JP4988695B2 - Anaerobic treatment apparatus and waste treatment system provided with the same - Google Patents

Description

  The present invention relates to an anaerobic treatment apparatus that performs anaerobic treatment of organic waste such as garbage, livestock manure, waste paper, and sludge, and a waste treatment system including the same.

  Anaerobic treatment refers to biological treatment that decomposes organic waste using anaerobic bacteria. Examples of anaerobic treatment include methane fermentation treatment and hydrogen fermentation treatment. Here, there is a technique for separating waste such as municipal waste into organic waste that can be methane-fermented and waste that is not suitable for methane fermentation, and treating the organic waste with methane fermentation. The methane fermentation treatment refers to a treatment for anaerobically decomposing organic waste by the action of methane fermentation bacteria. Energy can be recovered in the form of fuel, electricity or heat using methane gas obtained by decomposition of organic waste.

  The methane fermentation treatment is a wet methane fermentation treatment in which the concentration (TS (solid matter concentration)) of organic waste that is a treatment target is adjusted to about 15% or less and methane fermentation is performed, and TS is about 15 to 30%. It is roughly divided into dry methane fermentation treatment that adjusts and performs methane fermentation. Since the dry methane fermentation process is a process with a higher TS than the wet methane fermentation process, that is, a high load process, according to the dry methane fermentation process, the wastewater treatment facility can be made smaller than in the case of the wet methane fermentation process. There is an advantage that you can. The technique regarding this dry methane fermentation process is described in Patent Document 1, for example.

  As described in Patent Document 1, usually, in dry methane fermentation treatment, in order to facilitate the handling of organic waste that is a processing target, and to appropriately treat organic waste, methane fermentation treatment, In practice, it is often necessary to adjust the moisture by adding moisture to the organic waste. Therefore, the fermentation residue remaining after the methane fermentation treatment is solid-liquid separated into solids and moisture by a dehydrator or the like, and the separated filtrate (water) is sent to a wastewater treatment facility for treatment.

JP 2004-17024 A

  As described above, according to the dry methane fermentation treatment, there is an advantage that the waste water treatment facility can be made smaller than in the case of the wet methane fermentation treatment. However, as described in Patent Document 1, the conventional methane fermentation treatment requires a wastewater treatment facility for treating the filtrate (moisture) from the residue regardless of wet or dry processes. Even with dry methane fermentation, wastewater treatment was necessary except when the digestive juice was used as liquid fertilizer. In other words, a methane fermentation process that requires no wastewater treatment facility or a very small wastewater treatment facility is desired.

  Here, in order to eliminate the wastewater treatment facility, it is conceivable that the moisture of the organic waste is not adjusted, that is, the organic waste is subjected to methane fermentation treatment while TS is high. On the other hand, in the methane fermentation treatment, it is necessary to keep the inside of the container used for methane fermentation anaerobic, and it is important to improve the sealing performance of the container. In conventional dry methane fermentation treatment, organic waste is pumped into a container using a mono pump or hydraulic pump. When sealed by a pump such as a MONO pump, the airtightness is ensured, so the organic waste inlet provided in the container is blocked from the outside, and the inside of the container is kept anaerobic. However, organic waste with a high TS is difficult to be pumped using a Mono pump because of poor fluidity.

  The present invention has been made in view of the above circumstances, and the purpose thereof is to maintain anaerobic inside the container even when the organic waste is processed under a high TS condition. Is to provide an anaerobic treatment apparatus having a structure capable of supplying water into a container.

Means and effects for solving the problems

In order to solve the above problems, the present invention provides a container for anaerobically treating organic waste, an input device for introducing organic waste into the container, and a residue remaining after anaerobic treatment. and a discharge device for discharging to the outside of the container, the closing device is internally subjected provided we are in the lower end of the container from above of the container is opened, cylindrical body organic waste is turned And a lower end of the cylindrical body, and is disposed so as to be positioned above the organic waste charged in the container, and the organic charged in the cylindrical body a receiving section for storing the sexual wastes, provided with a stirring blade to be rotated in the horizontal direction is disposed in the gap, provided you supply organic waste from the gap into the vessel by rotation of the stirring blade An anaerobic treatment device comprising a feeding device.

  According to this configuration, the organic waste is put into the cylindrical body and falls onto the receiving portion, so that the organic waste is consolidated in the cylindrical body by its own weight. The inside of the container is blocked from the outside by the consolidated organic waste. Thereby, even if it is not the pumping means using a Mono pump etc., the input part of the organic waste in a container can be interrupted | blocked from the outside. That is, even when organic waste is processed under conditions where TS is high, the organic waste can be supplied into the container while keeping the inside of the container anaerobic. In addition, by operating the supply device, the consolidated organic waste in the cylindrical body can be supplied (dropped) from the cylindrical body into the container.

