed below describes "an air purifier comprising a housing having an air passage, a dust collection and adsorption means arranged in the air passage of the housing and comprising an integrated filter for capturing pollutant particles suspended in the air and an adsorption section for adsorbing pollutant gases, at least one heating means arranged in the vicinity of the dust collection and adsorption means for heating the dust collection and adsorption means, and a blowing means for passing air through the dust collection and adsorption means." Patent Document 1 also describes that the filter may be a honeycomb structure having a large number of through-holes formed by porous ceramic partition walls, and that the honeycomb structure may be heated to incinerate or decompose the captured and adsorbed pollutant particles and pollutant gases. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 10-113522 Summary of the Invention [Problem to be solved by the invention]

[0007] Although air purifiers such as those described in Patent Document 1 can capture general particles such as dust, it is difficult to capture smaller pathogens.

[0008] The present invention has been made to solve the above-mentioned problems, and one of its objects is to provide a honeycomb filter for removing pathogens and a pathogen removal filter device that can capture pathogens and can be regenerated, reducing the frequency of replacement. [Means for solving the problem]

[0009] Item 1. In one embodiment, the present invention relates to a honeycomb filter for removing pathogens, the honeycomb filter comprising: a ceramic honeycomb structure having an outer peripheral wall; inlet cells disposed inside the outer peripheral wall, each open at its inlet end face and sealed at its outlet end face; outlet cells disposed inside the outer peripheral wall, each open at its outlet end face and sealed at its inlet end face; and porous partition walls disposed between the inlet cells and the outlet cells; and a ceramic porous gas-permeable membrane disposed on the partition walls, wherein the partition walls and the gas-permeable membrane are configured to capture 99.97% or more of particles of 0.3 μm as a fluid flows in through the inlet cells and flows out through the outlet cells, and the captured particles can be burned off by heating.

[0010] Item 2. The present invention may relate to the honeycomb filter for removing pathogens according to Item 1, wherein the gas-permeable membrane is a porous membrane made of ceramic particles having an oxide film formed on the surface thereof and provided on the surface of the inlet cell, the porous membrane has an average thickness T of 2 μm or more and 40 μm or less and a porosity P of 65% or more and 90% or less, and the partition walls have a porosity of 40% or more and 80% or less, have pores penetrating from one surface of the partition wall to the other surface, and have an average pore diameter of 4 μm or more and 20 μm or less.

[0011] Item 3. The present invention may relate to the honeycomb filter for removing pathogenic bacteria according to Item 2, wherein the ceramic particles constituting the gas-permeable membrane contain at least one element selected from the group consisting of cordierite, mullite, zirconium phosphate, aluminum titanate, silicon carbide, a silicon-silicon carbide composite, a cordierite-silicon carbide composite, zircon, zirconia, spinel, indialite, sapphirine, corundum, titania, and silicon nitride.

[0012] Item 4. The present invention may relate to the honeycomb filter for removing pathogenic bacteria according to Item 1 or 2, wherein the partition walls contain at least one element selected from the group consisting of cordierite, mullite, zirconium phosphate, aluminum titanate, silicon carbide, a silicon-silicon carbide composite, a cordierite-silicon carbide composite, zircon, zirconia, spinel, indialite, sapphirine, corundum, titania, and silicon nitride.

[0013] Item 5. The present invention provides a honeycomb filter for removing pathogenic bacteria according to any one of Items 1 to 4, wherein the honeycomb structure supports an oxidation catalyst in the inlet cells and the outlet cells.

[0014] Item 6. In one embodiment, the present invention relates to a pathogen removal filter device comprising at least one pathogen removal honeycomb filter according to any one of Items 1 to 5, and a heating unit that heats the pathogen removal honeycomb filter.

[0015] Item 7. The present invention may relate to the pathogen removal filter device according to Item 6, which includes a plurality of pathogen removal honeycomb filters, the heating unit being configured to heat the plurality of pathogen removal honeycomb filters individually, and further including a heating selection unit that selects a pathogen removal honeycomb filter to be heated by the heating unit based on the pressure drop and / or flow rate of the plurality of pathogen removal honeycomb filters.

[0016] Item 8. The present invention may relate to the pathogen removal filter device according to Item 6 or 7, wherein at least one pathogen removal honeycomb filter is housed in a chamber, the chamber having a chamber body with an inlet opening and an outlet opening, and a lid that is placed over the inlet opening and the outlet opening when the pathogen removal honeycomb filter is heated, and when the lid is placed over the inlet opening and / or the outlet opening, the area of ​​the lid within the inlet opening and / or the outlet opening is 90% or more and less than 100% of the area of ​​the inlet opening and / or the outlet opening.

[0017] Item 9. The present invention may relate to a pathogen removal filter device according to any one of Items 6 to 8, further comprising a ceramic fiber insulating material surrounding each honeycomb structure of at least one pathogen removal honeycomb filter.

[0018] Item 10. The present invention may relate to the pathogen removal filter device according to any one of Items 6 to 9, further comprising a notification means for monitoring the pressure loss and / or the flow rate through the pathogen removal honeycomb filter heated by the heating unit, and for notifying that maintenance is required when the pressure loss exceeds a predetermined pressure loss threshold or the flow rate through the honeycomb filter falls below a predetermined flow rate threshold within a predetermined operating time after heating by the heating unit.

[0019] Item 11. The present invention may relate to the pathogen removal filter device according to any one of Items 6 to 10, wherein the pathogen removal honeycomb filter further comprises a conductor and / or a magnetic material contained in the honeycomb structure, and the heating unit includes a coil provided around the pathogen removal honeycomb filter and is configured to inductively heat the pathogen removal honeycomb filter by magnetic flux from the coil.

[0020] Item 12. The present invention may relate to the pathogen removal filter device according to any one of Items 6 to 11, wherein the heating unit includes electrodes connected to the pathogen removal honeycomb filter and is configured to electrically heat the pathogen removal honeycomb filter using a current from the electrodes.

[0021] Item 13. The present invention may relate to the pathogen removal filter device according to any one of Items 6 to 12, wherein the pathogen removal honeycomb filter further comprises an electric resistor incorporated in the honeycomb structure, and the heating unit includes electrodes connected to the electric resistor, and is configured to heat the pathogen removal honeycomb filter through the electric resistor by passing a current through the electrodes to heat the electric resistor.

[0022] Item 14. The present invention may relate to the pathogen removal filter device according to any one of Items 6 to 13, wherein the heating section includes a heater arranged upstream of the pathogen removal honeycomb filter in the flow direction of a fluid introduced into the pathogen removal honeycomb filter, and is configured to heat the pathogen removal honeycomb filter by flowing the fluid heated by the heater through the pathogen removal honeycomb filter. [Effects of the Invention]

[0023] According to one embodiment of the honeycomb filter for removing pathogens and the pathogen removal filter device of the present invention, the partition walls and gas-permeable membranes are configured to capture 99.97% or more of particles of 0.3 μm as the fluid flows in through the inlet cells and out through the outlet cells, and the captured particles can be burned off by heating. This means that the filter can capture pathogens and can be regenerated, reducing the frequency of replacement. [Brief explanation of the drawings]

[0024] [Figure 1] 1 is a perspective view showing a honeycomb filter for removing pathogens according to an embodiment of the present invention. [Figure 2] 2 is a schematic cross-sectional view of the pathogenic bacteria removal honeycomb filter of FIG. 1, observed in a cross section parallel to the cell extension direction. FIG. [Figure 3] FIG. 2 is a schematic partial enlarged view of the pathogenic bacteria removal honeycomb filter of FIG. 1 when observed at a cross section perpendicular to the cell extension direction. [Figure 4] FIG. 2 is a schematic diagram of a cross section of a honeycomb filter for removing pathogenic bacteria cut out for determining the average thickness T of the porous membrane. [Figure 5] 1 is a schematic diagram for explaining the configuration of a particle attachment device according to an embodiment of the present invention. [Figure 6] 1 is an explanatory diagram schematically showing a first embodiment of a pathogen removal filter device according to an embodiment of the present invention. [Figure 7] FIG. 3 is an explanatory diagram schematically showing a second embodiment of a pathogen removal filter device according to the present invention. [Figure 8] FIG. 10 is an explanatory diagram schematically showing a third embodiment of a pathogen removal filter device according to an embodiment of the present invention. [Figure 9] FIG. 10 is an explanatory diagram schematically showing a fourth embodiment of a pathogen removal filter device according to an embodiment of the present invention. [Figure 10] FIG. 10 is an explanatory diagram schematically showing a fifth embodiment of a pathogen removal filter device according to an embodiment of the present invention. [Figure 11] FIG. 10 is a perspective view schematically showing a sixth embodiment of a pathogen removal filter device according to an embodiment of the present invention. [Figure 12] FIG. 12 is a plan view showing the pathogen removal filter device of FIG. [Figure 13] 1 is an SEM image of a gas-permeable membrane prepared as an example. DETAILED DESCRIPTION OF THE INVENTION

[0025] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is not limited to each embodiment, and the components can be modified and embodied without departing from the spirit of the present invention. Furthermore, various inventions can be formed by appropriately combining multiple components disclosed in each embodiment. For example, some components may be omitted from all the components shown in the embodiments. Furthermore, components of different embodiments may be appropriately combined.

