Fermentation apparatus

Abstract

To provide a fermentation apparatus capable of easily controlling a position of water to be treated falling on a microorganism carrier.SOLUTION: A fermentation apparatus 1 is configured to be able to ferment organic matter in water to be treated W by microorganisms. The fermentation apparatus 1 has a fermentation tank 2, a water to be treated supply part 3 that supplies the water to be treated W into the fermentation tank 2, a water to be treated spray part 4 that spreads the water to be treated W supplied from the water to be treated supply part 3 into the fermentation tank 2, and a plurality of microorganism carriers 5 that are disposed below the water to be treated spray part 4 and configured to be capable of carrying microorganisms. The water to be treated spray part 4 has a water storage part 41 for storing the water to be treated W and a plurality of water spraying holes 42 that penetrate the bottom of the water storage part 41. Around the water spraying holes 42 in a bottom surface 413 of the water storage part 41, a protrusion 43 protruding downward is provided.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a fermentation device.

Background Art

[0002] Conventionally, fermentation by microorganisms has been used for the purpose of removing organic substances from water to be treated containing organic substances and recovering resources. As a method for efficiently performing water treatment using microorganisms, treated water is sprayed onto a microorganism carrier supporting sludge containing microorganisms, and the treated water is fermented by the microorganisms in the sludge while allowing the treated water to permeate by gravity. The down-flow hanging sponge (DHS) method is known.

[0003] For example, Patent Document 1 discloses a water treatment device that forms a treatment space in a hollow tank, is provided with a water spraying section, and includes a treated water supply means for supplying treated water from the water spraying section to the microorganism carrier in a state where the microorganism carrier is filled and arranged below the water spraying section, a treated water discharge means for taking out the treated water purified by the microorganism carrier, an air supply pipe for supplying an oxygen-containing gas into the treatment space, and an exhaust pipe for discharging the gas in the treatment space.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the sprinkling unit of the sprinkling type purification device described in Patent Document 1, there is a dish-shaped member that receives the treated water supplied from a water supply pipe as a treated water supply means, and a large number of sprinkling holes are provided on the bottom surface of the dish-shaped member. When the water to be treated is supplied to the sprinkling unit having such a structure, the water to be treated that has passed through the sprinkling holes may travel along the lower surface of the dish-shaped member and fall downward from a position different from the sprinkling holes. Therefore, in some cases, there is a bias in the position where the water to be treated falls, and there is a possibility that some of the microbial carriers in the tank are less likely to come into contact with the water to be treated.

[0006] The present invention has been made in view of such problems, and aims to provide a fermentation device capable of easily controlling the position of the water to be treated that falls onto the microbial carrier.

Means for Solving the Problems

[0007] One aspect of the present invention is a fermentation device configured to be able to ferment organic substances in the water to be treated by microorganisms, comprising: a fermentation tank, a water-to-be-treated supply unit that supplies the water to be treated into the fermentation tank, a water-to-be-treated spraying unit that sprays the water to be treated supplied from the water-to-be-treated supply unit into the fermentation tank, a plurality of microbial carriers disposed below the water-to-be-treated spraying unit and configured to be able to carry the microorganisms, wherein the water-to-be-treated spraying unit has a water storage unit that stores the water to be treated, a plurality of sprinkling holes that penetrate the bottom of the water storage unit, and a protruding portion provided around the sprinkling holes on the lower surface of the water storage unit and protruding downward, in the fermentation device.

Effects of the Invention

[0008] The water to be treated spraying section of the fermentation device includes a water storage section where the water to be treated is stored, a plurality of water spraying holes penetrating the bottom of the water storage section, and a protruding section provided around the water spraying holes on the lower surface of the water storage section and protruding downward. By providing a protruding section having a shape corresponding to the lower surface of the water storage section, the water to be treated passing through the water spraying holes is likely to gather at the lower end of the protruding section. As a result, it is possible to easily avoid the water to be treated from flowing along the lower surface of the water storage section and falling from an unintended position, and to make the water to be treated fall from within a specific range, namely, the inside of the protruding section.

[0009] As described above, according to the above aspect, it is possible to provide a fermentation device capable of easily controlling the position of the water to be treated falling onto the microbial carrier.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Mode for Carrying Out the Invention

[0011] (Embodiment 1) An embodiment of the fermentation device will be described with reference to FIGS. 1 to 3. The fermentation device 1 of this embodiment is configured to be able to ferment organic substances in the water to be treated W by microorganisms. As shown in FIG. 1, the fermentation device 1 includes a fermentation tank 2, a water supply part 3 for supplying the water to be treated W into the fermentation tank 2, a water-spraying part 4 for spraying the water to be treated W supplied from the water supply part 3 into the fermentation tank 2, and a plurality of microorganism carriers 5 arranged below the water-spraying part 4 and configured to be able to carry microorganisms. The water-spraying part 4 has a water storage part 41 for storing the water to be treated W and a plurality of water-spraying holes 42 penetrating the bottom of the water storage part 41. As shown in FIGS. 1 and 3, a protruding part 43 protruding downward is provided around the water-spraying holes 42 on the lower surface 413 of the water storage part 41.

