JP2002186943A - Organic waste treatment equipment and method for composting therefrom - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a treatment equipment and a method for obtaining compost with reduced volume by efficiently fermenting and drying organic wastes such as garbage containing a large amount of water at high temperatures and high speed, and also reducing a moisture content efficiently. SOLUTION: The organic waste treatment equipment includes a stirring device, an equipment composed of a fermenter for organic wastes with a heating device and an exhaust opening and a device for discharging waste gas containing moisture from the exhaust opening, an equipment with a device for removing moisture from the waste gas, and further an energy saving equipment for heat-exchanging the waste gas from which the moisture has been removed with the waste gas from the exhaust opening to return to the fermenting device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a facility for treating organic waste such as garbage discharged from homes, restaurants, hotels and the like, and a method for treating and composting organic waste using the facility. About.

[0002]

2. Description of the Related Art Conventionally, organic waste mainly composed of garbage discharged from homes, restaurants, hotels and the like is treated by composting, gasification, etc. in addition to incineration.
Processing such as fermentation processing, decomposition processing, and drying processing is generally performed by a closed processing apparatus equipped with a stirrer. Moreover, in order to start fermentation promptly after charging the raw materials, culture bacteria and fermentation bacteria are charged and the processing speed is significantly increased by heating.
High speed processors have been proposed as an improved process.

[0003] However, such an improved process is also generally a closed type process, so that the organic waste containing a large amount of water does not change quantitatively even after the treatment, and its volume decreases little. In order to feed the raw material, it is necessary to discharge the compost which is the acquired material every time. For this reason, it takes considerable time to input raw materials and take out compost,
Requires human power. Since the volume does not decrease much,
There is a problem to be solved practically that the waste cannot be landfilled and the composting costs high transportation cost. Generally 70% for organic waste mainly composed of garbage.
% Or more, and about 90% in the case of a large amount, and the water content does not change even after fermentation / decomposition, so that the weight and volume are not significantly reduced even after the treatment. In addition, when fermentation is performed by aerobic bacteria, active fermentation is inhibited due to the presence of excess water, and it is difficult to obtain a high processing rate.

In recent years, as a weight-reduction type organic waste treatment apparatus, a treatment apparatus including a fermenter equipped with a dehydration apparatus or a compost manufacturing apparatus equipped with a pretreatment apparatus has been proposed (for example, Japanese Patent Application Laid-Open No. 12-125745). Such). These are used for dehydration treatment by mechanical pressing, and the water content after the treatment is reduced, which is a reduction type treatment.However, polluted wastewater treatment is required, and a large amount of power is required for pressing. There is a problem such as consumption. In addition, a method has been practiced in which sawdust (dust), rice husk, activated carbon, carbide, or the like is charged as a moisture adjusting material for raw garbage. (The same amount), and there are practical problems such as the need to obtain, store, cost, and inject the moisture adjusting material, or require a large apparatus because the processing amount is reduced accordingly. Further, it is an economical problem that a large amount of low-temperature energy generated in the fermenter is not effectively used.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to efficiently remove organic waste such as garbage, paper, sludge, and livestock manure.
An object of the present invention is to provide a facility for performing processes such as a fermentation process and a drying process and a method for composting organic waste. In particular, an object of the present invention is to perform a fermentation treatment and a drying treatment at a high temperature of an organic waste mainly composed of garbage containing a large amount of water at a high temperature, and to reduce the water content efficiently and reduce the volume. An object of the present invention is to provide a fermentation treatment facility and method capable of obtaining compost.

