JPH0733573A - Method and apparatus for composting, and rotating drum type fermenter and product storage tank used in this apparatus - Google Patents

Abstract

(57) [Summary] [Purpose] To continuously and efficiently ferment and compost organic exhaust gas without adjusting the water content in advance. [Structure] The highly water-containing organic waste put in the fermenter 5 is stirred and mixed with intermediate compost, and finely crushed,
Change to aerobic condition. Fermenter 5 internal temperature or fermenter 5
The amount of carbon dioxide gas in the exhaust gas discharged from the inside is measured to detect the fermented and composted state of the organic waste in the fermentation tank 5. From this measured value, the air supply amount for making the organic waste into the optimum fermentation and composting state is determined and controlled and supplied into the fermenter 5, and the organic waste is composted and fermented, and along with the fermentation Heat is recovered from the generated hot exhaust gas of high temperature of 60 to 70 ° C to obtain hot water or hot air of 50 to 60 ° C.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composting method and an apparatus for composting highly water-containing organic waste such as household waste, business-related kitchen waste, and a rotary drum type fermenter and a product storage tank used in this apparatus. It is a thing.

[0002]

2. Description of the Related Art As is well known, organic waste includes, for example, household kitchen waste, business establishment kitchen waste, or organic residues discharged from food business establishments, agriculture, forestry and fisheries industries,
These organic wastes generate over 30,000 tons per day. Among these organic wastes, those containing a nitrogen compound that can be decomposed by microorganisms are used as a promising fertilizer raw material for the recovery of the soil fertility of a land thinned by a chemical fertilizer.

By the way, most of the organic waste has a high water content rate of around 80%, and if the water content remains high, the raw material is in an anaerobic condition in which it is difficult to combine with oxygen in the air. Therefore, in order to form the aerobic conditions necessary for composting fermentation, the composting method using organic waste as a raw material adjusts the water content of the organic waste until the water content rate is around 60%. Although composting and fermentation are indispensable, the conventional composting methods have the following problems.

[0004]

Since most of organic waste has a high water content of about 80%, the organic waste, which is a raw material, is in an anaerobic condition in which it is difficult to combine with oxygen in the air. However, if the aerobic conditions necessary for composting fermentation are not formed and the water content is not adjusted, or if the water content adjustment is insufficient, the organic waste cannot be composted.

In order to adjust the water content of an organic waste having a water content of about 80% to a water content of about 60%, a water conditioner (sawdust, rice bran,
It is necessary to add returned compost, zeolite, etc.), but it is difficult to stably supply this moisture conditioner, and the treatment cost is high.

[0006] When an attempt is made to perform composting fermentation by adding a water content adjusting material to reduce the water content rate of the organic waste to around 60%, a large amount of the water adjusting material is required, resulting in a large amount of input material. As a result, the fermentation apparatus becomes large.

There is also a method of adjusting the water content of an organic waste having a water content of about 80% to about 60% by a thermal drying operation, but this method requires high equipment costs and operating costs. It is difficult in terms of practical use.

In the conventional composting fermentation, air is blown to a raw material whose water content is adjusted to about 60% in advance, and the fermentation heat promotes drying of the compost, so that microorganisms such as bacteria and actinomycetes 6 most active water content
The state of about 0% is created only temporarily, and the fermentation decomposition rate decreases as the drying progresses.

In the conventional composting and fermenting apparatus, since the state of fermentation and decomposition is not grasped from the steam and carbon dioxide gas components in the exhaust gas from the fermenter, the composting and fermentation cannot always be continued under the optimal fermentation conditions.

The secondary fermentation centering on microorganisms such as filamentous fungi is also referred to as sedimentary fermentation of compost, but the optimum fermentation conditions cannot be maintained due to insufficient aeration and temperature control,
It takes too long to complete composting.

In the conventional composting device, the exhaust gas from the fermenter is guided to the deodorizing equipment as it is or is released to the atmosphere, and the exhaust heat is not effectively used at all. On the other hand, the moist exhaust gas at a high temperature of 60 to 70 ° C. from the fermenter causes an increase in the amount of water and the temperature in the absorption tower and the biological deodorization tower, which are originally cheap and stable deodorizing methods, and significantly reduces the deodorizing performance. However, there were restrictions on the selection of these deodorizing devices.