[0026] <1.Honeycomb filter for removing pathogens> Figure 1 is an oblique view showing a honeycomb filter 1 for removing pathogens according to an embodiment of the present invention, Figure 2 is a schematic cross-sectional view of the honeycomb filter 1 for removing pathogens of Figure 1 when observed at a cross section parallel to the cell extension direction, Figure 3 is a schematic enlarged partial view of the honeycomb filter 1 for removing pathogens of Figure 1 when observed at a cross section perpendicular to the cell extension direction, and Figure 4 is a schematic cross-sectional view of the honeycomb filter 1 for removing pathogens cut out to determine the average film thickness T of the porous membrane.

[0027] The honeycomb filter 1 for removing pathogenic bacteria of this embodiment is used to remove pathogenic bacteria from the atmosphere. Examples of pathogenic bacteria include tuberculosis bacteria. For reference, tuberculosis bacteria may have an elongated outer shape with a length of 2 to 10 μm and a width of 0.3 to 0.6 μm. The honeycomb filter 1 for removing pathogenic bacteria is expected to be incorporated into a pathogenic bacteria removal filter device 6 (see FIGS. 6 to 12) described below and used mainly in a static indoor environment. The pathogenic bacteria removal filter device 6 is characterized in that it is possible to circulate the air to be filtered by the pathogenic bacteria removal honeycomb filter 1 and heat the pathogenic bacteria removal honeycomb filter 1 using an externally supplied power source.

[0028] 1 and 2 are a schematic perspective view and a cross-sectional view, respectively, of a pathogenic bacteria removal honeycomb filter 1. The pathogenic bacteria removal honeycomb filter 1 has a honeycomb structure 10 and a gas permeable membrane 11 (see FIG. 3).

[0029] The honeycomb structure 10 is made of ceramic and includes an outer peripheral wall 100, inlet cells 101 disposed inside the outer peripheral wall 100, each opening at an inlet end face 10a (one end face) and plugged at an outlet end face 10b (the other end face), outlet cells 102 disposed inside the outer peripheral wall 100, each opening at the outlet end face 10b and plugged at the inlet end face 10a, and porous partition walls 103 disposed between the inlet cells 101 and the outlet cells 102. The inlet cells 101 are plugged at the outlet end face 10b by plugging portions 104, and the outlet cells 102 are plugged at the inlet end face 10a by plugging portions 104. The inlet side cells 101 and the outlet side cells 102 may be alternately arranged adjacent to each other with a porous partition wall 103 sandwiched therebetween, and the inlet side end face 10a and the outlet side end face 10b may each have a honeycomb shape. Hereinafter, the inlet side cells 101 and the outlet side cells 102 may be collectively referred to simply as "cells."

[0030] The gas permeable membrane 11 is a porous ceramic membrane provided on the partition walls 103 of the honeycomb structure 10.

[0031] In the pathogen removal honeycomb filter 1 of this embodiment, the inlet end face 10a is treated as the end face on the inlet side of the fluid, and the outlet end face 10b is treated as the end face on the outlet side of the fluid. When a fluid containing pathogens is supplied to the inlet end face 10a, the fluid is introduced into the inlet cells 101 and flows downstream within the inlet cells 101. Because the inlet cells 101 are sealed at the outlet end face 10b, the fluid permeates through the partition walls 103 and gas permeable membranes 11 between the inlet cells 101 and the outlet cells 102, flows into the outlet cells 102, and then passes through the outlet cells 102 and flows out from the outlet end face 10b.

[0032] The honeycomb filter 1 for removing pathogens of this embodiment is configured so that the partition walls 103 and the gas-permeable membranes 11 capture 99.97% or more of particles of 0.3 μm in size as the fluid flows in through the inlet cells 101 and flows out through the outlet cells 102. This allows the filter to capture not only general particles such as dust but also pathogens.

[0033] Furthermore, the honeycomb filter 1 for removing pathogenic bacteria is configured so that the captured particles can be burned off by heating. This allows for regeneration and reduces the frequency of replacement. Here, it is assumed that particles containing pathogenic bacteria can be burned off by heating the honeycomb filter 1 for removing pathogenic bacteria to a temperature range of 400°C or higher and 800°C or lower. The honeycomb structure 10 and gas permeable membrane 11, including the partition walls 103 of the honeycomb filter 1 for removing pathogenic bacteria, are made of ceramics that can withstand repeated heating in such a temperature range.

[0034] The gas permeable membrane 11 may be composed of ceramic particles having an oxide film formed on the surface thereof, and may be a porous membrane provided on the surface of the inlet-side cells 101 (the surface of the partition walls 103 that form the inner surfaces of the inlet-side cells 101) as shown in Fig. 3. Additionally or alternatively, the gas permeable membrane 11 may include a porous membrane provided on the surface of the outlet-side cells 102 (the surface of the partition walls 103 that form the inner surfaces of the outlet-side cells 102).

[0035] In one embodiment, the average thickness T of the porous membrane is 2 μm or more and 40 μm or less. By making the average thickness of the porous membrane 2 μm or more, preferably 3 μm or more, it is possible to obtain the advantage of being able to improve the collection efficiency. Furthermore, by making the average thickness of the porous membrane 40 μm or less, preferably 30 μm or less, more preferably 20 μm or less, and even more preferably 10 μm or less, it is possible to obtain the advantage of being able to suppress an increase in pressure loss.

[0036] In this specification, the average thickness T of the porous membrane of the pathogen removal honeycomb filter 1 is measured by the following procedure. The extension direction of the inlet side cells 101 of the pathogen removal honeycomb filter 1 is taken as the extension direction of the coordinate axes, the coordinate value of the inlet side end face 10a is taken as 0, and the coordinate value of the outlet side end face 10b is taken as X. Then, the average thickness of the porous membrane is measured in five fields of view at the following six locations A1, A2, A3, B1, B2, and B3, and the overall average value of these measurements is taken as the average thickness T of the porous membrane. A1: The center of the cross section perpendicular to the extension direction of the inlet-side cells 101 of the pathogenic bacteria removing honeycomb filter 1 in the coordinate range of 0.1X to 0.3X. B1: The outer periphery of the cross section perpendicular to the extension direction of the inlet side cells 101 of the honeycomb filter 1 for removing pathogenic bacteria in the coordinate range of 0.1X to 0.3X. A2: The center of the cross section perpendicular to the extension direction of the inlet-side cells 101 of the honeycomb filter 1 for removing pathogenic bacteria in the coordinate range of 0.4X to 0.6X. B2: The outer periphery of the cross section perpendicular to the extension direction of the inlet side cells 101 of the pathogenic bacteria removing honeycomb filter 1 in the coordinate range of 0.4X to 0.6X. A3: The center of the cross section perpendicular to the extension direction of the inlet-side cells 101 of the pathogenic bacteria removing honeycomb filter 1 in the coordinate range of 0.7X to 0.9X. B3: The outer periphery of the cross section perpendicular to the extension direction of the inlet side cells 101 of the pathogenic bacteria removing honeycomb filter 1 in the coordinate range of 0.7X to 0.9X.

[0037] When measuring the average thickness of the porous membrane, the central and outer periphery of the pathogenic bacteria removal honeycomb filter 1 are determined as follows. When the pathogenic bacteria removal honeycomb filter 1 is observed in a cross section perpendicular to the extension direction of the inlet-side cells 101, a line segment is drawn from the center of gravity of the cross section to the outer surface of the outer peripheral wall 100, and the extension direction of the line segment is set to the extension direction of the coordinate axes, with the coordinate value of the center of gravity set to 0 and the coordinate value of the outer surface of the outer peripheral wall 100 set to R. In this case, on the line segment, the range of coordinate values ​​0 to 0.2R is the central part, and the range of coordinate values ​​0.7R to 0.9R is the outer periphery. By drawing many such line segments on the cross section and aggregating the central and outer periphery parts on each line segment, the ranges of the central and outer periphery parts on the cross section can be obtained.

[0038] The average thickness of the porous membrane at each of the points A1, A2, A3, B1, B2, and B3 is measured by the following method. A cross section is cut out from the point (center or outer periphery) where the average thickness of the porous membrane of the pathogen removal honeycomb filter 1 is to be determined, the cross section being parallel to the extension direction of the inlet cells 101 and parallel to a line segment extending from the outer surface of the outer wall 100 toward the center of gravity. The cross section is observed using a 3D shape measuring device (e.g., Keyence VR-3200) at a magnification of 25x and with an observation field of view of 12.5 mm (width) × 9.5 mm (length). The horizontal direction of the observation field is set parallel to the extension direction of the inlet cells 101.

[0039] Figure 4 shows a schematic diagram of the cut cross section. By observing the cross section, the inlet cells 101 with porous membranes and the outlet cells 102 without porous membranes are identified. Next, the three adjacent inlet cells 101 closest to the center on the cross section are identified. The central regions 102a (reference planes) of the two outlet cells 102 sandwiched between the three adjacent inlet cells 101 closest to the center on the cross section are identified, and leveling is performed using image processing software (e.g., software included with the Keyence VR-3200 3D shape measuring instrument) to ensure that the reference planes are as horizontal as possible based on the profiles of both regions. After leveling, the central regions 102a of the two outlet cells 102 are designated and the average height H2 of the regions is measured. After leveling, the central regions 101a of the three inlet cells 101 are designated and the average height H1 of the regions is measured. The difference between the average height H1 and the average height H2 in one field of view is defined as the average thickness of the porous membrane in that field of view. Note that the central regions 101a and 102a refer to the central regions when the distance between a pair of partition walls 103 that separate each cell is divided into three equal parts.