[0012] The water to be treated W and microorganisms used in the fermentation device 1 are not particularly limited and may be appropriately selected according to the desired fermentation mode. For example, as the water to be treated W, for example, sewage containing organic waste such as sewage sludge and food residues can be used. Also, as the water to be treated W, for example, industrial wastewater containing organic substances such as waste water-soluble coolant recovered from a processing device performing machining can be used.

[0013] In addition, the microorganisms in the fermentation device 1 of this embodiment include methane-producing bacteria and are configured to be able to ferment the organic substances in the water to be treated W and generate biogas containing methane. Examples of methane-producing bacteria include Methanobacterium and Methanosarcina.

[0014] The shape and size of the fermentation tank 2 can take various forms. For example, the shape of the fermentation tank 2 in the fermentation apparatus 1 of this embodiment is cylindrical. Also, the height and diameter of the fermentation tank 2 in this embodiment are each 2 m.

[0015] A partition plate 22 that divides the internal space 21 of the fermentation tank 2 into an upper space 211 and a lower space 212 is provided in the fermentation tank 2. The partition plate 22 is configured such that the water to be treated W can flow through it. The partition plate 22 in this embodiment is composed of a metal plate and has a number of through-holes (not shown) for allowing the water to be treated W to pass through.

[0016] In the upper space 211 of the fermentation tank 2, a water supply section 3 for the water to be treated, a water spraying section 4 for the water to be treated, and a microbial carrier 5 are arranged. Also, in the lower space 212 of the fermentation tank 2, a water outlet pipe 23 for guiding the water to be treated W after fermentation by microorganisms to the outside of the fermentation tank 2 is provided.

[0017] The water supply section 3 for the water to be treated is configured to be able to guide the water to be treated W supplied from outside the fermentation apparatus 1 to the water spraying section 4 for the water to be treated. The specific form of the water supply section 3 for the water to be treated is not particularly limited and can take various forms. For example, the water supply section 3 for the water to be treated in this embodiment has a water supply pipe 31 that opens above the water spraying section 4 for the water to be treated and is configured to be able to discharge the water to be treated W from above the water spraying section 4 for the water to be treated.

[0018] The treated water spraying unit 4 has a water storage unit 41 that stores the treated water W supplied from the treated water supply unit 3. The specific form of the water storage unit 41 is not particularly limited and can take various forms. For example, as shown in FIGS. 1 and 2, the water storage unit 41 of this form has a bottom plate portion 411 having a disc-like shape and a side wall portion 412 erected upward from the periphery of the bottom plate portion 411. Further, as shown in FIG. 1, the bottom plate portion 411 of this form faces the opening 311 of the treated water supply pipe 31. The water storage unit 41 can store the treated water W supplied from the treated water supply unit 3 inside the side wall portion 412. Note that the positional relationship between the bottom plate portion 411 and the opening 311 of the treated water supply pipe 31 can take various forms as long as the treated water W can be stored in the water storage unit 41.

[0019] A plurality of water spray holes 42 penetrating the bottom plate portion 411 are provided in the bottom plate portion 411. Thereby, the treated water W in the water storage unit 41 can be sprayed below the treated water spraying unit 4. The number, arrangement, and cross-sectional shape of the water spray holes 42 in the water storage unit 41 are not particularly limited and may be appropriately set according to the desired spraying position, spraying amount, etc. of the treated water W. From the viewpoint of further reducing the bias of the treated water W sprayed into the fermentation tank 2, it is preferable that the plurality of water spray holes 42 are arranged such that the intervals between adjacent water spray holes 42 are equal, as shown in FIG. 2, for example.

[0020] The water spray hole 42 preferably has a tapered portion 421, at least a part of which, as shown in FIG. 3, for example, has the largest inner diameter at the upper end and the inner diameter becomes smaller as it approaches the lower end. By providing the tapered portion 421 in the water spray hole 42, the treated water W in the water storage unit 41 can more easily enter the water spray hole 42. As a result, the water spray hole 42 is less likely to become clogged.

[0021] The position and range where the tapered portion is provided can take various forms. Although not shown in the figure, the water spray hole 42 may have a shape in which the entire length direction thereof is a tapered portion, that is, a shape in which the inner diameter at the upper end of the water spray hole 42 is the largest and the inner diameter gradually becomes smaller as it approaches the lower end.

[0022] In addition, a tapered portion may be provided in a part of the water spray holes 42. In this case, the portions of the water spray holes 42 other than the tapered portion can take various forms as long as the above-described effects are not impaired. For example, as shown in FIG. 3, the water spray holes 42 in the water spray portion 4 of the present embodiment have a tapered portion 421 provided at the upper end thereof and a straight pipe portion 422 that is continuous with the lower side of the tapered portion 421 and has the same inner diameter as the lower end of the tapered portion 421. In FIG. 1, for the sake of convenience, the shape of the water spray holes 42 is shown in a simplified manner. When the tapered portion 421 is provided at the upper end of the water spray holes 42 as in the present embodiment, the shape below the tapered portion 421 in the water spray holes 42 is not limited to the straight pipe portion 422 and can take various forms.