The present invention has been made in view of the above-mentioned problems, and it is possible to stably and aerobically dispose of organic waste having a water content of about 80%, which has conventionally been difficult to compost and ferment. Method and composting device and composting device that can ferment fermentative treatment under static conditions and can significantly improve the treatment speed, and can recover the fermentation heat to extract hot water or hot air. It is an object of the present invention to provide a rotary drum type fermenter and a product storage tank that constitute the device.

[0013]

In order to achieve the above object, the composting method of the present invention according to claim 1 is a highly water-containing organic waste having a water content of about 80% introduced into a fermenter. Is stirred and mixed with the intermediate compost having a water content of about 40% retained in the fermenter, finely crushed into fine particles, and the surface area thereof is increased to increase the contact area with air and anaerobically. The fermented and composted state of the organic waste in the fermenter by measuring the temperature in the fermenter or the amount of CO ₂ in the exhaust gas discharged from the fermenter while changing the static state to the aerobic state. Detect and determine from this measured value the amount of air required to bring the organic waste into the optimal fermentation and composting state, and supply the air to the fermentation tank by controlling it to the above required amount. By composting organic waste With fermentation, with each other to the fact that by heat recovery from 60 to 70 ° C. hot wetness exhaust gas generated due to fermentation obtain 50-60 ° C. warm water or warm air.

Further, the composting apparatus of the present invention according to claim 2 stores a fermenter for composting and fermenting the organic waste supplied from the raw material feeder, and an intermediate compost processed by the fermenter. At the same time, the product storage tank for making the fully-ripened compost and the exhaust gas in the steam-saturated state at 60 to 70 ° C. discharged from the fermentation tank is exchanged with water or air to take out hot water or warm air at 50 to 60 ° C. An exhaust gas heat exchanger for cooling the heat-exchanged exhaust gas to 30 ° C. or lower, an absorption tower and a biological deodorization tower for deodorizing the exhaust gas containing ammonia as a main component discharged from the fermentation tank and the product storage tank, Suctioning exhaust gas from the absorption tower, a deodorizing blower for preventing odor leakage from the apparatus and piping from the fermentation tank to the absorption tower, and the exhaust gas discharged from the fermentation tank temperature or the fermentation tank Determine the supply amount from the amount of CO ₂ measurements of air required for the organic waste with optimum fermentation composting conditions, and supply control means for supplying air of the required amount in the fermentation tank I am preparing for it.

Further, in the rotating drum type fermenter according to the third aspect of the present invention, the drum main body which can be intermittently rotated, and the drum main body so as to be rotatable independently of the drum main body are installed in a penetrating manner. A stirrer, a plurality of intermediate compost lifting lifters arranged on the inner wall of the drum body, and a drum for supplying air rich in oxygen to the organic waste containing the intermediate compost accumulated in the drum body. It is composed of an air-supply mother tube inserted from the outside into the main body and a dispersion tube extending in the axial direction of the air-supply mother tube at a predetermined interval.

Further, the product storage tank of the present invention according to claim 4 is provided with an input port for the intermediate compost and an outlet for the fully-ripened compost, and an air supply port and an exhaust port for air necessary for aging and drying the intermediate compost. Inside the main body of the vertical cylindrical storage tank, a screen for separating impurities and non-decomposed substances contained in the compost and a circulation lifter for ensuring good contact between the supplied air and the intermediate compost are installed. However, the ripe compost having a water content of about 30% can be stably taken out.

[0017]

Since the present invention is configured as described above, the water content of the organic waste that is put into the fermenter and is subjected to composting treatment is 120 to 17 times the organic waste input amount per hour.
Since it is mixed with the intermediate compost remaining in the fermenter of 0 times with stirring, and is dried by the air sent into the fermenter, the water content is adjusted and the optimum fermented composting condition is controlled. , Always composting under aerobic conditions.

Further, since air is also sent to the product storage tank for storing the intermediate compost discharged from the fermentation tank to age and dry the intermediate compost, a fully-ripened compost having a water content of about 30% is formed. Therefore, it is possible to grow a large amount of thermophilic microorganisms under aerobic conditions without adjusting the water content of the organic waste in the fermenter before inputting it. Can be made.