[0040] The average thickness of the porous membrane in any five fields of view is determined for each of the points A1, A2, A3, B1, B2, and B3, and these are defined as the average thicknesses of the porous membrane at each of the points A1, A2, A3, B1, B2, and B3. The overall average value is defined as the average thickness T of the porous membrane of the honeycomb filter 1 for removing pathogens.

[0041] In one embodiment, the porosity P of the porous membrane is 65% or more and 90% or less. Controlling the porosity P of the porous membrane within this range in combination with the average thickness T of the porous membrane described above is effective for achieving both high collection efficiency and low pressure loss. From the viewpoint of suppressing an increase in pressure loss, the porosity P of the porous membrane is preferably 65% ​​or more, and more preferably 68% or more. Furthermore, from the viewpoint of achieving high collection efficiency, the porosity P of the porous membrane is preferably 90% or less, more preferably 85% or less, and even more preferably 80% or less.

[0042] The porosity P of the porous membrane is determined by taking backscattered electron images of the in-lens of any two fields of view in the central region 101a of the inlet cell 101 where the porous membrane is formed, for each cross section where the average thickness of the porous membrane at each of the locations A1, A2, A3, B1, B2, and B3 has been determined, using a field emission scanning electron microscope (FE-SEM) (e.g., ZEISS model: ULTRA55). Next, using image analysis software (e.g., HALCON), the images are binarized using the mode method to separate the membrane portion and the void portion, and the ratio of the membrane portion to the void portion is calculated, which is then used as the porosity P of the porous membrane at each of the locations A1, A2, A3, B1, B2, and B3. The overall average of these values ​​is then used as the porosity P of the porous membrane of the honeycomb filter 1 for removing pathogenic bacteria.

[0043] In order to achieve both high collection efficiency and low pressure loss, in addition to controlling the average film thickness and porosity of the porous film within the above-mentioned ranges, it is preferable that the average film thickness T (unit: μm) and the porosity P (unit: %) satisfy the relational expression 0.36T + 60 ≦ P ≦ 0.75T + 72, and more preferably the relational expression 0.42T + 67 ≦ P ≦ 0.75T + 68.

[0044] From the viewpoint of keeping fluid pressure loss low, the porosity of the partition walls 103 is preferably 40% or more, more preferably 45% or more, and even more preferably 50% or more. Furthermore, from the viewpoint of ensuring the strength of the pathogenic bacteria removal honeycomb filter 1, the porosity of the partition walls 103 is preferably 80% or less, more preferably 75% or less, and even more preferably 70% or less. The porosity of the partition walls 103 refers to a value measured with a mercury intrusion porosimeter in accordance with JIS-R1655:2003.

[0045] The partition walls 103 have pores that penetrate from one surface to the other surface of the partition walls 103, and the average diameter of the pores is preferably 20 μm or less, more preferably 18 μm or less, and even more preferably 16 μm or less. When the average pore diameter is within the above range, the pathogen collection efficiency is significantly improved. Furthermore, the average pore diameter is preferably 4 μm or more, more preferably 6 μm or more, and even more preferably 8 μm or more. When the average pore diameter is within the above range, a decrease in pressure loss can be suppressed. The average pore diameter of the partition walls 103 refers to a value measured with a mercury intrusion porosimeter in accordance with JIS-R1655:2003.

[0046] From the viewpoint of suppressing pressure loss, the upper limit of the average thickness of the partition walls 103 in the pathogen removal honeycomb filter 1 is preferably 0.59 mm or less, more preferably 0.33 mm or less, and even more preferably 0.26 mm or less. However, from the viewpoint of ensuring the strength of the pathogen removal honeycomb filter 1, the lower limit of the average thickness of the partition walls 103 is preferably 0.15 mm or more, more preferably 0.16 mm or more, and even more preferably 0.18 mm or more. In this specification, the thickness of the partition walls 103 refers to the length of a line segment that intersects the partition walls 103 when the line segment connects the centers of gravity of adjacent cells in a cross section perpendicular to the cell flow path. The average thickness of the partition walls 103 refers to the average value of the thicknesses of all the partition walls 103.

[0047] By configuring the average film thickness T and porosity P of the porous film constituting the gas-permeable membrane 11, and the porosity and pores of the partition walls 103 as described above, the honeycomb filter 1 for removing pathogens can be more reliably configured so that the partition walls 103 and the gas-permeable membrane 11 capture 99.97% or more of 0.3 μm particles as the fluid flows in from the inlet cells 101 and out from the outlet cells 102.

[0048] The ceramic particles constituting the gas-permeable membrane 11 may contain ceramics containing at least one element selected from the group consisting of cordierite, mullite, zirconium phosphate, aluminum titanate, silicon carbide, silicon-silicon carbide composites, cordierite-silicon carbide composites, zircon, zirconia, spinel, indialite, sapphirine, corundum, titania, and silicon nitride. Among these, for reasons of cost, availability, thermal shock resistance, and peeling resistance, the ceramic particles constituting the gas-permeable membrane 11 preferably contain a total of 50% by mass or more of one or more elements selected from silicon carbide, cordierite, alumina, silica, mullite, and aluminum titanate, more preferably 70% by mass or more, and even more preferably 90% by mass or more. For reasons of peeling resistance, the porous membrane particularly preferably contains 50% by mass or more of silicon carbide, more preferably 70% by mass or more, and even more preferably 90% by mass or more.

[0049] Materials constituting the outer peripheral wall 100 and the partition walls 103 of the honeycomb filter 1 for removing pathogenic bacteria according to this embodiment include, but are not limited to, porous ceramics containing at least one element selected from the group consisting of cordierite, mullite, zirconium phosphate, aluminum titanate, silicon carbide, silicon-silicon carbide composites, cordierite-silicon carbide composites, zircon, zirconia, spinel, indialite, sapphirine, corundum, titania, and silicon nitride. These ceramics may contain one type alone or two or more types simultaneously. In the case of the honeycomb filter 1 for removing pathogenic bacteria, cordierite is preferably used as the ceramic because it does not cause problems with size or corrosion resistance even when the temperature is changed. Therefore, the outer peripheral wall 100 and the partition walls 103 preferably contain cordierite at 50% by mass or more, more preferably 70% by mass or more, and even more preferably 90% by mass or more.

[0050] The honeycomb structure 10 may support an oxidation catalyst in the inlet cells 101 and the outlet cells 102. This can lower the temperature at which dust and other particles adhering to the pathogen removal honeycomb filter 1 are burned off. Examples of the oxidation catalyst include platinum and palladium.

[0051] The end face shape of the honeycomb structure 10 is not limited, and may be, for example, a round shape such as a circle, an ellipse, a racetrack shape, or an oval, or a polygonal shape such as a triangle or a rectangle. The honeycomb structure 10 in Fig. 1 has a circular end face shape and is cylindrical as a whole.

[0052] Although there are no limitations on the shape of the cells in a cross section perpendicular to the cell extension direction, a quadrangle, a hexagon, an octagon, or a combination thereof is preferred. Among these, a square and a hexagon are preferred. By using such a cell shape, it is possible to reduce the pressure loss when a fluid flows through the honeycomb filter 1 for removing pathogens.

[0053] The cell density (the number of cells per unit cross-sectional area perpendicular to the cell extension direction) is not particularly limited, but is preferably, for example, 6 to 2000 cells / square inch (0.9 to 311 cells / cm 2 ), preferably 50 to 1000 cells / in² (7.8 to 155 cells / cm²) 2 ), more preferably 100 to 400 cells / square inch (15.5 to 62.0 cells / cm 2 ) can be used.

[0054] The pathogenic bacteria removal honeycomb filter 1 can also be provided as an integrally molded product. Alternatively, the pathogenic bacteria removal honeycomb filter 1 can be provided as a segment assembly, in which multiple pathogenic bacteria removal honeycomb filter 1 segments, each having an outer peripheral wall 100, are joined together at their side surfaces to form an integrated unit. By providing the pathogenic bacteria removal honeycomb filter 1 as a segment assembly, it is possible to improve thermal shock resistance.

[0055] <2. Manufacturing method of honeycomb filter for removing pathogens> A manufacturing method of the honeycomb filter 1 for removing pathogenic bacteria is described below by way of example. First, a raw material composition containing ceramic raw materials, a dispersion medium, a pore-forming material, and a binder is kneaded to form a clay, and then the clay is extrusion-molded to form the desired columnar honeycomb molded body. Additives such as a dispersant can be blended into the raw material composition as needed. During extrusion molding, a die having the desired overall shape, cell shape, partition wall thickness, cell density, etc. can be used.

[0056] After drying the columnar honeycomb formed body, plugging portions 104 are formed at predetermined positions on both end faces of the columnar honeycomb formed body, and then the plugging portions 104 are dried to obtain a columnar honeycomb formed body having the plugging portions 104. Thereafter, the columnar honeycomb formed body is degreased and fired to manufacture a columnar honeycomb structure.

