JP2008246462A - Pretreatment apparatus for methane fermentation and methane fermentation treatment system using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pretreatment apparatus for methane fermentation which improves efficiency of methane fermentation treatment, and a methane fermentation treatment system using it. <P>SOLUTION: The pretreatment apparatus for methane fermentation comprises first and second crusher 12-1, 12-2 for coarsely crushing garbage waste 11, a sorter 14 for sorting foreign materials 13, a solubilization tank 15 for solubilizing the garbage waste 11, a drum screen 16 for drawing solubilized liquid 18A from the vicinity of the tank bottom and removing the remaining foreign materials 13, a return line L3 for returning solubilized liquid 18B, from which the foreign materials 13 have been removed, to the solubilization tank, and a supply line L<SB>4</SB>for supplying solubilized liquid 19 for methane fermentation to a methane fermentation tank 20. The solubilization tank is divided into a front chamber and a rear chamber by a partition wall 15a. The solubilized liquid overflows the partition wall 15a, the solubilized liquid 18A is drawn from the bottom of the rear chamber to be supplied to the drum screen 16 side, and the solubilized liquid 18B of the return line L<SB>3</SB>is returned in a shower form from the upper part of the rear chamber through a shower nozzle 15b. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a methane fermentation pretreatment apparatus and a methane fermentation treatment system using the same, for example, when food waste such as garbage is recycled in a methane fermentation treatment facility.

  Conventionally, when organic waste such as food waste, fishery processing waste, human waste, sewage sludge, septic tank sludge, etc. (hereinafter referred to as “waste”) is subjected to methane fermentation, in order to improve its methane fermentation efficiency In addition, various solubilization techniques using predetermined moisture have been proposed (see, for example, Patent Document 1). The methane fermentation pretreatment apparatus proposed as the example is shown in FIG.

  As shown in FIG. 2, the conventional methane fermentation pretreatment apparatus 100 crushes raw garbage, which is an organic waste, into a crushed garbage 101, which is then sent to a storage tank 102 where stirring and mixing are performed. Then, a part mixed and stirred by the stirring means 103 of the storage tank 102 is circulated to the storage tank by the circulation means 107, and the remaining part is subjected to methane fermentation treatment in the methane fermentation tank. In the pretreatment of the methane fermentation, the garbage 101 is circulated by the circulation means 107, and water is added and solubilized so that the moisture content of the garbage becomes about 85% to 90%. At the same time, after removing the contaminants from the garbage by the contaminant removal means 105, the organic waste from which the contaminants have been removed by adding water 108a from the water supply means 108 is stirred again in the storage tank 102. Mixed Reforming to tone, to obtain a tone pledge 104. Reference numeral 106 denotes washing water.

  In circulation, the organic waste that has been stirred and mixed is withdrawn from the lower part of the storage tank 102 and returned to the upper part of the storage tank into which new organic waste is introduced.

Japanese Patent No. 3710938

However, the apparatus according to Patent Document 1 has the following problems.
1) When removing the contaminants from the crushed garbage 101 by the contaminant removal means 105, the solid garbage is removed at the same time as the contaminants, increasing the amount of contaminants generated and the raw food to be originally processed. As a result of the removal of garbage, there is a problem that the amount of methane gas generated in the methane fermentation tank is reduced.

2) Further, the method of removing contaminants by precipitation separation in the contaminant removing means 105 has a problem that impurities that do not precipitate, such as light impurities (vinyl, fibers, etc.) cannot be removed at all.
In particular, even in the sorting means for removing impurities from the crushed garbage, the vinyl and fibrous materials remain in the garbage without being completely sorted by the sorting means. It is also eager to remove it.

3) Also, when the sediment is pulled out from the bottom of the tank of the contaminant removal means 105, heavy contaminants (such as sand) can be removed, but light contaminants (such as vinyl and fiber) are liquids. Since it floats as a scum on the surface, there is a problem that its removal is difficult.

