JPS624113B2 - - Google Patents

Abstract

PURPOSE:The floor that separates the fermentation and gas-exhausting chambers is projected upward at the peripheral part to make a space for collecting the exhausting gas and holes for blowing out the gas into the exhausting chamber are bored near the top of the projection, thus breaking foam produced during the fermentation continuously and steadily. CONSTITUTION:Air is blown from the pipe connected to the bottom of fermentation chamber 1 continuously, atomized by distributers 9 and accumulates as foam on the liquid surface. The foam is pushed up in turn by bubbles coming up from the bottom to come into projecting space 4 and blown out of holes 5 into air-exhaustion chamber 2 and defoamed. The gas is expelled from pipe 7 and the liquid fraction is circulated through pipe 8. The remaining bubbles reach near holes 5 and are broken by the high-speed air-liquid mixture and further by revolving defoamer 6.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an aerobic culture device and an aerobic culture method, and more particularly to an aerobic culture device and an aerobic culture method that can mechanically eliminate foam generated in a culture tank.

In general, the culture solution has a high foaming property, and when gas (generally air) is blown into the bottom of the culture tank, foam is generated at the top of the liquid level. Harmful effects such as overflowing from the mouth may occur.

Conventionally, the necessity of defoaming such generated foam has been recognized, and various proposals have been made, such as methods using defoaming agents or mechanical methods.

The method of using antifoaming agents has many unresolved aspects, including their physiological effects on microorganisms and safety when mixed into products.

As one of the mechanical methods, a widely known method is to blow out foam from an orifice or nozzle to eliminate the foam. However, with this defoaming means, complete defoaming is not achieved, and some foam accumulates in the exhaust chamber. The exhaust chamber is located in the body and above the culture tank, and has an orifice or nozzle that communicates with the culture tank and is provided for gas-liquid separation. Therefore, foam accumulation in the exhaust chamber inhibits the defoaming function.
This is because if the area around the opening of the orifice or nozzle is surrounded by foam, the gas blown out afterwards will act as a foaming agent, producing the opposite effect.

As another mechanical method, it is widely known to blow gas or a gas-liquid multiphase fluid onto the upper part of the foam tank at high speed to eliminate foam. However, with this defoaming means, it is necessary to supply a large amount of spraying fluid, and the power consumption associated with this is large. Moreover,
If the superficial velocity of the gas blown from the bottom of the culture tank is high, the antifoaming effect will not be as expected.

As another mechanical method, a means for defoaming using a rotary defoaming machine equipped with defoaming blades such as a propeller is also widely known. However, with this defoaming means, when the culture tank becomes large, it is necessary to treat exhaust gas containing a large amount of foam, and accordingly, the defoaming machine inevitably becomes larger. Increasing the size of the defoaming machine poses problems in manufacturing and maintenance. This is because the speed of the gas passing around the defoaming blade increases, thereby reducing the defoaming effect.

Therefore, when using a rotary defoamer, it is desirable to keep the gas velocity as low as possible.

The inventors have discovered a mechanical method that does not have the drawbacks of the prior art described above. One method is to blow out the foam generated in the culture tank from an orifice or nozzle through an exhaust pipe, and spray it onto the top of the foam remaining in the exhaust chamber (Japanese Patent Laid-Open No. 53-26384). ), and the other is an exhaust chamber that blows out the foam generated in the culture tank from the top of the tank through an exhaust pipe and an orifice or nozzle to break the foam, and a position that is at the same level or lower than the position of the foam outlet. This method uses a rotary defoaming machine that is equipped to perform defoaming operations (Japanese Patent Application Laid-open No.
- Publication No. 15488).