According to the present invention, an organic waste treatment apparatus and method having the following configuration is provided, and the above object of the present invention is achieved. 1. A fermentation treatment tank for organic waste having a stirring device, a heating device, and an exhaust port, and an exhaust device for exhausting waste gas containing water in the fermentation treatment tank through the exhaust port are provided. Organic waste treatment equipment. 2. A fermentation treatment tank for organic waste having a stirrer, a heating device, and an exhaust port, a moisture removal device for removing moisture from waste gas containing moisture from the fermentation treatment tank sent through the exhaust port, and the moisture removal An organic waste treatment facility comprising a deodorizing device for removing harmful odors from waste gas from which water has been removed by the device, and an exhaust device for exhausting the deodorized waste gas. 3. A fermentation treatment tank for organic waste having a stirring device, a heating device, and an exhaust port, a moisture removal device for removing moisture from waste gas in the fermentation treatment bath, and heating the waste gas from which moisture has been removed by the moisture removal device. And a device for circulating waste gas heated by the heating device into the fermentation treatment tank. 4. The organic waste treatment performed in the organic waste treatment facility is a fermentation treatment and a drying treatment, and the obtained material obtained by these treatments is compost, wherein Organic waste treatment equipment. 5. A method for composting organic waste, wherein the organic waste is subjected to a fermentation treatment and a drying treatment while removing water in the fermentation treatment tank to the outside of the system. 6. The composting method according to the above item 5, wherein the fermentation treatment and the drying treatment are performed using the organic waste treatment equipment according to any one of the items 1 to 4.

[0007] By performing the fermentation treatment of the organic waste using the treatment equipment and method of the present invention and performing the drying treatment for removing the water to the outside of the system, the composting can be performed while reducing the weight. The compost capacity is 1/3 to 1/8 of the raw material, and it is not necessary to discharge the entire amount of the compost as a raw material every time for inputting the raw material of the next batch, and the labor can be greatly reduced. Compost transportation costs are reduced.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention provides a method for removing organic water from a fermentation tank at a high temperature and at a high speed while removing water from the fermentation tank. Acquisition is a basic technical idea.
Hereinafter, examples of an organic waste treatment apparatus used in the above technical idea of the present invention and a method of using the same will be described in detail with reference to the accompanying drawings. However, the present invention is not construed as being limited to only the following embodiments, and can take many variations.

(Embodiment 1) FIG. 1 shows a schematic flow sheet showing an example of an organic waste treatment facility (hereinafter simply referred to as "treatment facility"). The treatment facility A includes a hopper 2 for storing and supplying organic waste, and a fermentation treatment tank 3 for fermenting and drying organic waste into compost.
And an exhaust blower 4 as an exhaust device for forcibly exhausting waste gas containing water generated in the fermenter. The fermentation treatment tank 3 has a raw material supply port 5, a stirring device 6 provided with a stirring blade 14 connected to the rotating shaft 13, a heating device 7 for enabling high-temperature and high-speed fermentation, the obtained reduced waste or An outlet 8 for taking out compost and an exhaust port 9 connected to the duct line 10 are provided in the suction device 4. It is desirable that the discharge port 9 be as open as possible at the highest position, since the dust in the fermentation treatment tank 3 will not be sucked.

The shape of the fermentation treatment tank 3 is not particularly limited, but is desirably an inverted conical shape in which the lower part is narrowed. Further, in order to discharge the product efficiently, it is preferable that the outlet 8 is located below. The stirrer 6 is a stirrer having a rotation axis in the vertical direction, but is not limited thereto. The stirrer having a rotation axis in the horizontal direction, or a stirrer that moves while moving the position of the rotation axis, or Various types of stirring devices such as a vortex mixer and a twin-screw extruder can be selected. Above all, a stirrer with a strong torque is desirable. The stirrer 6 shown in FIG.
3. A stirring device having a stirring blade 14 connected thereto and a driving motor 12 near the bottom of the tank is generally used, and can be preferably used. The stirring blade 14 can have various types and various shapes. As a heating method in the heating device 7, a method of directly heating with a nichrome wire buried in the inner wall of the fermentation treatment tank, an electric heater wound along the outer wall, a gas burner, or the like; A heating method such as a method of indirect heating through a jacket or tube attached to the tank wall surface can be used.

As the exhaust device 4, various types of gas transporters such as fans, blowers, blowers, gas compressors and the like can be employed, but the pressure rise is preferably 1000 mmAq to 1 kg.
/ Cm ² , an exhaust blower such as a positive displacement roots blower, a turbo axial flow blower, or a turbo centrifugal blower is generally used.

