JPH0310672A - Fermentation tank having variable liquid capacity - Google Patents

Abstract

PURPOSE:To obtain the subject fermentation tank applicable to continuous fermentation process and facilitating the quality control of product by providing a sensor for detecting the volume of the reaction liquid and controlling a valve of the reaction liquid discharging port at the bottom of the tank. CONSTITUTION:A feeding port 5 connected with a raw material feed line 6 is attached to the top of a fermentation tank and a precipitation and separation part 11 for the solid-gas separation and a flow-control valve 14 connected to a reaction liquid discharge line are provided at the bottom of the tank. The objective fermentation tank is further provided with a flow rate sensor 15 to detect the reaction liquid volume by a liquid pressure detected by a diaphragm- type pressure sensor and the flow-control valve 14 is controlled by the signal detected by the flow rate sensor 15.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a fermentation reactor used for continuous fermentation of alcohol and the like, and more particularly to a fermenter in which the amount of liquid in the reaction system is variable.

[Prior art and its problems] Fermentation reactors used for continuous alcohol fermentation and other processes are usually continuous stirred tank reactors C5TR (Continuum).
ous 5tirred Tank Reactor
). In this method, a vertical cylindrical reaction tank is used, and raw materials are fed into the tank from the top or bottom of the tank, and the fermentation reaction liquid is discharged from the top by overflow, thus keeping the liquid volume in the reaction system constant. ing. In addition, the raw material supply amount and productivity are regulated by controlling the raw material supply pump, the reaction liquid discharge pump, and the like.

However, in this method, the range of flow rate adjustment is limited by the specified capacity of the pump, so it is difficult to flexibly adjust the flow rate according to the state of the fermentation reaction system. Additionally, in order to make the amount of liquid in the reaction system variable, it is necessary to take measures such as providing multiple overflow ports, but such measures would complicate the structure of the device and pose a problem in terms of microbial hygiene. It becomes a problem.

The present inventors have overcome the technical problems as described above and ? a
To provide a variable volume fermenter (as a result of extensive research, we have completed this invention.

[Means for Solving Problems] The liquid volume variable fermenter according to the present invention has a raw material supply port at the top and a reaction liquid discharge port at the bottom, and has a reaction liquid discharge port by detecting the reaction liquid volume. It is characterized by being equipped with a liquid level sensor that sends a signal to control the flow rate adjustment valve.

A diaphragm pressure sensor is preferably used as the flow rate sensor. This detects the amount of liquid by measuring the liquid pressure.

Centrifugal pumps are used as the raw material supply pump and the reaction liquid discharge pump. These pumps are always operated at a constant capacity, regardless of their specified capacity. therefore,
Depending on the state of the fermentation reaction system, from low flow rate operation for maturation of fermentation bacteria at the initial stage of operation to high performance operation during steady operation,
By changing the setting value of the liquid amount sensor, the flow rate of the reaction liquid, that is, the productivity can be easily adjusted. Moreover, since the amount of raw material supplied is stable, the linear velocity of the rising liquid in the reaction tank is kept constant. Therefore, this fermenter is particularly effective in processes that require the flow of immobilized cells, such as the immobilized cell method.

The fermenter according to the invention preferably includes a sedimentation section for solid-gas-liquid separation at the bottom. The sedimentation separation section is composed of an inclined pipe installed diagonally upward on the side of the bottom of the tank. The diameter of this inclined tube is set to be large enough to separate the immobilized bacterial cells from the generated gas bubbles. In the upper half, bubbles of generated gas cause an upward flow, and in the lower half, a downward flow of immobilized bacterial cells occurs, resulting in effective solid-gas-liquid separation. The sedimentation separation section also serves as a reaction liquid discharge port, and the fermentation reaction liquid is discharged from the extraction port provided at the upper end of the sedimentation separation section to the outside of the reaction system via a discharge pump.

In the fermentation industry, stirring and aeration of fermentation raw materials, as well as treatment of foam generated by fermentation reactions, are major problems, and in practice these problems are addressed by adding expensive antifoaming agents.

The fermenter according to the present invention is equipped with a heating device for defoaming at the top.

As the heating device, one having a simple structure such as a steam blowing pipe having a large number of nozzle holes is preferably used. Due to the installation of this heating device, the gas bubbles generated in the fermenter are easily destroyed by their own thermal expansion when approaching the heating device. Therefore, as before,
There is no need to add expensive antifoaming agents to the fermenter.

Therefore, there is no risk that such antifoaming agent residues will be mixed into the product, and product quality control becomes easier.

〔Example〕

Next, the present invention will be specifically explained based on illustrated embodiments.

In FIG. 1, a variable liquid volume fermenter (1
) is of the basic C5TR method. Fermenter (1)
The diameter is 1420IIa+, the height is 47301m, and the capacity is about 7000/. A stirring device (2) is installed in the center of the fermenter and hangs down from the top.
) is located at the bottom. Above the top of the tank is a stirring device (2
) is provided.

