JP2001070990A - Reaction tank having stirring function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform stirring in a reaction tank without requiring excessive power. SOLUTION: A reaction tank 1 forming an airtight space to perform a fermentation process, the temporary storage tank 2 arranged to the upper part of the reaction tank 1 to form an airtight space, the pipeline 11 connecting the gaseous phase part 1a of the reaction tank 1 to the gaseous phase part 2a of the temporary storage tank 2, the siphon pipe 13 connecting the liquid phase part 1b of the reaction tank 1 to the liquid phase part 2b of the temporary storage tank 2 and the transfer system 14 for transferring the liquid in the reaction tank 2 are provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for stirring a reaction tank in a sludge regeneration treatment center, a methane fermentation facility, a fermentation industry, and the like, and more particularly to a reaction tank having a stirring function.

[0002]

2. Description of the Related Art In recent years, surplus sludge generated in biological treatment and the like in human waste treatment facilities has been composted and reused as a national policy. In the fermenter for composting the sludge, the fermentation liquid in the tank is stirred in order to perform fermentation suitably, and the stirring method is as follows. 1. A mechanical stirring method in which a stirring screw, a stirring paddle, and the like are immersed in a fermentation liquid and driven by a motor to generate a swirling flow in the tank and stir the fermentation liquid. 2. A pump stirring method in which the fermented liquid in the tank is forcibly circulated and stirred inside and outside the tank using a pump. 3. A gas stirring method in which biogas or the like is blown into a fermentation liquid using a blower, and the fermentation liquid is stirred by a circulating flow generated by a gas lift effect.

[0003]

However, in the above-mentioned conventional mechanical stirring system, when the tank is enlarged, very large screws and paddles are required, and the power required for driving the screws and paddles becomes excessive. Pump stirring can be applied even if the tank is enlarged, but the power is excessive to sufficiently stir the fermentation liquid in the tank. Gas agitation is very effective in the case of aerobic fermentation because aeration and agitation can be performed simultaneously. However, in anaerobic fermentation such as methane fermentation, the inside of the tank is made airtight so that biogas generated in the tank is circulated and agitated.However, biogas is often corrosive, so The durability decreases. In addition, when the tank becomes large, the power becomes excessive to sufficiently stir the fermentation liquid in the tank.

An object of the present invention is to solve the above-mentioned problem, and an object of the present invention is to provide a reaction tank having a stirring function that can stir the inside of the reaction tank without requiring excessive power.

[0005]

In order to solve the above-mentioned problems, a reaction tank having a stirring function according to the present invention according to claim 1 includes a reaction tank which forms an airtight space and performs a fermentation process;
It has a temporary storage tank arranged above the reaction tank to form an airtight space, a pipe connecting the gas phase of the reaction tank and the gas phase of the temporary storage tank, and a valve for opening and closing this pipe. And a siphon pipe communicating the liquid phase of the reaction tank with the liquid phase of the temporary storage tank.

With the above configuration, in the initial state,
The pressure control system is in a state where the communication between the reaction tank and the temporary storage tank is cut off by operating the valve. As the biogas is generated in the reaction tank, the biogas accumulates in the gas phase of the reaction tank, the pressure of the gas phase of the reaction tank increases, and the pressure difference with the gas phase of the temporary storage tank increases. appear. When the gas phase of the reaction tank expands and acts as a force to push down the liquid surface of the liquid phase, the liquid in the tank of the reaction tank siphons due to the siphon effect according to the pressure difference between the gas phase and the temporary storage tank. It is pushed up to a temporary storage tank through a pipe.

After a predetermined time, it is detected that a predetermined amount of liquid in the temporary storage tank has accumulated in the temporary storage tank by, for example, a timer or measurement of the liquid level by a liquid level meter, and the valve of the pressure adjustment system is operated. The gas phase portions of the reaction tank and the temporary storage tank are communicated with each other to adjust them to an equal pressure. In this state, the liquid in the temporary storage tank stays in the temporary storage tank and rapidly flows into the reaction tank through the siphon pipe due to the water level difference between the liquid level in the temporary storage tank and the liquid level in the reaction tank. Is stirred.