  In the present invention, the bottom portion of the container is inclined downward from one end side to the other end side, and the discharge device is provided on one end side of the bottom portion and provided on the other end side of the bottom portion. A liquid outlet, a pump for extracting the liquid accumulated on the other end side of the bottom part from the liquid outlet and sending it to the upper part of the container, and a pump disposed at the upper part in the container and sent from the pump And a spraying device for spraying the liquid into the container.

  According to this configuration, the liquid that has oozed out from the organic waste in the container can be efficiently collected on the other end side (lower side) of the container bottom provided with the liquid discharge port. Anaerobic bacteria are returned from the bottom of the container to the top of the container by spraying the liquid accumulated on the other end (low side) of the bottom of the container to the top of the container and spraying it into the top of the container. Can be advanced.

  In addition, the moisture content of a residue falls in the one end side (high side) of the container bottom part provided with the discharge device. Thereby, the moisture content of the residue discharged | emitted outside the container can be made lower.

  Furthermore, in this invention, it is preferable to provide the residue return apparatus for returning a part of residue from the said discharge apparatus to the said injection apparatus or a direct container.

  According to this structure, the residue which remains after anaerobic treatment can be used as seed sludge, and the anaerobic treatment in a container can be advanced suitably.

  Furthermore, in this invention, it is preferable to provide the crushing apparatus arrange | positioned in the front | former stage of the said injection | throwing-in apparatus and crushing organic waste.

  According to this configuration, the organic waste becomes fine by being crushed, and the compactness of the organic waste in the cylindrical body is increased. As a result, the sealing effect by organic waste can be enhanced. In addition, the efficiency of the anaerobic treatment is increased.

  Furthermore, in this invention, it is preferable to provide the residue heat processing apparatus which heat-processes the residue discharged | emitted from the said discharge device.

  Organic waste remains in the residue discharged from the discharge device. And there exists a possibility that biogas, such as methane gas and hydrogen gas, may generate | occur | produce by this anaerobic decomposition | disassembly of this residual organic waste. However, according to this structure, anaerobic bacteria are inactivated by heat-processing a residue. Thereby, the production | generation of the said biogas can be suppressed. In addition, you may provide the gas supply apparatus which supplies air or oxygen to a residue instead of a residue heat processing apparatus. By supplying air or oxygen to the residue, anaerobic bacteria are similarly inactivated, and production of biogas such as methane gas and hydrogen gas can be suppressed.

  According to the second aspect of the present invention, there is provided a waste treatment system comprising the anaerobic treatment device of the present invention, and an incinerator for incineration the residue discharged from the anaerobic treatment device. provide. According to this waste treatment system, even if an organic waste having a high TS is a treatment target, the anaerobic treatment and the incineration treatment can be suitably performed.

  Furthermore, according to the third aspect of the present invention, a waste treatment comprising the anaerobic treatment device of the present invention and an aerobic treatment facility for composting the residue discharged from the anaerobic treatment device. Provide a system. According to this waste treatment system, even if an organic waste having a high TS is a treatment target, the anaerobic treatment and the composting treatment can be suitably performed.

  Furthermore, according to the fourth aspect of the present invention, there is provided an organic waste charging method for charging an organic waste into a container of an anaerobic treatment apparatus according to the present invention, wherein the organic material is disposed on an upper portion of the cylindrical body. Supplying waste and compacting the organic waste onto the receiving part; and operating the supply device to supply the compacted organic waste into the container through the gap And an organic waste charging method comprising a supplying step.

  According to this configuration, the inside of the container is blocked from the outside by the consolidated organic waste. Thereby, the input part of the organic waste into the container can be shut off from the outside. That is, even when organic waste is processed under conditions where TS is high, the organic waste can be supplied into the container while keeping the inside of the container anaerobic. By operating the supply device, the consolidated organic waste in the cylindrical body can be supplied (dropped) into the container without clogging the cylindrical body.

  Moreover, in this invention, after crushing organic waste, it is preferable to supply organic waste to the upper part of the said cylindrical body. According to this configuration, the organic waste becomes fine by being crushed, and the compactness of the organic waste in the cylindrical body is increased. As a result, the sealing effect by organic waste can be enhanced. In addition, the efficiency of the anaerobic treatment is increased.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a waste treatment system 100 according to an embodiment of the present invention. The waste treatment system 100 shown below uses municipal waste as a treatment target. In addition, the methane fermentation apparatus 1 constituting the waste treatment system 100 uses organic waste (raw garbage and paper) separated from municipal waste as a processing target. Note that the waste treatment system of the present invention is a system that can treat various general wastes, industrial wastes, and the like as well as municipal waste. Similarly, the methane fermentation apparatus of the present invention is an apparatus that can treat not only raw garbage and papers but also organic waste such as livestock manure and sludge.

(Configuration of waste treatment system)
As shown in FIG. 1, the waste treatment system 100 of the present embodiment includes a methane fermentation apparatus 1, a sorter 3 disposed on the upstream side of the methane fermentation apparatus 1 in the treatment process, and a downstream side of the methane fermentation apparatus 1. Incinerator 2, desulfurization tower 5, and gas holder 6. First, as an overall description, after explaining these devices constituting the waste treatment system 100, an outline of municipal waste processing by the waste treatment system 100 will be described. The methane fermentation apparatus 1 will be described later.

