JP2005007312A - Apparatus and method for waste disposal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a methane fermentation tank, an apparatus and method for waste disposal that can easily and surely carry out methane fermentation of an organic waste material containing a biodegradable sheet-form article without passing through any complicated process. <P>SOLUTION: The apparatus 10 for waste disposal is equipped with a crusher 12 to crush the organic waste material 11 containing the biodegradable sheet-form article as it is, and the methane fermentation tank 14 to ferment the crushed product. The crusher 12 is organized so as to crush the biodegradable sheet-form article to pieces of 150 mm or less at longest. Thus, the crushed biodegradable sheet-form article does not cause any trouble such as getting entangled and blinding in an agitator and a transfer device in the apparatus 10. In other words, the troubles caused by the crushed biodegradable sheet-form article can be minimized in methane fermenting the organic waste material 11 containing the above biodegradable sheet-form article as it is. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a methane fermentation tank for treating organic waste such as garbage by methane fermentation, a waste treatment apparatus, and a waste treatment method, and in particular, separates garbage collected in a biodegradable garbage bag. The present invention relates to a methane fermentation tank, a waste treatment apparatus, and a waste treatment method that can be directly subjected to methane fermentation.
[0002]
[Prior art]
Plastic bags such as vinyl chloride and polyethylene are used for garbage bags that collect garbage. Among these garbage bags, those made of vinyl chloride contain chlorine, which is a cause of generation of dioxins when incinerated, so that their use is being regulated. For this reason, it is being recommended to use biodegradable garbage bags that are decomposed by microorganisms. This biodegradable garbage bag is decomposed under aerobic conditions, and is decomposed over several days to several years by microorganisms in the soil by contact with the soil in a field or the like.
[0003]
Examples of composting treatment of garbage collected by the biodegradable garbage bag include, for example, a method of separating the garbage and the biodegradable garbage bag and then separately fermenting them (hereinafter referred to as “separation method”). In addition, a method of fermenting the entire amount of garbage with a biodegradable garbage bag (hereinafter referred to as “total amount processing method”) is known.
[0004]
Of these, in the separation treatment method, the fermentation rate differs between the garbage and the biodegradable garbage bag, so the garbage and the biodegradable garbage bag must be separated. Have difficulty. In addition, there are two processes, a garbage disposal process and a biodegradable garbage bag treatment process, which makes the treatment facility large-scale and complicates the treatment process. (For example, refer to Patent Document 1).
[0005]
On the other hand, since the biodegradable garbage bag is decomposed under aerobic conditions in the total amount treatment method, generally, both the garbage and the biodegradable garbage bag are fermented under aerobic conditions. If the garbage bag is not sufficiently crushed, the air required for aerobic fermentation is blocked by the biodegradable garbage bag and becomes partially anaerobic, resulting in spoilage and appropriate fermentation treatment such as a reduction in fermentation temperature. The biodegradable garbage bag was entangled with the agitation device, the transfer device, the stopper, etc. of the fermentation apparatus, and sufficient agitation / transfer was not performed, causing trouble.
[0006]
[Patent Document 1]
JP 2001-205233 A
[Problems to be solved by the invention]
The present invention has been made in view of such circumstances, and the problem is that organic waste containing biodegradable sheet-like material is easily and reliably treated by methane fermentation without going through complicated steps. An object of the present invention is to provide a methane fermentation tank, a waste treatment apparatus, and a waste treatment method.
[0008]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the invention of the waste treatment apparatus according to the first aspect of the present invention is a crusher for crushing organic waste containing a biodegradable sheet material together with the biodegradable sheet material. And a methane fermentation tank for treating the crushed material by methane fermentation, wherein the crusher is configured to crush at least the biodegradable sheet material to 150 mm or less. It is characterized by being.
[0009]
Here, “biodegradable” refers to the property of being degraded by microorganisms under aerobic conditions. Therefore, the “biodegradable sheet-like material” refers to a sheet-like material such as a garbage bag that is decomposed over several days to several years under aerobic conditions.