After a certain period of time, it is detected that all the liquid in the temporary storage tank has flowed out, for example, by a timer or by measuring the liquid level with a liquid level gauge, and the valve of the pressure adjustment system is operated to initialize the tank. Return to. In this way, the power is used by storing the liquid in the tank in small amounts by using the pressure gradually rising with the generation of biogas and discharging the stored liquid in the tank at a time at a large flow rate. Without this, a large stirring effect can be obtained.

According to the second aspect of the present invention, the reaction tank having the stirring function of the present invention includes a reaction tank that forms an airtight space and performs a fermentation process, and a temporary storage tank that is disposed above the reaction tank to form an airtight space. A pipe connecting the gas phase of the reaction tank to the gas phase of the temporary storage tank, a siphon pipe connecting the liquid phase of the reaction tank to the liquid phase of the temporary storage tank, and a liquid in the tank of the reaction tank. And a transfer system for transferring to a temporary storage tank.

With the above configuration, in the initial state of the cycle, the liquid level in the temporary storage tank is at the lowermost position, and the liquid level in the siphon tube is at the same height as the liquid level in the reaction tank. The liquid in the reaction tank is quantitatively supplied to the temporary storage tank by the transfer system. The liquid level in the temporary storage tank exceeds the top of the siphon pipe, and the head of the temporary storage tank acting on the top of the siphon pipe is
When the liquid in the reaction tank exceeds the water head acting on the opening of the siphon pipe, the liquid in the tank staying in the temporary storage tank pushes out the biogas remaining in the siphon pipe to the reaction tank to form a siphon. The liquid rapidly flows into the reaction tank through the siphon tube, and the water flow stirs the inside of the reaction tank.

According to the third aspect of the present invention, there is provided a reaction tank having a stirring function according to the present invention, comprising: a reaction tank that forms an airtight space to carry out a fermentation process; and a temporary storage tank that is disposed above the reaction tank to form an airtight space. A pipe connecting the gas phase of the reaction tank to the gas phase of the temporary storage tank, a siphon pipe connecting the gas phase of the reaction tank to the liquid phase of the temporary storage tank, and a liquid in the tank of the reaction tank. And a transfer system for transferring to a temporary storage tank.

With the above configuration, in the initial state of the cycle, the liquid level in the temporary storage tank is at the lowest position. The liquid in the reaction tank is quantitatively supplied to the temporary storage tank by the transfer system. When the liquid level in the temporary storage tank exceeds the top of the siphon pipe, a siphon is established, and the liquid in the temporary storage tank falls sharply into the reaction tank through the siphon pipe, scum is crushed by this fall, and the Is stirred.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, a reaction tank 1 is responsible for a fermentation process using surplus sludge or the like generated in human waste treatment equipment as a raw material, and forms an airtight space. A temporary storage tank 2 is disposed above the reaction tank 1, and the temporary storage tank 2 forms an airtight space. A siphon pipe 3 communicates with the bottom of the temporary storage tank 2, and the siphon pipe 3 opens into the liquid in the reaction tank 1. The pressure regulating system 4 is connected to the gas phase section 1a of the reaction tank 1, the gas phase section 2a of the temporary storage tank 2 and a pipe communicating with the next system for processing biogas.
a, 2a and a plurality of valves 5a, 5
b, 5c are arranged. The pressure adjusting system 4 has a blower 6 and a pipe 7 which separately serve as a forcible pressure adjusting device, for pumping gas remaining in the gas phase portion 2a of the temporary storage tank 2 to the gas phase portion 1a of the reaction tank 1. A raw material supply system 8 and a fermentation product removal system 9 communicate with the reaction tank 1, and a liquid level meter 10 is provided in the temporary storage tank 2.