Further, at this time, since the malodorous component containing ammonia as a main component in the exhaust gas generated from the organic waste in the fermentation tank is removed by the absorption tower and the biological deodorization tower,
At the same time, the exhaust gas can be deodorized. Further, in the process of cooling the exhaust gas of 60 to 70 ° C. discharged from the fermenter to 30 ° C. or lower and guiding it to the absorption tower, hot water or hot air of 50 to 60 ° C. can be taken out.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on an embodiment shown in the accompanying drawings. FIG. 1 is a flow sheet showing the entire composting apparatus according to an embodiment of the present invention, FIG. 2 is an enlarged view of a fermenter, FIG. 1 (a) is a sectional view of the fermenter, and FIG. a) A sectional view taken along the line aa in FIG. 3, FIG. 3 is a view for explaining a system for controlling and supplying an optimum air amount into the fermenter, and FIG. 4 is an enlarged view of the product storage tank.

In these drawings, 1 is a raw material hoist, 2 is a drum overturning device, and these raw material hoists 1
With the drum overturning device 2, the organic waste accommodated in the drum is unloaded into the raw material receiving hopper 3 and input. Then, the organic waste stored in the raw material receiving hopper 3 is continuously fed into the fermentation tank 5 described later by the raw material feeder 4 arranged at the take-out port of the raw material receiving hopper 3.

Reference numeral 5 denotes a rotary drum fermenter (hereinafter simply referred to as "fermentor") having a highly airtight structure which is insulated by a heat insulating material.
2 (a) and 2 (b), in order to adjust the water content of the organic waste discharged into the drum body 5a by the raw material feeder 4 and the drum body 5a which rotates intermittently. , An agitator 5c attached to a rotary shaft 5b penetratingly provided in the drum body 5a so as to be rotatable independently of the drum body 5a, and an organic waste containing intermediate compost accumulated in the drum body 5a An air supply mother pipe 5d inserted from the outside into the drum body 5a for supplying oxygen-rich air therein, and the drum body 5a of the air supply mother pipe 5d.
It is possible to effectively cut back the organic waste during fermentation by rotating the drum 5a and the dispersion pipe 5e that is installed in an extended manner at a predetermined interval in the portion located in the inside thereof. As described above, the drum main body 5a includes a plurality of intermediate compost lifting lifters 5f arranged on the inner wall thereof.

On both end surfaces of the drum body 5a, there are provided a front hood 5g and a rear hood 5h for supporting the apparatus disposed inside the drum body 5a and maintaining airtightness. In addition, a weir plate 5i is provided inside the rear hood 5h to keep the amount of organic waste held in the drum body 5a constant.

Reference numeral 6 denotes a wet compost conveyor that conveys the wet compost discharged from the fermenter 5.
The wet compost conveyed by is once put into the wet compost feeder 7, and the wet compost feeder 7 puts the wet compost into the product storage tank 8 while keeping the internal pressure balance between the fermentation tank 5 and the product storage tank 8 described later. To do.

Reference numeral 8 denotes a product storage tank for drying the wet compost fed from the wet compost feeder 7 and storing the compost which has been made into a dry product. As shown in FIG. 4, a wet compost input port 8a and a dry product are provided. Inside the vertical cylindrical storage tank main body 8c provided with the take-out port 8b for the converted compost, the wet compost feeder 7 is provided.
Screen 8d for removing impurities and non-decomposed substances such as tableware pieces that are contained in the moist compost fed from, and the separated moist compost and the product storage tank 8 are already dried products. A vertical rotary screw type circulation lifter for forcibly circulating and stirring the dried dry compost and for making good contact with the drying air supplied from the air supply port 8e provided in the storage tank body 8c. 8f is arranged.

8g is an air exhaust port provided in the storage tank body 8c, and the dry compost fine particles scattered from the exhaust port 8g along with the dry exhaust gas are captured and collected by the collector 9.
It is made into a product together with the dried compost extracted from the outlet 8b.

Reference numeral 10 denotes an air supply blower for supplying external air to the fermentation tank 5 and product storage tank 8 described above, and 11 introduces the exhaust gas discharged from the fermentation tank 5 through the exhaust gas duct 11a and takes in it from the outside. It is an exhaust gas heat exchanger that cools exhaust gas by exchanging heat with normal temperature water such as city water and at the same time recovers heat from normal temperature water as hot water.

The deodorizing blower 13 attracts the exhaust gas from the fermentation tank 5 cooled by the exhaust gas heat exchanger 11 and the dry exhaust gas discharged from the product storage tank 8 by the deodorizing blower 13 to remove the malodorous components contained in the exhaust gas. Of these, a water-washing absorption device for preliminarily absorbing and removing ammonia gas by washing with water, and a water-spraying absorption tower 12a
Pump 1 for circulating the water in 2a and spraying it from above
2b and.