[0023] Although not shown in the drawings, the tapered portion may be provided at the lower end of the water spray holes 42 or may be provided between the upper end and the lower end of the water spray holes 42. In any case, by providing a straight pipe portion having the same inner diameter as the upper end of the tapered portion above the tapered portion in the water spray holes 42, the treated water W can easily enter the tapered portion.

[0024] As shown in FIG. 3, a protruding portion 43 is provided around the water spray holes 42 on the lower surface 413 of the water storage portion 41. The protruding portion 43 only needs to protrude downward from the water storage portion 41, and the specific shape of the protruding portion 43 can take various forms. For example, the protruding portion 43 of the present embodiment has a cylindrical shape erected downward from the lower surface 413 of the water storage portion 41, and the inside of the cylinder of the protruding portion 43 constitutes a part of the water spray holes 42. Therefore, in the fermentation apparatus 1 of the present embodiment, the treated water W flowing from the water storage portion 41 into the water spray holes 42 gathers at the lower end of the protruding portion 43 and falls from the lower end of the protruding portion 43.

[0025] As shown in FIG. 1, the microbial carrier 5 is placed on the partition plate 22 in the upper space 211 of the fermentation tank 2. As the microbial carrier 5, for example, a porous body such as a resin sponge, a cylindrical body such as a plastic molded into a cylindrical shape, a porous body with a plastic frame provided around the porous body, etc. can be used. Specifically, the microbial carrier 5 of this embodiment is a porous body with a plastic frame provided around a resin sponge.

[0026] The microbial carrier 5 carries sludge containing microorganisms. The microorganisms in the sludge may be appropriately selected according to the type of organic matter in the water to be treated W and the desired fermentation mode. For example, when attempting to ferment the organic matter in the water to be treated W to produce biogas containing methane, sludge containing methane-producing bacteria may be carried on the microbial carrier 5.

[0027] The fermentation tank 2 may be provided with a gas outlet 24 for guiding the gas generated by the fermentation of the water to be treated W to the outside of the fermentation tank 2. For example, the gas outlet 24 of this embodiment is provided at the upper end of the fermentation tank 2. The gas led out from the gas outlet 24 is used for various purposes according to its composition. For example, biogas containing methane gas is used as fuel for a generator, etc. Also, methane gas purified from biogas may be used as a raw material for C1 chemistry.

[0028] Further, the fermentation tank 2 may have a gas passage 25 configured to connect the space below and above the treated water spraying section 4 and allow gas to flow through. For example, as shown in FIG. 2, in the fermentation apparatus 1 of this embodiment, a gap serving as the gas passage 25 is provided between the side wall portion 412 of the treated water spraying section 4 and the fermentation tank 2. Thus, by providing the gas passage 25 in the fermentation tank 2, the space below and above the treated water spraying section 4 can be communicated via the gas passage 25, and gas can be circulated between them. Therefore, for example, when attempting to generate biogas in the microbial carrier 5 as in the fermentation apparatus 1 of this embodiment, the biogas generated from the microbial carrier 5 can be guided to the space above the treated water spraying section 4 and taken out from the fermentation apparatus 1 to the outside through the gas outlet section 24.

[0029] As shown in FIG. 1, the treated water spraying section 4 in the fermentation apparatus 1 of this embodiment includes a water storage section 41 in which the treated water W is stored, a plurality of water spraying holes 42 penetrating the bottom of the water storage section 41, and a protruding portion 43 provided around the water spraying holes 42 on the lower surface of the water storage section 41. Further, the protruding portion 43 protrudes downward from the water storage section 41. Therefore, the treated water W passing through the water spraying holes 42 is likely to gather at the lower end of the protruding portion 43 due to its own weight. As a result, it is possible to easily avoid the treated water W from falling from an unintended position along the lower surface 413 of the water storage section 41, and the treated water W can be made to fall from within a specific range inside the protruding portion 43.

[0030] Therefore, the fermentation apparatus 1 of this embodiment can easily control the position of the treated water W falling on the microbial carrier 5.

[0031] (Embodiment 2) In this embodiment, an example of a fermentation apparatus in which a plurality of electrodes are provided in the fermentation tank will be described. Among the reference numerals used hereinafter, the same reference numerals as those used in the previous embodiments represent the same components as those in the previous embodiments unless otherwise specified.

[0032] As shown in FIG. 4, the fermentation apparatus 102 of this embodiment has a fermentation tank 2 and a partition plate 22 that divides the internal space 21 of the fermentation tank 2 into an upper space 211 and a lower space 212. In the upper space 211 of the fermentation tank 2, a water to be treated supply unit 3, a water to be treated spraying unit 4, a microbial carrier 5, and a gas outlet 24 are arranged. Further, a water to be treated outlet pipe 23 is provided in the lower space 212 of the fermentation tank 2.

