JPH07184635A - Fermentation of organic waste and fermentation apparatus - Google Patents

Abstract

PURPOSE:To provide a fermentation method capable of performing uniform aerobic fermentation of an organic waste without causing excessively moistened state or hard-dried state of the bottom sediment generated in a fixed bottom fermentation tank furnished with a fixed bottom plate for precipitating the organic waste and to provide a fermentation apparatus for performing the fermentation method. CONSTITUTION:This fermentation method alternately performs an upward aeration to pass air upward from the bottom of the sediment of an organic waste and a downward aeration to pass air from the top toward the sedimentation bottom of the organic waste. The characteristic of the fermentation apparatus for performing the fermentation method comprises connecting a blower 4 with an aeration chamber 3 under the bottom plate 2 of the fermentation tank 1 through a channel-switching means composed of automatic valve V1 and V4 and a dust and selectively connecting the aeration chamber to the exhaustion side or the suction side of the blower by the automatic control of the channel-switching means with a timer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fermentation method and a fermentation apparatus for aerobically fermenting an organic waste, and more specifically, a fermentation method in which an oxygen-containing gas aeration method is improved in an organic waste accumulation layer in a fermenter. And a fermenter.

[0002]

Fermentation apparatus for fermenting organic wastes such as horse droppings, cows, pigs, chickens and other livestock manure, livestock straws, kitchen waste, sludge, agricultural and forestry wastes, and municipal wastes under aerobic conditions to compost them. Conventionally, various types are known. For example, a vertical structure such as a structure in which trapdoors are arranged to form a shelf or a structure in which a plurality of rotating rods provided with claw-shaped, plate-shaped, or acute-angled protrusions on the outer periphery are arranged in parallel at intervals. A multi-stage, door-type composting and fermentation apparatus is known. This multi-paragraph door-to-door type composting fermenter drops organic waste deposits on the tray to the next lower tray by opening the trapdoor on each stage or rotating the rotating rod. There is an advantage that the whole sediment above can be agitated and relatively aerobically fermented, and the site area can be reduced.

However, since this vertical type multi-paragraph door type composting and fermenting apparatus requires a large number of mechanical elements and is expensive, a fixed bottom type composting and fermenting apparatus is often employed. In this bottom fixed type composting fermentation apparatus, generally, a rectangular parallelepiped fermenter with an open upper part is generally adopted.Furthermore, a fixed bottom plate having a cutout portion is arranged in multiple stages to collect organic waste deposits at each stage. There is one that is moved and dropped from the notch to the lower step. Further, these bottom fixed type composting and fermenting devices are provided with various cutting machines for vertically stirring the organic waste deposits in order to uniformly perform aerobic fermentation. For example, an auger type that scrapes the deposit upwards with a spiral screw, a paddle type that flips the deposit back to the side opposite to the direction of movement of the paddle with a rotating flip-up paddle, and a shape with a scraping plate or bucket attached to the chain conveyor. There are various cutting devices such as a scoop type which scoops up the deposit backward by the scoop.

[0004]

However, in the above-mentioned fixed bottom type composting and fermentation apparatus, even if the organic waste accumulation layer is cut back by various cutting machines, it cannot be mechanically scraped to the bottom of the fermentation tank. As a result, a piled-up portion that is not cut back occurs at the bottom of the fermenter. That is,
When the fermentation process is actually performed, in a certain type of bottom fixed type composting fermenter, the piled-up part that is difficult to turn over at the bottom of the fermenter becomes sticky and sticky, causing pests and giving off a strange odor. Further, there is an adverse effect that these are occasionally scraped off by a turning machine and mixed into the fermented product as a lump. Further, in another type of bottom fixed type composting fermenter, the piled up part that is difficult to turn over at the bottom of the fermenter is in a dry state and fermentation is stopped and hardened. The scraper is scraped off by a cutting machine, and the fermented product is contaminated in the form of lumps.

Upon close examination, in the bottom fixed composting fermenter of the downward circulating air system, which sucks air from the bottom of the organic waste deposit in the fermenter and takes in air from the surface of the organic waste deposit, the bottom of the fermenter is used. The part that accumulates at the bottom becomes sticky and over-humidified, while air is supplied from the bottom of the organic waste stack in the fermenter to discharge and disperse from the surface of the organic waste stack. In the fermenter, it was found that the accumulated portion at the bottom of the fermenter was in a hard and dry state.