[0010]
In addition, “crush the biodegradable sheet material to 150 mm or less” means that when the biodegradable sheet material is crushed and becomes, for example, a rectangle, the longest side length becomes a circle. The longest part should just be 150 mm or less. Moreover, the crushed biodegradable sheet material should just be crushed to 150 mm or less on average, and it does not prevent inclusion of the magnitude | size exceeding this.
[0011]
According to this feature, at least the biodegradable sheet is crushed to 150 mm or less by a crusher, so that the crushed biodegradable sheet causes problems such as clogging and entanglement in a methane fermentation tank or the like. There is no. Therefore, the crushed biodegradable sheet can be reliably discharged from the waste treatment apparatus.
[0012]
That is, since the biodegradable sheet is decomposed under an aerobic condition, it is not treated by methane fermentation under anaerobic conditions. For this reason, when the biodegradable sheet material is not sufficiently crushed, problems such as entanglement have occurred in the waste treatment apparatus. In the present invention, the organic waste containing the biodegradable sheet material is obtained by a crusher. Since the material is crushed to 150 mm or less, there is no such inconvenience, and the crushed biodegradable sheet can be discharged from the waste treatment apparatus as it is.
[0013]
In addition, since organic waste containing biodegradable sheets is processed by methane fermentation, the processing conditions such as fermentation temperature and moisture can be easily controlled as compared to conventional aerobic processing. At the same time, organic waste can be treated in a relatively short time.
[0014]
In the waste treatment apparatus according to the second aspect of the present invention, in the first aspect, the methane fermenter includes a stirring unit, and the stirring unit spirals along the rotation axis. It has the helical blade comprised in the shape.
[0015]
According to this feature, the pulverized biodegradable sheet can be uniformly dispersed in the methane fermentation liquid by stirring the methane fermentation liquid with the stirring means having the spiral blade. In other words, the methane fermentation broth can be sufficiently circulated by the entrainment effect of the spiral blade, so that the crushed biodegradable sheet is floated on the liquid surface of the methane fermentation broth or localized in the methane fermentation broth. Evenly distributed without Therefore, problems such as entanglement can be avoided.
[0016]
Moreover, the invention of the waste disposal apparatus according to the third aspect of the present invention is the plate blade according to the second aspect, wherein the stirring means further extends in a direction substantially orthogonal to the rotation axis. It is characterized by having.
[0017]
According to this feature, the crushed biodegradable sheet-like material can be more reliably dispersed in the methane fermentation broth. That is, even if it is a highly viscous liquid such as methane fermentation broth, the methane fermentation broth can be reliably stirred by large overall stirring by the plate blade and entrainment stirring by the spiral blade in the second aspect. Is possible. Therefore, the crushed biodegradable sheet can be more uniformly dispersed in the methane fermentation broth.
[0018]
Moreover, the invention of the methane fermenter according to the fourth aspect of the present invention is a methane fermenter for treating an object to be processed by methane fermentation, and a spiral blade configured spirally along the rotation axis; A stirring means having a plate-like blade extending in a direction substantially orthogonal to the rotating shaft is provided.
[0019]
According to this feature, even a liquid having a high viscosity such as a methane fermentation liquid can be reliably stirred by the entrainment stirring by the spiral blade and the large overall stirring by the plate blade. That is, it is possible to stir the methane fermentation liquid without causing stagnation in the methane fermentation tank. Therefore, even if the methane fermentation broth contains foreign matter such as sheet pieces, the foreign matter can be uniformly dispersed in the methane fermentation broth, so that the influence of the foreign matter (for example, the foreign matter wraps around the stirring means) , And so on) can be minimized.
[0020]
The invention of the waste treatment method according to the fifth aspect of the present invention includes a crushing step of crushing an organic waste containing a biodegradable sheet material to 150 mm or less together with the biodegradable sheet material, It has the methane fermentation process which processes a processed material by methane fermentation.
[0021]
According to this feature, the organic waste containing the biodegradable sheet material is crushed to 150 mm or less by the crushing process, so that the biodegradable material that has been crushed during the treatment process. Sheets do not cause problems such as clogging or entanglement. Therefore, the crushed biodegradable sheet can be reliably discharged from the treatment process.