The operation of the above configuration will be described below. In the initial state, the pressure adjusting system 4
a of the gas phase part 2 of the temporary storage tank 2 is closed.
The valve 5b for a and the valve 5c for the next system are opened. In a state where the communication between the reaction tank 1 and the temporary storage tank 2 is cut off in the pressure adjusting system 4, the biogas accumulates in the gas phase portion 1 a of the reaction tank 1 as the biogas is generated in the reaction tank 1, and the reaction tank 1 As a result, the pressure of the gas phase 1 a rises, and a pressure difference is generated between the gas phase 2 a of the temporary storage tank 2. When the gas phase part 1a of the reaction tank 1 expands and acts as a force to push down the liquid surface of the liquid phase part 1b, the reaction tank 1 is simulated by the siphon effect according to the pressure difference between the gas phase part 2a and the temporary storage tank 2. Is pushed up to the temporary storage tank 2 through the siphon tube 3.

The measurement of the liquid level by the liquid level meter 10 detects that a predetermined amount of liquid in the temporary storage tank 2 has accumulated. This detection can be time measurement by a timer. Next, the valve 5a of the pressure adjustment system 4 is opened to communicate the gas phase portions 1a and 2a of the reaction tank 1 and the temporary storage tank 2 so as to adjust them to the same pressure. In this state, the liquid in the temporary storage tank 2 stays in the temporary storage tank 2 rapidly through the siphon pipe 3 due to the water level difference h between the liquid level of the liquid phase part 2b of the temporary storage tank 2 and the liquid level of the liquid phase part 1a of the reaction tank 1. Then, the liquid in the reaction tank 1 is stirred by the water flow.

When the liquid level in the temporary storage tank 2 is detected by measuring the liquid level with the liquid level meter 10, the valve 5a of the pressure adjusting system 4 is operated to return to the initial state. When the amount of biogas generated in the reaction tank 1 is small, the valves 5a, 5b, and 5c of the pressure adjusting system 4 are closed, and the biogas in the temporary storage tank 2 is pressure-fed to the reaction tank 1 by the blower 6, and 1 gas phase part 1a and temporary storage tank 2
A pressure difference is forcibly generated between the liquid and the gaseous phase part 2a, and a predetermined amount of liquid in the tank is stored in the temporary storage tank 2. Thereafter, the valves 5a and 5b are opened, and the liquid in the temporary storage tank 2 is allowed to flow down to the reaction tank 1 at a stretch through the siphon pipe 3 to stir the liquid in the tank.

Therefore, the liquid in the tank is stored little by little by utilizing the pressure gradually increasing with the generation of biogas,
By discharging the stored tank liquid at a large flow rate at a time,
A large stirring effect can be obtained. Moreover, basically, there is no need to use power, and even when power is used, less power is required. FIG. 2 shows another embodiment of the present invention. Components that perform the same operations as those in the previous embodiment are denoted by the same reference numerals, and description thereof is omitted. In FIG. 2, a gas phase portion 1a of the reaction tank 1 and a gas phase portion 2a of the temporary storage tank 2 communicate with each other via a pipe 11, and the pipe 11 has a valve 12 for opening to the atmosphere. The liquid phase portion 1b of the reaction tank 1 and the liquid phase portion 2b of the temporary storage tank 2 communicate with each other via a siphon tube 13, and the top portion 1 of the siphon tube 13
3a is an opening 1 of the siphon tube 13a in the temporary storage tank 2.
At a predetermined height from 3b, the distance is short. Reaction tank 1
A transfer system 14 for transferring the liquid in the reaction tank 1 to the temporary storage tank 2 is provided between the temporary storage tank 2 and the temporary storage tank 2, and the transfer system 14 has a pump 14a and a valve 14b.

With the above configuration, in the initial state of the cycle, the liquid level in the temporary storage tank 2 is at the lowermost position, and the liquid level inside the siphon tube 13 is at the same height as the liquid level in the reaction tank 1. A constant amount of the liquid in the reaction tank 1 is supplied to the temporary storage tank 2 by the pump 14 a of the transfer system 14. The liquid level in the temporary storage tank 2 exceeds the top 13a of the siphon pipe 13 and the head h1 of the temporary storage tank 2 acting on the top 13a of the siphon pipe 13b is moved to the opening 13 of the siphon pipe 13 in the reaction tank 1.
When the liquid exceeds the water head h2 acting on c, the liquid in the tank staying in the temporary storage tank 2 pushes out the biogas remaining in the siphon tube 13 to the reaction tank 1 to form a siphon, and the liquid in the tank in the temporary storage tank 2 The water rapidly flows down into the reaction tank 1 through the siphon tube 13, and the inside of the reaction tank 1 is stirred by the water flow. When the liquid level in the temporary storage tank 2 reaches the lowermost position, the siphon pipe 1
The opening 13b of No. 3 is exposed and the siphon breaks, returning to the initial state of the cycle.

