JPS624115B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a fermentation tank in which a lower part of the processing tank is provided with an outlet for the filling material that falls under its own weight within the tank, and a flow path for supplying oxygen-containing gas is connected to the tank. Regarding.

In the above method, even though the material to be processed is fermented by retaining it for a predetermined period of time, it may be taken out in an insufficiently fermented state, and in those cases,
Conventionally, this has generally been dealt with by extending the residence time. As a result, the fermentation treatment time became longer and the treatment efficiency decreased.

In view of the above points, an object of the present invention is to study various causes of poor fermentation, and to make simple improvements based on the study results to enable efficient fermentation treatment.

Next, embodiments of the present invention will be described in detail based on illustrative drawings.

A mixing device 3 is provided for mixing the sewage sludge supplied through the first hopper 1 and the seed sludge supplied through the second hopper 2, and the mixed product from the mixing device 3 is transferred to the air with a blower 4. While supplying oxygen gas through the supply path 5,
An aerobic fermentation tank 6 is provided to ferment the sewage sludge using aerobic bacteria, and the sewage sludge is either taken out as it is, or after taken out, it is composted by post-processing such as drying to obtain compost as a product. A device 7 is configured.

The fermentation tank 6 is configured by providing a hopper-like upwardly widening supply port 9 for supplying the processed material from the mixing device 3 in the upper part of the processing tank 6, and a downwardly narrowing outlet 10 in the lower part. And the falling path R of the filling
By installing dampers 11 in parallel in the middle and on the lower side, and opening and closing the dampers 11 with different levels in the vertical direction shifted for a predetermined time, the final damper can store, for example, about one day's worth of products. The amount of filling equivalent to the amount to be taken out is intermittently dropped,
The sludge is dropped onto a conveyor 12 that can be rotated in forward and reverse directions through the outlet 10, and a portion is transferred to a storage tank 13 as a seed sludge, and then supplied to a second hopper 2 by a conveyor 14, while the remainder is collected as a product in a recovery tank 15. It is configured to be stored.

A lid 17 is provided on the supply port 9 and can be driven open and closed by a hydraulic cylinder 16. In the space S above the upper or topmost damper 11 in the processing tank 6, the suction port 18 is placed on the upper side, and the discharge port 19 is placed on both the upper and lower sides of the suction port 18, or on either side thereof. In this position, a circulation channel 21 with a blower 20 interposed therein is connected, and with the lid 17 closed, excess air and carbon dioxide gas generated during fermentation are collected. The carbon dioxide gas is supplied into the filling, and the carbon dioxide gas is reacted with the water contained in the filling to generate carbonic acid, thereby lowering the atmosphere in the treatment tank 8 to pH 9 or lower.

Incidentally, if the properties of the filling material are PH9 or lower and there is no problem in the fermentation process, the blower 20 may be stopped. At that time, the suction port 18 is connected to the pipe 5 exiting from the blower 4 via the valve 8, and the suction port 18 is used to supply air, while the discharge ports 19, 19 are used to collect exhaust gas. , the entire amount of exhaust gas in the tank 6 is guided to the exhaust gas treatment device.

The oxygen gas to be supplied into the processing tank 6 is not limited to air, but may also be, for example, high-concentration oxygen gas, which is collectively referred to as oxygen-containing gas.

Scraping blades 22 are rotatably provided corresponding to the inclined surfaces f, f located at the center of the lowermost part of the lowermost damper 11, respectively, and although not shown, the lowermost damper 11 and It is configured to be driven in conjunction with each other, and when the damper 11 at the bottom is opened and the filled material is taken out as a product, it is configured so that it can be smoothly discharged without being retained on the slopes f, f. It has been done.

If necessary, an exhaust gas cooler may be provided in the circulating air path in order to remove moisture from the circulating air.

In summary, the present invention, in the above-mentioned fermenter, connects a flow path 21 in the processing tank 6 to take out gas from the upper tank space and to supply the taken out gas into the filling material in the vicinity thereof. characterized by something.

In other words, after various studies on the causes of poor fermentation, we found that alkaline components such as limestone were mixed in the material to be processed that was put into tank 6, and the atmosphere inside the tank was
We found that the fermentation rate significantly decreases when the pH is 9 or higher, and based on the above results, we further considered the fact that carbon dioxide gas is generated in the tank 6 during the fermentation process, and Focusing on the fact that the filling in the tank 6 contains water, we made a simple improvement by effectively utilizing these gases and supplying them into the filling, thereby reacting carbon dioxide gas with water to generate carbonic acid. The acidity of the carbonic acid can neutralize the atmosphere in the tank and quickly lower the pH to below 9, quickly avoiding an increase in the fermentation processing time due to the mixing of alkaline components in the input processed material. Fermentation processing can now be carried out efficiently.

[Brief explanation of the drawing]

The drawings illustrate embodiments of the fermenter according to the present invention, and FIG. 1 is a flow sheet of the composting apparatus, and FIG. 2 is a longitudinal sectional view of the fermenter. 5... Oxygen-containing gas supply channel, 6... Processing tank,
10... Outlet port, 21... Gas supply channel.

Claims (1)

[Claims] 1 A fermentation tank which is provided with an outlet 10 at the lower part of the processing tank 6 for the filling which falls under its own weight in the tank 6, and is connected with a flow path 5 for supplying oxygen-containing gas into the tank 6, A fermentation tank characterized in that, in the processing tank 6, a flow path 21 is connected to take out gas from the upper tank space and supply the taken out gas into a filling material in the vicinity thereof.