JP2000061432A - Organic waste treating method and device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable the continuous and efficient refining of organic wastes in which impurities are mixed and to easily miniaturize a device therefor. SOLUTION: Soft impurites are successively separated and removed with a trommel from crushed products, which are produced by successively crushing impurities-incorporating organic waste into pieces of 2 cm to 4 cm in size with a biaxial crushing equipment. The crushed products are successively charged into a refining vessel 3 together with a circulating refining liq. The crushed products are agitated and mixed with a pulper type screw agitator 4 while being heated, thereby refining the mixture to a slurried refined product 5 having a percentage of water content of about 85% and a solubilization rate of about 85%. The refined product 5 is made to successively and spirally flow into a separation vessel 8 by gravity, thereby separating and removing the heavy impurities while being washed. A portion of the supernatant refining liq. is returned to the refining vessel 3 for circulation by properly supplying water from a water supply pipe 21 with a circulating means 20, and the remainder is carried away to a methane fermentation treating vessel. The continuous treatment is available, the refining vessel 3 is miniaturized and efficient refining is ensured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic waste treatment method and apparatus for conditioning organic waste to a predetermined water content for methane fermentation treatment.

[0002]

2. Description of the Related Art Garbage, garbage, marine product processing waste, human waste,
When methane fermentation treatment of organic waste such as sewage sludge and septic tank sludge, in order to efficiently perform methane fermentation treatment,
Predetermined water content, for example 85% -90% water content
It is necessary to add water to the organic waste in advance with stirring so that the content becomes about 100%, and to condition the slurry into a slurry with a solubilization rate of 85% or more.

That is, in the treatment of organic waste, which is a pretreatment of conventional methane fermentation treatment, for example, as shown in FIG. 10, a crushing device 32 such as a hammer mill for feeding organic waste such as kitchen waste by a supply conveyor 31. This crushing device 32
After transporting the organic waste crushed by the conveyor 33 to a sorting device 34 such as a trommel to remove light contaminants, the transport conveyor 35 is a stirring device having a hanging stirring blade.
Conveying pump 37 to the conditioning tank 37 equipped with 36, mixing and agitating while adding water appropriately, conditioning and conditioning the organic waste.
Configuration for carrying out to methane fermentation tank at 38, or FIG.
As shown in FIG. 4, the organic waste conveyed by the supply conveyor 41 is crushed by a crushing device 42 such as a screw mill, and the crushed organic waste is conveyed by a palpa-type stirring device 44 by a transfer conveyor 43. Various methods are known, such as transporting to the equipped tempering tank 45, stirring and mixing while appropriately adding water, conditioning, and carrying out the tempered organic waste to the methane fermentation tank with the carrier pump 46. Has been.

[0004]

By the way, the organic wastes such as the above-mentioned kitchen wastes and kitchen wastes include light impurities such as vinyl bags, styrene plates, papers, and metal pieces, glass pieces, pebbles, Heavy impurities such as shells are mixed.
Due to the mixed contaminants, there are problems such as clogging during the process of treating the organic waste, damage to the transportation device, and decrease in the efficiency of methane fermentation treatment. Therefore, in the above-described various conventional processes shown in FIGS. 10 and 12,
Contaminants are removed in advance before the methane fermentation treatment.

Therefore, in various conventional treatments, when water is added to the organic waste while stirring and mixing the organic waste,
The organic waste must be treated in batches corresponding to the volume of the tank in which the organic waste is conditioned, and there is a problem that the organic waste cannot be treated continuously and efficiently in a sequential manner.

In view of the above-mentioned problems, the present invention provides a method and an apparatus for treating organic waste, which can continuously and efficiently condition the organic waste mixed with contaminants and can be easily miniaturized. To aim.

[0007]

According to a first aspect of the present invention, there is provided a method for treating an organic waste, wherein the organic waste mixed with the contaminant is stirred and mixed, and the contaminant is removed to adjust the water content to a predetermined amount. In the method for treating an organic waste, which performs the conditioning for the methane fermentation treatment by the method, water is added to the organic waste and is circulated and mixed while being stirred and mixed to perform the conditioning.

Then, water is added to the organic waste mixed with contaminants so that a predetermined water content is obtained, and the organic waste is circulated while stirring and mixing, so that the methane fermentation treatment is performed. Even if waste is input, it is conditioned in a substantially uniform manner in a short period of time. It is not necessary to improve the quality, and the organic waste can be continuously and efficiently conditioned.

The method of treating organic waste according to claim 2 is
In the method for treating organic waste according to claim 1, the circulation is to withdraw the organic waste that is being stirred and mixed and return it to the upper portion where new organic waste is input.

[0010] Since the organic waste that has been stirred and mixed is withdrawn from the lower part and returned to the upper part where new organic waste is input and circulated, a substantially uniform tempering is facilitated in a short time. .

The method for treating organic waste according to claim 3 comprises:
The method for treating organic waste according to claim 1 or 2, wherein the circulating organic waste is crushed.

Since the circulating organic waste is crushed, substantially uniform conditioning can be easily performed in a short time.

The method for treating organic waste according to claim 4 comprises:
In the method for treating organic waste according to any one of claims 1 to 3, water is added to the circulating organic waste.

Further, since water is added to the circulating organic waste to adjust the water content to a predetermined amount, it is possible to easily adjust the temperature to be substantially uniform in a short time.

The method for treating organic waste according to claim 5 is
The method for treating organic waste according to any one of claims 1 to 4, wherein impurities are removed before the organic waste is conditioned.

[0016] Further, in order to remove impurities mixed in advance before conditioning the organic waste, the energy for stirring and mixing and circulation during the conditioning can be used for conditioning the organic waste without loss. And can be refined efficiently.

The method for treating organic waste according to claim 6 is
The method for treating organic waste according to any one of claims 1 to 5, wherein contaminants are removed before the conditioned organic waste is subjected to methane fermentation treatment.