(Separator)
The sorter 3 is a machine that separates input municipal waste into organic waste (raw garbage and paper) that can be methane-fermented and waste such as waste plastic that is not suitable for methane fermentation. It arrange | positions in the front | former stage of the methane fermentation apparatus 1. FIG. As the sorter 3, a rotary sieve such as a trommel, wind sorting, magnetic sorting, etc. are used in combination as necessary. Moreover, it is preferable to perform bag breaking and crushing as pretreatment for separation.

(Incinerator)
The incinerator 2 is an incinerator for incinerating the fermentation residue discharged from the methane fermentation apparatus 1 and the waste such as waste plastic separated by the sorter 3. Examples of the incinerator 2 include a fixed bed furnace, a fluidized bed furnace, and a stoker furnace. The fermentation residue discharged from the methane fermentation apparatus 1 is once put in the garbage pit 4 and then incinerated in the incinerator 2. In addition, wastes such as waste plastics sorted by the sorter 3 are also once put into the garbage pit 4, and fermentation residues and wastes such as waste plastics are thrown into the incinerator from the waste pits 4.

(Desulfurization tower)
The desulfurization tower 5 is an apparatus for removing hydrogen sulfide contained in the biogas discharged from the methane fermentation apparatus 1. Examples of the desulfurization tower 5 include a wet desulfurization tower and a dry desulfurization tower, which are used alone or in combination. According to the wet desulfurization tower, carbon dioxide contained in the biogas can be removed. Here, the components of the biogas immediately after being discharged from the methane fermentation apparatus 1 are about 60% of methane and about 40% of carbon dioxide, and other gases such as nitrogen and hydrogen sulfide are contained in a small amount in the biogas. ing. By removing carbon dioxide contained in the biogas and increasing the methane gas concentration, the calorific value of the biogas is increased. Note that carbon dioxide cannot be completely removed by a normal wet desulfurization tower. Also, the dry desulfurization tower is often used as a desulfurization finish.

(Gas holder)
The gas holder 6 stores the biogas that has exited the desulfurization tower 5, and is disposed at the rear stage of the desulfurization tower 5. The biogas stored in the gas holder 6 can be used as fuel, for example, as auxiliary fuel in an incinerator, or by driving a gas engine, gas turbine, fuel cell, etc., and recovering energy in the form of electricity or heat (hot water) Or

(Outline of municipal waste disposal)
The solid arrows in FIG. 1 indicate the flow of solid matter, and the dotted arrows indicate the flow of gas. Organic waste (raw garbage) separated by the sorter 3 is sent to the methane fermentation apparatus 1 and subjected to methane fermentation treatment in the methane fermentation apparatus 1. The fermentation residue remaining after the methane fermentation treatment is sent from the methane fermentation apparatus 1 to the garbage pit 4 and then put into the incinerator 2. The fermentation residue put into the incinerator 2 is incinerated together with the waste separated by the separator 3. On the other hand, the biogas generated by the methane fermentation treatment is desulfurized through the desulfurization tower 5 and then sent to the gas holder 6 to be stored. The fermentation residue taken out from the methane fermentation apparatus 1 may be subjected to an aerobic fermentation process (composting process) instead of being incinerated.

  Since the waste treatment system 100 of this embodiment does not have wastewater treatment equipment, the laying area can be reduced as a whole. Even if a wastewater treatment facility is provided, the amount of treatment can be made extremely small as compared with the conventional case, so that the laying area can be reduced also from this viewpoint.

(Methane fermentation equipment)
The methane fermentation apparatus 1 is an apparatus for anaerobic treatment (methane fermentation) of organic waste (garbage / paper). In FIG. 2, the detail of the methane fermentation apparatus 1 of FIG. 1 is shown. FIG. 3 is a detailed view of part A of FIG.

  As shown in FIG. 2, the methane fermentation apparatus 1 includes a container 11 for methane fermentation of organic waste (garbage / paper), an input apparatus 14 for introducing garbage etc. into the container 11, and methane fermentation. A discharge device 15 for discharging the fermentation residue remaining after processing to the outside of the container 11 is provided. Further, a conveying device 13 for garbage etc. is connected to the charging device 14, and a crusher 12 is provided in the front stage of the conveying device 13. Hereinafter, these devices constituting the methane fermentation apparatus 1 will be described in order from the upstream side of the processing step.