In practice, it is desirable to use a dustproof blower that is resistant to blockage by dust and dust. If necessary, ordinary dustproof equipment such as a cyclone and a bag filter is installed in the middle of the duct line 10. The line on the exhaust side communicates with a vent 11 which is opened to the atmosphere. In addition, two or more exhaust blowers can be installed in series or in parallel as needed.

Next, a method for treating organic waste using the treatment facility 1 having the above-described structure and shown in FIG. 1 will be described in detail. First, organic waste mainly composed of garbage to be composted is passed through the hopper 2,
It is supplied from a raw material supply port 5 attached to the fermentation treatment tank 3. The raw material usually contains 50 to 90% by mass or more of water. Depending on the nature of the organic waste, various types of crushers can be installed at the top or bottom of the hopper as necessary to reduce the size of the garbage to a predetermined size or less, so that the processing proceeds smoothly. It is effective in doing.

In the fermentation treatment tank 3, a predetermined amount of the reduced compost obtained in the previous batch remains, which contains the necessary fermenting microorganisms and functions as a water conditioner. It is preferable to operate the stirrer and mix both well. The amount of residual compost of the previous batch required here is preferably 5 to 80 kg, more preferably 10 to 50 kg, per 100 kg of fresh raw material.
g. In addition, when the fermentation microorganism is insufficient or when a higher-speed treatment is desired, a fermentation microorganism prepared separately can be added to the compost of the previous batch. As the fermenting microorganism, a low-temperature fermenting bacterium, a high-temperature fermenting bacterium, or the like can be used, but an aerobic high-temperature fermenting bacterium is particularly preferred because of its high processing speed. Next, the organic waste in the tank is sufficiently stirred while being heated by the heating device 7 provided in the fermentation tank 3. The temperature in the tank is controlled to be maintained at 25 to 120 ° C, more preferably at a temperature of about 80 to 110 ° C. The stirring speed is preferably 80 to 150.
rpm, more preferably 100 to 130 rpm.
The freshly charged organic waste is mixed with the remaining compost of the previous batch and the temperature in the tank is approximately 50 ° C.
, Fermentation is actively started by the fermenting microorganisms contained in the compost.

Further, the temperature in the tank gradually rises, fermentation in the tank becomes active, and the temperature of 100 ° C. takes about 90 to 120 minutes.
Reach nearby. After the temperature reaches 100 ° C., the exhaust device (exhaust blower) 4 is operated, and the steam and gas generated in the fermentation treatment tank 3 are forcibly discharged through the exhaust port 9 and discharged to the atmosphere via the vent line 11. Then, the drying process of the organic waste proceeds rapidly, and the amount of compost is reduced.
Here, the pressure in the tank is maintained at a slightly reduced pressure from normal pressure with a water column of -100 to -500 mm. 5 fermentation and drying processes
After 10 to 10 hours, organic waste is reduced to about 1
５〜 to １ ／. New organic waste materials are added to the reduced compost, and high-temperature and high-speed fermentation treatment is repeated several times in the same manner as above, and when the accumulated amount of compost in the tank reaches a predetermined amount, fermentation treatment The compost of the product is taken out through a discharge port 8 provided at the lower part of the inverted cone of the tank 3. The water content of the product compost thus obtained is reduced to 15 to 30% by weight. In addition, the water content of the organic waste raw material is about 50 to 90% by weight.

(Embodiment 2) In this embodiment, in addition to the above-mentioned Embodiment 1, an improvement is made with respect to the treatment of waste gas containing a large amount of water exhausted from the fermentation treatment tank 3 and is more practical. It is an aspect. FIG. 2 shows a schematic flow sheet of the organic waste treatment facility B of the general embodiment. In the middle of a duct line 10 for guiding waste gas from an exhaust port 9 provided in the same fermentation treatment tank 3 as shown in FIG. 1, a water removing device 23 for removing moisture from waste gas.
And deodorizing device 24 for removing harmful odors from waste gas
This is an embodiment for various organic waste raw materials provided with: This will be described below with reference to the flow of FIG.