[0018] Then, in order to remove the contaminants which are mixed in before the conditioned organic waste is subjected to the methane fermentation treatment, the condition that the separability between the organic waste and the contaminants is increased by the conditioning is considered. The contaminants can be removed efficiently and easily, the energy for the subsequent methane fermentation treatment can be used without loss, and the load of the methane fermentation treatment can be reduced, which improves the efficiency of the methane fermentation treatment. Is improved.

The method for treating organic waste according to claim 7 is
In the method for treating organic waste according to claim 5 or 6, the water to be added is cleaning waste water obtained by cleaning contaminants.

Since the cleaning wastewater obtained by cleaning the removed contaminants is used as the water to be added at the time of conditioning, a step of separately treating the cleaning wastewater is unnecessary, and the contaminants are removed by adhering to the contaminants. The organic waste is efficiently methane-fermented without being discharged to the outside as a cleaning wastewater, and the water is effectively used to improve the treatment efficiency.

The organic waste treatment device according to claim 8 is:
A storage tank for storing organic waste mixed with contaminants, a stirring means provided in the storage tank for stirring and mixing the organic waste, and a circulation provided in the storage tank for circulating the organic waste. Means, and water supply means for adding water to the organic waste.

Then, water is added to the organic waste mixed with the contaminants stored in the storage tank by the water supply means so as to have a predetermined water content, and the circulating means is stirred and mixed by the stirring means. Since it is circulated and conditioned for methane fermentation treatment, even if organic waste is sequentially fed to the storage tank, it is conditioned in a short time and evenly, so for example, increase the volume of the storage tank. It is not necessary to retain the organic wastes that are sequentially charged for a long period of time to prepare a substantially uniform mixture, and it is possible to continuously and efficiently prepare the organic wastes.

The organic waste treatment device according to claim 9 is:
9. The organic waste treatment device according to claim 8, wherein the storage tank has a charging port into which the organic waste is charged and which is opened at the top.
The circulation means draws out the organic waste from the bottom of the storage tank and returns the drawn organic waste to the upper part of the storage tank.

Then, a circulation means for opening an input port for inputting the organic waste to the upper part is used to pull out the organic waste from the bottom part of the storage tank and open an input port for inputting the organic waste in the storage tank. Since it is returned to the upper part, it is easy to perform uniform heat treatment in a short time.

According to a tenth aspect of the present invention, in the organic waste treatment apparatus according to the eighth or ninth aspect, the circulation means is provided with a crushing means for crushing the organic waste. .

Since the circulation means is provided with the crushing means for crushing the organic waste, the substantially uniform conditioning can be facilitated in a short time.

The organic waste treatment apparatus according to claim 11 is the organic waste treatment apparatus according to any one of claims 8 to 10, wherein the water supply means is provided in the circulation means.

Since the circulating means is provided with the water supply means for adding water to the organic waste to adjust the water content to a predetermined amount, substantially uniform heat adjustment is facilitated in a short time.

An organic waste treatment apparatus according to a twelfth aspect of the present invention is the organic waste treatment apparatus according to any one of the eighth to eleventh aspects, which removes contaminants from the organic waste put into the storage tank. It is equipped with a screen means.

Since the organic waste to be put into the storage tank is previously removed of contaminants by the removing means, the energy for stirring and mixing by the stirring means and the circulation by the circulation means at the time of refining is not lost. It is used for refining organic waste and can be refined efficiently.

An organic waste treatment apparatus according to a thirteenth aspect is the organic waste treatment apparatus according to any one of the eighth to twelfth aspects, wherein contaminants are obtained from the tempered organic waste in the storage tank. It is equipped with a means for removing contaminants.

Since contaminants mixed in by the contaminant removing means are removed from the organic wastes that have been conditioned in the storage tank, the qualification increases the separability of the organic wastes and the contaminants. The contaminants can be removed efficiently and easily, the energy for the subsequent methane fermentation treatment can be utilized without loss in the methane fermentation treatment, and the load of the methane fermentation treatment can be reduced. The efficiency of the fermentation process is improved.

The organic waste treatment apparatus according to claim 14 is the organic waste treatment apparatus according to claim 13,
The foreign matter removing means is provided in the circulation means.

Since the foreign matter removing means is provided in the circulating means, the circulating organic waste passes through the foreign matter removing means a plurality of times to efficiently remove the foreign matter.

The organic waste treatment apparatus according to claim 15 is the organic waste treatment apparatus according to claim 13,
The storage tank is provided with an opening for discharging the conditioned organic waste, and the contaminant removing means is provided with a screen for closing the exhaust opening.

Since the outlet for discharging the conditioned organic waste is closed and the screen for the foreign matter removing means is provided, when the conditioned organic waste is carried out to the subsequent methane fermentation treatment. Contaminants mixed in by the screen are removed, and the device can be downsized.

An organic waste treatment apparatus according to a sixteenth aspect is the organic waste treatment apparatus according to any one of the twelfth to fifteenth aspects, further comprising a cleaning means for cleaning the removed contaminants, and a water supply means. Is for using the cleaning wastewater generated by the cleaning means as water to be supplied for adjusting the amount of water.

Since the water supply means uses the cleaning waste water generated by cleaning the impurities removed by the cleaning means as the water supplied for adjusting the amount of water, there is no need to separately process the cleaning waste water. Therefore, the organic waste that has adhered to the contaminants and is removed is efficiently methane-fermented without being discharged out of the system as cleaning wastewater, and the water is effectively used to improve the treatment efficiency.

[0039]

BEST MODE FOR CARRYING OUT THE INVENTION The configuration of an embodiment of the organic waste treatment apparatus of the present invention will be described below with reference to the drawings.