Numeral 14 is sent by the deodorizing blower 13 the malodorous components in the exhaust gas from which the ammonia gas has been absorbed and removed by the water washing and absorption device 12, and is absorbed and decomposed by the liquid in which the microorganisms (activated sludge) have grown. The deodorizing tower 14a is a packed bed type deodorizing tower and a pump 14b for circulating the liquid in the deodorizing tower 14a.

The deodorizing blower 13 attracts and sends the exhaust gas from the fermentation tank 5 and the dry exhaust gas discharged from the product storage tank 8 to the water washing absorption device 12 and the microorganism absorption device 14, and at the same time, the fermentation tank 5 and the product storage tank. It also has the function of maintaining a negative pressure in the inside of the cylinder 8.

Further, reference numeral 15 in the drawing is C provided in the middle of the exhaust gas duct 11a and generated by fermentation decomposition.
CO ₂ meter for measuring the concentration of O ₂ gas, 16 ・
17 is the amount of air sent to the fermentation tank 5 and the fermentation tank 5, respectively.
An air volume control damper for adjusting the amount of exhaust gas from the CO ₂ meter 15 according to the instruction, a thermometer 18 for measuring the temperature in the fermentation tank 5, and 19 and 20 for the amount of air sent to the fermentation tank 5 and the exhaust gas heat exchanger 11 respectively. 2 and 22 are thermometers for measuring the temperature of the exhaust gas from the exhaust gas heat exchanger 11 and the ambient temperature of city water such as city water to the exhaust gas heat exchanger 11.

Next, the operation of the above configuration will be described. First, the organic waste having a water content of about 80% contained in the drum can is unloaded by the raw material hoist 1 and thrown into the raw material receiving hopper 3 by the drum overturning device 2. The organic waste supplied from the raw material receiving hopper 3 into the raw material feeder 4 is advanced by the screw in the raw material feeder 4 and continuously and quantitatively fed into the fermenter 5.

The input organic waste is used in the fermentation tank 5
First, the agitator 5c first agitates and mixes with the intermediate compost in the fermenter 5, so that the water content suitable for fermentation is 40 to 60.
Immediately adjusted to%, the air permeability becomes good.

In the fermenter 5, the aerobic fungus is most active due to the self-generated heat caused by the fermentation of the aerobic fungus and the feeding of air controlled to the optimum amount by detecting the state of the fermentation. Fermentation progresses rapidly under the conditions of 60 to 70 ° C. for fermenting and decomposition and high humidity atmosphere (75 to 85%) in the tank, and the ripe wet compost (moisture content of about 40% is obtained in 5 to 7 days).
%). The pathogens in organic waste are 6
It is almost sterilized and killed in the fermenter 5 having a temperature of 0 to 70 ° C.

The state of fermentation in the fermenter 5 is detected by the CO ₂ meter 15 attached to the exhaust gas duct 11a, and the concentration of CO ₂ gas generated by fermentation decomposition becomes 4 to 6% (dry exhaust gas standard). The air volume is controlled by the air volume control dampers 16 and 17 so that The temperature in the fermenter 5 can be detected by the thermometer 18,
Also, the amount of air sent and the amount of exhaust gas are respectively measured by the flow meter
It can be detected by 9 and 20.

The water content discharged from the fermenter 5 is about 4
0% of the wet compost is introduced into the product storage tank 8 by the wet compost conveyor 6 and the wet compost feeder 7. The wet compost that has been put into the product storage tank 8 is first cleaned of foreign substances such as tableware pieces mixed in the raw material organic waste by the screen 8d, and falls into the dry compost stored in the product storage tank 8, Next, it is circulated / stirred together with the dry compost by the circulation lifter 8f, and is dried during circulation / stirring by the air supplied from the lower intake port 8e to become a product compost having a water content rate of about 30%, which is taken out from the take-out port 8b. . The compost particles scattered in the dry exhaust gas discharged from the exhaust port 8g of the product storage tank 8 are captured by the collector 9,
Recovered as product compost.

Since the exhaust gas discharged from the fermenter 5 through the exhaust gas duct 11a at 60 to 65 ° C. contains water vapor having a humidity of 80 to 90% and close to saturation, the exhaust gas heat exchanger 1
When the heat is exchanged at 1 and cooled to 30 ° C. or lower, the steam condenses to generate 7
0 to 80% becomes warm water of 50 ° C or higher and is efficiently recovered. The temperature of the exhaust gas passing through the exhaust gas heat exchanger 11 is detected by the thermometer 21, and the temperature of the recovered hot water is detected by the thermometer 22.