[0033] In the fermentation tank 2 of the fermentation apparatus 102 of this embodiment, a plurality of electrodes 6 are provided, and these electrodes 6 are in contact with the microbial carrier 5. Therefore, when a voltage is applied between the electrodes 6 while spraying the water to be treated W, an electric current can flow through the water to be treated W attached to the microbial carrier 5. Then, the microorganisms supported on the microbial carrier 5 receive electrons from the electric current, making it easier to promote the fermentation of the water to be treated W. As a result, a further improvement in the fermentation efficiency of the water to be treated W can be expected.

[0034] From the viewpoint of more surely obtaining the effect of promoting fermentation by an electric current, the microorganisms supported on the microbial carrier 5 preferably include organotrophic bacteria having the property of fermenting organic substances in the water to be treated W and electron-emitting bacteria having the property of transferring electrons taken in from the outside to the organotrophic bacteria. In this case, by transferring electrons between the electron-emitting bacteria and the organotrophic bacteria, the fermentation of organic substances by the organotrophic bacteria can be promoted.

[0035] The type of organotrophic bacteria is not particularly limited. For example, the microbial carrier 5 in the fermentation apparatus 102 of this embodiment supports methanogenic bacteria as organotrophic bacteria and is configured to be able to ferment the organic substances in the water to be treated W and generate biogas containing methane.

[0036] Further, the electron-emitting bacteria have the property of transferring electrons taken in from the outside to the organotrophic bacteria. Examples of microorganisms having such a property include Morganella morganii and Proteus mirabilis.

[0037] The specific form of the electrode 6 can take various forms. For example, the number of electrodes 6 disposed in the fermentation tank 2 may be two or more. The position of the electrode 6 is not limited as long as it is in contact with the microbial carrier 5. The shape of the electrode 6 can take various forms such as plate-like, net-like, and rod-like. Also, among the plurality of electrodes 6, at least some of the electrodes 6 may be configured to function as other components.

[0038] For example, the fermentation apparatus 102 of this embodiment has two electrodes 6 (6a, 6b). Among the two electrodes 6, the first electrode 6a is in contact with the microbial carrier 5 located at the uppermost position among the microbial carriers 5 in the fermentation tank 2, as shown in FIG. 4. As shown in FIG. 5, the shape of the first electrode 6a is disc-shaped. Further, the first electrode 6 has a plurality of through-holes 61 for allowing the water to be treated W to pass through. These through-holes 61 are provided at positions corresponding to the water spray holes 42 of the water spray section 4 for the water to be treated, that is, at positions where the region corresponding to the through-holes 61 overlaps the water spray holes 42 when the first electrode 6a is projected upward.

[0039] Also, as shown in FIG. 4, in the fermentation apparatus 102 of this embodiment, the partition plate 22 also serves as the second electrode 6b. The microbial carrier 5 between the first electrode 6a and the second electrode 6b is compressed in the vertical direction by these electrodes 6. The configuration of other parts in the fermentation apparatus 102 of this embodiment is the same as that of the fermentation apparatus 1 of the first embodiment.

[0040] In the fermentation apparatus 102 of this embodiment, as shown in FIG. 5, the first electrode 6a located at the uppermost position among the plurality of electrodes 6 has a plate-like shape with a plurality of through-holes 61. Also, the through-holes 61 are disposed at positions corresponding to the water spray holes 42 of the water spray section 4 for the water to be treated. Therefore, the water to be treated W sprayed from the water spray holes 42 easily passes through the through-holes 61 of the first electrode 6a and falls onto the microbial carrier 5. In this way, by dropping the water to be treated W into the through-holes 61 of the electrode 6, it is possible to easily avoid the water to be treated W sprayed from the water spray holes 42 being blocked by the electrode 6, and it is possible to easily control the position of the water to be treated W that falls onto the microbial carrier 5.

[0041] Further, the microbial carrier 5 is compressed in the vertical direction between the partition plate 22 serving as the first electrode 6a and the second electrode 6b. As a result, adjacent microbial carriers 5 in the fermentation tank 2 are likely to come into contact with each other. When adjacent microbial carriers 5 come into contact, the treated water W flowing on the surface of the microbial carrier 5 makes it easier to form a current path from the first electrode 6a to the second electrode 6b. As a result, electrons can be easily supplied by the microorganisms, and the effect of improving the fermentation efficiency can be obtained more reliably. In addition, the fermentation device 102 of this embodiment can achieve the same effects as the fermentation device 1 of Embodiment 1.