(Crushing machine)
The crusher 12 is a device for crushing raw garbage. In the case of municipal waste, bag-breaking treatment and crushing treatment are performed as pre-treatment of the above-described sorting machine 3. Efficiency is improved. Further, as will be described in detail later, the garbage is supplied into the container 11 after passing through the cylindrical body 20 of the charging device 14 provided in the upper part of the container 11. By crushing and making the garbage fine, the compactness of the garbage in the cylindrical body 20 is increased. As a result, the sealing effect by garbage between the inside of the container 11 and the outside can be enhanced. In addition, although a uniaxial crusher and a biaxial crusher can be utilized as a crusher, it is preferable to use a crusher etc. from the point which can improve compaction and can crush effectively.

(Transport device)
The transport device 13 is a device for quantitatively sending the crushed garbage to the input device 14. Examples of the conveying device 13 include a screw feeder and a pipe conveyor. According to the conveying device 13 such as a screw feeder or a pipe conveyor, even organic waste with high TS (organic waste with poor fluidity) can be sent without problems.

(Input device)
The charging device 14 is a device for charging garbage into the container 11. The charging device 14 is provided with a gap between the tubular body 20 disposed so as to penetrate the container 11 from above the container 11 toward the inside thereof and the lower end 20a of the tubular body 20. The receiving part 17 and the electric supply device 29 provided on the upper side of the cylindrical body 20 are provided.

(Tubular body)
The cylindrical body 20 is a cylindrical body having a predetermined length, and penetrates the container 11 in the vertical direction from above the container 11 toward the inside thereof. A downstream end portion of the transport device 13 is connected to a side portion of the portion located outside the container 11. The lower end 20 a of the cylindrical body 20 is an opening and is opened in the container 11. The upper end of the cylindrical body 20 is closed and blocked from the outside. Both the connection part of the cylindrical body 20 and the conveying apparatus 13 and the penetration part of the cylindrical body 20 in the container 11 are sealed.

  In addition, it is preferable that the cylindrical body 20 is arrange | positioned so that the lower end part may be located in the position near the ceiling of the container 11. FIG. Thereby, the gas phase part in the container 11 can be reduced, and as a result, replacement with air or an inert gas is facilitated during maintenance, and a large amount of processing object can be put into the container 11. become.

(Reception Department)
The receiving part 17 is for accumulating the raw garbage thrown into the cylindrical body 20 from the conveying apparatus 13. As shown in detail in FIG. 3, the receiving portion 17 is disposed below the cylindrical body 20 with a gap having a dimension h between the lower end 20 a of the cylindrical body 20. The receiving part 17 is a disk-shaped board | plate material, for example. The diameter of the receiving part 17 is slightly larger than the diameter of the stirring blade 18 constituting the supply device 29. In addition, when it has enough space which discharges organic waste with the stirring blade 18 mentioned later, the one where the clearance gap between the stirring blade 18 and the cylindrical body 20 is narrow is good.

  Moreover, the receiving part 17 is arrange | positioned so that it may be located above the upper surface of the garbage in the container 11. FIG. Thereby, supply of garbage from the inside of the cylindrical body 20 into the container 11 can be performed without stagnation.

(Supply device)
The supply device 29 is a device for supplying raw garbage from the inside of the cylindrical body 20 into the container 11. The supply device 29 is an electric or hydraulic device including the stirring blade 18 and a shaft 19 for rotating the stirring blade 18.

  The stirring blade 18 is disposed in the gap between the lower end 20 a of the cylindrical body 20 and the receiving portion 17. The stirring blade 18 is composed of, for example, three blades arranged at equal intervals around the shaft 19 with a phase difference of 120 degrees, and the lower end portion of the shaft 19 is attached to the center of the blade. In addition, the stirring blade 18 which consists of one cantilever blade with which the axis | shaft 19 is attached to an edge part may be sufficient. The shaft 19 is arranged in the vertical direction at the center in the cylindrical body 20, and an electric motor M is attached to the upper end. The stirring blade 18 is preferably a paddle blade having a blade retracted (curved backward) with respect to the rotation direction, preferably two blades to six blades, more preferably two blades to four blades. It is preferable to use those. The reason why the stirring blade 18 is a retreating blade is that the garbage can be pushed out by the rotation of the stirring blade 18, so that clogging in the vicinity of the blade (especially in front of the blade in the rotation direction) can be prevented. Also, 2 to 6 blades, and 2 to 4 blades are preferred, with one blade being unbalanced, and depending on the quality and size of the dust, if there are more than 7 blades, the gap between the blades becomes narrow and clogged. This is because it becomes easier.

The lower end of the shaft 19 is fixed to the receiving portion 17 so that the shaft 19 can rotate. Further, the receiving portion 17 is fixed to the lower side surface of the cylindrical body 20 with three fixing members 30. By adopting such a structure, it is possible to prevent shake of the stirring blade 18 when an unbalanced load is applied to the rotating stirring blade 18. The fixing member 30 is formed of , for example, a metal pipe material (pipe material) having a small diameter. By using the pipe material, it is possible to prevent clogging of garbage between the stirring blade 18 and the fixing member 30.