The exhaust gas from the fermentation tank 5 cooled to 30 ° C. or lower by the exhaust gas heat exchanger 11 joins with the exhaust gas from the product storage tank 8 and the like, and then is absorbed in the absorption tower 12a and the deodorization tower 14a.
The ammonia gas, which is a foul-smelling component, and other odorous components are absorbed and removed by being guided to the atmosphere and released into the atmosphere as odorless exhaust gas.

In carrying out the composting method of the present invention, in order to carry out the fermentation at high speed and smoothly, the temperature, water content, air permeability of the feed air, etc. in the fermentation tank 5 of the organic waste to be fermented should be controlled. It is important that the optimum conditions do not fluctuate rapidly, but for this purpose it is effective to satisfy the items listed below.

1. Continuously input organic waste as a raw material for 24 hours. 2. A flexible tube is used as the air dispersion pipe 5e, and the tips of these are smoothly slid into the organic waste that is cut back with the rotation of the drum body 5a, so that the distribution of the air to be sent is evenly distributed. To do.

3. A plurality of lifters 5f having an appropriate angle and height with respect to the inner wall surface of the fermenter 5 are attached in parallel with the rotating shaft 5b, and the organic waste is mixed with the intermediate compost by the rotation of the drum main body 5a to be consolidated. And maintain good ventilation.

4. Rotating the drum body 5a so that the fermentation heat and the fermentation decomposition gas can be discharged continuously by turning back without fluctuation.

As a result of using the apparatus of this embodiment shown in FIGS. 1 to 4 described above, the following results were obtained. The high-speed composting significantly reduces the amount of organic waste, and the product compost can be effectively used as a fully-ripened composting fertilizer with a water content of about 30%.

Even if a dry battery containing a heavy metal is mixed in the organic waste, it is discharged before it is corroded and destroyed by high-speed composting, so that it can be easily separated and the compost safety can be secured. . 90% or more of the organic matter can be decomposed, and the exothermic reaction at this time enables the evaporation of water, so even if the water content of the organic waste is 80%, the water conditioner (sawdust, rice bran,
It can be composted without zeolite).

By not using the moisture conditioner,
It is possible to significantly reduce the amount of organic substances in the garbage (95% or more). Optimum fermentation conditions for the intermediate compost in the fermenter 5 (temperature 65 ° C
In order to maintain the water content before and after 40 to 60%), the CO ₂ concentration becomes high when the water content is low and the CO ₂ content becomes high when the water content is high, with respect to the water content fluctuation of the organic waste to be fed.
₂ Smooth composting is possible by controlling the air flow so that the concentration becomes low.

In the apparatus of this embodiment, the fermenter 5 is thermally insulated.
Since it is hermetically sealed and the amount of supplied air and the amount of exhaust gas are optimally controlled, the exhaust gas from the fermenter 5 is close to saturated steam,
The heat exchange between the exhaust gas and water or air releases the latent heat due to the condensation of water vapor, and heat recovery becomes large. By the way, in this example, 5 kg of water at 20 ° C. was applied to the garbage treatment at 100 kg / day.
1200 kg / day of 0 ° C. warm water was obtained.

Since the inside of the fermenter 5 is in a high temperature and moist atmosphere, it is considered that this moistness works like free water required for fermenting bacteria. Therefore, the fermentation proceeds smoothly with a water content lower than about 60%, which is generally said to be suitable for fermentation. As a result, the water content of the intermediate compost can be reduced, and the intermediate compost can be in a free-flowing state suitable for keeping the properties of the intermediate compost even more aerobic.

[0048]

As described above, according to the present invention,
Even without actively adjusting the water content of high water content organic waste
By adjusting the water content in the fermenter that is continuously charged and detecting the CO ₂ gas concentration in the discharged exhaust gas to adjust the fermentation state, fermentation composting can be performed at a speed 7 to 10 times higher than usual. There is an effect that it can be treated and a stable ripe compost can be obtained, and further, there is an effect that recycling of organic waste such as kitchen waste can be achieved at low cost.

[Brief description of drawings]

FIG. 1 is a flow sheet showing the entire composting apparatus according to an embodiment of the present invention.

FIG. 2 shows an enlarged view of a fermenter, FIG. 2 (a) is a sectional view of the fermenter, and FIG. 2 (b) is a sectional view taken along the line aa in FIG. 2 (a).