[0042] (Embodiment 3) In this embodiment, an example of the fermentation device 103 in which the treated water spraying unit 403 and the electrode 6 are in contact is described. As shown in FIG. 6, the fermentation device 103 of this embodiment includes a fermentation tank 2 and a partition plate 22 that divides the internal space 21 of the fermentation tank 2 into an upper space 211 and a lower space 212. In the upper space 211 of the fermentation tank 2, a treated water supply unit 3, a treated water spraying unit 403, a microbial carrier 5, a gas outlet unit 24, and a first electrode 6a are arranged. The partition plate 22 also serves as the second electrode 6b. A treated water outlet pipe 23 is provided in the lower space 212 of the fermentation tank 2.

[0043] The water storage unit 41 in the treated water spraying unit 403 of this embodiment has a bottom plate portion 411 having a disc shape and a side wall portion 412 erected upward from the periphery of the bottom plate portion 411. The bottom plate portion 411 of this embodiment faces the opening 311 of the treated water supply pipe 31.

[0044] A plurality of water spraying holes 42 penetrating the bottom plate portion 411 are provided in the bottom plate portion 411. As shown in FIGS. 6 and 7, a groove portion 414 is provided around the water spraying holes 42 on the lower surface 413 of the water storage unit 41, and the inside of the groove portion 414 forms a protruding portion 43 that protrudes downward with respect to the bottom of the groove portion 414.

[0045] As shown in Fig. 6, the first electrode 6a is in contact with the lower surface of the bottom plate portion 411. Further, the first electrode 6a is in contact with the microbial carrier 5 located at the uppermost position among the microbial carriers 5 in the fermentation tank 2.

[0046] As shown in Figs. 6 and 7, the first electrode 6a in this embodiment has a plurality of through holes 61. Further, the through holes 61 are provided at positions corresponding to the outer peripheral edges of the groove portions 414 in the bottom plate portion 411, and the entire water spray holes 42 and the protruding portions 43 are disposed inside the through holes 61. The configurations of the other parts in the fermentation apparatus 103 of this embodiment are the same as those of the fermentation apparatus 102 of Embodiment 2.

[0047] In the fermentation apparatus 103 of this embodiment, as shown in Fig. 6, the first electrode 6a located at the uppermost position among the plurality of electrodes 6 is in contact with the lower surface of the water to be treated spraying portion 403. Therefore, the water to be treated W that has passed through the water spray holes 42 can more surely pass through the through holes 61 of the first electrode 6a and fall downward without contacting the first electrode 6a. Therefore, the fermentation apparatus 103 of this embodiment can more easily control the position of the water to be treated W falling onto the microbial carrier 5. In addition, the fermentation apparatus 103 of this embodiment can achieve the same effects as the fermentation apparatus 102 of Embodiment 2.

[0048] (Embodiment 4) In this embodiment, an example of a fermentation apparatus 104 in which the water to be treated spraying portion 403 also serves as an electrode will be described. As shown in Fig. 8, the fermentation apparatus 104 of this embodiment includes a fermentation tank 2 and a partition plate 22 that divides the internal space 21 of the fermentation tank 2 into an upper space 211 and a lower space 212. In the upper space 211 of the fermentation tank 2, a water to be treated supply portion 3, a water to be treated spraying portion 403, a microbial carrier 5, and a gas outlet portion 24 are arranged. Further, a water to be treated outlet pipe 23 is provided in the lower space 212 of the fermentation tank 2.

[0049] In the fermentation apparatus 104 of this embodiment, the water to be treated spraying unit 403 is in contact with the microorganism carrier 5 located at the uppermost position among the microorganism carriers 5 in the fermentation tank 2, and is configured to also function as the first electrode 6a. Further, the partition plate 22 is configured to also function as the second electrode 6b. The microorganism carrier 5 between the water to be treated spraying unit 403 and the partition plate 22 is compressed in the vertical direction by the water to be treated spraying unit 403 and the partition plate 22. The rest is the same as the fermentation apparatus 103 of Embodiment 3.

[0050] The uppermost electrode 6 in the fermentation apparatus 104 of this embodiment is the water to be treated spraying unit 403. In this way, by configuring the water to be treated spraying unit 403 itself as the electrode 6, it is possible to avoid the water to be treated W sprayed from the water to be treated spraying unit 403 being blocked by the electrode 6 before falling onto the microorganism carrier 5. Therefore, the fermentation apparatus 104 of this embodiment can more easily control the position of the water to be treated W falling onto the microorganism carrier 5. In addition, the fermentation apparatus 104 of this embodiment can achieve the same effects as the fermentation apparatus 103 of Embodiment 3.

[0051] (Embodiment 5) In this embodiment, an example of the water to be treated spraying unit 405 provided with the cleaning unit 44 will be described. As shown in FIG. 9, the water to be treated spraying unit 405 of this embodiment has a water storage unit 41 including a bottom plate portion 411 having a disc-like shape and a side wall portion 412 erected upward from the periphery of the bottom plate portion 411. A plurality of water spray holes 42 are provided in the bottom plate portion 411. Further, a protruding portion 43 is provided around the water spray holes 42 on the lower surface of the water storage unit 41. The configurations of the water storage unit 41, the water spray holes 42, and the protruding portion 43 in the water to be treated spraying unit 405 of this embodiment are the same as those of the water to be treated spraying unit 4 of Embodiment 1.