In FIG. 2, reference numeral 1 denotes a crushing device as a crushing means. This crushing device 1 is an organic waste, that is,
Kitchen waste such as garbage, human waste water such as human waste and septic tank sludge, organic industrial waste such as food processing sludge, wastewater containing organic substances such as village drainage, sewage sludge, livestock excrement, etc. Not equipped with a biaxial crusher. This biaxial crusher is set to have a pair of rotary shafts so that a plurality of crushing blades integrally provided at a pitch of 2 cm to 4 cm are superposed in the axial direction. That is, when the pitch of the crushing blade is narrower than 2 cm, the shape of light foreign substances such as vinyl materials, styrene containers, plastic materials, and paper, and organic substances such as vegetable waste, which are raw garbage, are similar, and in the subsequent process. The solid-liquid separability of foreign substances and organic waste from
Processing efficiency decreases. Also, if the pitch of the crushing blade is wider than 4 cm, the crushing state of organic waste such as root vegetables will be insufficient and the tempering property in the subsequent process will deteriorate, so the pitch of the crushing blade is 2 cm or more 4 cm. Set as follows.

The biaxial crusher crushes the organic waste to about 2 cm to 4 cm by crushing the organic waste, and the light contaminants such as vinyl and plastic are crushed into a slightly larger string. Crush into pieces.

The biaxial crusher is connected with a trommel which is a separating device 2 as a removing means. This trommel is a substantially cylindrical shape into which the organic waste crushed by the biaxial crusher is put on the inner peripheral side, for example, from the mesh size which is the pitch dimension when crushing the biaxial crusher. A plurality of through holes are provided with a slightly larger size of 2 cm to 8 cm.
Further, the axial direction is arranged so as to be inclined with respect to the horizontal direction by about 2 ° to 10 °. And, Trommel passes through the through hole and the crushed organic waste that cannot pass through the through hole and the light impurities such as styrene tray pieces, plastic pieces, vinyl pieces, etc. Separation into crushed items such as crushed vegetable waste and other heavy objects.

If the width of the trommel mesh is less than 2 cm, most of the crushed organic waste is discharged as impurities, and it becomes impossible to obtain organic matter for methane fermentation treatment in a later step. In addition, if the mesh width is larger than 8 cm, it becomes impossible to separate and remove the impurities by passing through the through-holes even to lightweight impurities such as string-shaped vinyl pieces, so that the mesh width should be 2 cm to 8 cm. Set. Further, if the inclination is less than 2 °, the sequentially crushed organic wastes cannot move on the inner peripheral side of the trommel, and cannot be separated into foreign matters and crushed materials. Also, the inclination is 10 °
If it is larger than this, the slope becomes steep, and the organic waste thrown into the inner peripheral side immediately passes, and the contaminants and the crushed substances can hardly be separated and discharged as contaminants.
Set to 10 °.

Since the trommel has a simple cylindrical shape and has no member projecting on the inner peripheral surface, the crushed material passing on the inner peripheral side is caught by the projecting member and the through hole is closed to contaminate it. It is possible to prevent the separability between the crushed material and the crushed material from decreasing, the deterioration of the processing efficiency due to the impaired passage on the inner circumference side, and the generation of odors and harmful insects such as maggots due to the crushed crushed material. Can be suppressed. The removed impurities are processed into, for example, solid fuel.

Further, the trommel is connected to a refining tank 3 as a refining means which is a storage tank for storing organic waste and refining it into a refined material. Then, as shown in FIG. 1, in the tempering tank 3, for example, 2 to 10 kw / as a stirring means for stirring and mixing the charged crushed material to a predetermined solubilization rate, for example, a solubilization rate of 85% or more. One pulper-type screw agitator 4 which is a pulper-type agitator having an agitation capacity of m ³ and capable of agitation even when the agitation resistance is large is provided, and a heating means (not shown) for heating the crushed material that has been input. Is provided.

The solubilization rate is the rate at which it passes through a 10 mm mesh sieve, and when the solubilization rate is less than 85%, it is due to COD which is an organic substance that is decomposed during the subsequent methane fermentation treatment to produce methane. This is because the amount of organic substances used is greatly reduced and efficient methane fermentation treatment cannot be performed.
Further, the heating means may not be provided, but it may be provided in order to promote the acid fermentation at the time of tempering and improve the efficiency of the methane fermentation treatment in the subsequent step.

In the upper part of the tempering tank 3, there is formed an opening (not shown) into which a crushed material from which light impurities have been removed is charged. Further, for example, the crushed material is stirred and mixed in the bottom of the tempering tank 3 while heating for 30 minutes or more, the acid fermentation is slightly advanced by the heating, and the crushed material is cut into a slurry by stirring. A discharge port (not shown) for discharging the refining product 5 stored therein is formed. At this discharge port, a transfer pipe 7 as a discharge passage having a first opening / closing valve 6 is inclined about 30 degrees in the axial direction with respect to the horizontal direction, and the tempered material in the tempering tank 3 is Are connected in a substantially tangential direction to the peripheral surface of the bottom of the tempering tank 3 so as to be discharged in a vortex shape by gravity.

Further, a substantially cylindrical separation tank 8 is connected to the lower end of the transfer pipe 7 as a foreign matter removing means. The connection between the transfer pipe 7 and the separation tank 8 is such that the axial direction of the transfer pipe 7 is along a substantially tangential direction of the peripheral surface of the separation tank 8 and is separated in the vortex flow direction of the tempered product 5 discharged from the tempering tank 3. The transfer pipe 7 is connected to the upper part of the peripheral surface of the separation tank 8 so as to flow into the tank 8 in a spiral shape.

At the bottom of the separation tank 8, there is provided a funnel-shaped settling section 9 whose diameter is reduced downward. Further, a cleaning water supply pipe 10 as a cleaning means for supplying water is connected to the separation tank 8. The washing water supply pipe 10 is branched into two branches, one of which is tangentially connected to the middle portion of the separation tank 8 so as to supply water to the refining material 5 which has flowed in along the vortex flow direction for washing, and the other of which precipitates. In order to wash the heavy impurities such as glass pieces, metal pieces, pebbles, and shells mixed in the tempered material 5 precipitated in the portion 9 with water along the vortex direction, the precipitation portion 9 is washed. Connected tangentially. And
A foreign matter discharge pipe 12 having a second opening / closing valve 11 is connected to the bottom of the precipitation unit 9. In addition, the removed impurities are
It is processed into building materials and landfilled.