  The diameter of the stirring blade 18 is slightly larger than the outer diameter of the cylindrical body 20. Here, during the period when the stirring blade 18 is stopped, it is necessary to leave the garbage accumulated in the lower part of the cylindrical body 20 as it is (so as not to fall). By making it slightly larger than the outer diameter of the shaped body 20, the garbage can be prevented from falling. Moreover, when the diameter of the stirring blade 18 is slightly larger than the outer diameter of the cylindrical body 20, when the stirring blade 18 is rotated, garbage is easily dropped. Note that a vibration device that vibrates the cylindrical body 20 or the shaft 19 may be provided in preparation for a case where garbage is blocked in the cylindrical body 20.

(container)
The container 11 is a container for methane fermentation of raw garbage inside. For example, the periphery is covered with a heat insulating material such as glass wool in an airtight container (tank) made of steel plate. In the upper part of the container 11, the aforementioned charging device 14 and a nozzle (discharge port) for discharging biogas are provided. The space in the container 11 is filled with biogas, and the pressure is adjusted to, for example, 100 to 200 mmAq. In addition, a residue dropping device 16 is provided at the bottom of the container 11. The residue dropping device 16 may be a rotary type like the feeding device 29 that constitutes the charging device 14, or scrapes raw garbage into the discharging device 15 by reciprocating a rectangular plate. A reciprocating drive type may also be used. The residue dropping device 16 can prevent garbage bridging (a state in which the garbage does not fall) in the container 11. The container 11 may be provided with a stirring device (not shown) for stirring the garbage in the container 11. The main purpose of this stirrer (not shown) is to prevent bridging of garbage in the container 11, but the methane fermentation efficiency is also improved by stirring by this stirrer (not shown). Further, in order to make the garbage in the container 11 uniform without unevenness, a scraping member such as a stirring blade or a scraper or a pusher for leveling the surface of the garbage may be provided.

  Further, as another method for preventing bridging of garbage in the container 11, there is a method of injecting an inert gas such as nitrogen from the outside of the container 11 toward the garbage in the container 11. Furthermore, if it is a small amount, compressed air may be injected from the outside of the container 11 toward the garbage in the container 11 instead of the inert gas. Further, as another method for preventing bridging of garbage in the container 11, the rod-shaped member may be reciprocated from the outside of the container 11 toward the garbage in the container 11. In the case of using the above-described inert gas ejection or a rod-shaped member, it is preferable to provide a plurality of them on the wall surface of the container 11, and it is preferable to provide them with different heights.

  Here, the methane fermentation process includes a medium temperature fermentation process of about 35 ° C. and a high temperature fermentation process of about 55 ° C. Therefore, it is preferable to heat the garbage to perform the methane fermentation treatment. Prior to putting the garbage into the container 11, the garbage may be heated in advance, or a heating device may be provided in the container 11 itself. When providing a heating apparatus in container 11 itself, there exists the method of laying a heating water pipe (not shown) so that it may wind spirally along the outer peripheral surface of the container 11, for example. Examples of the heated water pipe include a steel pipe, a vinyl chloride pipe, and a flexible resin hose.

(Discharge device)
The discharge device 15 is a device for discharging the fermentation residue remaining after the methane fermentation process in the container 11 to the outside of the container 11. Examples of the discharge device 15 include a screw feeder and a pipe conveyor. According to the discharge device 15 such as a screw feeder or a pipe conveyor, even a fermentation residue having a low moisture content (fermentation residue having poor fluidity) can be sent without problems. The discharge device 15 is disposed at the bottom of the container 11 and below the residue dropping device 16.

The residence time (solid residence time) of the garbage in the container 11 is adjusted by controlling the discharge device 15, the transport device 13, the input device 14, and the like. The solid material residence time in the container 11 is 20 to 30 days in the case of a medium temperature fermentation process, and about 10 days in the case of a high temperature fermentation process. If the high-temperature fermentation treatment is employed to shorten the solids residence time, the volume of the container 11 can be reduced.
In addition, the garbage is consolidated in the discharge part, and it is partly decomposed and becomes fine, and the discharge device 15 can be kept in a state where the fermentation residue is always clogged, so that the sealing performance in the container 11 can be maintained. Moreover, it does not specifically limit about the position of the discharge apparatus 15, The structure which extracts a fermentation residue from a container center part may be sufficient, and the structure which extracts in the container wall surface vicinity may be sufficient.

(Operation of the charging device)
Next, the operation of the input device 14 will be described. FIG. 4 is a view for explaining the operation of the charging device 14 shown in FIG.

  First, the raw garbage thrown into the container 11 is discharged | emitted sequentially outside as a fermentation residue from the discharge device 15 arrange | positioned at the lower part of the container 11, when predetermined | prescribed residence time passes. Since the amount of garbage in the container 11 is reduced, the input device 14 is operated to input the garbage into the container 11.

  4A shows a state where the supply device 29 of the charging device 14 is stopped, and FIG. 4B shows a state where the supply device 29 is operating.