[0052] The water to be treated spraying unit 405 of this embodiment has a cleaning unit 44 including a rod-shaped portion 441 inserted into the water spray holes 42 and a floating portion 442 provided at the upper end of the rod-shaped portion 441 and configured to float on the water to be treated W.

[0053] The rod-shaped part 441 has a rod shape thinner than the inner diameter of the water sprinkling hole 42, and is configured to be movable in the vertical direction within the water sprinkling hole 42. The floating part 442 is disposed on the bottom plate part 411 and has an outer dimension larger than the opening diameter of the water sprinkling hole 42 on the upper surface of the bottom plate part 411. The specific configuration of the floating part 442 is not particularly limited as long as it can float on the water to be treated W. For example, the floating part 442 may be composed of a hollow structure, a foaming material, or the like.

[0054] The cleaning part 44 may have a maximum length larger than the inner diameter of the lower end of the water sprinkling hole 42 and may have a retaining part 443 provided at the lower end of the rod-shaped part 441. Thus, by providing the retaining part 443 at the lower end of the rod-shaped part 441, even when the cleaning part 44 floats as the water level in the water storage part 41 rises, it is possible to prevent the cleaning part 44 from coming out of the water sprinkling hole 42.

[0055] The specific shape of the retaining part 443 can take various forms. For example, the retaining part 443 may be rod-shaped or plate-shaped. For example, the retaining part 443 in this embodiment has a rod shape extending in a direction perpendicular to the rod-shaped part 441. Also, the length of the retaining part 443 is longer than the inner diameter of the lower end of the water sprinkling hole 42.

[0056] The operation of the water to be treated spraying part 405 of this embodiment will be described below. The water to be treated W supplied from the water to be treated supply part 3 is first stored in the water storage part 41 of the water to be treated spraying part 405. Also, the water to be treated W in the water storage part 41 passes through the water sprinkling hole 42 and falls onto the microorganism carrier 5. Therefore, when the balance between the supply amount of the water to be treated W from the water to be treated supply part 3 and the spraying amount of the water to be treated W in the water to be treated spraying part 405 is achieved, the water level of the water to be treated W in the water storage part 41 is generally constant.

[0057] On the one hand, when the fermentation device is operated for a long time, for example, as shown in FIG. 10, deposits S such as biofilms containing microorganisms may be formed on the water to be treated spraying section 405. When such deposits S are formed in the water spraying holes 42, the amount of the water to be treated W passing through the inside of the water spraying holes 42 per unit time decreases. Therefore, when deposits are formed in the water spraying holes 42, the supply amount of the water to be treated W from the water to be treated supply section 3 becomes excessive with respect to the spraying amount of the water to be treated W in the water to be treated spraying section 405, and as shown in FIG. 11, the water level of the water to be treated W in the water storage section 41 rises.

[0058] When the water level of the water to be treated W in the water storage section 41 rises, as shown in FIG. 11, the position of the floating body section 442 rises along with the rise of the water level of the water to be treated W, and the rod-shaped section 441 connected to the floating body section 442 also rises. Then, as the rod-shaped section 441 rises, the deposits S in the water spraying holes 42 are lifted by the rod-shaped section 441. As a result, the deposits S in the water spraying holes 42 can be discharged to the outside of the water spraying holes 42.

[0059] When the deposits S in the water spraying holes 42 are discharged from the water spraying holes 42 in this way, the amount of the water to be treated W passing through the inside of the water spraying holes 42 per unit time returns to the state before the deposits S are formed. As a result, the state where the supply amount of the water to be treated W is excessive with respect to the spraying amount is eliminated, and the rise of the water level of the water to be treated W in the water storage section 41 stops.

[0060] In addition, the amount of the water to be treated W passing through the water spraying holes 42 per unit time changes according to the water level of the water to be treated W in the water storage section 41, and the higher the water level of the water to be treated W rises, the larger the amount of the water to be treated W passing through the water spraying holes 42 becomes. Since the water level of the water to be treated W in the water storage section 41 at the time when the deposits in the water spraying holes 42 are removed is higher than the water level before the deposits are formed in the water spraying holes 42, after the deposits in the water spraying holes 42 are removed, the spraying amount of the water to be treated W becomes larger than the supply amount, and the water level of the water to be treated W in the water storage section 41 drops. This drop in the water level continues until the spraying amount of the water to be treated W becomes equal to the supply amount, and the drop in the water level stops when the balance between the spraying amount and the supply amount of the water to be treated W is achieved.

[0061] As described above, even when deposits S are formed in the water spray holes 42 of the water to be treated spraying unit 405 of this embodiment, the cleaning unit 44 can easily remove the deposits S in the water spray holes 42. Therefore, the fermentation device provided with the water to be treated spraying unit 405 of this embodiment can reduce the maintenance frequency of the water to be treated spraying unit 405.