Further, in Japanese Utility Model Publication No. 63-27839 filed by the same applicant as the present application, as shown in FIG. 4, an intake pipe 20 having a large number of holes in the longitudinal direction is provided in the fermentation tank. There is described a bottom fixed fermentation apparatus arranged on the side wall 21 of the fermenter at an intermediate position of the sedimentary layer of the organic waste. In this device, a fixed bottom plate 2 having a large number of air inlet holes is formed.
Air is sent from 2 by a blower 23, and at the same time, air is sucked by a suction blower 24 via an intake pipe 20 and treated by a deodorizing device 25. As a result, as shown by the arrow in the figure, the downward flow air system is used in the deposition layer above the intake pipe 20, but the upward flow air system is used in the deposition layer below the intake pipe 20, At the bottom of the fermenter, a hard, dry state occurs at the deposit.

Therefore, the present invention has been made to solve the above-mentioned problems peculiar to a fixed bottom type fermenter, and implements a fermentation method and a method for uniformly aerobic fermentation of organic waste. It is an object of the present invention to provide a fermentation device for

[0008]

The method for fermenting organic waste according to the first aspect of the present invention for achieving the above object comprises aerobically fermenting the organic waste in a fermenter equipped with a fixed bottom plate for depositing the organic waste. In the method, an upflow gas that ventilates an oxygen-containing gas upward from the bottom of the organic waste deposit and a downflow air that vents the oxygen-containing gas from above to the bottom of the organic waste deposit are alternately performed. It is characterized by that.

The organic waste fermenter according to the second aspect of the present invention is a fermenter in which a ventilating means is provided in the vicinity of a fixed bottom plate for accumulating the organic waste, and the ventilating means includes a passage switching means that is switched by a timer. When the discharge side and the suction side of the gas blowing means are selectively communicated with each other and the ventilation means and the discharge side of the gas blowing means are communicated with each other,
The suction side of the gas blowing means is connected to an oxygen-containing gas source.

In the present specification, the term "organic waste" is to be understood in a broad sense, and it can be fermented under aerobic conditions to be composted, and the dung of horses, cattle, pigs, chickens, etc. In addition to organic wastes such as straw, kitchen waste, sludge, agricultural and forestry wastes, and municipal wastes, compost as a product obtained by aerobically fermenting these is also included. The "oxygen-containing gas" may be any kind of gas as long as it contains oxygen essential for aerobic fermentation, but it is generally air (atmosphere).
Can be used.

[0011]

According to the present invention having the above-mentioned structure, since the upward air flow and the downward air flow are alternately performed, the fermentation tank bottom deposition portion of the conventional bottom fixed fermentation apparatus of the upward air flow system. There is no occurrence of a hard dry condition such as that which occurs in the above, or a sticky and over-humidified condition which occurs in the bottom part of the fermentation tank of the conventional fixed bottom type bottom-fermented fermentation apparatus. As a result, even when using a fixed bottom type fermenter that causes mechanical flipping or scraping of the fermenter bottom that is difficult to scrape, uniform aerobic fermentation can be performed up to the bottom of the fermenter. .

There is no particular limitation on the switching time in the case where the upward air flow and the downward air flow are alternately performed, and the drying and overhumidity of the sediment in the fermenter, especially the bottom sedimentation part, is prevented. It may be appropriately switched so that uniform fermentation can be obtained over the whole sediment, but preferably 1 hour or more, usually 3 to 4
It is desirable to switch over every hour or more, more preferably every 12 hours.

[0013]

EXAMPLES Examples of the present invention will be described below. 1 and 2 show a first embodiment of a fermentation apparatus according to the present invention, in which a bottom plate 2 of a fermenter 1 has a large number of holes, and a ventilation chamber 3 is provided below the bottom plate 2. It is provided. An air suction duct having an automatic valve V1 is connected to the suction side 4a of the air supply blower 4. On the other hand, the discharge side 4b of the air supply blower is connected to the ventilation chamber 3 of the fermentation tank 1 via a duct having an automatic valve V2, and further to the deodorizing device 5 via a duct having an automatic valve V3. The suction side 4a of the air supply blower 4 is further connected to the aeration chamber 3 of the fermenter 1 via a duct having an automatic valve V4. The fermentation tank 1 is entirely installed in a building 6, a hood 7 is provided in the building above the fermentation tank 1, and is connected to a deodorizing fan 8 and a deodorizing device 5 via a duct having an automatic valve V5. A ventilation fan 9 and an automatic valve V6 are installed on the roof of the building. The switching operation of each automatic valve V1 to V6 can be automatically controlled by the timer setting in the control panel.