  In view of the above problems, the present invention is capable of removing impurities without reducing the efficiency of the methane fermentation treatment, and can prevent the adverse effects of the treatment equipment depending on the impurities, and the methane fermentation pretreatment device. It is an object to provide a methane fermentation treatment system using the above.

  1st invention of this invention for solving the subject mentioned above is crushed with the 1st crusher which carries out rough crushing processing of the food waste waste, the 2nd crusher which carries out fine crushing after rough crushing processing, and A sorter that sorts out contaminants mixed in the waste, a solubilization tank that solubilizes food waste waste from which the contaminants have been removed, and a solubilizing solution from the bottom of the solubilization tank. A drum screen that removes the contaminants remaining in the extracted solubilized liquid, a return line that returns the solubilized liquid from which the contaminants have been removed by the drum screen to the solubilization tank, and the solubilization tank. A supply line for supplying a methane fermentation solubilizing solution to the methane fermentation tank is provided, and the solubilization tank is divided into a front chamber and a rear chamber by a partition wall, and the solubilizing solution overflows the partition wall. At the same time, the solubilized liquid is extracted from the bottom of the front chamber. Supplies to the screen side, in the methane fermentation pretreatment apparatus characterized by comprising back in a shower-like by the shower nozzle from the top of the front chamber lysate of return line from the drum screen.

  A second invention is the pretreatment apparatus for methane fermentation according to the first invention, wherein the screen width of the drum screen is 5 mm to 10 mm.

  According to a third aspect of the present invention, there is provided the pretreatment apparatus for methane fermentation according to the first or second aspect, wherein the foreign matter to be removed is a vinyl-based recovered foreign matter.

  4th invention comprises the methane fermentation pretreatment apparatus of any one of 1st thru | or 3, and the methane fermentation tank which performs the methane fermentation process of the solubilization liquid for methane fermentation pre-processed by the said methane fermentation pre-treatment apparatus. It is in the methane fermentation processing system characterized by doing.

  According to the present invention, without reducing the processing efficiency when processing food wastes by methane fermentation, it is possible to remove foreign substances and prevent adverse effects depending on the foreign substances, and to the food garbage recycling system. Apply to be good.

  Hereinafter, the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments. In addition, constituent elements in the following embodiments include those that can be easily assumed by those skilled in the art or those that are substantially the same.

A methane fermentation pretreatment device and a methane fermentation treatment system according to an embodiment of the present invention will be described with reference to the drawings.
Drawing 1 is a key map showing the methane fermentation pretreatment device concerning an example.
As shown in FIG. 1, the methane fermentation pretreatment apparatus 10 according to the present embodiment includes a first crusher 12-1 that roughly crushes food waste waste 11 and a second crusher that finely crushes after the coarse crushing process. Crusher 12-2, sorter 14 for sorting out contaminants (vinyl) 13 mixed in the crushed waste, and solubilization for solubilizing food waste waste from which the contaminants have been removed The tank 15, the solubilizing liquid 18 </ b> A is extracted from the vicinity of the bottom of the solubilizing tank 15, and the drum screen 16 for removing the impurities 13 remaining in the extracted solubilizing liquid 18 </ b> A, Is provided with a return line L ₃ for returning the solubilized liquid 18B from the solubilizing tank 15 to the solubilizing tank 15 and a supply line L ₄ for supplying the solubilizing liquid 19 for methane fermentation from the solubilizing tank 15 to the methane fermentation tank 20. And the solubilization tank is in front The chamber 15-1 and the rear chamber 15-2 are divided into two by a partition wall 15a. The solubilized liquid overflows the partition wall 15a, and the solubilized solution 18A is extracted from the bottom of the front chamber 15-1. supplies to the drum screen 16 side, is made back in the shower-like by the shower nozzle 15b from the upper portion of the front chamber lysate 18B of line L ₃ return from the drum screen.