FIG. 2 shows a water-removing device 13 which is a direct cooling device for spraying and cooling water, which is a gas-liquid contact type cooler such as a multi-stage tray type or a bell bubble tray type. However, the present invention is not limited thereto, and a heat-exchange-type cooler using an indirect cooling method between a low-temperature gas (generally air) or a liquid (generally water) can be used. In FIG. 2, the water in the waste gas is condensed by water circulated by the circulation pump 27 and water sprinkled through the valve 25,
The water is removed from the system as wastewater with the watering. At this time,
It is suitable for simultaneously removing water-soluble harmful gases such as dust, ammonia, and sulfur dioxide contained in waste gas.

On the other hand, the deodorizing device 24 is installed when the waste gas from which water has been removed contains an odorous and harmful gas in excess of the environmental standard and cannot be released to the atmosphere as it is. That is, as the odorous harmful gas generated by the fermentation treatment,
Mixtures of mercaptans, ammonia, hydrogen sulfide and other minor odorous components are included. As the deodorizer, an absorption tower using a liquid absorbent such as an alkaline solution or an acidic solution, an adsorption tower filled with a solid adsorbent, and the like are installed.

The waste gas thus dehydrated and deodorized is discharged to the atmosphere through the vent line 11 by the exhaust blower 4 as described in the first embodiment. In addition, when it is necessary to remove dust and dust contained in the waste gas, a dustproof device such as a cyclone or various filters can be installed.

Next, using the processing equipment 2 shown in FIG.
A method for treating organic waste will be specifically described.
The production of compost by the high-temperature and high-speed fermentation treatment using the fermentation treatment tank 4 is the same as the method of FIG. 1 described above, and further includes a cooling device 23 and a deodorizing device 2 between the exhaust port 9 and the exhaust device 4.
The steam in the waste gas is condensed by cooling, and after confirming safety, the waste gas is removed as wastewater. Further, the waste gas containing a certain bad odor is removed by the deodorizing device 24 and discharged to the atmosphere without harm and odor. FIG. 2 shows a direct water cooling method as a cooling method. Of course, an indirect cooling method can also be adopted.
When the temperature in the fermentation treatment tank reaches 100 ° C., the exhaust device (exhaust blower) 4 is operated, and at the same time, the circulation pump 27 is operated to start circulating water and opening the valve 25 to start water spraying. . During the operation of the exhaust blower 4, the operation of these devices continues to spray cold water in the cooling device 23.

On the other hand, in the deodorizer 24, a known liquid absorbent or a solid adsorbent such as activated carbon is used in order to remove harmful and odorous gases such as mercaptans, ammonia and hydrogen sulfide. The gas before and after the deodorizer is periodically collected and replaced with a new absorbent when the odorous gas starts to leak. As the absorption method, there are a method of spraying and contacting a liquid absorbent, a method of bubbling waste gas with the absorbent, and a method of a plate-type gas-liquid contact method. Further, a known removal method using a solid absorbent / adsorbent can also be used. That is, the waste gas is passed through an adsorption tower filled with a solid adsorbent such as activated carbon, silica gel, alumina or molecular sieves. Activated carbon is most preferably used as the solid adsorbent.