These methods use gas blown into the tank to blow out bubbles generated in the tank from an orifice or nozzle into an exhaust chamber to separate the primary gas.
The foam is either sprayed onto the top of the foam accumulated in the exhaust chamber, or in addition to this, the foam is defoamed using a rotary defoamer. By configuring the outlet to the exhaust chamber and the rotary defoamer in this manner, the outlet to the exhaust chamber can always be located above the top surface of the foam in the gas separation tank. , it was possible to most effectively perform the bubble breaking and gas separation effects that occur when foam is blown out. Note that when a rotary defoamer is installed, defoaming occurs after the primary gas is separated in the exhaust chamber, so it is not necessary to treat the entire amount of air blown into the culture tank. Therefore, the amount of gas passing through the defoaming blade is small, and it is possible to improve the defoaming effect.

The present invention further improves the defoaming technology previously proposed by the present inventors so that it can exhibit high performance even in large-capacity culture tanks.

An object of the present invention is to provide an aerobic culture device and an aerobic culture method that continuously and reliably eliminate foam generated during the culture process.

The present invention is characterized in that an exhaust chamber is installed in the upper part of the culture tank, and a plurality of protruding chambers (exhaust pipes) are provided to guide foam generated in the culture tank to the exhaust chamber.
A foam outlet such as an orifice or a nozzle is provided near the top end of each of the ejection chambers so as to spray the foam onto the upper portion of the foam accumulated in the exhaust chamber.

An embodiment of the present invention will be described below with reference to the drawings.

The inside of the body 100 is divided into a lower culture tank 1 and an upper exhaust chamber. A gas supply pipe 3 for culturing is provided at the bottom of the main body of the culture tank 1, and a return pipe 8 (described later) opens slightly above it. A plurality of protruding chambers 4 are vertically provided at the top of the culture tank 1. Inside the culture tank 1, five dispersion plates 9 such as perforated plates are provided in the longitudinal direction. Projection chamber 4
The outlet of each protruding chamber 4 opens into the exhaust chamber 2.
A plurality of air outlets 5 are provided in the vicinity of the upper tip. Further, in the exhaust chamber 2, a so-called rotary defoamer 6 is provided which rotates a defoaming blade (propeller) which is rotationally driven by an electric motor via a transmission device in order to break the accumulated foam. An exhaust pipe 7 is provided in the upper part of the exhaust chamber 2 to discharge the gas separated from the foam to the outside of the tank, and in the lower part of the exhaust chamber 2, the culture liquid separated from the foam is returned to the inside of the culture tank 1. A return pipe 8 is provided for this purpose.

The operation of this embodiment is as follows. Air is continuously blown into the culture tank 1 from a gas supply pipe 3 provided at the bottom thereof. This air rises in the culture solution charged in the culture tank 1. The rising air is subdivided by a dispersion plate 9. The fragmentation of the bubbles makes the gas-liquid contact more effective. The air bubbles that have become finer in this way move upward while repeating dispersion, coalescence, etc. The bubbles that reach the upper surface of the liquid charged in the culture tank 1 do not burst immediately, but become foam and accumulate on the upper surface of the liquid. The accumulated foam is pushed up by foam generated from below and enters the ejection chamber 4. The foam further rises within the ejection chamber 4, reaches the outlet 5, and is blown out into the exhaust chamber 2. When the foam is blown out, it undergoes a rapid pressure change and is broken. The gas that has been broken and separated is discharged to the outside of the tank from an exhaust pipe 7 provided at the top of the exhaust chamber, and the gas that has been separated and has a large liquid content is provided at the bottom of the exhaust chamber 2. The liquid is returned to the lower part of the culture tank 1 from the return pipe 8 by the driving force due to the head difference between the liquid and the liquid in the culture tank 1. By the way, the foam that is not broken due to the pressure change when being blown out from the outlet 5 remains in the exhaust chamber 2. The foam remaining in the exhaust chamber 2 gradually accumulates and reaches the vicinity of the outlet 5 provided near the upper part of the protrusion chamber 4 in the exhaust chamber 2. At this time, the high-speed gas-liquid multiphase fluid blown out from the outlet 5 collides with the upper surface of the stagnant foam. Here, this high-speed gas-liquid multiphase fluid blows through the foam layer retained in the exhaust chamber 2, thereby obtaining a defoaming effect. In addition, a rotary defoaming machine 6 is provided in the exhaust chamber 2, and the foam that stays in the exhaust chamber 2 and reaches the defoaming blades of the rotary defoaming machine 6 is removed from the rotating defoaming blades. The bubbles are broken by the impact. In this way, the foam accumulated in the exhaust chamber 2 is broken by the effects of the high-speed gas-liquid multiphase fluid from the outlet 5 and the impact of the defoaming blade of the rotary defoamer 6, and is separated. The separated gas is discharged to the outside of the body 100 through the exhaust pipe 7, and the separated liquid with increased apparent density moves to the lower part through the accumulated bubbles and is returned to the lower part of the culture tank 1 through the return pipe 8. be done. As described above, the bubbles generated by the air continuously blown from the gas supply pipe 3 at the bottom of the culture tank 1 are continuously broken in the exhaust chamber 2 and separated into gas and liquid. , the gas is in the exhaust pipe 7
The liquid is then drained back into the culture tank 1 through the return pipe 8 to achieve a continuous defoaming effect.