FIG. 3 shows another embodiment of the present invention. Components that perform the same operations as those in the previous embodiment are denoted by the same reference numerals, and description thereof is omitted. In FIG. 3, the siphon tube 15 communicates the gas phase part 1 a of the reaction tank 1 and the liquid phase part 2 b of the temporary storage tank 2, and has a lower end opening to the ceiling part of the reaction tank 1. With the above configuration, in the initial state of the cycle, the liquid level of the temporary storage tank 2 is at the lowest position. A constant amount of the liquid in the reaction tank 1 is supplied to the temporary storage tank 2 by the pump 14 a of the transfer system 14. When the liquid level in the temporary storage tank 2 exceeds the top 15a of the siphon pipe 15, a siphon is established, and the liquid in the temporary storage tank 2 falls rapidly into the reaction tank 1 through the siphon pipe 15, and this drop causes the reaction tank 1 to drop. Is crushed, and the inside of the reaction tank 1 is stirred.

[0020]

As described above, according to the present invention, a siphon pipe is provided for communicating the reaction tank with the temporary storage tank, and the liquid in the temporary storage tank is allowed to flow down to the reaction tank at once. Thus, the inside of the reaction tank can be efficiently stirred without requiring excessive power.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating a configuration of a reaction tank according to an embodiment of the present invention.

FIG. 2 is a schematic diagram illustrating a configuration of a reaction tank according to another embodiment of the present invention.

FIG. 3 is a schematic diagram showing a configuration of a reaction tank according to another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Reaction tank 1a Gas-phase part 2 Temporary storage tank 2a Gas-phase part 3,13,15 Siphon pipe 4 Pressure regulation system 5a, 5b, 5c Valve 6 Blower 7 Pipe line 8 Raw material supply system 9 Fermentation product removal system 10 Liquid level meter

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Toshiyuki Shibata 2-47, Shikitsu-Higashi 1-chome, Namiwa-ku, Osaka-shi, Osaka (72) Inventor Shinichiro Wakahara Higashi-ichi, Shichitsu, Naniwa-ku, Osaka-shi, Osaka No.2-47 F-term in Kubota Corporation (reference) 4D059 AA02 AA05 BA48 BA60 BJ20 BK30 CA30 EA03

Claims (3)

[Claims] 1. A reaction tank that forms an airtight space and performs a fermentation process, a temporary storage tank that is disposed above the reaction tank to form an airtight space, a gas phase portion of the reaction tank, and a gas phase of the temporary storage tank. A pressure regulating system having a valve for opening and closing the pipe, and a siphon pipe for communicating the liquid phase of the reaction tank with the liquid phase of the temporary storage tank. A reaction tank having a characteristic stirring function. 2. A reaction tank for forming a hermetically sealed space and carrying out a fermentation process, a temporary storage tank disposed above the reaction tank to form an airtight space, a gas phase portion of the reaction tank and a gas phase of the temporary storage tank. And a transfer system for transferring the liquid in the reaction tank to the temporary storage tank, and a siphon pipe for connecting the liquid phase of the reaction tank to the liquid phase of the temporary storage tank. A reaction tank having a characteristic stirring function. 3. A reaction tank for forming a gas-tight space to carry out a fermentation process, a temporary storage tank disposed above the reaction tank to form a gas-tight space, a gas phase portion of the reaction tank, and a gas phase of the temporary storage tank. And a transfer system for transferring the liquid in the reaction tank to the temporary storage tank, and a siphon pipe for connecting the gas phase part of the reaction tank and the liquid phase part of the temporary storage tank. A reaction tank having a characteristic stirring function.