[0057] The ceramic raw material can be any raw material capable of forming the above-described ceramics after firing. The ceramic raw material can be provided, for example, in the form of a powder. Examples of the ceramic raw material include raw materials for obtaining ceramics, such as cordierite, mullite, zirconium phosphate, aluminum titanate, silicon carbide (SiC), silicon-silicon carbide composites (e.g., Si-bonded SiC), cordierite-silicon carbide composites, zircon, zirconia, spinel, indialite, sapphirine, corundum, titania, and silicon nitride. Specific examples include, but are not limited to, silica, talc, alumina, kaolin, serpentine, pyroferrite, brucite, boehmite, mullite, magnesite, and aluminum hydroxide. The ceramic raw material may be used singly or in combination of two or more.

[0058] In the case of use in a honeycomb filter for removing pathogens, cordierite can be suitably used as the ceramic. In this case, a cordierite-forming raw material can be used as the ceramic raw material. The cordierite-forming raw material is a raw material that becomes cordierite when fired. The cordierite-forming raw material preferably has a chemical composition of 30 to 45 mass % alumina (Al2O3) (including aluminum hydroxide converted to alumina), 11 to 17 mass % magnesia (MgO), and 42 to 57 mass % silica (SiO2).

[0059] Examples of the dispersion medium include water and a mixed solvent of water and an organic solvent such as alcohol, with water being particularly preferred.

[0060] The pore-forming material is not particularly limited as long as it forms pores after firing, and examples thereof include wheat flour, starch, foamed resin, water-absorbent resin, porous silica, carbon (e.g., graphite), ceramic balloons, polyethylene, polystyrene, polypropylene, nylon, polyester, acrylic, and phenol. One type of pore-forming material may be used alone, or two or more types may be used in combination. From the viewpoint of increasing the porosity of the fired body, the content of the pore-forming material is preferably 0.5 parts by mass or more, more preferably 2 parts by mass or more, and even more preferably 3 parts by mass or more, per 100 parts by mass of the ceramic raw material. From the viewpoint of ensuring the strength of the fired body, the content of the pore-forming material is preferably 10 parts by mass or less, more preferably 7 parts by mass or less, and even more preferably 4 parts by mass or less, per 100 parts by mass of the ceramic raw material.

[0061] Examples of binders include organic binders such as methyl cellulose, hydroxypropyl methyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, and polyvinyl alcohol. It is particularly preferable to use a combination of methyl cellulose and hydroxypropyl methyl cellulose. Furthermore, from the viewpoint of increasing the strength of the honeycomb formed body, the binder content is preferably 4 parts by mass or more, more preferably 5 parts by mass or more, and even more preferably 6 parts by mass or more, per 100 parts by mass of the ceramic raw materials. From the viewpoint of suppressing cracks due to abnormal heat generation during the firing process, the binder content is preferably 9 parts by mass or less, more preferably 8 parts by mass or less, and even more preferably 7 parts by mass or less, per 100 parts by mass of the ceramic raw materials. One type of binder may be used alone, or two or more types may be used in combination.

[0062] The dispersant may be ethylene glycol, dextrin, fatty acid soap, polyether polyol, etc. One type of dispersant may be used alone, or two or more types may be used in combination. The content of the dispersant is preferably 0 to 2 parts by mass per 100 parts by mass of the ceramic raw material.

[0063] The method for plugging the end faces of the columnar honeycomb formed body is not particularly limited, and well-known methods can be used. The material for the plugging portions is not particularly limited, but ceramics are preferred from the viewpoints of strength and heat resistance. The ceramic is preferably a ceramic material containing at least one selected from the group consisting of cordierite, mullite, zircon, zirconium phosphate, aluminum titanate, silicon carbide, silicon nitride, zirconia, spinel, indialite, sapphirine, corundum, and titania. It is even more preferred that the plugging portions have the same material composition as the partition walls of the honeycomb formed body, as this allows for the same expansion coefficient during firing, leading to improved durability.

[0064] After drying the honeycomb formed body, degreasing and firing are performed to manufacture a columnar honeycomb structure. The conditions for the drying, degreasing and firing processes may be well known conditions depending on the material composition of the honeycomb formed body, and no particular explanation is required, but examples of specific conditions are given below.

[0065] In the drying step, a conventionally known drying method can be used, for example, hot air drying, microwave drying, dielectric drying, reduced pressure drying, vacuum drying, freeze drying, etc. Among them, a drying method that combines hot air drying with microwave drying or dielectric drying is preferred, since it can dry the entire molded body quickly and uniformly.

[0066] When forming the plugging portions 104, it is preferable to form the plugging portions 104 on both end faces of the dried honeycomb formed body and then dry the plugging portions 104. The plugging portions 104 are formed at predetermined positions so that the inlet side cells 101 and the outlet side cells 102 are alternately arranged adjacent to each other with the partition wall 103 sandwiched therebetween.

[0067] Next, the degreasing step will be described. The combustion temperature of the binder is about 200°C, and the combustion temperature of the pore-forming material is about 300 to 1000°C. Therefore, the degreasing step can be carried out by heating the honeycomb formed body to a temperature in the range of about 200 to 1000°C. The heating time is not particularly limited, but is usually about 10 to 100 hours. The honeycomb formed body after the degreasing step is called a calcined body.

[0068] The firing step may be performed by, for example, heating the calcined body to 1350 to 1600°C and holding the calcined body for 3 to 10 hours, although this depends on the material composition of the honeycomb formed body. In this way, a ceramic honeycomb structure 10 is produced, which includes an outer peripheral wall 100, inlet-side cells 101 arranged inside the outer peripheral wall 100, open at the inlet-side end face 10a and plugged at the outlet-side end face 10b, outlet-side cells 102 arranged inside the outer peripheral wall 100, open at the outlet-side end face 10b and plugged at the inlet-side end face 10a, and porous partition walls 103 arranged between the inlet-side cells 101 and the outlet-side cells 102.

[0069] Next, a gas permeable membrane 11 is formed on the surfaces of the partition walls 103 of the honeycomb structure 10 that has been subjected to the firing step. When forming the gas permeable membrane 11 on the surfaces of the inlet-side cells 101, a step is carried out in which an aerosol containing ceramic particles is sprayed toward the inlet-side end face 10a where the inlet-side cells 101 open, while applying suction force to the outlet-side end face 10b to suck the sprayed aerosol from the inlet-side end face 10a, thereby adhering the ceramic particles to the surfaces of the inlet-side cells 101.

[0070] In this case, it is desirable for the ceramic particles in the aerosol to have a sharp and fine particle size distribution. When the ceramic particles in the aerosol have a sharp and fine particle size distribution, the resulting porous film has a homogeneous three-dimensional structure with fine pores, making it easier to achieve high collection efficiency even with a thin film thickness. By making the film thinner, it is also possible to achieve low pressure loss. Although it is difficult to accurately identify this homogeneous three-dimensional structure with fine pores, at least a part of it is manifested as low porosity.

[0071] Specifically, the ceramic particles in the aerosol preferably satisfy the relationship of 0.1≦D50≦6.0 and 0.4≦D50 / (D90−D10), where D50 (unit: μm) is the median diameter, D10 (unit: μm) is the 10% diameter, and D90 (unit: μm) is the 90% diameter in the volume-based cumulative particle size distribution measured by laser diffraction / scattering.

[0072] The upper limit of D50 of the ceramic particles is preferably 6.0 μm or less, more preferably 4.0 μm or less, and even more preferably 3.0 μm or less. The lower limit of D50 of the ceramic particles is not particularly set, but from the viewpoint of ease of preparation, it is usually 0.1 μm or more, preferably 0.5 μm or more, and more preferably 1.0 μm or more.

[0073] The sharpness of the particle size distribution can be expressed by D50 / (D90-D10). Using D50 / (D90-D10) as an index makes it possible to express the degree of aggregation of ceramic particles in particular. The D50 / (D50-D10) ratio specified in JP 2001-79321 A by the present applicant cannot express the sharpness of the particle size distribution. A large D50 / (D90-D10) indicates a sharp particle size distribution. Specifically, 0.4≦D50 / (D90-D10) is preferred, 0.6≦D50 / (D90-D10) is more preferred, 0.8≦D50 / (D90-D10) is even more preferred, and 1.0≦D50 / (D90-D10) is even more preferred, e.g., 0.4≦D50 / (D90-D10)≦1.5.

[0074] The ceramic particles used are the same as those used to form the porous film. Specifically, the ceramic particles may contain one or more ceramics selected from silicon carbide (SiC), cordierite, talc, mica, mullite, cerium, aluminum titanate, alumina, silicon nitride, sialon, zirconium phosphate, zirconia, titania, and silica (SiO). Among these, for reasons of cost, availability, thermal shock resistance, and peeling resistance, the ceramic particles preferably contain a total of 50% by mass or more of one or more ceramics selected from silicon carbide, cordierite, alumina, silica, mullite, and aluminum titanate, more preferably 70% by mass or more, and even more preferably 90% by mass or more. For reasons of thermal shock resistance and peeling resistance, the ceramic particles preferably contain 50% by mass or more of silicon carbide, more preferably 70% by mass or more, and even more preferably 90% by mass or more.