[0062] The present invention is not limited to the above-described embodiments, and can be applied to various embodiments without departing from the gist thereof. For example, the cleaning unit described in Embodiment 5 can be applied to the water to be treated spraying unit in the fermentation devices of Embodiments 1 to 4.

[0063] Also, from another perspective, the present invention can also be grasped as inventions according to the following [1-1] to [1-6].

[0064] 〔1-1〕A fermentation device configured to be able to ferment organic substances in water to be treated by microorganisms, a fermentation tank, a water to be treated supply unit that supplies the water to be treated into the fermentation tank, a water to be treated spraying unit that sprays the water to be treated supplied from the water to be treated supply unit into the fermentation tank, a plurality of microorganism carriers arranged below the water to be treated spraying unit and configured to be able to carry the microorganisms, a plurality of electrodes provided in the fermentation tank and in contact with the microorganism carriers, wherein the water to be treated spraying unit has a water storage unit for storing the water to be treated, and a plurality of water spray holes penetrating the bottom of the water storage unit, the uppermost electrode among the plurality of electrodes has a plate-like shape with a plurality of through holes and is in contact with the lower surface of the water to be treated spraying unit, and at least a part of the through holes is arranged at a position corresponding to the water spray holes of the water to be treated spraying unit.

[0065] 〔1-2〕The fermentation device according to 〔1-1〕, wherein at least a part of the water-dispersing holes has a tapered portion whose inner diameter is the largest at the upper end and becomes smaller as it approaches the lower end. 〔1-3〕The fermentation device according to 〔1-1〕 or 〔1-2〕, wherein the microbial carrier is compressed between the plurality of electrodes. 〔1-4〕The fermentation device according to any one of 〔1-1〕 to 〔1-3〕, wherein the fermentation tank has a gas passage that connects the space below and the space above the water-treated water spraying section and is configured to allow gas to flow through.

[0066] 〔1-5〕The fermentation device according to any one of 〔1-1〕 to 〔1-4〕, wherein the water-treated water spraying section has a cleaning section including a rod-shaped portion inserted into the water-dispersing holes and a floating portion provided at the upper end of the rod-shaped portion and configured to float on the water-treated water. 〔1-6〕The fermentation device according to 〔1-5〕, wherein the cleaning section has a maximum length larger than the inner diameter of the lower end of the water-dispersing holes and has a retaining portion provided at the lower end of the rod-shaped portion.

[0067] The fermentation device according to 〔1-1〕 to 〔1-6〕 has a plurality of electrodes in contact with the microbial carrier. Also, the uppermost electrode among the plurality of electrodes is in contact with the lower surface of the water-treated water spraying section. Therefore, the water-treated water passing through the water-dispersing holes can more surely pass through the through-holes of the electrodes and fall downward without contacting the electrodes. Accordingly, the fermentation device of this embodiment can more easily control the position of the water-treated water falling on the microbial carrier.

[0068] Also, from another perspective, the present invention can also be grasped as an invention according to the following 〔2-1〕 to 〔2-6〕.

[0069] 〔2-1〕A fermentation device configured to be able to ferment organic substances in water to be treated by microorganisms, a fermentation tank, a water-treated water supply section for supplying the water-treated water into the fermentation tank, A treated water spraying unit that sprays the treated water supplied from the treated water supply unit into the fermentation tank; It is disposed below the treated water spraying unit and has a plurality of microorganism carriers configured to be capable of supporting the microorganisms. The treated water spraying unit A water storage unit for storing the treated water; A plurality of water spraying holes penetrating the bottom of the water storage unit; A cleaning unit including a rod-shaped part inserted into the water spraying hole and a floating part provided at the upper end of the rod-shaped part and configured to float on the treated water. The fermentation device has these components.

[0070] 〔2-2〕The cleaning unit has a maximum length greater than the inner diameter of the lower end of the water spraying hole and has a retaining part provided at the lower end of the rod-shaped part. The fermentation device according to 〔2-1〕. 〔2-3〕At least a part of the water spraying hole has a tapered part where the inner diameter is the largest at the upper end and becomes smaller as it approaches the lower end. The fermentation device according to 〔2-1〕 or 〔2-2〕. 〔2-4〕The fermentation device has a plurality of electrodes provided in the fermentation tank, and the electrodes are in contact with the microorganism carriers. The fermentation device according to any one of 〔2-1〕 to 〔2-3〕.

[0071] 〔2-5〕The uppermost electrode among the plurality of electrodes has a plate-like shape with a plurality of through holes, and at least a part of the through holes is disposed at a position corresponding to the water spraying holes of the treated water spraying unit. The fermentation device according to 〔2-4〕. 〔2-6〕The uppermost electrode among the plurality of electrodes is in contact with the lower surface of the treated water spraying unit. The fermentation device according to 〔2-5〕.