(Embodiment 3) This embodiment is a practical treatment facility that circulates and uses high-temperature waste gas in addition to the treatment tanks of Embodiments 1 and 2 described above. FIG. 3 is a schematic flow sheet showing a processing facility C suitable for a mode of processing organic waste that has taken in heat recovery. A heat exchanger 32 is installed in connection with a circulation line 31 connected to an exhaust port 9 provided in the same fermentation treatment tank 3 as in FIG. 1 or FIG. 2, and is connected via a circulation line 33 connected to the heat exchanger 32. The cooler 13 is installed. A circulation line 34, a blower 36, and a circulation line 35 are installed in the cooler 13 in this order so that the waste gas from which moisture has been removed by the cooling device 13 is introduced into the heat exchanger 32. Connected to exchanger 32. The heat exchanger 32 exchanges heat between the waste gas from the fermentation tank 3 and the waste gas from which moisture has been removed by the cooler 13 to heat the waste gas from which moisture has been removed. The heated waste gas is circulated through a circulating gas inlet 37 provided in the treatment tank 3 to maintain the temperature in the fermentation treatment tank at a high temperature, enabling high-temperature, high-speed fermentation treatment in the treatment tank 3. I do. In order to control the temperature in the fermenter 3, an auxiliary heating device 38 using a gas burner, an electric heater, or the like is provided in the middle of the circulation line 36 to control the temperature of the circulation gas. In addition, a vent line 41 for discharging waste gas to the outside of the system is provided in the circulation line 34 together with the valve 39 in order to return the pressure to around normal pressure when the pressure in the fermentation treatment tank 3 increases. You may.

In this embodiment, the apparatus for circulating the waste gas into the fermentation treatment tank includes circulation lines 31, 33, 3
4, 35, 36, 37 and a blower 40.

Further, if necessary, a deodorizing device (not shown) for removing harmful and odorous gases in the waste gas as in the second embodiment may be provided in the middle of the vent line 31.

A method for treating organic waste using the treatment facility C shown in FIG. 3 will be specifically described. The method of composting organic waste by high-temperature and high-speed fermentation using the fermentation treatment tank 3 is basically the same as the method shown in Embodiment 1, and the cooling device 13 is shown in Embodiment 2. It is on the street. The low-temperature waste gas dehydrated by the cooler 13 is sent to the heat exchanger 32 via the circulation line 34, the blower 40, and the line 35. The circulated waste gas is heated to 65 to 100 ° C. by 70 to 120 ° C. waste gas introduced from the circulation line 31 in the heat exchanger 32, and is passed through the circulation gas line 36 and the circulation gas inlet 37 to the fermentation treatment tank 3. Circulated. At this time, heating is performed to a temperature of 120 to 200 ° C. by the heater 38. Thus fermenter 3
The high temperature and high speed fermentation inside is actively maintained. Further, by controlling the flow rate of the circulating gas and controlling the temperature in the tank to 80 to 110 ° C., the evaporation heat can be assisted by supplying the heat of evaporation of water.

When the fermentation treatment in the tank is completed, the water content of the obtained compost decreases to 15 to 40% by weight,
Compost weight reduction and volume reduction are achieved. The organic waste raw material is supplied from the raw material input port at the top of the fermenter while the compost is left at the bottom, and the process proceeds to the next batch fermentation treatment as in the first embodiment. After repeating the batch several times, when the reduced and reduced volume of compost is full in the fermenter, the compost is discharged from the fermenter through the outlet 8.

[0027]

EXAMPLES Next, it will be shown on an experimental scale that the volume of compost obtained can be greatly reduced by fermentation while removing (drying) water generated from organic waste outside the system.

The procedure was performed according to the flow shown in FIG. However, the equipment used is as follows. (1) Fermentation tank (cylindrical type) Diameter: 100 cm Volume: 570 liter Stirrer: Vertical type, connected to four rotating shafts (2) Exhaust device Blower suction type Restaurant garbage crushed in the fermentation tank 170
One liter (100 kg) was added, 1,000 g of bacteria for fermentation were added, and the fermentation treatment was performed while rotating the stirring device at 130 rpm. After the temperature reached 95 ° C., the exhaust device was operated, and the generated water was discharged out of the system. After performing this operation for 6 hours, the temperature was returned to normal temperature. The capacity of the obtained compost was about 40 liters (20 kg).
For comparison, the same operation was performed without operating the exhaust system, and the resulting compost volume was about 170 liters (1 liter).
00 kg).

According to the above experiment, when composting is performed while discharging water, the obtained compost capacity becomes about 1 /
It can be seen that it decreases to 5.