Here, the line L ₁ is a waste line for feeding the food waste from which the impurities 13 have been removed by the sorter 14 to the solubilization tank 15, and L ₂ is for extracting the solubilizing liquid 18 A to the drum screen 16. L ₃ is an extraction line, and L ₃ is a return line for returning the solubilized liquid 18B from which residual impurities have been removed by the drum screen 16 to the solubilizing tank 15, and L _{1 to} L ₃ constitute a circulation line for the solubilized liquid. Yes.

  The crusher for crushing the garbage waste 11 is a two-stage crushing in this embodiment, and in the first crusher 12-1, the particle size after crushing is 200 mm or less, more preferably 50 mm or less. Then, in the second crusher 12-2 that is further finely crushed, the particle size after crushing is 50 mm or less, more preferably 25 mm or less. Since the types of waste are various, the number, type and combination of crushers may be appropriately selected according to the form of waste to be brought in.

  For example, the first crusher 12-1 has a cutter width of 43 mm, and the second crusher 12-2 is crushed in two stages with a cutter width of 25 mm, so that a plastic bag that wraps food waste, such as a lunch box, yogurt, or retort, is used. A plastic container such as food can be efficiently crushed.

Thereby, for example, food waste in a plastic bag with a volume of 100 L or less or food waste as described above having a shape of 30 cm square or less can be efficiently crushed, and the outlet shape of the second crusher 12-2 is 25 mm or less. be able to.
Thereby, garbage waste (a food waste containing a container or a bag is included) can be efficiently taken out from a plastic bag or a plastic container.

Moreover, as the sorter 14 which sorts out the said impurities 13, the cylindrical part of the drum screen 16 consists of punching metal, The hole diameter is about 20 mm in diameter.
In addition, the centrifugal force generated by the rotation of the cylinder and the punched metal opening portion separates the heavy portion of the garbage that has been crushed by the aforementioned crusher, specifically the garbage containing moisture, by the specific gravity, and the outside of the cylinder. To be discharged.

On the other hand, lightweight vinyl or plastic remains inside the cylinder of the drum screen 16, and is further transported in the direction of the center axis of the cylinder by wind force means (not shown) arranged to flow in the direction of the center axis of the cylinder, and discharged to the outside. The
By combining this specific gravity sorting and wind sorting, it becomes possible to efficiently separate, and the volume of the sorter can be reduced.

The solubilization tank 15 is mixed with a solubilized liquid originally containing crushed and sorted garbage waste, and the temperature is set to, for example, 20 to 80 ° C., preferably 30 to 60 ° C. or 35 to 55 ° C. This is intended to reduce the energy loss by substantially matching the fermentation treatment temperature in the methane fermentation tank 20. In addition, water is added and solubilized so that the water content of the garbage waste in the solubilization tank 15 is about 85% to 90%. Garbage is solubilized in liquid form.
Here, as for the impurities 13 which are not solubilized, the light weight thing floats on the whole surface of the solubilization liquid in a tank, and a heavy thing deposits as the deposit 17 in the tank bottom part.

In the present invention, a partition wall 15a standing from the bottom of the solubilization tank 15 is provided, and the inside of the tank is divided into a front chamber 15-1 and a rear chamber 15-2 through the partition wall 15a. 15a is made to overflow the solubilized liquid as overflow water 18C.
By dividing the inside of the tank into two in this manner, the front chamber 15-1 is made a part into which the contaminants 13 are mixed, and the rear chamber 15-2 is composed of a solubilized liquid that has overflowed. A thing will already be isolate | separated as the precipitate 17 in the front chamber 15-1, and the mixing rate of the contaminant 13 will fall.
Thereby, in the solubilization liquid for methane fermentation supplied to the methane fermentation tank 20, suspended matter and contaminants are reduced as much as possible, and as a result, further improvement in methane fermentation efficiency can be achieved.

  Further, as a drawing line for drawing the solubilized liquid to the drum screen 16, the sediment 17 consisting of the deposited contaminants 13 can be efficiently pulled out by pulling out the solubilized liquid 18 </ b> A from the bottom of the solubilizing tank 15. Can do.