[0075] Fig. 5 is a schematic diagram illustrating the configuration of a particle attachment device 500 according to one embodiment of the present invention. Fig. 5 shows a schematic configuration of the particle attachment device 500 suitable for carrying out a step of attaching ceramic particles to the surfaces of the inlet-side cells 101 (see Fig. 2, etc.) of the honeycomb structure 10. The particle attachment device 500 includes an aerosol generator 510, a laser diffraction particle size distribution analyzer 520, a gas inlet pipe 530, a holder 540, a differential pressure gauge 550, an exhaust pipe 560, and a blower 570.

[0076] The aerosol generator 510 a cylinder 513 containing ceramic particles 512; a piston or screw 514 for sending the ceramic particles 512 contained in the cylinder 513 through a cylinder outlet 513e; a crushing chamber 515 communicating with the cylinder outlet 513e and equipped with a rotor 516 for crushing the ceramic particles 512 delivered from the cylinder outlet 513e; a gas flow path 517 for flowing a medium gas, which is connected to a crushing chamber outlet 515e midway and can spray an aerosol containing the medium gas and ceramic particles 512 from a nozzle 511 attached to the tip of the gas flow path 517; Equipped with.

[0077] The aerosol generator 510 can spray an aerosol from a nozzle 511. Ceramic particles 512 adjusted to a predetermined particle size distribution are stored in a cylinder 513. The ceramic particles 512 stored in the cylinder 513 are extruded from a cylinder outlet 513e by a piston or screw 514. The extrusion speed can be adjusted. The ceramic particles 512 discharged from the cylinder outlet 513e enter a crushing chamber 515. The ceramic particles 512 introduced into the crushing chamber 515 move within the crushing chamber 515 while being crushed by a rotor 516, and are discharged from a crushing chamber outlet 515e. For example, a rotating brush can be used as the rotor 516. The rotor 516 can be driven by a motor, and its rotational speed can be controlled.

[0078] The ceramic particles discharged from the crushing chamber outlet 515e are mixed with the medium gas flowing through the gas flow path 517 to form an aerosol, which is then sprayed from the nozzle 511. The nozzle 511 is preferably installed at a position and in a direction such that the aerosol is sprayed toward the center of the inlet-side end face 10a of the honeycomb structure 10 held by the holder 540 in a direction perpendicular to the inlet-side end face 10a.

[0079] The medium gas can be a compressed gas such as compressed air with adjusted pressure, thereby controlling the flow rate of the medium gas sprayed from the nozzle 511. A laser diffraction particle size distribution measuring device 520 is installed in the gas flow path 517, which can measure in real time the particle size distribution of the ceramic particles in the aerosol discharged from the aerosol generator 510. This makes it possible to monitor whether ceramic particles having the desired particle size distribution are being supplied to the honeycomb structure 10.

[0080] Fine ceramic particles have a tendency to agglomerate. However, by using the aerosol generator 510 according to this embodiment, crushed ceramic particles are sprayed, which makes it possible to prevent agglomeration and ensure that ceramic particles with the desired particle size distribution adhere to the surface of the inlet cell 101.

[0081] The aerosol sprayed from the aerosol generator 510 passes through the gas introduction pipe 530 by the suction force of the blower 570, and is then sucked into the inlet side cells 101 of the honeycomb filter 1 for removing pathogens from the inlet side end face 10a of the honeycomb structure 10 held by the holder 540. The ceramic particles in the aerosol sucked into the inlet side cells 101 adhere to the surfaces of the inlet side cells 101.

[0082] A plurality of ventilation holes 531 are provided in the wall surface of the gas introduction pipe 530, which allows ambient gas such as air to be sucked in. This makes it possible to adjust the flow rate of gas flowing into the gas introduction pipe 530 according to the suction force from the blower 570. A filter may be installed in the ventilation holes 531 to prevent foreign matter from entering.

[0083] An exhaust pipe 560 connected to a blower 570 is provided downstream of the outlet end face 10b of the honeycomb structure 10. Therefore, when the aerosol from which the ceramic particles have been removed is discharged from the outlet end face 10b of the honeycomb structure 10, it passes through the exhaust pipe 560 and is then exhausted through the blower 570.

[0084] As the process of adhering ceramic particles to the surfaces of the inlet-side cells 101 continues, the pressure loss between the inlet-side end face 10a and the outlet-side end face 10b of the honeycomb structure 10 increases as the amount of ceramic particles attached increases. By determining the relationship between the amount of ceramic particles attached and the pressure loss in advance, the end point of the process of adhering ceramic particles to the surfaces of the inlet-side cells 101 can be determined based on the pressure loss. Therefore, the particle attachment device 500 can be equipped with a differential pressure gauge 550 to measure the pressure loss between the inlet-side end face 10a and the outlet-side end face 10b of the honeycomb structure 10, and the end point of the process can be determined based on the value of the differential pressure gauge.

[0085] When the process of adhering ceramic particles to the surface of the inlet cell 101 is carried out, the ceramic particles adhere to the inlet end face 10a of the honeycomb structure 10, so it is preferable to smooth the inlet end face 10a with a tool such as a scraper while suctioning and removing the ceramic particles using a vacuum or the like.

[0086] Thereafter, the columnar honeycomb structure having ceramic particles attached to the surfaces of the inlet cells 101 is heat-treated under conditions of maintaining a maximum temperature of 1000°C or higher for one hour or more, typically maintaining a maximum temperature of 1100°C to 1400°C for one to six hours, thereby completing the honeycomb filter 1 for removing pathogenic bacteria. The heat treatment can be carried out, for example, by placing the honeycomb structure 10 in a continuous firing furnace (e.g., a tunnel kiln) or a batch firing furnace (e.g., a shuttle kiln). In order to increase the production rate, the average temperature rise rate from room temperature (25°C) to the maximum temperature is preferably 100°C / Hr or higher. In addition, in order to suppress the occurrence of cracks, the average temperature rise rate from room temperature (25°C) to the maximum temperature is preferably 200°C / Hr or lower. Furthermore, in order to prevent cracking and reduce the burden on the kiln materials, the average temperature drop rate from the maximum temperature to room temperature (25°C) is preferably 200°C / Hr or less during the heat treatment. The heat treatment bonds the ceramic particles together and causes them to adhere to the partition walls 103 in the inlet cells 101, forming a porous film on the surface of the inlet cells 101. When the heat treatment is performed under oxygen-containing conditions, such as in air, a surface oxide film is formed on the ceramic particle surface, promoting bonding between the ceramic particles. This results in a porous film that is less likely to peel off.

[0087] The average thickness T (unit: μm) of the porous membrane formed on the surface of the inlet cell 101 by heat treatment preferably satisfies the relationship between the D50 (unit: μm) of the ceramic particles and the average thickness T (unit: μm): 4 × D50≦T≦20 × D50. This relationship indicates that when D50 is small, the average thickness T should be small, and when D50 is large, the average thickness T should be large. This is because the smaller the D50, the smaller the exhaust gas flow path of the porous membrane, thereby improving the collection efficiency.

[0088] <3. Pathogen removal filter device> 6 is an explanatory diagram schematically showing a first mode of a pathogen removal filter device 6 according to an embodiment of the present invention. The pathogen removal filter device 6 according to this embodiment has at least one pathogen removal honeycomb filter 1 and a heating section 3 that heats the pathogen removal honeycomb filter 1. The pathogen removal honeycomb filter 1 is as described above. When the heating section 3 heats the pathogen removal honeycomb filter 1, particles captured by the pathogen removal honeycomb filter 1 are burned away.

[0089] Various configurations can be used for the heating section 3. In a first embodiment of a pathogen removal filter device 6 shown in Fig. 6, the pathogen removal honeycomb filter 1 further has a conductor and / or magnetic material 105 included in the honeycomb structure 10. The heating section 3 includes a coil 30 provided around the pathogen removal honeycomb filter 1, and is configured to inductively heat the pathogen removal honeycomb filter 1 by magnetic flux from the coil 30.

[0090] The conductor and / or magnetic material 105 may be present in at least a portion of the radial and axial directions within the honeycomb structure 10. Furthermore, the conductor and / or magnetic material 105 may be present inside the outer peripheral wall 100, inside the partition walls 103, inside the cells (the inlet-side cells 101 and the outlet-side cells 102), and / or on the outer peripheral wall 100. The conductor and / or magnetic material 105 present inside the cells may be filled in the cells or coated on the surfaces of the partition walls 103. Figure 6 shows an embodiment in which the conductor and / or magnetic material 105 is provided on the outer peripheral wall 100 and the conductor and / or magnetic material 105 is filled inside the cells.

[0091] The conductor and / or magnetic material 105 filled in the cells may form plugging portions 104 that plug the ends of the cells. The conductor and / or magnetic material 105 coated on the surface of the partition wall 103 can form a coating layer together with an adhesive material in which the conductor and / or magnetic material 105 are dispersed. As the adhesive material, glass, crystallized glass, ceramics, etc. containing silicic acid, boric acid, or borosilicate, or glass, crystallized glass, ceramics, etc. containing other oxides can be used.