[0022]
That is, since the biodegradable sheet is decomposed under an aerobic condition, it is not treated by methane fermentation under anaerobic conditions. Therefore, when the biodegradable sheet-like material is not sufficiently crushed, problems such as entanglement have occurred in the methane fermentation process, but in the present invention, the organic waste containing the biodegradable sheet-like material is not contained in the crushing process. Since it is crushed to 150 mm or less, there is no such inconvenience, and the crushed biodegradable sheet can be discharged from the treatment process as it is.
[0023]
In addition, since organic waste containing biodegradable sheets is processed by methane fermentation, the processing conditions such as fermentation temperature and moisture can be easily controlled as compared to conventional aerobic processing. At the same time, organic waste can be treated in a relatively short time.
[0024]
Moreover, invention of the waste processing method which concerns on the 6th aspect of this invention is sprayed on the soil after the said methane fermentation process in the said 5th aspect, It is characterized by the above-mentioned.
[0025]
According to this feature, the biodegradable sheet-like material contained in the fermented material after the methane fermentation step can be decomposed under aerobic conditions by microorganisms in the soil. In addition, since the biodegradable sheet material sprayed on the field which is an example of soil is crushed to 150 mm or less according to the fifth aspect, it does not hinder the cultivation of plants in the field. It can be decomposed in a relatively short time.
[0026]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the waste treatment method and the waste treatment method according to the present invention will be described. Here, FIG. 1 is a flowchart relating to waste treatment. The waste treatment apparatus 10 includes, as organic waste, a crusher 12 that crushes the garbage 11 collected by a biodegradable garbage bag, which is an example of a biodegradable sheet material, together with the biodegradable garbage bag, methane It corresponds to a pretreatment stage of fermentation, and includes an adjustment tank 13 for adjusting the moisture content of the garbage and a methane fermentation tank 14 for treating the garbage by methane fermentation.
[0027]
The garbage 11 collected by the biodegradable garbage bag is first put into the crusher 12 as a crushing process. The crusher 12 can be used without particular limitation as long as it can crush raw garbage into a biodegradable garbage bag of 150 mm or less, preferably 100 mm or less, more preferably 50 mm or less. That is, at least the length of the longest side when the biodegradable garbage bag is crushed and becomes a rectangle, for example, and the length of the longest part when the shape is a circle is 150 mm or less, preferably 100 mm or less, It is more preferable to crush so that it may become 50 mm or less. Moreover, what is necessary is just to be crushed on the average to 150 mm or less, and if it is in the range which does not have influence later, it will not prevent that exceeding this is included.
[0028]
Here, FIG. 2 is a schematic configuration diagram illustrating an example of a crusher. The crusher 12 is disposed below the middle between the first roller 41 rotating around the axis A, the second roller 42 rotating around the axis B, and the first roller 41 and the second roller 42, This is a triaxial crusher having a third roller 43 that rotates about an axis C, and each of the rollers (41, 42, 43) is provided with a plurality of crushing blades (rotating blades 48). Further, a fixed blade 49 as a fixed crushing blade is disposed in the vicinity of the third roller 43.
[0029]
The garbage 11 thrown into the crusher 12 is compressed and crushed by a rotary blade 48 of a first roller 41 rotating in the direction of arrow 31 and a second roller 42 rotating in the direction of arrow 32 while moving along the arrow 36. Is done. Thereafter, the material is sheared and crushed by the rotary blade 48 of the first roller 41 and the third roller 43 rotating in the direction of the arrow 33 while moving along the arrow 37. Further, it is sheared and crushed by the rotary blade 48 and the fixed blade 49 of the third roller 43. The biodegradable garbage bag and garbage crushed to a predetermined size are discharged from the crusher 12 along the arrow 38.