Further, the separation tank 8 is connected to a discharge pipe 16 having a third opening / closing valve 14 and a discharge pump 15. One end of the carry-out pipe 16 is opened substantially in the center of the separation tank 8,
The other end is provided outside and provided to the outside of the separation tank 8 as a refining liquid which is a supernatant obtained by precipitating and separating impurities from the refining product 5. The carry-out pipe 16 has one end open above the settling portion 9 of the separation tank 8 at a position of 2/3 or less, preferably 2/3, below the upper end of the separation tank 8. That is, the refining liquid can be discharged without entraining the contaminants that settle in the settling section 9, and one end of the carry-out pipe 16 is located at a position where the contaminants are sufficiently settled and separated from the refining substance 5 that spirally flows in from the transfer pipe 7. Connect.

Further, one end of the unloading pipe 16 is connected between the third on-off valve 14 and the unloading pump 15, and the other end is connected to the inlet of the tempering tank 3 in communication therewith. A circulation pipe 19 with 18 is connected. Then, the transfer pipe 7, the separation tank 8, the carry-out pipe 16 and the circulation pipe 19 of the tempering tank 3 constitute a circulation means 20 for returning the tempering liquid to the tempering tank 3 for circulation. The circulation of the conditioning liquid has a flow rate of 0.5.
m / sec or less. That is, when the circulation flow velocity is higher than 0.5 m / sec, the removal rate of heavy contaminants is greatly reduced.

Further, water is added to the circulation pipe 19 which constitutes the circulation means 20 so that water is added to the refining liquid to be circulated so that a predetermined water content, for example, water content becomes 85% to 90%. A water supply pipe 21 as a means for supplying water is connected. If the water content is less than 85%, it becomes difficult to stir and convey to the subsequent step and the decomposability of organic substances during methane fermentation decreases, and if the water content exceeds 90%, the concentration decreases and the subsequent step. The water content is set to about 85% to about 90% because the efficiency of the methane fermentation in the method decreases.

Then, the carry-out pipe 16 is connected to a methane fermentation tank (not shown) for methane-fermenting the adjusted liquid which is not circulated by the circulation means 20.

Next, the operation of the above embodiment will be described with reference to the drawings.

First, the collected organic waste is crushed by the biaxial crusher of the crusher 1 to about 2 cm to 4 cm. In addition, organic matter such as vegetable scraps in organic waste is 2 cm.
It is crushed to about 4 cm, and lightweight impurities such as vinyl and plastics are crushed to a slightly larger string.

The crushed organic waste is
The light impurities contained in the trommel of the sorting device 2 in sequence and crushed in a string shape cannot pass through the holes of the trommel, and are discharged from the inner circumference side of the trommel as impurities, and are about 2 cm to 4 cm. The organic matter crushed in step 1 passes through the through hole and is recovered as crushed matter, and is separated into foreign matter and crushed matter. The foreign matters are separately processed into solid fuel or incinerated.

Further, the crushed material is sequentially charged together with the refining liquid circulated in the refining tank 3 so that the solubilization rate becomes about 85% or more, for example, for 30 minutes or more by a heating means (not shown). While being heated, the mixture is stirred and mixed by the pulper type screw stirrer 4 to be refined into a slurry-like refined material 5.

Next, the refining product 5 is sequentially discharged from the refining tank 3 by its own weight through a discharge port, and sequentially flows into the separation tank 8 through the transfer pipe 7 in a spiral shape. Due to the vortex flow of the tempering material 5, heavy and heavy impurities are located on the inner peripheral surface of the separation tank 8 on the outer peripheral side for the tank, and the remaining light and light impurities and organic materials are located on the center side. The heavy contaminants gradually settle in the sedimentation section 9 at the bottom of the separation tank 8, and the organic matter and the light contaminants form a vortex at the center of the vortex.

Then, water is appropriately supplied from the cleaning water supply pipe 10 of the cleaning means along the vortex flow direction to wash the heavy contaminants settling in the settling section 9 to wash away the attached organic substances and light contaminants. It winds up in a vortex and separates adhering organic matter and light impurities. The water supplied as the cleaning water is supplied within the range of the above-mentioned predetermined water content. Then, the heavy impurities that have settled in the settling unit 9 are discharged through the foreign matter discharge pipe 12 by opening the second opening / closing valve 11, and are separately used as a building material or landfilled.

Further, the conditioning liquid, which is the supernatant liquid forming the vortex, is successively carried out of the separation tank 8 from the carry-out pipe 16 by driving the carry-out pump 15, and a part thereof is driven by the circulation pump 18 to make the circulation pipe 19 Is sequentially returned to the refining tank 3 via the tank and circulated, and the rest is sequentially conveyed to the methane fermentation tank for methane fermentation treatment.

The conditioning liquid circulated through the circulation pipe 19 is appropriately supplied with water from the water supply pipe 21 so as to be conditioned to the conditioning liquid having the above-mentioned predetermined water content.

Next, the operation of the above embodiment will be described with reference to the drawings.

First, using a biaxial crusher having a crushing blade pitch of 2 cm, the garbage that is an organic waste obtained from a food supply center and a caterer is crushed into a crushed product, and the crushed product has a volume of about 4 It is put into the conditioning tank 3 of 0.5 m ³ and the water content is 85%.
Water was added so that the mixture was appropriately stirred with a pulper type screw stirrer 4 having a stirring capacity of 5 kw / m ³ to prepare a tempered product 5 having different solubilization rates. The results are shown in Table 1 and FIG.

