JPH0243520Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to an apparatus for anaerobically digesting (methane fermentation) organic wastewater such as sewage sludge, other organic sludge, alcohol distillation waste liquid, and human waste. .

[Prior art]

In order to effectively carry out anaerobic digestion of organic sludge and organic sewage, it is necessary to heat the anaerobic digestion tank to around 35℃, and conventionally, the heat source for this heating was generated using heat generated within the digestion tank. It used digested gas (mainly composed of methane).

[Problem that the invention attempts to solve]

In this way, in the past, most of the digestion gas generated from the anaerobic digestion process was consumed to heat the digestion tank, but the energy contained in the digestion gas can be effectively used for drying the sludge cake, incineration, heating the inside of the building, etc. I couldn't do it.

The present invention aims to provide an apparatus that can heat an anaerobic digestion tank in an energy-saving manner without relying on digestion gas, and can effectively utilize the digestion gas for other purposes.

[Means for solving problems]

The present invention has a digestion tank that performs anaerobic digestion and a blower that aerates organic sewage or sludge, and the digested material in the digestion tank and/or the material to be fed to the digestion tank is directly connected to the air discharged from the blower. The anaerobic digestion apparatus is characterized in that a flow path is provided that allows air to flow into the digestion tank through a blower discharge air piping system that is configured to make contact with the blower discharge air.

〔Example〕

One embodiment of the present invention will be described with reference to the drawings. Reference numeral 1 denotes a digestion tank that performs methane fermentation (anaerobic digestion) of methane fermentation targets such as sewage sludge and human waste. An aeration blower 3 having a discharge air piping system 4 for supplying aeration air to the aeration tank 2 is also installed.

Further, the inside of the digestion tank 1 is connected to the discharge air piping system 4 through a pipe 5 and a pipe 6, and a supply pipe 7 for the methane fermentation target is opened in the pipe 5 (the supply pipe 7 is connected to the discharge air piping system 4 through a pipe 5 and a pipe 6). ), the digested sludge 8 in the digestion tank 1 and/or the methane fermentation target supplied from the supply pipe 7 are passed from the pipe 5 to the discharge air piping system 4 and then from the pipe 6 to the digestion tank. 1.

Between the connecting parts 4' of the discharge air piping system 4 of these pipes 5 and 6, the digested sludge 8 in the digestion tank 1 and/or the methane fermentation target material supplied from the supply pipe 7 is transferred to the aeration blower 3. Direct gas-liquid contact with the discharge air is made to increase the heat recovery rate, and this part may be a simple pipe, but it may also be formed into a plate column as in the illustrated example, or a packed column. , it can also be formed into a wet wall tower.

In the figure, 9 is a digestive gas discharge pipe installed in the digestion tank 1;
10 is a digested sludge drawing pipe connected to a dehydrator 11 for obtaining a dehydrated cake 12; 13 is an inflow pipe for organic sewage or sludge guided to the aeration tank 2; 14;
indicates an outflow pipe for slurry flowing out from the aeration tank 2.

Next, to explain its operation, the digested sludge 8 in the digestion tank 1 and/or the methane fermentation target material supplied from the supply pipe 7 is transferred into the discharge air piping system 4 of the aeration blower 3 via the pipe 5. and introduce it. The temperature of the air discharged from the aeration blower 3 rises due to the adiabatic compression of the air, and reaches a temperature of approximately 60 to 80 degrees Celsius (this heat has rarely been effectively utilized in the past). Direct gas-liquid contact is performed with the digested sludge 8 and/or the methane fermentation target from the pipe 5, and the digested sludge 8 and/or the methane fermentation target is
It is heated to about 40℃, flows into the digestion tank 1 via the pipe 6, and the temperature inside the digestion tank 1 reaches 30 to 35℃.
℃, effective methane fermentation (anaerobic digestion) takes place.

Therefore, the digestion gas generated in the digestion tank 1 is discharged from the digestion gas discharge pipe 9, and the entire amount thereof can be effectively used as fuel for drying and incineration of the sludge dewatered cake, or for heating the inside of the building. Can be done.

Note that when the digested sludge 8 and the air discharged from the aeration blower 3 come into direct contact in the discharge air piping system 4, a foul odor such as hydrogen sulfide is generated from the digested sludge 8, but this foul odor component is naturally caused by organic sewage. Otherwise, it will be blown into the aeration tank 2 for sludge treatment, and a very convenient phenomenon will occur in which it is biologically deodorized by the bacteria present in large quantities in the aeration tank 2.
This means that no special deodorizing equipment is required.

Further, the digested sludge 8 in the digestion tank 1 is appropriately drawn out from the digested sludge drawing pipe 10 and dehydrated by a dehydrator 11 to become a dehydrated cake 12.

[Effect of idea]

As described above, the present invention has the following extremely beneficial effects.

Since the anaerobic digestion tank can be heated using the compressed heat of the air discharged from the aeration blower, the generated digestion gas can be effectively used for purposes other than heating the digester, such as drying and incinerating the sludge dewatering cake. As a result, energy savings can be achieved including in the sludge treatment process.

The fluid to be heated is heated in the discharge air piping system of the aeration blower by direct contact with the high temperature air discharged from the aeration blower, increasing the heat recovery rate, so an expensive heat exchanger is not required.

The bad odor generated from the digested sludge can be automatically blown into the organic sewage or sludge aeration tank for biological deodorization, so no special deodorization equipment is required.

[Brief explanation of the drawing]

The drawings are configuration explanatory diagrams showing one embodiment of the present invention. 1...Digestion tank, 2...Aeration tank,
3...Aeration blower, 4...Discharge air piping system,
5... Pipe line, 6... Pipe line, 7... Supply pipe, 8...
Digested sludge, 9... Digested gas discharge pipe, 10... Digested sludge withdrawal pipe, 11... Dehydrator, 12... Dehydrated cake, 13... Inflow pipe, 14... Outflow pipe.

Claims (1)

[Scope of utility model registration request] A digestion tank that performs anaerobic digestion and a blower that aerates organic sewage or sludge are installed together, and the digested material in the digestion tank and/or the feed to the digestion tank is brought into direct contact with the air discharged from the blower. An anaerobic digestion processing apparatus characterized in that a flow path is provided that allows air to flow into the digestion tank through the configured blower discharge piping system.