(Consolidation process)
First, as shown in FIG. 4A, the garbage is supplied to the upper part of the cylindrical body 20 by operating the transport device 13, and the garbage is consolidated on the receiving unit 17. Here, for example, a level meter (not shown) for detecting the accumulated height of garbage is attached to the cylindrical body 20. Based on the signal from the level meter, the conveying device 13 is stopped in a state where the accumulation height of the garbage in the cylindrical body 20 is within a predetermined range.

  Here, according to the input device 14, the raw garbage is put into the cylindrical body 20 and falls onto the receiving portion 17, so that the raw garbage is consolidated in the cylindrical body 20 by its own weight. The inside of the container 11 is shut off from the outside by the consolidated garbage. Thereby, even if it is a case where organic wastes, such as garbage, are processed on conditions with high TS, organic waste can be supplied in a container, keeping the inside of a container anaerobic. That is, for example, even if the organic waste is poor in fluidity with 50% TS, the organic waste can be supplied into the container without problems while keeping the inside of the container anaerobic.

  Note that it is preferable to supply a small amount of an inert gas such as nitrogen to the upper space in the cylindrical body 20 to enhance the sealing performance by garbage with the inert gas.

(Organic waste supply process)
When the predetermined residence time has elapsed, the fermentation residue of raw garbage put in the container 11 is discharged to the outside from the lower part of the container 11 by the discharge device 15. At this time, since the amount of garbage in the container 11 decreases, the transport device 13 and the input device 14 are operated to input the garbage into the container 11 corresponding to the decrease.

  As shown in FIG. 4B, when the supply of garbage to the container 11 is started, the transport device 13 is restarted and the supply device 29 is operated. By operating the supply device 29, the compacted garbage in the cylindrical body 11 is supplied (dropped) into the container 11 from the gap between the lower end 20a of the cylindrical body 20 and the receiving portion 17. The number of rotations of the stirring blade 18 is appropriately determined. In addition, it is preferable that the electric motor M of the supply device 29 is configured to be inverter-controlled so that the rotational speed of the stirring blade 18 can be arbitrarily changed. The amount of falling garbage can be adjusted by changing the rotation speed according to the properties of the garbage.

  During the organic waste supply process, it is preferable to maintain the accumulated height of garbage in a predetermined range based on a signal from a level meter (not shown) that detects the accumulated height of garbage. Specifically, operation / stop of the supply device 29 is performed based on a signal from a level meter that detects the accumulated height of garbage. For example, when the supply speed of the garbage into the container 11 by the supply device 29 is higher than the supply speed of the garbage into the cylindrical body 20 by the transport device 13, the height of the garbage is a predetermined height. At the time when the pressure drops to, the operation of the supply device 29 is stopped, or the rotation speed of the electric motor M is reduced. Thereafter, when the height of the garbage rises to a predetermined height (recovers), the operation of the supply device 29 is restarted or the rotation speed of the electric motor M is increased. In this way, garbage is supplied into the container 11 while keeping the inside of the container 11 anaerobic.

(Other embodiment 1)
FIG. 5 is a schematic view showing another embodiment of the methane fermentation apparatus according to the present invention. The present embodiment will be described with emphasis on the differences from the above embodiment. Moreover, the same code | symbol is attached | subjected about the same component apparatus as the component apparatus of the said embodiment.

  The main difference between the methane fermentation apparatus 21 of the present embodiment and the methane fermentation apparatus 1 of the embodiment is that the bottom shape of the container and the methane fermentation apparatus 21 of the present embodiment are further a bottom liquid return device and a residue return device 27. , And a residue heat treatment device 26.

(Bottom shape of container)
The container 22 of the present embodiment is inclined downward from one end side to the other end side. The discharge device 15 is provided on one end side (high side) of the bottom of the container 22. Further, a liquid discharge port 22a is provided on the other end side (lower side) of the bottom portion. Here, the moisture in the raw garbage supplied into the container 22 has a specific gravity greater than the solid content in the raw garbage, so that it exudes from the raw garbage and gradually moves to the bottom of the container 22. Since the bottom portion of the container 22 is inclined, the exuded water (liquid) gathers at the other end side (lower side) of the container bottom portion where the liquid discharge port 22a is provided, and the discharge device 15 is provided. On the one end side (high side) of the container bottom, the moisture content of the fermentation residue decreases. Thereby, the liquid containing the methane bacteria in the container 22 can be efficiently collected. In addition, it is good also as a structure which made the container bottom part double bottom, provided the inclination or the water collecting channel in the lower bottom, and provided the fermentation residue discharge port and the fine hole for draining in the upper bottom.

(Bottom liquid return device)
The bottom liquid return device includes a pump P, an ammonia removing device 23, and a spraying device 25.

  The pump P is a pump for extracting the liquid accumulated at the bottom of the container 22 from the liquid outlet 22a and sending it to the upper part of the container 22, and is disposed in the vicinity of the liquid outlet 22a. The liquid that accumulates at the bottom of the container 22 is a highly viscous liquid. As the pump P, for example, a Mono pump is used. In addition, when a liquid with low viscosity can be obtained, a centrifugal pump or the like may be used.