The operation of this fermenter will be described below. FIG. 1 shows a state of daytime operation, in which automatic valves V1 and V2 are closed and V3 and V4 are opened. By operating the air supply blower 4 in this state, the air from the ventilation chamber 3 is automatically controlled by the automatic valve V.
4 will be sucked in and air will be taken into the sedimentary layer from the surface of the organic waste depositing layer. The air containing the high-concentration odor that has been sucked by the air supply blower after passing through the deposited layer of the organic waste passes through the automatic valve V3 and the deodorizing device 5
Sent to and deodorized. Emission of odor from the surface of the deposited layer is extremely small because air is taken in from the surface of the deposited layer during the deposition, and low-concentration odor in the building 6 is simply taken into consideration in the working environment and the automatic valve V6 is opened to turn the ventilation fan 9 on. It suffices to drive it and release it outdoors, and there is no particular need for deodorizing treatment. Therefore, the automatic valve V5 is closed and the deodorizing fan 8 is not operated.

FIG. 2 shows a nighttime operation state in which the automatic valves V1 and V2 are opened and V3 and V4 are closed. By operating the air supply blower 4 in this state, the automatic valve V1
The fresh air sucked through is sent to the ventilation chamber 3 through the automatic valve V2, and further supplied through the bottom plate 2 from the lower part of the organic waste accumulation layer to the accumulation layer. The air containing the high-concentration odor that has passed through the accumulated layer is sucked from the hood 7 and processed by the deodorizing device 5 by operating the deodorizing fan 8 by opening the automatic valve V5. The automatic valve V6 on the roof of the building 6 is closed and the operation of the ventilation fan 9 is stopped.

In general, a fixed bottom type fermenter often uses an open horizontal fermenter having an open upper surface. Also in the illustrated first embodiment, the open horizontal fermentor 1 is used,
Since the surface area of the tank is large, the odor will diffuse into the building 6. Especially during the daytime, workers often enter the building,
Deodorization measures that combine ventilation are required, and a large amount of ventilation and deodorization processing are required. Therefore, there is also a problem that the deodorizing equipment for odor control becomes large. Therefore, in the illustrated first embodiment, an upward flow air system in which air is supplied from the bottom surface of the fermenter 1 by the air supply blower 4, and air is sucked from the bottom surface of the fermenter tank 1 by the air supply blower 4 to suck air from the surface of the deposition layer. Alternately with the downward circulation air system to take in, the bottom of the sedimentary layer is prevented from becoming dry or overhumid and uniform fermentation is obtained throughout the sedimentary layer. By reducing the odor concentration inside the building, and by performing an upward circulation air system at night when the building becomes unattended, it is possible to minimize the deodorization inside the building. Can be planned.

FIG. 3 shows a second embodiment of the fermentation apparatus according to the present invention, and the method of the present invention can be carried out by modifying the conventional fermentation apparatus described in JP-B-63-27839 shown in FIG. It was done like this. In the figure, the same members as those in FIG. 4 are designated by the same reference numerals, and the description thereof will be omitted.
The fermentation apparatus of the present invention shown in FIG. 3 is different from the conventional apparatus of FIG. 4 in that the blower 23 is equipped with a passage switching means composed of automatic valves V21 to V24 and a duct so that the blower 23 can be installed in the organic waste deposit layer. This is a point that the upflow air and the upflow air are alternately performed. Automatic valve V2 in the second embodiment
The configurations of the ducts 1 to 24 and the duct are the same as the configurations of the automatic valves V1 to V4 and the duct in the first embodiment, and therefore the description thereof will be omitted. When using the downward flow system, automatic valves V21 and V
The blower 23 is operated by closing 22 and opening V23 and V24. As a result, air is taken into the deposition layer from the surface of the deposition layer, and downward airflow as shown by the dotted arrow in the figure is made. The air containing the odor sucked by the blower 23 passes through the automatic valve V23 and is processed by the deodorizing device 25. At this time, the suction blower 24 may be stopped or may be in an operating state. Suction blower 2
When 4 is set in the operating state, part of the air taken into the deposit layer from the deposit layer surface is sucked from the suction blower 24 through the intake pipe 20.