Next, each component will be explained in more detail. First, in order to facilitate the installation of the exhaust chamber 2 into the culture tank 1, it is better to provide it directly above the culture tank 1 rather than to place it apart from the culture tank 1 and to the side. The capacity and position of the exhaust chamber 2 are determined in consideration of the size of the culture tank 1, the amount of ventilation, etc. The protrusion chamber 4 that guides the foam from the culture tank 1 to the exhaust chamber 2 is installed directly vertically from the culture tank 1, and as shown in FIG. In order to avoid this problem, it is better to arrange the plurality of protruding chambers 4 evenly within the cross section of the exhaust gas 2. This protrusion chamber 4
The height, that is, the distance from the bottom of the exhaust chamber 2 to the foam outlet 5, is determined in consideration of the amount of liquid remaining in the exhaust chamber 2, etc. If the outlet 5, such as an orifice or nozzle, provided at the outlet of the ejection chamber 4 is located at the bottom of the exhaust chamber 2, it will be quickly covered with accumulated foam, and the bubble-breaking effect of blowing out will be lost. It is better to provide it near the upper tip of the protruding chamber 4. Further, the blowing direction of the blowing outlet 5 is oriented horizontally or slightly diagonally downward in order to blow onto the upper surface of the foam layer accumulated in the exhaust chamber 2. Although FIG. 2 shows the case where the air is blown out perpendicularly to the circumference of the ejection chamber 4, the air may be blown out in a tangential direction to the circumference of the ejection chamber 4 as shown in FIG. The number of blow-off ports 5 is determined based on the blow-off speed, pressure loss, etc., taking into account the amount of air blown into the culture tank 1, and is arranged so that the foam can be sprayed over the entire upper surface of the foam remaining in the exhaust chamber 2. Moreover, if the opening of the air outlet 5 is made variable,
Since the blowing speed can be adjusted to the optimum speed according to the amount of aeration blown into the culture tank 1, it is possible to cope with a decrease in defoaming ability and an increase in pressure loss due to changes in the amount of aeration. The rotary defoamer 6 is particularly effective when the foaming property is strong and the foam cannot be defoamed only by blowing the foam into the exhaust chamber 2. However, in order to achieve the effect, the position of the blowout port 5 and the It should be installed so that defoaming operation can be performed at the same level or lower. In FIG. 1, the return pipe 8 is exposed to the outside of the body 100, but if the foam is relatively easily defoamed, it can be allowed to hang inside the culture tank 1 as shown in FIG. The number of return pipes 8 is determined depending on the size of the culture tank 1, the amount of circulating fluid, etc.

