JPS627158B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fermenter capable of continuously fermenting waste such as human and animal human waste and sewage sludge under aerobic conditions by forcibly supplying air.

Conventionally, a box-shaped fermenter with an air supply hole provided at the bottom has been most commonly used as a fermenter for aerobically fermenting by forcibly supplying air. However, in such a fermenter, air is supplied from the bottom of the fermenter, so the height of the tank is limited and a large installation area is required. In addition, since it is a batch type and it is necessary to replace the fermented product with the treated product each time fermentation is completed, there is a drawback that workability is poor.

Recently, fermenters have been developed that have multi-tiered floors in a vertical fermenter to facilitate the flow of supply air and to move the processed material step by step, making it possible to perform continuous fermentation treatment with a small footprint. being developed. However, not only is a special means required to move the processed material step by step, but the equipment becomes complicated and equipment costs are high, so batch-type fermenters as mentioned above are still often used. The current situation is that

The present invention was made in view of the current situation, and aims to enable continuous fermentation processing in a vertical fermentation tank that requires a small installation area without using special means for moving the processed materials. purpose. That is, the present invention provides a suction hole connected to a suction device in the middle part of a vertical fermentation tank that has an input port at the top and an output port at the bottom, and whose diameter increases downward.
In addition, air is supplied from the top and bottom of the fermenter, and the suction hole is located in a vertical position near the bottom of the fermenter so that more air is supplied from the bottom than from the top of the fermenter. It is a type fermentation device.

Hereinafter, the present invention will be explained in detail with reference to the drawings.

FIG. 1 is an explanatory diagram showing a vertical fermentation apparatus according to the present invention. In the figure, 1 is a fermentation tank, which has an elongated shape whose diameter gradually increases downward. At the top of the fermenter 1, there is provided an inlet 4 for the material to be treated, which is connected to a bucket conveyor 3 having an inlet 2 below. Further, at the lower part of the fermenter 1, an outlet 5 is provided for taking out the fermented product. The intake port 4 and the outlet port 5 are open and also serve as an air supply port.

Directly above the outlet 5, a rotary damper 6 is provided with blades attached around the shaft. This rotary damper 6 supports the processed material introduced into the fermenter 1, and also takes out the fermented product from the outlet 5.
It has the function of scraping it down. Air entering from the outlet 5, which is also an air supply port, is sent into the fermenter 1 through the gap between the rotary dampers 6.

A suction pipe 7 is inserted in the middle of the fermenter 1 so as to cross the inside of the fermenter 1, and around this suction pipe 7, a large number of small suction holes 8 are bored. has been done. The suction pipe 7 is connected to the suction side of the blower 10 via a strainer tank 9 for removing dust. The blowing side of the blower 10 is branched into an exhaust pipe 12 having a valve 11a and a circulation pipe 13 having a valve 11b and connected to the upper part of the fermenter 1.

Note that 14 is a transfer conveyor for carrying out the fermented product dropped from the outlet 5 to a depositing place or the like.

From input port 2 to bucket conveyor 3 and intake port 4
The processed material sent into the fermenter 1 through the suction hole 8
The fermentation process is carried out aerobically by suctioning the inside of the fermentation tank 1 with a blower 10 and using air supplied from the intake port 4 and the output port 5 and the circulation pipe 13. That is, when the rotary damper 6 is rotated to take out the fermented product from the lower part of the fermenter 1, and the processed material is replenished from the intake port 4 in proportion to the amount, the temperature inside the fermenter 1, which has been increased due to fermentation, decreases. Fermentation is quickly started by the air supplied from the top of the fermenter 1. Then, after a certain period of time has elapsed, the rotary damper 6 is rotated again to take out a predetermined amount of the fermented product, and at the same time, the processed material is replenished from the intake port 4. By repeating this process, the fermentation tank 1
The processed material inside is fermented and moved downward,
The fermentation product is ultimately extracted as a fermented product to be used as fertilizer or soil improver.

In this way, the processed material is scraped off by the rotary damper 6 and is moved downward by its own weight, but especially in the case of this device, the diameter of the fermenter 1 gradually expands downward. Because of the shape, the processed material does not cause bridging within the fermenter 1, and the falling movement of the processed material is not hindered. Therefore, the fermentation process can be carried out continuously without using any special means for moving the processed materials.

Furthermore, since the fermenter 1 is vertical, it is possible to install a device that can ferment a large amount of material with a small installation area, and the fermenter 1 can be heated by suction from the middle part of the fermenter 1. Since air is supplied from above and below, even if it is vertical, air can be supplied to the entire area without difficulty. In addition, treated materials such as human and animal excrement and sewage sludge are mixed with moisture regulators such as sawdust and defatted bran as needed so that the water content is around 40 to 60%, and then sent to the fermenter 1. However, it would be more effective if it was granulated to aid air supply.

The suction pipe 7 may be a single suction pipe or a plurality of suction pipes, but it is necessary that the suction pipe 7 does not obstruct the falling movement of the material to be treated. Further, in order to uniformly draw suction from the surrounding area, it is preferable that the suction pipe 7 is shaped like a cross, as shown in FIG. Further, in addition to inserting the suction pipe 7 and providing the suction hole 8 therein, it is also possible to provide a suction hole 8 around the fermenter 1 .