[0092] When the conductor and / or magnetic body 105 forms the plugging portion 104, the conductor and / or magnetic body 105 may have a columnar outer shape that matches the shape of the cell. The conductor and / or magnetic body 105 may have such an outer shape before being filled into the cell, or may have such an outer shape after being filled into the cell. In other words, the conductor and / or magnetic body 105 may constitute a shaped material having a predetermined shape, or may constitute a paste-like unshaped material.

[0093] The shaped material and the unshaped material may be composed of a composite composition of a conductor and / or magnetic material 105 and a binder or adhesive material. Examples of binders include materials mainly composed of metal or glass. Examples of adhesive materials include materials mainly composed of silica or alumina. In addition to the binder or adhesive material, an organic or inorganic substance may be further contained. The conductor and / or magnetic material 105 may be filled all the way from one end face to the other end face of the honeycomb structure 10. Alternatively, the conductor and / or magnetic material 105 may be filled from one end face of the honeycomb structure 10 to partway through the cells.

[0094] The conductor and / or magnetic body 105 may contain at least one selected from the group consisting of Fe, Cr, Ni, Mn, Zn, Co, Cu, and Si. Examples of the conductor and / or magnetic body 105 include: balance Co-20% by mass Fe, balance Co-25% by mass Ni-4% by mass Fe, balance Fe-15 to 35% by mass Co, balance Fe-17% by mass Co-2% by mass Cr-1% by mass Mo, balance Fe-49% by mass Co-2% by mass V, balance Fe-18% by mass Co-10% by mass Cr-2% by mass Mo-1% by mass Al, balance Fe-27% by mass Co-1% by mass Nb, balance Fe-20% by mass Co-1% by mass Cr-2% by mass V, balance Fe-35% by mass Co-1% by mass Cr, pure cobalt, pure iron, soft magnetic iron, balance Fe-0.1 to 0.5% by mass Mn, balance Fe-3% by mass Si ... Examples of the metal include Fe-6.5% by mass Si, balance Fe-18% by mass Cr, balance Fe-16% by mass Cr-8% by mass Al, balance Ni-13% by mass Fe-5.3% by mass Mo, balance Fe-45% by mass Ni, balance Fe-10% by mass Si-5% by mass Al, balance Fe-36% by mass Ni, balance Fe-45% by mass Ni, balance Fe-35% by mass Cr, balance Fe-13% by mass Cr-2% by mass Si, balance Fe-20% by mass Cr-2% by mass Si-2% by mass Mo, balance Fe-20% by mass Co-1% by mass V, balance Fe-13% by mass Cr-2% by mass Si, and balance Fe-17% by mass Co-2% by mass Cr-1% by mass Mo. Examples of the conductor and / or magnetic body 105 include oxides such as Mn-Zn ferrite, Cu-Zn ferrite, Ni-Zn ferrite, and Cu-Zn-Mg ferrite.

[0095] The coil 30 is a conductor wound around a predetermined axis. The coil 30 is disposed on the outer periphery of the honeycomb structure 10. The axis of the coil 30 may be parallel to the axial direction of the honeycomb structure 10. The axis may be coaxial with the central axis of the honeycomb structure 10. Although a band-shaped conductor with a rectangular cross section is shown in FIG. 6, the shape of the conductor is arbitrary and may be other shapes such as circular or tubular. The conductor may be molded with an insulating material. Examples of the insulating material that can be used include alumina, mullite, and / or heat-resistant resin.

[0096] A power supply circuit 31 is connected to the coil 30. When an alternating current is supplied from the power supply circuit 31 to the coil 30, a magnetic flux is generated in the vicinity of the coil 30. The honeycomb structure 10 and the conductor and / or magnetic body 105 can be induction heated by the magnetic flux from the coil 30.

[0097] The pathogen removal filter device 6 may further include a ceramic fiber insulating material 7 surrounding each honeycomb structure 10 of at least one pathogen removal honeycomb filter 1. Examples of ceramics that may be used for the insulating material 7 include alumina and silicon dioxide. FIG. 6 shows a cylindrical insulating material 7 arranged on the outer periphery of the honeycomb structure 10. However, the outer shape of the insulating material 7 may be changed as desired. The conductor and / or magnetic material 105 may be arranged inside the insulating material 7, and the coil 30 may be arranged outside the insulating material 7.

[0098] Next, FIG. 7 is an explanatory diagram schematically showing a second aspect of a pathogen removal filter device 6 according to an embodiment of the present invention. The heating section 3 may include an electrode 32 connected to the pathogen removal honeycomb filter 1. The pathogen removal filter device 6 may be configured so that the pathogen removal honeycomb filter 1 is electrically heated by a current from the electrode 32. The pathogen removal honeycomb filter 1 may be heated by Joule heat when the current from the electrode 32 flows through the outer peripheral wall 100 and the partition walls 103. The electrode 32 may be a metal strip-shaped member arranged on the outer peripheral wall 100 so as to sandwich the central axis of the honeycomb structure 10. Although FIG. 7 shows the electrode 32 extending over the entire length of the honeycomb structure 10, the length and outer shape of the electrode 32 may be changed as desired.

[0099] Although not shown, an electrode layer may be disposed between the electrode 32 and the outer peripheral wall 100. By disposing an electrode layer with a lower volume resistivity than the outer peripheral wall 100, the current is more likely to spread in the circumferential direction of the honeycomb structure 10 and in the cell extension direction, thereby improving the uniform heat generation of the pathogenic bacteria removal honeycomb filter 1. The volume resistivity of the electrode layer is preferably 1 / 10 or less, more preferably 1 / 20 or less, and even more preferably 1 / 30 or less, of the volume resistivity of the outer peripheral wall 100 and the partition walls 103. However, if the difference in volume resistivity between the two is too large, current will concentrate between the ends of the opposing electrode layers, resulting in uneven heat generation in the honeycomb structure 10. Therefore, the volume resistivity of the electrode layer is preferably 1 / 200 or more, more preferably 1 / 150 or more, and even more preferably 1 / 100 or more, of the volume resistivity of the outer peripheral wall 100 and the partition walls 103. Therefore, the volume resistivity of the electrode layer is, for example, preferably 1 / 200 to 1 / 10, more preferably 1 / 150 to 1 / 20, and even more preferably 1 / 100 to 1 / 30 of the volume resistivity of the outer peripheral wall 100 and the partition walls 103. The volume resistivities of the electrode layer, outer peripheral wall 100, and partition walls 103 herein are values ​​measured at 25°C by a four-terminal method.

[0100] The material of the electrode layer is not limited to, but may be a composite (cermet) of metal and ceramic (especially conductive ceramic). Examples of metals include, for example, Cr, Fe, Co, Ni, Si, or Ti, or alloys containing at least one metal selected from these metals. Examples of ceramics include, but are not limited to, silicon carbide (SiC), as well as metal compounds such as metal silicides, such as tantalum silicide (TaSi2) and chromium silicide (CrSi2). Specific examples of composites (cermets) of metal and ceramic include composites of silicon and silicon carbide, composites of metal silicides, such as tantalum silicide or chromium silicide, and silicon and silicon carbide. Furthermore, composites of one or more of the above metals with one or more insulating ceramics, such as alumina, mullite, zirconia, cordierite, silicon nitride, and aluminum nitride, to reduce thermal expansion. As the material for the electrode layer, among the various metals and ceramics described above, a composite material of a metal silicide such as tantalum silicide or chromium silicide, silicon, and silicon carbide is preferred because it can be fired simultaneously with the outer peripheral wall 100 and the partition walls 103, thereby contributing to simplifying the manufacturing process. The other configurations are the same as those of the first embodiment.

[0101] Next, Fig. 8 is an explanatory diagram schematically showing a third aspect of a pathogen removal filter device 6 according to an embodiment of the present invention. The pathogen removal honeycomb filter 1 may further include an electric resistor 106 incorporated in the honeycomb structure 10. The heating section 3 may include an electrode 33 connected to the electric resistor 106. The pathogen removal filter device 6 may be configured such that the electric resistor 106 is heated by passing a current through the electrode 33, thereby heating the pathogen removal honeycomb filter 1 through the electric resistor 106.

[0102] As shown in FIG. 8, the electrical resistor 106 may be arranged so as to be in contact with at least one of the inlet-side end face 10a, the outlet-side end face 10b, the outer peripheral wall 100, and the partition wall 103. The electrical resistor 106 may be made of, for example, nichrome. The electrode 33 may be provided integrally with the electrical resistor 106. In the illustrated embodiment, the electrode 33 is a portion extending in the radial direction of the honeycomb structure 10 from the electrical resistor 106 arranged on the inlet-side end face 10a and the outlet-side end face 10b. As shown in the figure, the electrode 33 may protrude radially outward from the outer peripheral wall 100 of the honeycomb structure 10. The other configurations are the same as those of the first and second embodiments.

[0103] Next, Fig. 9 is an explanatory diagram schematically showing a fourth aspect of a pathogen removal filter device 6 according to an embodiment of the present invention, and Fig. 10 is an explanatory diagram schematically showing a fifth aspect of a pathogen removal filter device 6 according to an embodiment of the present invention. The heating section 3 may include a heater 34 arranged upstream of the pathogen removal honeycomb filter 1 in the flow direction of a fluid introduced into the pathogen removal honeycomb filter 1. The pathogen removal filter device 6 may be configured so that the pathogen removal honeycomb filter 1 is heated by flowing a fluid heated by the heater 34 through the pathogen removal honeycomb filter 1.