When the upward circulating air system is used, an automatic valve V
21 and V22 are opened and V23 and V24 are closed to operate the blower 23 and the suction blower 24. As a result, the fresh air sucked through the automatic valve 21 is supplied into the sediment layer from the bottom of the sediment layer, is sucked from the suction blower 24 through the intake pipe 20, and thus flows upward in the sediment layer below the intake pipe 20. Qi (solid arrow in the figure) is formed. On the other hand, since the suction blower 24 is in the operating state, downward flowing air (solid line arrow in the figure) from the surface of the deposited layer toward the suction pipe 20 is formed. Therefore, all the odor-containing air flow that has passed through the deposited layer is sucked from the suction pipe 20 and deodorized by the deodorizing device 25, effectively preventing the odor emission from the open surface of the deposited layer. be able to. Although not particularly shown, automatic valves V21 to V24
Switching of is automatically controlled by the timer setting.

In each of the illustrated first and second embodiments, an aeration chamber provided below the fermenter bottom plate having a large number of holes is used as an aeration means, and air is supplied to the aeration chamber. Is introduced or air is sucked from the ventilation chamber to ventilate the organic waste deposit layer in the fermenter. However, the ventilation means in the fermentation apparatus of the present invention is not limited to this, for example, a pipe having a large number of holes bored in the longitudinal direction is arranged near the upper surface of the fermenter bottom plate as the ventilation means, and this pipe is It is also possible to employ a configuration in which air is introduced or sucked through.

Further, in both the illustrated first and second embodiments, the type of fermenter having only one fermenter bottom plate is used. It is also possible to have a type of fermenter in which a plurality of trays are formed.

Further, the passage switching means can be generally constituted by an automatic valve and a duct or a piping system, but as the automatic valve, a damper, a two-way valve such as an electromagnetic type, a hydraulic type, a gas type or a three-way valve is adopted. be able to.

[0022]

As can be seen from the above description, in the present invention, an upward flowing air system in which air is vented upward from the bottom of the organic waste deposit, and a downward air flow in which air is vented from above to the bottom of the deposit. By alternately combining these methods, it is possible to effectively prevent the occurrence of a dry condition at the bottom of the pile, which can be seen only when the air flows upward, and an over-humidity condition at the bottom of the deposit, which can be seen only when the air flows downward. be able to. Therefore, even in a bottom fixed type fermenter where it is difficult to mechanically cut off the bottom of the pile or scrape it off, it is possible to keep the water content of the organic waste sedimentary layer in the fermenter uniform from the bottom to the top of the sedimentary layer. Aerobic fermentation can be performed.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an operating state of a downward circulation air system in a first embodiment of a fermentation apparatus according to the present invention.

FIG. 2 is an explanatory view showing an operating state of an upward circulation air system in the first embodiment of the fermentation apparatus according to the present invention shown in FIG.

FIG. 3 is an explanatory view showing a second embodiment of the fermentation apparatus according to the present invention.

FIG. 4 is an explanatory view showing an example of a conventional bottom fixed fermentation apparatus.

[Explanation of symbols]

 1: Fermenter 2: Bottom plate 3: Ventilation chamber 4: Air supply blower V1 to V4: Automatic valve 22: Bottom plate 23: Blower V21 to V24: Automatic valve

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location C05F 7/00 7537-4H 9/04 7537-4H 17/00 7537-4H C12M 1 / 00H

Claims (2)

[Claims] 1. A method of aerobically fermenting an organic waste in a fermenter equipped with a fixed bottom plate for depositing the organic waste, in which an oxygen-containing gas is upwardly ventilated from the bottom of the organic waste to be aerated. A method for fermenting an organic waste, which comprises alternately performing downward flow air in which an oxygen-containing gas is aerated from above toward the bottom of the organic waste accumulation. 2. A fermenter in which a ventilating means is disposed in the vicinity of a fixed bottom plate for accumulating organic waste, the ventilating means being provided on a discharge side and a suction side of a gas blowing means via a passage switching means switched by a timer. The organic waste is characterized in that the ventilation side and the discharge side of the gas blowing means are communicated selectively and the suction side of the gas blowing means is communicated with the oxygen-containing gas source. Fermentation equipment.