The suction hole 8 is located slightly below the fermenter 1 so that more air is supplied from the bottom of the fermenter 1 than from the top. As a result, fermentation of the processed material introduced from the intake port 4 is promoted in the upper layer with the suction hole 8 as a boundary, and as it moves to the lower layer, it is cooled and dried by a large amount of supplied air, and is brought into a dry state. It can be extracted as a good fermented product, that is, as a high-quality fertilizer or soil conditioner. Therefore, there is no need to provide a separate drying device to dry the fermented product taken out from the fermenter 1.

The position of the suction hole 8 depends on the shape and size of the fermenter 1,
Although it varies somewhat depending on the condition of the material to be treated, the amount of input, and the state of air supply from the upper and lower parts of the fermenter 1, as a result of experiments conducted by the present inventor using an apparatus as shown in the examples described later, the fermentation It has been confirmed that it is preferable to set the position 30 to 40% from the bottom of the part where the treated material is deposited in the tank 1 in order to obtain the above-mentioned effects.

Although the circulation pipe 13 is not necessarily required, it is preferable to provide it in order to promote fermentation and deodorize the exhaust gas. In other words, the exhaust gas from the fermenter 1 sucked through the suction hole 7 is considerably warmed and humidified by the fermentation heat. Therefore, if this is returned to the upper part of fermenter 1,
This helps raise the temperature of the newly introduced material to be processed, and prevents moisture from being removed from the material to be processed in the early stages of fermentation, resulting in a better start-up of fermentation. In addition, the sucked exhaust gas contains a large amount of malodorous components such as ammonia and hydrogen sulfide, but by returning this to the fermenter 1, these are adsorbed to the fermentation process and the fermentation process is carried out. Exhaust pipe 12
This can greatly reduce the odor of exhaust gas emitted from the air. In particular, Japanese Unexamined Patent Publication No. 1983-1981 relating to the invention of the present inventor
As shown in No. 92684 (Japanese Patent Application No. 158161/1983), fermentation at pH 9 to 12 in the presence of ammonia provides a good fermentation condition with a high fermentation temperature, but the ammonia contained in the processed material Since ammonia tends to be insufficient in the active fermentation zone near the suction hole 7, where a large amount of ammonia is scattered in the initial stage, it is also possible to maintain a good fermentation state by replenishing this zone with ammonia.

When the circulation pipe 13 is provided, the circulating exhaust gas also contains a sufficient amount of air necessary for fermentation, so the intake port 4 can be sealed to completely prevent drying of the processed material in the upper layer. You can expect it. Furthermore, in order to adjust the moisture content of the processed material, separated waste water or water can be showered from the top of the fermenter 1 to prevent the processed material in the upper layer of the fermenter 1 from drying out.

Next, an example will be described.

Example Using the apparatus shown in Figure 1, sewage sludge (70% moisture, 39% organic content) and seed sludge (30% moisture, organic A mixture (water content: 43%, organic content: 33.5%, apparent density: 0.82) was fermented in a ratio of 1:2. The fermenter has an upper part of 1.2×
1.1m, bottom 1.2 x 1.6m, height 3.16m, capacity approximately 6
m ³ , trapezoidal, 4-inch pipe with 10 mm diameter holes drilled in a staggered manner at 100 mm intervals, 1.68 mm from the bottom.
It was inserted at position m to serve as a suction pipe. 20 to 60 with a ring blower (302A type) from this suction pipe
/minton of said mixture while suctioning at a rate of
4.92 tons were added at a rate of 0.82 tons each day for 6 days. The fermented product taken out after 6 days had a 10% decrease in organic content compared to when it was first introduced, and was in good dry condition. Additionally, there was almost no odor from the exhaust gas emitted from the exhaust pipe during treatment.

[Brief explanation of the drawing]

FIG. 1 is a construction diagram of a vertical fermentation apparatus according to the present invention. 1: Fermentation tank, 2: Inlet, 3: Bucket conveyor, 4: Inlet, 5: Outlet, 6: Rotary damper, 7: Suction pipe, 8: Suction hole, 9: Strainer tank, 10: Blower, 11a, 11
b: Valve, 12: Exhaust pipe, 13: Circulation pipe.

Claims (1)

[Scope of Claims] 1. A vertical fermentation tank having an inlet at the top and an outlet at the bottom, the diameter of which expands downward, has a suction hole connected to a suction device in the middle part of the fermentation tank. The fermenter is characterized in that air is supplied from the top and bottom, and the suction hole is positioned toward the bottom of the fermenter so that more air is supplied from the bottom than from the top of the fermenter. Vertical fermentation equipment. 2. The vertical fermentation apparatus according to claim 1, wherein the suction holes are a large number of small holes bored around a suction pipe inserted across the inside of the fermenter. 3. The vertical fermentation apparatus according to claim 1, further comprising a circulation pipe for returning part of the exhaust gas sucked out from the suction hole to the fermentation tank from the upper part.