There is a raw material supply port (5) with an inner diameter of 50 mm on the top wall of the fermenter (1).
is provided, to which a raw material supply line (6) is connected,
A raw material supply pump (7) is provided in the same line (6). This pump (7) is a centrifugal pump with a discharge rate of 600 to 800/hr.

A steam inlet (8) with an inner diameter of 20 cm is also provided on the top wall of the fermenter (1), and an annular steam blowing pipe (9) is connected to the inner end of the inlet (8). The blowing pipe (9) has a large number of nozzle holes (10) provided at equal intervals in the length direction, and water vapor with a steam pressure of about 5 kg/crp2 is introduced into the top of the tank from these nozzle holes 10). be done.

At the bottom of the fermenter (1), there is a settling section (for solid-gas separation).
11) is provided. The sedimentation separation section (11) is composed of an inclined pipe installed at the bottom side of the tank. The diameter of this inclined tube is set to be large enough to separate the immobilized bacterial cells from the generated gas bubbles. In the upper half, bubbles of generated gas cause an upward flow, and in the lower half, a downward flow of immobilized bacterial cells occurs, resulting in effective solid-gas-liquid separation.

The sedimentation separation section (11) provided at the bottom of the tank also serves as a reaction liquid outlet. After the fermentation reaction liquid travels up the sedimentation separation unit (11), it is passed from the extraction port provided at the upper end of the sedimentation separation unit (11) via the reaction liquid discharge line (12) through the discharge pump (13) and the Am adjustment valve (14). It is discharged outside the reaction system. The discharge pump (13) has a discharge amount of 600
It is a centrifugal pump with ~8001/hour.

A flow rate sensor (15) is attached to the bottom side of the fermenter (]). This sensor (15) is a diaphragm pressure sensor, and reacts with hydraulic pressure.
&Q is detected and a signal is sent to the flow rate adjustment valve (14) of the reaction liquid discharge line (12) to control this. Therefore, by changing the set value of the liquid level sensor (15), the above-mentioned valve control is performed, and the fermentation tank (1) is
The amount of reaction liquid in the container can be changed as appropriate, and as a result, productivity can be easily adjusted.

Operation Example In the fermenter (1) shown in FIG. 1, a continuous alcohol fermentation test was carried out using Zymomonas bacteria attached and immobilized on vermiculite as the immobilized bacteria and blackstrap molasses as the fermentation raw material.

That is, first, 150 kg of vermiculite was put into the fermentation tank (1), and diluted blackstrap molasses containing 12% of total sugar was supplied to the fermentation tank (1). Raw material supply pump (7) and reaction liquid discharge pump (1
The discharge amount of 3) is 600 to 800/hour. Therefore, in normal continuous alcohol fermentation, low flow rate operation (residence time of about 1
0 hours) to high productivity operation during steady operation (residence time 2
It is difficult to stably control the flow rate over a wide range (up to 4 hours).

Therefore, in the initial stage of operation, in order to ensure a material residence time of 10 hours, the liquid volume setting value of the liquid volume sensor (15) installed at the bottom of the reaction tank (1) is set to 6000/h, and then the same setting value is 3000/, assuming that the pump flow rate is constant.
Continued driving.

This situation is shown in FIG.

As is clear from Figure 2, the residence time required for the maturation of fermentation bacteria at the initial stage of operation was stably secured, so the start-up of operation was smooth and subsequent operations were carried out without any problems. Ta.

[Effects of the Invention] The liquid volume variable fermenter according to the present invention has a raw material supply port at the top and a reaction liquid discharge port at the bottom, and detects the reaction liquid volume and adjusts the flow rate 1 for reaction liquid discharge. It is characterized by being equipped with a liquid level sensor that sends a signal to control the cooling valve, so it can be used from low flow rate operation for maturing fermentation bacteria at the initial stage of operation to high performance operation during steady operation. By changing the set value of the liquid amount sensor depending on the condition of the fermentation reaction system, the flow rate of the reaction liquid, that is, the productivity can be easily adjusted. Moreover, since the amount of raw material supplied is stable, the linear velocity of the rising liquid in the reaction tank is kept constant. Therefore, this fermenter is particularly effective in processes that require the flow of immobilized cells, such as the immobilized cell method.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view of a fermenter showing an embodiment of the present invention, and FIG. 2 is a graph showing the relationship between the number of operating days and concentration. (1)... Fermentation tank, (2)... Stirring device, (7)...
・・Raw material supply pump, (9) ・・Steam blowing pipe,
(11) ... Sedimentation separation section (reaction liquid outlet), (13
)...Discharge pump, (14)...Flow rate adjustment valve,
(15)...More than flow rate sensor

Claims (1)

[Claims] It has a raw material supply port at the top and a reaction liquid discharge port at the bottom, and is equipped with a liquid volume sensor that detects the volume of the reaction liquid and sends a signal to control the flow rate adjustment valve for discharging the reaction liquid. Features a variable liquid volume fermenter.