According to this embodiment, foam is generated sequentially during the culture process, and the foam is pushed up by the foam and is blown out from the outlet 5, thereby making use of the defoaming effect. It is possible to defoamer continuously and reliably. In addition, even if the culture tank 1 has a large capacity and the amount of air blown into the culture tank 1 increases, each air outlet 5 can effectively separate the liquid and gas that occur when foam is blown out. can be done. Since the air outlet 5 makes it possible to evenly spray the foam accumulated in the upper part of the exhaust chamber 2 evenly over the entire upper part thereof, it is possible to eliminate the unevenness of the defoaming surface within the exhaust chamber 2. Furthermore, since the rotary defoaming machine 6 is provided, defoaming is performed after the single carrier gas is separated in the exhaust chamber 2, and there is no need to treat the entire amount of air blown into the culture tank 1. As a result, the amount of air passing through the defoaming blade is small, and the defoaming effect can be improved.

As shown in FIG. 5, if a collision surface such as a baffle plate 10 is formed between the foam outlet 5 and the rotary defoamer 6, the foam-breaking effect can be improved and the rotary defoamer can be improved. The influence on the defoaming surface of No. 6 can be reduced. Further, if a splash prevention plate is provided on the exhaust pipe 7, splashes from the exhaust chamber 2 can be completely prevented. Although the invention has been described above in the scope of batch culture, it goes without saying that the present invention is also applicable to continuous culture.

According to the present invention, there is an effect that foam generated during the culture process can be defoamed continuously and reliably.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of an aerobic culture device showing an embodiment of the present invention, Fig. 2 is a view taken along the arrow A-A in Fig. 1, and Fig. 3 is a modification of the foam blowout shown in Fig. 2. FIG. 4 is a sectional view of an aerobic culture apparatus showing another embodiment of the present invention, and FIG. 5 is an explanatory drawing showing still another embodiment. 100...Body, 1...Culture tank, 2...Exhaust chamber, 3...Gas supply pipe, 4...Protrusion chamber, 5...Blowout port, 6...Rotary defoamer, 7...Exhaust pipe .

Claims (1)

[Scope of Claims] 1 Preferably, it has a culture tank and an exhaust chamber located above the tank in the body, a gas supply pipe opens into the culture tank, and an exhaust pipe opens into the exhaust chamber. In the aerobic culture device, the upper part of the culture tank partially projects into the exhaust chamber to form a plurality of projecting chambers that guide bubbles generated in the culture tank, and the projecting chambers have a plurality of projecting chambers that are formed from inside the projecting chambers. An aerobic culture apparatus characterized in that an air outlet for blowing out the foam toward the exhaust chamber is provided. 2. The aerobic culture apparatus according to claim 1, characterized in that a defoaming mechanism is provided in the exhaust chamber at a height comparable to or lower than the air outlet. 3. The aerobic culture apparatus according to claim 2, wherein the defoaming mechanism is a rotary defoamer such as a propeller. 4. Gas is supplied to the culture tank provided in the body to create an aerobic atmosphere, and the foam generated during the culture process is guided to an exhaust chamber provided separately from the culture tank in the body. In an aerobic culture method in which gas is exhausted after foam is extinguished, the foam is introduced into a plurality of ejection chambers that are opened at the upper part of the culture tank and protrude from the upper part into the evacuation chamber, and the foam is introduced into the ejection chamber. An aerobic culture method characterized in that the foam remaining in the exhaust chamber is defoamed by blowing from the inside of the ejection chamber toward the exhaust chamber using a provided blower outlet. 5. The preferred embodiment according to claim 4, characterized in that, in addition to defoaming by the outlet, defoaming is also carried out by a defoaming mechanism provided at a height comparable to or lower than the outlet. Temperament culture method. 6. The aerobic culture method according to claim 5, characterized in that the foam from the previous machine is defoamed by using a rotary defoamer such as a propeller as the defoaming mechanism.