The ammonia removing device 23 is a device for removing an ammonia component (NH ₄ —N state nitrogen) contained in the liquid. By removing the ammonia component contained in the liquid, fermentation inhibition can be prevented and the progress of methane fermentation can be more suitably maintained. The ammonia removing device 23 is provided in a pipe 24 that connects the pump P and the spraying device 25. In addition, ammonia stripping etc. can be utilized as an ammonia removal method.

  The spraying device 25 is a device that is disposed in the upper part of the container 22 and sprays the liquid sent from the pump P into the container 22. The spraying device 25 includes a pipe 25a and a plurality of nozzles 25b attached to the pipe 25a.

  The liquid accumulated at the bottom of the container 22 is sent to the top of the container 22 and dispersed in the container 22, so that anaerobic bacteria (methane fermentation bacteria) are returned from the bottom of the container to the top of the container, and methane fermentation is suitably performed throughout the container. Can be advanced.

  In the present embodiment, the nozzle 25 b is also arranged inside the cylindrical body 20 so that liquid can be sprayed on the garbage accumulated in the cylindrical body 20. By spraying the liquid on the garbage in the cylindrical body 20, the methane fermentation of the garbage in the cylindrical body 20 also proceeds easily. When the generated biogas fills the cylindrical body 20, the anaerobic property in the container 22 can be made more reliable. Further, if the garbage is high in TS, the compaction of the garbage is enhanced by spraying the liquid. From this viewpoint, the anaerobic property in the container 22 can be improved.

(Residue return device)
The residue return device 27 is a device for returning a part of the fermentation residue from the discharge device 15 to the upper portion of the input device 14 (the upper portion of the cylindrical body 20). As the residue return device 27, for example, a pipe conveyor or a flight conveyor can be used. According to the residue return apparatus 27, a fermentation residue can be used as seed sludge, and the methane fermentation in the container 22 can be suitably advanced.

  Also, for example, assume that there is no garbage to be supplied from the transport device 13 when the amount of garbage accumulated in the cylindrical body 20 is insufficient and the sealing performance deteriorates. At this time, the sealing property in the cylindrical body 20 can be recovered by returning the fermentation residue into the cylindrical body 20 by the residue return device 27. That is, the residue return device 27 can also be used as a backup of the seal in the cylindrical body 20.

(Residue heat treatment equipment)
The residue heat treatment device 26 is a device for heat-treating the fermentation residue discharged from the discharge device 15. Examples of the residue heat treatment apparatus 26 include an apparatus having an electric heater, an apparatus having a hot water heater, and a direct heating or indirect heating apparatus using waste heat in an incinerator or the like. The residue heat treatment device 26 is attached to the discharge device 15 at a rear portion of the connection portion of the residue return device 27.

  Here, organic waste capable of methane fermentation remains in the fermentation residue discharged from the container 22. And there exists a possibility that this residual organic waste may produce methane gas by methane fermentation. However, by heat-treating a fermentation residue to 70 degreeC or more with the residue heat processing apparatus 26, inactivation of a methane fermentation microbe is accelerated | stimulated and the production | generation of methane gas is suppressed. As shown in FIG. 1, the fermentation residue may be left in the garbage pit 4 for a while before being incinerated in the incinerator 2. In such a case, generation of methane gas in the garbage pit 4 can be suppressed.

  Instead of the residue heat treatment device 26, a gas supply device for blowing oxygen or air into the fermentation residue may be provided. Usually, since methane fermentation bacteria are anaerobic bacteria, inactivation of methane fermentation bacteria can be accelerated | stimulated by supplying air and oxygen to a fermentation residue, and the production | generation of methane gas can be suppressed. Examples of the gas supply device include an air compressor, an air cylinder, and an oxygen cylinder.

(Other embodiment 2)
FIG. 6 is a schematic view showing another embodiment of the methane fermentation apparatus according to the present invention. The present embodiment will be described with emphasis on the differences from the above embodiment. Moreover, the same code | symbol is attached | subjected about the same component apparatus as the component apparatus of the said embodiment.

  The main difference between the methane fermentation apparatus 31 of the present embodiment and the methane fermentation apparatus 1 of the embodiment is that a heating container 28 is provided between the crusher 12 and the transport apparatus 13.

(Heating container)
The heating container 28 is a container for heating the raw garbage sent through the crusher 12. The heating container 28 is provided with a stirring device (not shown) for stirring the inside thereof. Moreover, the heating container 28 is attached with a compressor (not shown) for supplying air therein. By stirring the garbage while supplying air to the garbage put into the heating container 28, the garbage is heated using aerobic fermentation and heated to about 60 ° C., for example. By heating the garbage in advance before supplying the garbage to the container 11, the start of methane fermentation in the container 11 can be accelerated. Thereby, the solid substance residence time in the container 11 can be shortened.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made as long as they are described in the claims. .