[0104] Any configuration may be used for the heater 34. An example of the heater 34 is shown in Figures 9 and 10.

[0105] 9 includes a heater honeycomb structure 340 and a heater electrode 341 connected to the heater honeycomb structure 340, and is configured so that the heater honeycomb structure 340 is heated by a current flowing from the heater electrode 341 through the heater honeycomb structure 340. The configuration of the heater electrode 341 may be the same as the configuration of the electrode 32 of the heating unit 3 in FIG.

[0106] The heater 34 in Fig. 10 includes a heater honeycomb structure 340, a heater electric resistor 342 incorporated in the heater honeycomb structure 340, and a heater electrode 343 connected to the heater electric resistor 342, and is configured such that the heater electric resistor 342 is heated by passing a current through the heater electrode 343, thereby heating the heater honeycomb structure 340 through the heater electric resistor 342. The configuration of the heater electric resistor 342 is the same as that of the electric resistor 106 of the heating unit 3 in Fig. 8. The other configurations are the same as those of the first to third embodiments.

[0107] Next, Fig. 11 is a perspective view schematically showing a sixth aspect of a pathogen removal filter device 6 according to an embodiment of the present invention, and Fig. 12 is a plan view showing the pathogen removal filter device 6 of Fig. 11. As shown in Figs. 11 and 12, the pathogen removal filter device 6 may have a plurality of pathogen removal honeycomb filters 1, and the heating section 3 (see Figs. 6 to 10) may be configured to heat the plurality of pathogen removal honeycomb filters 1 individually. In the illustrated embodiment, three pathogen removal honeycomb filters 1 are arranged side by side. However, the number and arrangement of the pathogen removal honeycomb filters 1 may be changed as desired.

[0108] The pathogen removal filter device 6 may further include a heating selection section 60 that selects a pathogen removal honeycomb filter 1 to be heated by the heating section 3 based on the pressure loss and / or flow rate of the plurality of pathogen removal honeycomb filters 1.

[0109] Any method may be used to measure the pressure loss and / or the flow rate through the plurality of pathogen removal honeycomb filters 1. The heating selection unit 60 may have a flow meter that measures the flow rate of the fluid passing through the pathogen removal honeycomb filter 1, a pressure meter that measures the differential pressure between the upstream and downstream sides of the pathogen removal honeycomb filter 1, and / or an ammeter that measures the drive current of the blower that supplies the fluid to the pathogen removal honeycomb filter 1, and the pressure loss and / or the flow rate through the pathogen removal honeycomb filter 1 may be determined based on these measured values.

[0110] There are three types of flow meters: thermal flow meters, ultrasonic flow meters, and vortex flow meters, but thermal flow meters are preferred because of their size and simple configuration. When using blowers, the same number of blowers as the number of honeycomb filters 1 for removing pathogenic bacteria may be used, or a large blower common to multiple honeycomb filters 1 for removing pathogenic bacteria may be used. In either case, a flow meter may be provided for each honeycomb filter 1 for removing pathogenic bacteria.

[0111] The differential pressure can be detected by measuring the pressure on the upstream and downstream sides of the pathogen removal honeycomb filter 1 and finding the difference between them, or by using a differential pressure gauge to directly measure the pressure difference between the upstream and downstream sides. Even in this case, the same number of blowers as the number of pathogen removal honeycomb filters 1 may be used, or a large blower common to multiple pathogen removal honeycomb filters 1 may be used. When using the same number of blowers as the number of pathogen removal honeycomb filters 1, a pressure gauge may be provided for each blower. In either case, a pressure gauge may be provided for each pathogen removal honeycomb filter 1.

[0112] The ammeter may measure the drive current of the drive motor of the fan, and is particularly suitable when the number of fans used is the same as the number of honeycomb filters 1 for removing pathogenic bacteria.

[0113] The heating selection unit 60 stores initial data such as air volume, pressure, and drive power in a memory or the like, and when the difference or ratio between the current data and the initial data exceeds a threshold, it may select the pathogen removal honeycomb filter 1 corresponding to that data as the filter to be heated by the heating unit 3. The heating selection unit 60 may select all pathogen removal honeycomb filters 1 simultaneously, may select a plurality of pathogen removal honeycomb filters 1 leaving at least one, or may select only one pathogen removal honeycomb filter 1. By selecting a plurality of pathogen removal honeycomb filters 1 leaving at least one, or only one pathogen removal honeycomb filter 1, it is possible to avoid stopping the filtering operation of the pathogen removal filter device 6 when the pathogen removal honeycomb filter 1 is heated.

[0114] At least one pathogen removal honeycomb filter 1 may be housed in a chamber 61. The chamber 61 is a container for housing the pathogen removal honeycomb filter 1. The chamber 61 may be made of, for example, a 1.0 mm thick stainless steel plate. Stainless steel does not rust, so pathogens do not get into the rust and it is effective for use in equipment that requires cleanliness. From the viewpoint of similar rust resistance, other metals such as titanium alloys, nickel alloys, copper, and aluminum alloys can also be used as the material for the chamber 61. FIG. 11 shows a state in which a pathogen removal honeycomb filter 1 is housed in each of multiple chambers 61. The multiple chambers 61 may be separated from each other by chamber partition walls 61a. Alternatively, the multiple chambers 61 may be spaced apart. The heat insulating material 7 shown in FIGS. 6 to 10 may be arranged to fill the space between the pathogen removal honeycomb filter 1 and the inner wall of the chamber 61.

[0115] The chamber 61 may have a chamber main body 62 having an inlet-side opening 62a and an outlet-side opening 62b, and a lid 63 that is placed over the inlet-side opening 62a and the outlet-side opening 62b. The lid 63 may be provided so as to be displaceable by an actuator (not shown). When the heating selection unit 60 selects a pathogen removal honeycomb filter 1 to be heated by the heating unit 3, the operation of the actuator may be controlled so that the lid 63 is placed over the inlet-side opening 62a and the outlet-side opening 62b of the chamber main body 62 that houses the pathogen removal honeycomb filter 1. Figure 12 shows the state when the middle pathogen removal honeycomb filter 1 is heated. When heating of the pathogen removal honeycomb filter 1 by the heating unit 3 is completed, the operation of the actuator may be controlled so that the inlet-side opening 62a and the outlet-side opening 62b are opened.

[0116] When the lid 63 is placed over the inlet-side opening 62a and / or the outlet-side opening 62b, the area of ​​the lid 63 within the inlet-side opening 62a and / or the outlet-side opening 62b is preferably 90% or more but less than 100% of the area of ​​the inlet-side opening 62a and / or the outlet-side opening 62b. This area of ​​the lid 63 corresponds to the effective area of ​​the lid 63 that closes the inlet-side opening 62a and / or the outlet-side opening 62b. When a hole is formed in the lid 63, the area of ​​the hole is not included in the area of ​​the lid 63. When the lid 63 is larger than the inlet-side opening 62a and / or the outlet-side opening 62b and the lid 63 protrudes from the inlet-side opening 62a and / or the outlet-side opening 62b, the area of ​​the protruding portion is not included in the area of ​​the lid 63.

[0117] By making the area of ​​the lid 63 90% or more, it is possible to reduce the amount of heat that escapes outside the chamber main body 62 through the inlet side opening 62a and / or the outlet side opening 62b when heating the pathogen removal honeycomb filter 1. By making the area of ​​the lid 63 less than 100%, it is possible to introduce external air or oxygen into the chamber main body 62 when heating the pathogen removal honeycomb filter 1, and it is possible to more reliably burn off particles captured by the pathogen removal honeycomb filter 1. It is more preferable that the area of ​​the lid 63 be 92% or more and 98% or less of the area of ​​the inlet side opening 62a and / or the outlet side opening 62b, and even more preferable that it be 94% or more and 96% or less.

[0118] The pathogen removal filter device 6 may further have an alarm means 64 that monitors the pressure loss and / or flow rate of the pathogen removal honeycomb filter 1 heated by the heating section 3, and notifies that maintenance is required when the pressure loss exceeds a predetermined pressure loss threshold or the flow rate falls below a predetermined flow rate threshold within a predetermined operating time after being heated by the heating section 3.

[0119] As described above, the method for measuring the pressure loss and / or the flow rate through the pathogenic bacteria removal honeycomb filter 1 is as follows: The notification means 64 may have a flowmeter for measuring the flow rate of the fluid passing through the pathogenic bacteria removal honeycomb filter 1, a pressure gauge for measuring the differential pressure between the upstream and downstream sides of the pathogenic bacteria removal honeycomb filter 1, and / or an ammeter for measuring the drive current of the blower that supplies the fluid to the pathogenic bacteria removal honeycomb filter 1, and may determine the pressure loss and / or the flow rate through the pathogenic bacteria removal honeycomb filter 1 based on these measured values.