[0030]

According to the present invention, organic waste (garbage,
In the treatment equipment and composting method for paper, sludge, livestock manure, and the like, treatments such as fermentation and drying are performed under conditions that remove moisture. Further, the present invention includes an embodiment in which heat generated by fermentation is used to maintain the temperature of the fermentation treatment tank at a high temperature. Therefore, the present invention has the following effects. (B) Since the processing speed is high and the weight and volume of the compost of the product are significantly reduced, a large amount of organic waste can be composted in a short time and with a small-scale facility. (B) Compost transportation costs can be reduced. (C) Product compost can be discharged only once in several batches. Therefore, labor and manpower required for the discharging process can be reduced. (D) As a water conditioning material for garbage, the mixing amount of sawdust, husk, etc. can be greatly reduced or sometimes unnecessary. Therefore, the acquisition, storage, cost, and time and labor of the water conditioning material are omitted. (E) The high-temperature waste gas generated in the fermentation treatment tank can be effectively used for vaporizing moisture and raising the temperature of the fermentation treatment tank.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view schematically showing one embodiment of an organic waste treatment facility of the present invention.

FIG. 2 is a schematic explanatory view schematically showing another embodiment of the organic waste treatment equipment of the present invention.

FIG. 3 is a schematic explanatory view schematically showing another embodiment of the organic waste treatment apparatus of the present invention.

[Explanation of symbols]

 A Organic waste treatment equipment B Organic waste treatment equipment C Organic waste treatment equipment 2 Hopper 3 Fermentation tank 4 Exhaust device 5 Garbage inlet 6 Stirrer 7 Heating device 8 Compost outlet 9 Exhaust outlet 10 Duct line 11 Vent line 12 Motor 13 Rotating shaft 14 Stirrer blade 23 Cooling device 24 Deodorizing device 25, 26 Valve 27 Circulating pump 30 Circulating line 31 Circulating line 32 Heat exchanger 33 Circulating line 34 Circulating line 35 Circulating line 36 Circulating line 37 Circulating Gas inlet 38 Heater 39 Valve 40 Blower 41 Vent line

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F26B 11/16 F26B 23/02 21/00 23/06 Z 23/02 B09B 3/00 ZABA 23/06 303M F-term (reference) 3L113 AA07 AC04 AC08 AC23 AC58 AC67 AC87 BA39 CA08 CB03 CB05 DA02 4D004 AA02 AA03 AA04 AC01 BA04 CA15 CA19 CA22 CA42 CA48 CB04 CB26 CB31 CB43 CB44 DA02 DA06 DA09 DA13 4H061 AA41 GG31 CC55 CC36 GG48 GG67 GG70

Claims (6)

[Claims] 1. A fermentation treatment tank for organic waste having a stirring device, a heating device, and an exhaust port, and an exhaust device for exhausting waste gas containing water in the fermentation treatment tank through the exhaust port are provided. An organic waste treatment facility characterized by the following. 2. An organic waste fermentation treatment tank having a stirrer, a heating device, and an exhaust port, and water removal for removing moisture from waste gas containing moisture from the fermentation treatment tank sent through the exhaust port. Organic waste, comprising: a device; a deodorizing device for removing harmful odors from waste gas from which water has been removed by the moisture removing device; and an exhaust device for exhausting the deodorized waste gas. Material processing equipment. 3. A fermentation treatment tank for organic waste having a stirring device, a heating device, and an exhaust port, a moisture removal device for removing moisture from waste gas in the fermentation treatment bath, and moisture removed by the moisture removal device. And a heating device for heating the waste gas, and a device for circulating the waste gas heated by the heating device into the fermentation treatment tank. 4. The organic waste treatment performed in the organic waste treatment facility is a fermentation treatment and a drying treatment, and the obtained material obtained by these treatments is compost. 3. The organic waste treatment equipment according to any one of 3. 5. A method for composting organic waste, wherein the organic waste is subjected to a fermentation treatment and a drying treatment while removing water in the fermentation treatment tank to the outside of the system. 6. The composting method according to claim 5, wherein the organic waste is subjected to fermentation treatment and drying treatment using the organic waste treatment equipment according to any one of claims 1 to 4.