  For example, when used in combination with the incinerator 2, the incinerator waste heat can be used as a heating heat source for the heating of the methane fermentation apparatus 1 and the residue heat treatment apparatus 26. Since low temperature may be sufficient for the heat utilized for methane fermentation and residue heat processing, the low temperature waste heat which generate | occur | produced in the incinerator 2 can be utilized suitably. The heating method is not particularly limited, but water or air is heated with waste heat generated in an incinerator or the like, and indirectly heated to methane fermentation equipment or residue using the heated hot water, steam, or air. The apparatus may be heated, or waste gas generated in the incinerator may be directly used as a heat source, and heated by indirect heating or direct contact with the waste gas.

  Further, instead of the incinerator 2, a composting device (aerobic treatment facility) may be provided. As the composting apparatus, aerobic fermentation in which air is supplied to the fermentation residue for fermentation can be used. In this case, it is preferable to stir the aerobic fermentation. In addition, since aerobic fermentation is an exothermic reaction, the generated heat may be used as a heat source for the preceding methane fermentation.

  Further, the dehydration process may be performed before the incineration process. Since the amount of liquid generated by the dehydration process is very small, it can be processed by a very small wastewater treatment facility as compared with conventional dry methane fermentation. Moreover, in order to draw out the liquid accumulated in the bottom of the container, one side is inclined. However, the present invention is not limited to this, and it is possible to provide a water collecting channel at the bottom of the container and collect the liquid in one place using the water collecting channel. good.

  In addition, although this embodiment demonstrated methane fermentation using a methane bacterium, this invention can be utilized not only for a methane bacterium but also for hydrogen fermentation using a hydrogen-producing bacterium.

It is a block diagram which shows the waste disposal system which concerns on one Embodiment of this invention. It is a mimetic diagram showing the methane fermentation device concerning one embodiment of the present invention. FIG. 3 is a detailed view of part A in FIG. 2. It is a figure for demonstrating the action | operation of the injection | throwing-in apparatus shown in FIG. It is a schematic diagram which shows other embodiment of the methane fermentation apparatus which concerns on this invention. It is a schematic diagram which shows other embodiment of the methane fermentation apparatus which concerns on this invention.

Explanation of symbols

1: Methane fermentation device 2: Incinerator 11: Container 13: Transport device 14: Input device 15: Discharge device 17: Receiving unit 20: Tubular body 29: Supply device

Claims (9)

A container for anaerobically treating organic waste;
An input device for introducing organic waste into the container;
A discharge device for discharging the residue remaining after the anaerobic treatment to the outside of the container,
The charging device is
A tubular body inside toward provided we are in the lower end of the container from above of the container is opened, organic waste is turned on,
Organic waste disposed in the cylindrical body, provided with a gap between the lower end of the cylindrical body and disposed above the organic waste charged in the container. A receiving section for storing things;
Equipped with a stirring blade is rotated in the horizontal direction is disposed in said gap, anaerobic treatment apparatus and a supply device that to supply the organic waste into the container from the gap by the rotation of the stirring blade . In the anaerobic treatment device according to claim 1,
The bottom of the container is inclined downward from one end side to the other end side,
The discharge device is provided on one end side of the bottom,
A liquid outlet provided at the other end of the bottom;
A pump for extracting the liquid accumulated on the other end side of the bottom from the liquid outlet and sending it to the top of the container;
An anaerobic treatment apparatus comprising: a spraying device disposed in an upper part of the container and spraying the liquid sent from the pump into the container. In the anaerobic processing apparatus of Claim 1 or 2,
An anaerobic treatment apparatus comprising a residue return device for returning a part of the residue from the discharge device to the charging device or directly into the container. In the anaerobic processing apparatus in any one of Claims 1-3,
An anaerobic treatment apparatus comprising a crushing device disposed in a front stage of the charging device and crushing organic waste. In the anaerobic processing apparatus in any one of Claims 1-4,
An anaerobic treatment apparatus comprising: a residue heat treatment apparatus that heats a residue discharged from the discharge apparatus; or a gas supply apparatus that supplies air or oxygen to the residue. An anaerobic treatment apparatus according to any one of claims 1 to 5,
An incinerator for incinerating the residue discharged from the anaerobic treatment device;
A waste treatment system comprising: An anaerobic treatment device according to any one of claims 1 to 5,
An aerobic treatment facility for composting the residue discharged from the anaerobic treatment device;
A waste treatment system comprising: An organic waste charging method for charging organic waste into the container of the anaerobic treatment device according to claim 1,
A compacting step of supplying organic waste to an upper part of the cylindrical body and compacting the organic waste on the receiving unit;
A supply step of operating the supply device to supply the consolidated organic waste into the container through the gap. The organic waste charging method according to claim 8,
An organic waste charging method, comprising: supplying organic waste to an upper portion of the cylindrical body after crushing the organic waste.

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