  The drum screen 16 of the present invention uses a wire mesh to reduce the slipping of long and thin vinyl pieces and to facilitate efficient separation. Therefore, for example, a screen made of a slit such as a wedge wire may pass through the slit, but such a problem is solved by using a wire mesh.

  Also, by setting the mesh width of the wire mesh that is the drum screen 16 to 5 to 10 mm, it is possible to efficiently use wood fibers, large shells, seeds, disposable chopsticks, skewers, bones, etc. in addition to vinyl and plastic as impurities. Can be removed. By using the drum screen, the solubilized solution in which the garbage is dissolved from the contaminants and the relatively soft garbage pass through the screen, and the impurities can be efficiently separated.

In the return line L ₃ for returning the solubilized liquid 18B to the solubilizing tank 15, the solubilized liquid 18B from which most of the impurities 13 have been removed by the drum screen 16 is returned from the upper part of the solubilized tank 15 into the tank. In this case, the scum is prevented from being formed on the liquid surface in the solubilization tank 15 by being lowered into a shower shape by the shower nozzle 15b. Thereby, the lightweight foreign substance floating in the solubilized liquid is mixed, and when circulating again, it is separated as the foreign substance 13 by the drum screen 16 and discharged to the outside.

  Moreover, the food raw material which is originally processed is made into the methane fermentation processing system which comprises the methane fermentation solubilization liquid 20 which carries out the methane fermentation process of the solubilization liquid 19 for methane fermentation pre-processed by the said methane fermentation pre-processing apparatus 10 mentioned above. As a result of efficiently removing impurities in the waste waste, it is possible to prevent a decrease in the amount of methane gas generated in the methane fermentation tank. As a result, it is possible to prevent a decrease in utilization efficiency when the methane gas obtained in the methane fermentation tank is used as fuel, for example.

  As described above, according to the methane fermentation pretreatment device and the methane fermentation treatment system according to the present invention, for example, impurities are reduced without reducing the treatment efficiency when treating organic waste such as garbage with methane fermentation. It is suitable for use in food waste recycling systems, because it can prevent adverse effects that depend on foreign substances.

1 is a schematic view of a methane fermentation pretreatment apparatus according to Example 1. FIG. It is the schematic of the methane fermentation pretreatment apparatus which concerns on a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Methane fermentation pretreatment apparatus 11 Food waste waste 12-1 1st crusher 12-2 2nd crusher 13 Contamination 14 Sorting machine 15 Solubilization tank 16 Drum screen 18A, 18B, 18C Solubilization liquid 19 Solubilizing solution for methane fermentation 20 Methane fermentation tank

Claims (4)

A first crusher for roughly crushing food waste waste;
A second crusher for fine crushing after the rough crushing treatment;
A sorter that sorts out impurities mixed in the crushed waste;
A solubilization tank for solubilizing food waste waste from which the contaminants have been removed;
A drum screen for extracting the lysate from the vicinity of the bottom of the solubilization tank and removing impurities remaining in the extracted lysate;
A return line for returning the solubilized liquid from which the contaminants have been removed by the drum screen to the solubilization tank again;
A supply line for supplying a solubilizing solution for methane fermentation from the solubilization tank to the methane fermentation tank; and the solubilization tank is divided into a front chamber and a rear chamber by a partition wall, solubilizing the partition wall As the liquid overflows,
The solubilized liquid is extracted from the bottom of the front chamber and supplied to the drum screen side, and the solubilized liquid in the return line from the drum screen is returned from the top of the front chamber in a shower shape by a shower nozzle. Methane fermentation pretreatment equipment. In claim 1,
The screen width of the drum screen is 5 mm to 10 mm. In claim 1 or 2,
A methane fermentation pretreatment device, wherein the foreign matter to be removed is a vinyl-based collected foreign matter. A methane fermentation pretreatment device according to any one of claims 1 to 3,
A methane fermentation treatment system comprising: a methane fermentation tank for methane fermentation treatment of a solubilized solution for methane fermentation pretreated by the methane fermentation pretreatment device.

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