[0072] 〔2-7〕The uppermost electrode among the plurality of electrodes is the treated water spraying unit. The fermentation device according to 〔2-4〕. 〔2-8〕The microorganism carriers are compressed between the plurality of electrodes. The fermentation device according to any one of 〔2-1〕 to 〔2-7〕. 〔2-9〕The fermentation tank has a gas passage configured to connect the space below and the space above the treated water spraying section and allow gas to flow therethrough, and is the fermentation device according to any one of 〔2-1〕 to 〔2-8〕.

[0073] The fermentation device according to 〔2-1〕 to 〔2-9〕 has a treated water spraying section provided with a cleaning section. Therefore, even when deposits are formed in the water spray holes, the cleaning section can easily remove the deposits in the water spray holes. Therefore, the fermentation device according to 〔2-1〕 to 〔2-9〕 can reduce the maintenance frequency of the treated water spraying section.

Explanation of Signs

[0074] 1, 102 to 104 Fermentation device 2 Fermentation tank 3 Treated water supply section 4, 403, 405 Treated water spraying section 41 Water storage section 42 Water spray hole 43 Protrusion 5 Microbial carrier

Claims

1. A fermentation device configured to be able to ferment organic matter in water to be treated by microorganisms, comprising a fermentation tank, a water to be treated supply unit for supplying the water to be treated into the fermentation tank, a water to be treated spraying unit for spraying the water to be treated supplied from the water to be treated supply unit into the fermentation tank, and a plurality of microorganism carriers disposed below the water to be treated spraying unit and configured to be able to carry the microorganisms. The water to be treated spraying unit comprises a water storage unit for storing the water to be treated, a plurality of water spraying holes penetrating the bottom of the water storage unit, and a protruding portion provided around the water spraying holes on the lower surface of the water storage unit, wherein the protruding portion protrudes downward from its outer peripheral portion. Fermentation device.

2. The fermentation device according to claim 1, wherein at least a part of the water spraying holes has a tapered portion whose inner diameter is the largest at the upper end and becomes smaller as it approaches the lower end.

3. The fermentation device according to claim 1, wherein the fermentation device has a plurality of electrodes provided in the fermentation tank, and the electrodes are in contact with the microorganism carriers.

4. The fermentation device according to claim 3, wherein the uppermost electrode among the plurality of electrodes has a plate-like shape with a plurality of through holes, and at least a part of the through holes is disposed at a position corresponding to the water spraying holes of the water to be treated spraying unit.

5. The fermentation device according to claim 4, wherein the uppermost electrode among the plurality of electrodes is in contact with the lower surface of the water to be treated spraying unit.

6. The fermentation device according to claim 3, wherein the uppermost electrode among the plurality of electrodes is the water to be treated spraying unit.

7. The fermentation device according to any one of claims 3 to 6, wherein the microbial carrier is compressed between the plurality of electrodes.

8. The fermentation device according to claim 1, wherein the fermentation tank has a gas passage that connects a space below the water to be treated spraying section and a space above the water to be treated spraying section and is configured to allow gas to flow therethrough.

9. The fermentation device according to claim 1, wherein the water to be treated spraying section has a cleaning section including a rod-shaped portion inserted into the water spraying holes and a floating portion provided at an upper end of the rod-shaped portion and configured to float on the water to be treated.

10. The fermentation device according to claim 9, wherein the cleaning section has a maximum length larger than an inner diameter of a lower end of the water spraying holes and has a retaining portion provided at a lower end of the rod-shaped portion.

11. A fermentation device configured to be able to ferment organic substances in water to be treated by microorganisms, a fermentation tank, a water to be treated supply section for supplying the water to be treated into the fermentation tank, a water to be treated spraying section for spraying the water to be treated supplied from the water to be treated supply section into the fermentation tank, a plurality of microbial carriers arranged below the water to be treated spraying section and configured to be able to carry the microorganisms, a plurality of electrodes provided in the fermentation tank and in contact with the microbial carriers, and having, the water to be treated spraying section, a water storage section for storing the water to be treated, a plurality of water spraying holes penetrating a bottom of the water storage section, and having, the uppermost electrode among the plurality of electrodes has a plate-like shape with a plurality of through holes and is in contact with a lower surface of the water to be treated spraying section, at least a part of the through holes is arranged at a position corresponding to the water spraying holes of the water to be treated spraying section.

12. A fermentation device configured to be able to ferment organic substances in water to be treated by microorganisms, a fermentation tank, a water to be treated supply unit that supplies the water to be treated into the fermentation tank, a water to be treated spraying unit that sprays the water to be treated supplied from the water to be treated supply unit into the fermentation tank, a plurality of microorganism carriers disposed below the water to be treated spraying unit and configured to be able to carry the microorganisms, and having, the water to be treated spraying unit, a water storage unit that stores the water to be treated, a plurality of water spray holes that penetrate the bottom of the water storage unit, a cleaning unit including a rod-shaped part inserted into the water spray hole, and a floating part provided at the upper end of the rod-shaped part and configured to float on the water to be treated. A fermentation device.

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