[0064]

[Table 1] From the results shown in Table 1 and FIG. 3, the solubilization rate was 75.
When it exceeds%, the COD _Cr recovery rate rapidly increases, and even when the solubilization rate becomes higher than 85%, the COD _Cr recovery rate does not change much. Then, in the methane fermentation treatment, the amount of methane gas decomposed and produced is 0.35 liter (CH ₄ ) / g COD _Cr , and the production amount is almost determined by the COD amount. Therefore, it can be seen that the methane fermentation treatment can be efficiently performed by setting the solubilization rate at which the increase in COD _Cr recovery rate is not expected to be 85% or more.

For stirring and mixing during tempering, the conventional hanging screw stirrer and pulper type screw stirrer 4 are used.
And were used to measure the time until a similar solubilization rate was obtained. The results are shown in Table 2.

[0066]

[Table 2] From the results shown in Table 2, the pulper type screw stirrer 4
In case of using, the tempered product 5 having a better solubilization rate in a shorter time
It can be seen that the heat treatment can be performed in a short time, and the further circulation can be performed in a shorter time.

The relationship between the pulper type screw agitator 4 and the circulation is shown in Table 3 and FIG.

[0068]

[Table 3] From the results shown in Table 3 and FIG. 4, even if the same pulper-type screw stirrer 4 is used for stirring and mixing, the solubilization rate increases substantially uniformly as the stirring time elapses when no circulation occurs. However, in the case of circulation in the present example, the solubilization rate greatly increased as the stirring time passed until the stirring time reached 30 minutes, and when the stirring time exceeded 30 minutes, the solubilization rate did not increase so much. Therefore, it can be understood that the refining product 5 having a good solubilization rate can be prepared by stirring and mixing with the pulper type screw agitator 4 while circulating for 30 minutes or more.

On the other hand, the relation between the inflow rate of the refining material 5 into the drum screen and the removal rate of the contaminants was measured when removing particularly heavy contaminants with the drum screen. The results are shown in Table 4 and FIG.

[0070]

[Table 4] From the results shown in Table 4 and FIG. 5, the removal rate of contaminants in the case of circulation is better than 10% or more as compared with the case of non-circulation, and when the inflow velocity exceeds 0.5 m / sec, it rapidly increases. It was found that the removal rate of impurities was reduced. In the case of this embodiment, since continuous processing is possible,
As in the embodiment shown in FIGS. 1 and 2, the circulation flow velocity in the separation tank 8 into which 100% of the refined material 5 flows is 0.
It is understood that the impurities can be removed efficiently by setting the speed to 5 m / sec or less.

Next, using the kitchen waste as an organic waste, the relationship between the time schedule and the scale of the equipment when conditioning 20 t / day of the organic waste within the working hours from 9 am to 5 pm Will be described. The actual processing ends by 4 pm, and the remaining 1 hour is used as a spare time such as cleaning up. The solid content of the kitchen waste is about 20 wt%. Further, as the temper, the water content is about 85% and the solubilization rate is about 85%.

As a structure for processing one batch per day, the structure shown in FIG.
It is conveyed to a crushing device 32 such as a hammer mill by 31, and the kitchen waste crushed by the crushing device 32 is conveyed to a sorting device 34 such as a trommel by a conveyor 33 to remove light contaminants, and then to a conveyer conveyor 35. And then the mixture is conveyed to a tempering tank 37 equipped with a stirrer 36 having a hanging type stirring blade having a stirring capacity of ³ kW / m ^{3, and} the mixture is stirred and mixed while appropriately adding water, and the tempered material is conditioned. Is used to transport the kitchen waste to the methane fermentation tank by the transport pump 38.

Further, as a constitution for processing in two batches per day, the constitution shown in FIG. 12, that is, the garbage conveyed by the supply conveyor 41 is crushed by the crushing device 42 such as a screw mill, and the crushed garbage is conveyed. 5kW / m ^{3 on} conveyor 43
Conditioning tank equipped with pulper type stirring device 44 having the stirring ability of
A configuration is used in which the material is conveyed to 45, stirred and mixed while appropriately adding water, and conditioned, and then the conditioned waste, which is a conditioned material, is conveyed to a methane fermentation tank by a conveyance pump 46.

Further, as a continuous treatment, a drum screen 23 and a screw press 24 as foreign matter removing means are provided in place of the separation tank 8 of the embodiment shown in FIGS. 1 and 2, that is, FIG. As shown in FIG. 2, a drum screen 23 for removing impurities in the tempered material 5 is connected to the transfer pipe 7 led out from the tempered material tank 3, and sludge components generated by solid-liquid separation on the drum screen 23 are further added. A configuration is used in which a screw press 24 for solid-liquid separation is connected, and the filtrate that has been solid-liquid separated by solid-liquid separation by the drum screen 23 and the screw press 24 is carried out to the methane fermentation treatment tank while partly circulating. The stirring capacity of the pulper type stirring device is the same in the configuration shown in FIG. 6 and the configuration shown in FIG.

Then, in order to finish the conditioning within one working hour with the apparatus having the structure shown in FIG. 10, as shown in FIG. 11, the conditioning is completed by 3:30 pm. In order to obtain a tempered product 5 having a predetermined property,
It is necessary to stop the input of kitchen waste by 2:00 and start the conditioning at 10:30 am. Therefore, in order to treat the garbage of 20 t / day, 6.7 t / H is required. In addition, kitchen waste with a solid content of 20 wt% has a water content of 85
When water is added so that the amount becomes%, the amount of conditioning is about 25t.
Becomes Therefore, since the specific gravity of the tempering material 5 is about 1, the volume of the tempering tank 37 needs to be about 25 m ³ . Further, in order to stir and mix about 25 m ³ of kitchen waste, 25 [m ³ ]
× It can be seen that the 3 [kW / m ^3] is required approximately 75kW.