[0030]
In this way, the crusher 12 can crush the garbage 11 together with the biodegradable garbage bag into a desired size. In the present invention, adjustment is made so that at least the biodegradable garbage bag is crushed to 150 mm or less, preferably 100 mm or less, more preferably 50 mm or less. Moreover, the size of the biodegradable garbage bag and garbage after crushing is, for example, the interval in the axial direction of the rotary blade 48 provided on each roller (41, 42, 43) and the rotary blade 48 of the third roller 43. It is possible to adjust appropriately according to the distance from the fixed blade 49. Here, it is preferable to set the gap between these blades to 150 mm or less, preferably 100 mm or less, more preferably 50 mm or less.
[0031]
The crushed biodegradable garbage bag (hereinafter referred to as “garbage bag piece”) and the garbage are conveyed to the adjustment tank 13 corresponding to the pretreatment in the methane fermentation process without being separated. Since general garbage has a water content of about 75%, in the adjustment tank 13, water is added to the crushed material, or a fermentation liquid 24 after the methane fermentation treatment in the methane fermentation tank 14 is added (so-called, The water content is adjusted to about 95% by “returned sludge”) to form a slurry. By this moisture adjustment, the subsequent methane fermentation treatment in the methane fermentation tank 14 can be promoted. Moreover, when the fermentation liquid 24 is added by return sludge, since microorganisms are thrown into the adjustment tank 13, the methane fermentation process in the methane fermentation tank 14 following this can be further accelerated | stimulated.
[0032]
The adjustment tank 13 is provided with a stirrer 50 as a stirring means for uniformly dispersing the garbage bag pieces 8. Since this stirrer 50 has the same configuration as the stirring means provided in the methane fermentation tank 14 described later, the description thereof is omitted here.
[0033]
The garbage containing the waste bag piece 8 and having its moisture adjusted is transferred to the methane fermentation tank 14. For the transfer from the adjustment tank 13 to the methane fermentation tank 14, for example, a snake pump can be used. The methane fermentation tank 14 that performs the methane fermentation process is configured by a tank that completely blocks air, and is capable of performing known methane fermentation. In this embodiment, it is comprised so that a methane fermentation process may be performed semi-continuously, and the to-be-processed liquid transferred from the adjustment tank 13 will remain in the methane fermentation tank 14 for about 8 hours, and a methane fermentation process is carried out. The liquid to be treated can be exchanged about three times a day.
[0034]
The methane fermentation tank 14 is provided with a stirrer as a stirring means for stirring the methane fermentation liquid. Here, FIG. 3 is a schematic configuration diagram for explaining the stirrer 50. In the stirrer 50, a spiral blade 52 and a plate blade 53 are provided on a rotating shaft 51 that is rotationally driven by a drive source 59. The spiral blade 52 is formed in a spiral shape around the rotation shaft 51 and rotates forward so that the methane fermentation solution 141 is directed from the liquid surface to the lower end of the rotation shaft 51 (that is, the bottom of the methane fermentation tank 14). Stir while entraining. The plate blade 53 is configured to extend in a direction orthogonal to the rotation shaft 51 and greatly agitates the entire liquid to be treated 141.
[0035]
With such a configuration, even the methane fermentation broth 141 having a solid content and a large viscosity can be reliably stirred, so that the garbage bag pieces 8 can be uniformly dispersed in the methane fermentation broth 141. Accordingly, it is possible to reliably avoid the garbage bag piece 8 from being entangled with the stirrer 50 or clogging the snake pump or the stopper. That is, the influence of the presence of the garbage bag piece 8 in the methane fermentation liquid 141 can be minimized, and after the methane fermentation treatment, the garbage bag piece 8 is put together with the methane fermentation liquid 141 from the methane fermentation tank 14. It can be discharged reliably. Here, as shown in FIG. 3, the configuration in which two plate blades 53 each having a predetermined interval are provided with blades extending in opposite directions around the rotation shaft 51 has been described. If the whole 141 can be stirred, it is not limited to this. For example, it is composed of more blades, or the blades are configured to extend in one direction from the rotating shaft 51. Alternatively, two or more can be provided.
[0036]
Moreover, the methane fermentation tank 14 can be provided with a temperature adjusting means. By controlling the fermentation temperature with this temperature adjusting means, methane fermentation can be performed under optimum conditions, and the processing time can be shortened.