[0120] The "predetermined operating time" used by the notification means 64 to determine whether maintenance is required may be set to, for example, 10 hours, but may be changed as desired. The notification means 64 may issue the notification by any perceptible means, such as sound or light. Additionally or alternatively, the notification means 64 may issue the notification by transmitting information via wired or wireless communication to another device, such as the administrator's mobile terminal or PC. The transmission of information may include the transmission of email. Other configurations are the same as those of the first to fifth aspects.

[0121] Although the preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, the present invention is not limited to these examples. It is clear that a person skilled in the art to which the present invention pertains can conceive of various modifications and alterations within the scope of the technical ideas set forth in the claims, and it is understood that these also naturally fall within the technical scope of the present invention. [Example]

[0122] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0123] Example A honeycomb formed body was formed using a filter material that, after firing, would have a partition wall porosity of 55%, an average pore diameter of 7 μm, and pores penetrating from one side of the partition wall to the other. The honeycomb formed body was then dried, and plugging portions were formed on both end surfaces of the honeycomb formed body to function as a filter. The honeycomb formed body was then degreased and fired to obtain a honeycomb structure. A porous film made of silicon carbide was formed as a gas permeable membrane on the surfaces of the inlet-side cells (partition walls) of the honeycomb structure. The porous film had an average thickness T of 20 μm, a porosity P of 75%, and an average pore diameter of 1.5 μm. This produced a honeycomb filter for removing pathogens with a gas permeable membrane. Figure 13 shows an SEM image of the gas permeable membrane formed on the surface of the inlet-side cells.

[0124] To confirm the gas permeability of the honeycomb filter for pathogen removal, the honeycomb filter was placed in an unused state at 25°C for 10 m 3 / min of air was passed through the honeycomb filter for removing pathogenic bacteria, and the gas permeation loss of the honeycomb filter for removing pathogenic bacteria was measured, and the permeation loss was found to be 7 kPa.

[0125] When the collection characteristics of a pathogen removal honeycomb filter were measured using soot instead of pathogens, airborne dust, or other targets, the collection efficiency for soot with a particle size of 0.3 μm was 99.8%. Furthermore, when the collection characteristics of the pathogen removal honeycomb filter were measured again after the pathogen removal honeycomb filter had collected soot until the amount of soot collected reached 5 g or more, the collection efficiency for soot with a particle size of 0.3 μm was 99.9%. This demonstrates that the pathogen removal honeycomb filter has the properties necessary to capture pathogens regardless of whether soot has accumulated.

[0126] Soot was collected in the pathogen removal honeycomb filter until the amount of soot collected reached 10 g. A heater was then installed in front of the pathogen removal honeycomb filter, and air heated to 600°C was passed through the pathogen removal honeycomb filter for 5 hours. When the weight of the pathogen removal honeycomb filter was measured after the temperature of the pathogen removal honeycomb filter had dropped to room temperature, the mass of the pathogen removal honeycomb filter was found to be the same as the mass before soot collection, confirming that 100% of the soot collected in the pathogen removal honeycomb filter could be burned off.

[0127] After burning off the soot, the honeycomb filter for removing pathogens is heated to 25°C for 10 m 3 When the gas permeability characteristics of the honeycomb filter for pathogen removal were measured again with an air flow rate of 1 / min, the permeability loss was 7 kPa, the same as when the filter was unused. This shows that the permeability loss of the honeycomb filter for pathogen removal was not affected by soot capture or soot burning.

[0128] Comparative Example A honeycomb structure was fabricated using the same materials as in the examples, and the collection efficiency was measured using the same test method as in the examples, without forming a gas-permeable membrane. As a result, the soot collection efficiency for particles with a size of 0.3 μm was 90%. This indicates that honeycomb filters without a gas-permeable membrane cannot be used to remove pathogenic bacteria and viruses. [Explanation of symbols]

[0129] 1:Honeycomb filter for removing pathogens 10: Honeycomb structure 10a: Inlet end face 10b: Outlet side end surface 100: Outer wall 101: Inlet cell 102: Outlet cell 103: Bulkhead 105: Conductive and / or magnetic materials 106: Electrical resistor 11: Gas permeable membrane 3: Heating section 30: Coil 31: Power supply circuit 32: Electrode 33: Electrode 34: Heater 6: Pathogen removal filter device 60: Heating selection section 61: Chamber 62: Chamber body 62a: Inlet opening 62b: Outlet opening 63: Lid 64: Notification means 7: Insulation material

Claims

1. a ceramic honeycomb structure including an outer peripheral wall, inlet-side cells disposed inside the outer peripheral wall, each open at an inlet end face and plugged at an outlet end face, outlet-side cells disposed inside the outer peripheral wall, each open at an outlet end face and plugged at an inlet end face, and porous partition walls disposed between the inlet-side cells and the outlet-side cells; a ceramic porous gas-permeable membrane provided on the partition wall; Equipped with the partition wall and the gas-permeable membrane are configured to capture 99.97% or more of particles of 0.3 μm in size during a process in which a fluid flows in from the inlet-side cell and flows out from the outlet-side cell, and the captured particles can be burned off by heating. Honeycomb filter for removing pathogens.

2. the gas permeable membrane is a porous membrane formed on the surface of the inlet cell and composed of ceramic particles having an oxide film formed on the surface thereof, the porous membrane having an average thickness T of 2 μm or more and 40 μm or less and a porosity P of 65% or more and 90% or less; the partition walls have a porosity of 40% or more and 80% or less, have pores penetrating from one surface of the partition walls to the other surface, and have an average diameter of the pores of 4 μm or more and 20 μm or less; The honeycomb filter for removing pathogens according to claim 1 .

3. The ceramic particles constituting the gas-permeable membrane contain at least one element selected from the group consisting of cordierite, mullite, zirconium phosphate, aluminum titanate, silicon carbide, silicon-silicon carbide composite material, cordierite-silicon carbide composite material, zircon, zirconia, spinel, indialite, sapphirine, corundum, titania, and silicon nitride. The honeycomb filter for removing pathogens according to claim 2 .

4. the partition walls contain at least one element selected from the group consisting of cordierite, mullite, zirconium phosphate, aluminum titanate, silicon carbide, a silicon-silicon carbide composite, a cordierite-silicon carbide composite, zircon, zirconia, spinel, indialite, sapphirine, corundum, titania, and silicon nitride; The honeycomb filter for removing pathogens according to claim 2 .

5. The honeycomb structure supports an oxidation catalyst in the inlet side cells and the outlet side cells. The honeycomb filter for removing pathogens according to claim 1 .

6. At least one honeycomb filter for removing pathogens according to any one of claims 1 to 5; a heating unit for heating the honeycomb filter for removing pathogens; Equipped with Pathogen removal filter device.

7. a plurality of the honeycomb filters for removing pathogens are provided, and the heating unit is configured to heat the plurality of honeycomb filters for removing pathogens individually; a heating selection unit that selects the honeycomb filters to be heated by the heating unit based on the pressure loss and / or flow rate of the plurality of honeycomb filters for removing pathogens; The pathogen removal filter device according to claim 6.

8. The at least one honeycomb filter for removing pathogens is housed in a chamber, The chamber comprises: a chamber body having an inlet side opening and an outlet side opening; a cover that is placed on the inlet opening and the outlet opening when the pathogen removal honeycomb filter is heated; It has When the lid is placed on the inlet side opening and / or the outlet side opening, the area of ​​the lid within the inlet side opening and / or the outlet side opening is 90% or more and less than 100% of the area of ​​the inlet side opening and / or the outlet side opening. The pathogen removal filter device according to claim 6.

9. The at least one honeycomb filter further includes a ceramic fiber heat insulating material surrounding each of the honeycomb structures. The pathogen removal filter device according to claim 6.

10. The honeycomb filter for removing pathogens further includes a notification means for monitoring a pressure loss and / or a flow rate of the pathogen removal honeycomb filter heated by the heating unit, and notifying that maintenance is required when the pressure loss exceeds a predetermined pressure loss threshold or the flow rate of the pathogen removal honeycomb filter falls below a predetermined flow rate threshold within a predetermined operating time after the filter is heated by the heating unit. The pathogen removal filter device according to claim 6.

11. The honeycomb filter for removing pathogens further includes a conductor and / or a magnetic material contained in the honeycomb structure, the heating unit includes a coil provided around the pathogen removal honeycomb filter, and is configured to inductively heat the pathogen removal honeycomb filter by magnetic flux from the coil. The pathogen removal filter device according to claim 6.

12. the heating unit includes electrodes connected to the pathogen removal honeycomb filter, and is configured to electrically heat the pathogen removal honeycomb filter by current from the electrodes. The pathogen removal filter device according to claim 6.

13. The honeycomb filter for removing pathogens further includes an electric resistor incorporated in the honeycomb structure, The heating unit includes an electrode connected to the electric resistor, and is configured to heat the pathogen removal honeycomb filter through the electric resistor by applying current from the electrode to heat the electric resistor. The pathogen removal filter device according to claim 6.

14. the heating unit includes a heater disposed upstream of the pathogen-removal honeycomb filter in the flow direction of a fluid introduced into the pathogen-removal honeycomb filter, and is configured to heat the pathogen-removal honeycomb filter by causing the fluid heated by the heater to flow through the pathogen-removal honeycomb filter. The pathogen removal filter device according to claim 6.

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