Furthermore, in order to finish the conditioning within the working hours at 2 batches / day with the apparatus having the configuration shown in FIG. 12, as shown in FIG. 13, the first batch of garbage is started at 9 o'clock. In the same way, in the second batch, the refining was finished by 3:30 pm, and the refining product 5 having the predetermined properties was obtained, so that the input of kitchen waste was stopped by 1:30 pm, It is necessary to start refining at 1:15 pm. Therefore, in the first batch, at the time of 10:30 am, the input of kitchen waste is stopped, the conditioning is started from 9:45 am, the conditioning is finished at 12:00 pm, and the first batch is finished from 12:30 pm The second batch of kitchen waste will be started, the kitchen waste will be stopped by 1:30 pm, and the tempering will be started from 1:15 pm.

In order to treat the garbage of 20 t / day, 10 t / H is required to be added. Therefore, when the garbage of solid content of 20 wt% is added with water so that the water content becomes 85%, Since the amount of refining is about 12.5 t each, the volume of the refining tank 45 is required to be about 12.5 m ³ . Further, in order to stir and mix about 12.5 m ³ / batch of garbage, 12.5 [m ³ ] × 5 [kW / m ³ ] to about 62.
It turns out that 5kW is required.

On the other hand, in the continuous type of the present embodiment in which the refining liquid circulates, as shown in FIG. 7, in order to finish the refining within working hours, the refining is performed by 3:30 pm In addition, in order to obtain the tempered product 5 having a predetermined property, it is necessary to finish the input of the kitchen waste by 2:30 pm. Therefore, in order to treat kitchen waste of 20 t / day, it is necessary to continuously feed the kitchen waste at 3.6 t / m ³ from 9:00 am, and the kitchen water content of solid content of 20 wt% is 85%.
When water is added so that the amount becomes%, the amount of refining is about 4.5.
Since the m ^3, the volume of refining vessel 3 will be be a 4.5 m ^3. Further, in order to stir and mix 4.5 m ³ of kitchen waste, 4.5 [m ³ ] × 5 [kW / m ³ ] to about 2
2.5kW will be good.

Therefore, the refining product 5 can be circulated for continuous treatment and the refining time can be shortened,
The volume of the tempering tank 3 can be greatly reduced, the size of the apparatus can be easily reduced, the load for stirring and mixing can be reduced, and the energy per unit time for stirring and mixing can be reduced, which enables efficient methane fermentation. It can be seen that the heat treatment, which is a pre-treatment, can be performed.

As described above, in order to prepare a conditioning liquid for methane fermentation treatment, water is appropriately added so as to have a predetermined water content, and is circulated while being stirred and mixed so as to have a predetermined solubilization rate. Since even if the organic wastes are sequentially added, the quality can be adjusted substantially uniformly in a short time, for example, by using a tank with a large volume for the adjustment, the organic wastes that are input sequentially can be retained for a long time and The organic waste can be continuously and efficiently conditioned without the need for uniform conditioning.

Further, in order to return and circulate the refining liquid of the refining product 5 extracted from the bottom of the refining tank 3 to the upper part of the refining tank 3 into which the crushed material of the crushed organic waste is put, Since the waste and the refining liquid are agitated in the refining tank 3 and the crushed material is added together with the already-conditioned refining liquid, the refining can be easily and substantially uniformly performed in a short time.

Furthermore, since the organic waste is crushed and conditioned in advance, it can be easily and substantially uniformly conditioned in a short time.

Since the crushing of the organic waste uses a biaxial crusher having crushing blades having two shafts axially overlapping with each other, the organic waste can be crushed together with impurities with a simple structure. At the same time, light impurities such as vinyl substances and plastic substances can be crushed into a string shape having a shape different from that of organic substances and having a large size, and these vinyl substances and plastic substances can be easily separated and removed.

Further, since water is added to the circulating conditioning liquid to adjust the water content to a predetermined amount, it is possible to easily and uniformly adjust the water content in a short time.

Further, since impurities are removed in advance before tempering, the proportion of impurities in the crushed material put into the tempering tank 3 is reduced, and the stirring / mixing and circulation means in the tempering tank 3 is reduced.
The energy for circulation by 20 can be efficiently used for stirring and mixing and circulation of organic matter, and efficient conditioning can be performed.

Since trommel is used for removing the impurities, the impurities can be easily removed with a simple structure.

Furthermore, in order to separate and remove particularly heavy contaminants that are mixed in before the conditioned fermentation product 5 is subjected to methane fermentation treatment, the load during methane fermentation treatment in the latter stage is reduced and The proportion of organic matter in the conditioning liquid used for fermentation treatment increases, and methane fermentation treatment can be performed efficiently. Further, because of the condition, the separability between the foreign matter and the organic matter is increased, so that the foreign matter can be easily separated and removed, and the treatment efficiency of the organic waste can be increased.

Further, it is obtained by washing separated impurities with water supplied from the washing water supply pipe 10 as water to be added for adjusting the water content of the tempered conditioning liquid used for methane fermentation. Since the cleaning wastewater is used in part, a separate process for treating the cleaning wastewater is not required, and the organic substances that have adhered to the contaminants and are removed are efficiently supplied to the methane fermentation process without being discharged outside the system as cleaning wastewater. In addition, the water can be effectively used, and the processing efficiency of organic waste can be improved.

In the above embodiment, the tempering tank 3 is used.
The foreign matter is removed from the tempered material 5 that has been tempered in
The configuration in which the obtained conditioning liquid is returned to the conditioning tank 3 and circulated has been described. For example, the conditioning product 5 pulled out from the conditioning tank 3 is returned to the upper part of the conditioning tank 3, or the conditioning product 5 is used. May be returned to the trommel of the sorting apparatus 2, or the conditioning liquid may be returned to the trommel. Here, by returning to the separation device, the remaining particularly light impurities can be further separated and removed, and stirring efficiency, circulation efficiency, methane fermentation treatment efficiency, etc. can be improved.

The circulating means 20 may be provided with a structure for crushing, for example, a circulating pump 18 having a structure for crushing while circulating the refining liquid by using a two-axis rotary pump or the like. With this configuration, it is possible to shorten the time taken to prepare the slurry-like refined material 5 having a substantially uniform composition, and improve the processing efficiency.