[0037]
Moreover, the methane fermentation tank 14 can be provided with a means for collecting biogas produced by the methane fermentation process. Here, the “biogas” refers to a gas mainly composed of methane produced mainly by metabolism of anaerobic microorganisms in methane fermentation. The biogas recovered by the gas recovery means can be used as a heat source for the heating means or other energy source.
[0038]
The liquid after methane fermentation (fermented liquid 24) can be stored in a storage tank (for example, a post-treatment tank not shown) and used as “liquid fertilizer”. At this time, the crushed biodegradable garbage bag (garbage bag piece) 8 is gradually decomposed under aerobic conditions. When this liquid fertilizer is applied to a field or the like, the decomposition reaction proceeds under aerobic conditions. In addition, when the fermented liquid 24 is dried to obtain a solid material having a low moisture content (for example, about 10%), the decomposition of the garbage bag piece 8 is temporarily stopped. proceed.
[0039]
As described above, the fermented matter 25 discharged from the methane fermenter 14 is usually sprayed on soil, for example, a farm field or farmland. In addition to the fermented product made from raw garbage, the fermented product 25 includes a garbage bag piece 8 that has not been treated in the methane fermentation process, but the garbage bag piece 8 is biodegradable. It is degraded by microorganisms in the soil under aerobic conditions in fields and the like. Moreover, since the garbage bag piece 8 is crushed to 150 mm or less by the crusher 12 described above, it does not hinder plant cultivation or the like even if sprayed on a field or the like, and it is relatively short time. Can be disassembled.
[0040]
【The invention's effect】
As described above, according to the present invention, since the biodegradable garbage bag is crushed into a predetermined size by the crusher, the influence of the crushed biodegradable garbage bag can be minimized. Therefore, the biodegradable garbage bag and the garbage can be processed without being separated, and the garbage collected by the biodegradable garbage bag can be processed easily and reliably, and the waste treatment apparatus. The configuration can be simplified.
In addition, by spreading fermented material after methane fermentation treatment to the soil, biodegradable garbage bags that were not treated in methane fermentation can be decomposed, so that all the garbage collected by biodegradable garbage bags can be reliably Can be processed.
[Brief description of the drawings]
FIG. 1 is a flowchart of waste treatment according to the present invention.
FIG. 2 is a schematic configuration diagram for explaining a crusher.
FIG. 3 is a schematic diagram for explaining the stirring means.
[Explanation of symbols]
8 Crushed biodegradable garbage bags (trash bag fragments)
DESCRIPTION OF SYMBOLS 10 Waste disposal apparatus 11 Garbage 12 Crusher 13 Adjustment tank 14 Methane fermentation tank 24 Fermented liquid 25 Fermented material 41 1st roller 42 2nd roller 43 3rd roller 48 Rotary blade 49 Fixed blade 50 Stirrer 51 Rotating shaft 52 Spiral Blade 53 Plate blade 59 Drive source 141 Methane fermentation liquid

Claims (6)

A crusher for crushing organic waste containing biodegradable sheet material together with the biodegradable sheet material;
A waste treatment apparatus comprising a methane fermentation tank for treating a crushed material by methane fermentation,
The waste crusher is configured to crush at least the biodegradable sheet material to 150 mm or less. The waste product according to claim 1, wherein the methane fermentation tank includes a stirring unit, and the stirring unit includes a spiral blade that is spirally formed along a rotation axis. Processing equipment. 3. The waste treatment apparatus according to claim 2, wherein the stirring means further includes a plate blade configured to extend in a direction substantially orthogonal to the rotation shaft. A methane fermentation tank for treating an object to be treated by methane fermentation, comprising: a spiral blade spirally formed along a rotation axis; and a plate blade extending in a direction substantially orthogonal to the rotation axis A methane fermenter comprising means. Crushing step of crushing organic waste containing biodegradable sheet material to 150 mm or less together with the biodegradable sheet material;
It has a methane fermentation process which processes a crushing processed material by methane fermentation, The waste processing method characterized by the above-mentioned. The waste treatment method according to claim 5, wherein the fermented material after the methane fermentation step is sprayed on soil.

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