FIG. 3 is a diagram for explaining a system for controlling and supplying an optimum air amount into a fermenter.

FIG. 4 is an enlarged view of a product storage tank.

[Explanation of symbols]

4 Raw material feeder 5 Fermenter 5a Drum body 5c Stirrer 5d Air supply mother pipe 5e Dispersion pipe 5f Lifter 8 Product storage tank 8a Input port 8b Outlet port 8c Storage tank body 8d Screen 8e Air supply port 8f Circulation lifter 8g Exhaust port 10 Air supply blower Exhaust gas heat exchanger 12a Absorption tower 13 Deodorization blower 14a Deodorization tower 15 CO ₂ meter 18 Thermometer

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Taizo Imoto 6-2-6 Iwata-cho, Higashi-Osaka City, Osaka Prefecture (72) Inventor Toshiki Miyazawa 5-3-28 Nishikujo, Konohana-ku, Osaka City, Osaka Prefecture Hitachi Shipbuilding (72) Inventor Terumasa Mabuchi 5-3-28 Nishikujo, Konohana-ku, Osaka City, Osaka Prefecture Hitachi Shipbuilding Co., Ltd. (72) Inventor Hiroshi Kanajima 5-28-3, Nishikujo, Konohana-ku, Osaka City, Osaka Prefecture No. Hitachi Shipbuilding Co., Ltd. (72) Inventor Teruo Kusaka 1-4-6 Sakurajima, Konohana-ku, Osaka City, Osaka Prefecture Hitachi Shipbuilding Engineering Co., Ltd.

Claims (4)

[Claims] 1. The water content in the fermenter is 80.
% Of highly water-containing organic waste is agitated and mixed with intermediate compost having a water content of about 40% retained in the fermenter, finely crushed and atomized to increase the surface area of the air. By changing the anaerobic state to the aerobic state by increasing the contact area with the organic substance in the fermentation tank by measuring the temperature in the fermentation tank or the CO ₂ amount in the exhaust gas discharged from the fermentation tank, Of fermented composting of organic waste, determine the amount of air required to bring the organic waste into the optimal state of fermented composting from this measured value, and supply air to the above required amount By controlling the temperature to be supplied to the fermentation tank, the organic waste is composted and fermented, and heat is recovered from the high-temperature moist flue gas of 60 to 70 ° C., which is generated by the fermentation, to obtain hot water of 50 to 60 ° C. Or getting warm air Composting method characterized. 2. A fermentation tank for composting and fermenting the organic waste supplied from the raw material feeder, and a product storage tank for storing the intermediate compost processed by the fermentation tank and making it a fully-ripened compost. , 60-70 ° C discharged from the fermenter
Exhaust gas heat exchanger for exchanging the steam-saturated exhaust gas with water or air to take out hot water or hot air of 50 to 60 ° C. and cooling the heat-exchanged exhaust gas to 30 ° C. or lower, the fermentation tank and the product Absorption tower and biological deodorization tower for deodorizing exhaust gas mainly composed of ammonia discharged from the storage tank, and sucking exhaust gas from the absorption tower, from the apparatus and piping from the fermentation tank to the absorption tower Deodorizing blower to prevent odor leakage, and necessary to make organic waste into an optimal fermented composting state based on the temperature in the fermentation tank or the measured value of CO _{2 in} the exhaust gas discharged from the fermentation tank. And a supply control means for supplying the required amount of air into the fermentation tank. 3. A drum body which can be intermittently rotated, an agitator installed through the drum body so as to be rotatable independently of the drum body, and an agitator provided on the inner wall of the drum body. A plurality of intermediate compost lifting lifters, and an air-supply mother tube inserted from the outside into the drum main body to supply oxygen-rich air into the organic waste containing the intermediate compost accumulated in the drum main body, and A rotary drum type fermenter, which is composed of a dispersion pipe extending in a predetermined interval in the axial direction of the air supply mother pipe. 4. The inside of a vertical cylindrical storage tank main body provided with an inlet for intermediate compost and an outlet for fully-ripened compost, and an air inlet and an outlet for air necessary for aging and drying the intermediate compost. In addition, a screen for separating impurities and non-decomposed substances contained in the compost, and a circulation lifter for making good contact between the supplied air and the intermediate compost are provided, and the moisture content is stable at 30%. A product storage tank that is configured so that it can take out ripe compost of around 10%.