Further, the explanation has been made by removing the contaminants mixed in the tempered material 5 in the separation tank 8 by separation and removal. For example, as shown in FIG. 6, a drum screen 23 and a screw press 24 may be used, As shown in, multiple separation tanks 8
The a and 8b are connected, and a contaminant removing means such as a screen is arranged at the outlet of the tempering tank 3 so that only the contaminants are captured by the screen and accumulated at the bottom of the tempering tank. Only the foreign matter can be discharged to the outside of the tempering tank 3, and the accumulated foreign matter can be scraped out or sucked out separately, and any type of foreign matter removing means may be used.

According to the structure shown in FIG. 6, the remaining light impurities can be removed. Further, as shown in FIGS. 8 and 9, the volume of the rear separation tank 8b and the diameter of the inflow opening are increased to reduce the flow velocity of the vortex generated in the rear separation tank 8b, so that sand and the like can be removed. It may be possible to remove the sediment on the bottom.

Similarly, the removing means for removing impurities before tempering is not limited to trommel and may have any configuration.

On the other hand, the stirring means provided in the tempering tank 3 is not limited to the pulper type screw stirrer 4, but may have any constitution such as a drooping type screw stirrer. By using the pulper type screw stirrer 4, it is possible to stir and mix to a predetermined solubilization rate in a short time and improve the processing efficiency.

[0095]

According to the method for treating organic waste of the first aspect of the present invention, water is added to the organic waste so as to have a predetermined water content, and the mixture is circulated while being stirred and mixed for methane fermentation treatment. Therefore, even if organic waste is sequentially fed, it can be tempered substantially uniformly in a short time. For example, organic waste is fed sequentially using a tank with a large volume for tempering. It is not necessary to retain the substance for a long period of time to prepare a substantially uniform product, and the organic waste product can be prepared continuously and efficiently.

According to the organic waste treatment method of the second aspect, in addition to the effect of the organic waste treatment method of the first aspect, the agitated and mixed organic waste is drawn out from the lower portion and newly added. Since the organic waste is returned to the upper part where it is thrown in and circulated, a substantially uniform heat treatment can be easily carried out in a short time.

According to the organic waste treatment method of claim 3, in addition to the effect of the organic waste treatment method of claim 1 or 2, since the circulating organic waste is crushed, it is substantially uniform. It can be easily tempered in a short time.

According to the organic waste treatment method of claim 4, in addition to the effect of the organic waste treatment method of any one of claims 1 to 3, water is added to the circulating organic waste. As a result, the water content is adjusted to a predetermined water content, so that a substantially uniform temperature adjustment can be easily performed in a short time.

According to the organic waste treatment method of claim 5, in addition to the effects of the organic waste treatment method of any one of claims 1 to 4, before the organic waste is conditioned, Since contaminants mixed in are removed, energy loss due to stirring and mixing and circulation during conditioning can be reduced, and efficient conditioning can be achieved.

According to the method for treating organic waste according to claim 6, in addition to the effect of the method for treating organic waste according to any one of claims 1 to 5, conditioned fermentation of organic waste is carried out by methane fermentation treatment. Since contaminants that are mixed in in advance are removed before the operation, the condition that the separation property between organic waste and contaminants is increasing due to the conditioning, and the contaminants can be removed efficiently and easily, and in the latter stage. The energy loss for the methane fermentation treatment can be reduced, the load of the methane fermentation treatment can be reduced, and the efficiency of the methane fermentation treatment can be improved.

According to the method for treating organic waste according to claim 7, in addition to the effect of the method for treating organic waste according to claim 5 or 6, contaminants removed as water to be added at the time of conditioning Since the cleaning wastewater obtained by cleaning the wastewater is used, a separate treatment step of the cleaning wastewater is not required, and the organic waste adhering to the contaminants can be efficiently treated as methane fermentation without being discharged outside the system as cleaning wastewater. , The water can be effectively used and the treatment efficiency can be improved.

According to the organic waste treatment apparatus of the eighth aspect, water is added to the organic waste stored in the storage tank by the water supply means so that the water content becomes a predetermined amount, and the stirring means is used. Since it is conditioned by circulating with a circulation means while stirring and mixing to perform methane fermentation treatment, even if organic waste is sequentially fed to the storage tank, it can be continuously and substantially uniformly conditioned in a short time. It is not necessary to increase the volume of the storage tank and hold the organic waste that is sequentially charged therein for a long period of time to adjust the quality of the organic waste substantially uniformly, and it is possible to continuously and efficiently adjust the quality of the organic waste.

According to the organic waste treatment device of the ninth aspect, in addition to the effect of the organic waste treatment device of the eighth aspect, the circulation means draws the organic waste from the bottom of the storage tank and stores it. Since the organic waste in the tank is returned to the upper part where the charging port for charging the organic waste is opened, substantially uniform conditioning can be easily performed in a short time.

According to the organic waste treatment apparatus of the tenth aspect, in addition to the effect of the organic waste treatment apparatus of the eighth or ninth aspect, the circulation means is provided with a crushing means for crushing the organic waste. Therefore, substantially uniform tempering can be easily performed in a short time.

According to the organic waste treatment apparatus of the eleventh aspect, in addition to the effect of the organic waste treatment apparatus of any one of the eighth to tenth aspects, water is added to the organic waste to give a predetermined value. Since the water supply means for adjusting the water content is provided in the circulation means, substantially uniform heat adjustment can be easily performed in a short time.

According to the organic waste treatment apparatus of the twelfth aspect, in addition to the effect of the organic waste treatment apparatus of any one of the eighth to eleventh aspects, the organic waste to be put into the storage tank is removed. In order to remove impurities in advance by means of residue,
Energy loss due to stirring and mixing by the stirring means and circulation by the circulation means at the time of tempering can be reduced, and the tempering can be efficiently performed.

According to the organic waste treatment apparatus of the thirteenth aspect, in addition to the effect of the organic waste treatment apparatus of the eighth aspect, the contaminant removal means can adjust the inside of the storage tank. Since contaminants mixed in from the treated organic waste are removed, the separation of organic waste and contaminants is increasing due to conditioning, and contaminants can be removed efficiently and easily. It is possible to reduce the energy loss for the subsequent methane fermentation treatment, and reduce the load of methane fermentation treatment.
The efficiency of methane fermentation treatment can be improved.

According to the organic waste treatment apparatus of the fourteenth aspect, in addition to the effect of the organic waste treatment apparatus of the thirteenth aspect, since the foreign matter removal means is provided in the circulation means, the circulating organic waste treatment The object passes through the foreign matter removing means a plurality of times,
Contaminants can be removed efficiently.

According to the organic waste treatment apparatus of the fifteenth aspect, in addition to the effect of the organic waste treatment apparatus of the thirteenth aspect, the outlet for discharging the conditioned organic waste is closed. Since the screen of the foreign matter removing means is provided, the foreign matter mixed in the screen can be removed when the conditioned organic waste is carried out to the subsequent methane fermentation treatment, and the apparatus can be downsized.

According to the organic waste treatment apparatus of the sixteenth aspect, in addition to the effects of the organic waste treatment apparatus of any one of the twelfth to fifteenth aspects, the washing means is used as the water supplied by the water supply means. Since the cleaning wastewater generated by cleaning the contaminants removed in step 2 is used, a separate treatment step for the cleaning wastewater is not required, and the organic waste adhering to the contaminants is not discharged outside the system as cleaning wastewater. Not only can the methane fermentation process be performed well, but water can be effectively used, and the treatment efficiency can be improved.

[Brief description of drawings]

FIG. 1 is a block diagram in the vicinity of a conditioning tank showing a configuration for conditioning an organic waste according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a constitution for refining an organic waste as above.

FIG. 3 is a graph showing the relationship between the solubilization rate and the COD _Cr recovery rate.

FIG. 4 is a graph showing the relationship between the stirring elapsed time and the solubilization rate.

FIG. 5 is a graph showing a relationship between an inflow rate into the foreign matter removing means and a heavy foreign matter removing rate.

FIG. 6 is a block diagram showing a configuration for conditioning organic waste according to another embodiment of the present invention.

FIG. 7 is an explanatory diagram showing a time schedule for tempering in the same as above.

FIG. 8 is a block diagram in the vicinity of a separation tank showing a constitution for conditioning an organic waste according to still another embodiment of the present invention.

FIG. 9 is an explanatory diagram showing a connected state of the above separation tank.

FIG. 10 is a block diagram showing a configuration for refining an organic waste of a conventional example.

FIG. 11 is an explanatory diagram showing a time schedule for tempering in the same as above.

FIG. 12 is a block diagram showing a configuration for refining another organic waste of a conventional example.

FIG. 13 is an explanatory diagram showing a time schedule for tempering in the same as above.

[Explanation of symbols]

1 Crushing device as crushing means 2 Separation device as means for removing residue 3 Conditioning tank as storage tank 4 Palpa type screw stirrer as stirring means 5 Refining products 8,8a, 8b Separation tank as a means for removing contaminants 20 Circulation means 21 Water supply pipe as water supply means 23 Drum screen as a means for removing contaminants 24 Screw press as a means for removing foreign substances

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Claims (16)

[Claims] 1. A method for treating organic waste, which comprises conditioning organic waste mixed with contaminants by stirring, removing the contaminants, and adjusting the water content to a predetermined amount to perform conditioning for methane fermentation treatment. 2. The method for treating organic waste according to claim 1, wherein water is added to the organic waste, and the mixture is agitated and mixed to be circulated and conditioned. 2. The organic waste according to claim 1, wherein the circulation is withdrawn from the lower portion of the organic waste that has been mixed with stirring and returned to the upper portion where new organic waste is input. Processing method. 3. The method for treating organic waste according to claim 1, wherein the circulating organic waste is crushed. 4. The method for treating organic waste according to claim 1, wherein water is added to the circulating organic waste. 5. The method for treating organic waste according to claim 1, wherein contaminants are removed before conditioning the organic waste. 6. The method for treating organic waste according to any one of claims 1 to 5, wherein contaminants are removed before the conditioned organic waste is subjected to methane fermentation treatment. 7. The method for treating organic waste according to claim 5 or 6, wherein the water to be added is washing waste water obtained by washing foreign matters. 8. A storage tank for storing organic waste mixed with contaminants, a stirring means provided in the storage tank for stirring and mixing the organic waste, and the organic waste provided in the storage tank. An organic waste treatment apparatus comprising: a circulation means for circulating a substance; and a water supply means for adding water to the organic waste. 9. The storage tank has a charging port into which an organic waste is charged, and the circulation means extracts the organic waste from the bottom of the storage tank, and the extracted organic waste. 9. The organic waste treatment device according to claim 8, wherein the waste is returned to the upper part of the storage tank. 10. The organic waste treatment device according to claim 8, wherein the circulation means is provided with a crushing means for crushing the organic waste. 11. The organic waste treatment device according to claim 8, wherein the water supply means is provided in the circulation means. 12. The organic waste treatment apparatus according to claim 8, further comprising a removing means for removing impurities from the organic waste to be put into the storage tank. 13. The organic waste treatment according to any one of claims 8 to 12, further comprising a foreign matter removing means for removing foreign matter from the organic waste that has been conditioned in the storage tank. apparatus. 14. The organic waste treatment device according to claim 13, wherein the foreign matter removing means is provided in the circulation means. 15. The storage tank is provided with an opening for opening an outlet for discharging the conditioned organic waste, and the contaminant removing means is provided with a screen for closing the outlet. Organic waste treatment equipment. 16. A washing means for washing the removed contaminants is provided, and the water supplying means uses the washing drainage generated by the washing means as water to be used for adjusting the amount of water. The organic waste treatment device according to any one of claims 12 to 15.