JPS61124371A - Stationary acetic acid fermentation device - Google Patents

Abstract

PURPOSE:To obtain well-mellowed vinegar in high yield, by circulating a gas in a stationary acetic acid culture device through a gas exchange device provided with a gas transmitting film, removing a carbonic acid gas, supplying oxygen, cooling and dehumidifying the circulating gas by a cooling and dehumidifying device. CONSTITUTION:A preparation solution containing vinegar seed and a raw material is fed from the raw material tank 8 to the stationary acetic acid fermentation tank 1, acetic acid bacteria are added to the tank, and acetic acid fermentation is carried out. Simultaneously, the gas circulating blower 27 is operated, a gas in the fermentation tank 1 is partially circulated through the exhaust pipe 21 to the gas exchange device 22 equipped with a gas transmitting film, a carbonic acid gas in the gas is exhausted out of the system, and oxygen is taken in from the outside of the system and supplied. The circulating gas is passed through the gas cooling and dehumidifying device 30, the circulating gas is cooled, steam in the circulating gas is condensed and removed. Unrefined vinegar having finished fermentation is sent to the continuous solid-liquid separator 16, and an acetic acid bacteria film is removed, to give the aimed vinegar.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a stationary acetic acid fermentation apparatus, and more specifically, the present invention relates to a stationary acetic acid fermentation apparatus, and more specifically, a method for discharging gas that has become highly concentrated in a stationary acetic acid fermentation tank to the outside of the system, and removing gas that has become low in concentration within the tank. This invention relates to a stationary acetic acid fermentation device that is capable of cooling and dehumidifying gas while being introduced into the system.

The fermenters used for acetic acid fermentation include deep acetic acid fermenters that supply air into the moromi without stirring, static acetic acid fermenters that supply air only to the surface layer of the moromi without stirring, and tanks. There are fermenters of the type in which acetic acid bacteria cells are attached to the solid surface filled in the tank, and moromi is dripped or poured onto the solid surface.

In the case of a static acetic acid fermenter, air is generally supplied only by natural ventilation through a gap between the tank and the lid. Note that acetic acid fermentation can be promoted by artificially ventilating the gas phase in the fermenter to increase ventilation. However, if ventilation is increased, the alcohol, acetic acid, etc. in the moromi will scatter as vapor, leading to a decrease in yield, and the odor of acetic acid will reach outside the factory, raising concerns about environmental pollution.

As a means of promoting acetic acid fermentation while maintaining a high yield in static acetic acid fermentation, it is possible to replenish the consumed oxygen with 100% oxygen gas by circulating air, and adsorb and separate the generated carbon dioxide gas using a chemical. Proposed. Although this method is effective in preventing the vapors of alcohol and acetic acid from scattering, there are problems such as the acetic acid vapor is adsorbed by the carbon dioxide adsorbent, making it difficult to regenerate it, and the cost of supplying oxygen is high. , impractical.

An object of the present invention is to provide a stationary acetic acid fermentation apparatus that eliminates such problems.

By passing the gas discharged from the static acetic acid fermenter through a gas exchange device and then returning it to the fermenter, it is possible to almost eliminate the dissipation of alcohol and acetic acid, and moreover, it is possible to eliminate excess carbon dioxide gas. It turned out that some of it was removed and the oxygen was reinforced.

In this way, it is possible to maintain the oxygen concentration in the fermenter at about 18 to 21%. However, in this case, the time from preparation to completion of fermentation, that is, the fermentation time, is extended by 15 to 30% compared to when acetic acid fermentation is carried out in a normal static acetic acid fermenter. Moreover, water condensed in the piping leading from the fermenter to the gas exchange device flows into the gas exchange device, reducing the performance of the gas exchange device.

When we investigated the causes of the prolongation of fermentation time, we found that the temperature control of the gas phase in the fermenter was insufficient, and that the water vapor in the gas phase in the fermenter was close to saturation, causing water droplets produced by condensation to become saturated. It has become clear that the acetic acid bacteria that are floating on the surface of the acetic acid bacteria fall onto the film and block the oxygen supply to the acetic acid bacteria.

Therefore, a tank filled with a large amount of silica gel was installed in the pipe leading from the fermenter to the gas exchange device, and the pipe leading from the gas circulation blower to the fermenter was routed through a heat pump, so that the temperature of the gas phase inside the fermenter could be maintained. When the temperature was controlled to 32-35°C, the above troubles were resolved and the fermentation time could be kept to the same level as in normal cases.

However, this improved technology requires large amounts of silica gel;
It requires a lot of power to operate the heat pump, making it difficult to put it into practical use. The inventors of the present invention have studied methods for cooling and dehumidifying gas passing through a gas exchange device, that is, circulating gas, at low cost, and have devised a gas cooling dehumidifier shown in FIG. 2, and have completed the present invention. .

That is, the present invention provides a stationary acetic acid fermenter that can continuously supply and exhaust air, (b) a gas exchange device equipped with a gas permeable membrane, and (c) a system that can perform cooling and dehumidification by pressurization. This is a stationary acetic acid fermentation device equipped with a gas cooling dehumidifier and (d) blower, and connected through a piping system.

The apparatus of the present invention will be explained with reference to FIG.

As the stationary acetic acid fermentation tank 1 in the present invention, an existing one can be modified and used.
．． Oxygen concentration meter6. Exhaust lower, lead-out insulation material 3. Commonly used equipment such as manhole 2 is usually equipped. Furthermore, as ancillary equipment, a lead tank 17. Piping connecting the tank and the fermenter 15. A pump 14, piping connecting the tank and the shower nozzle, and a solid-liquid separator 16 are also added to the equipment system. Similarly, raw material tank 8. Heat exchanger 9° pump 10. Piping 11 and the like are also used as incidental equipment.

Although there are no particular restrictions on the shape of the stationary acetic acid fermentation tank, it is preferable that the upper part of the tank forming the gas phase part has a mirror-like structure, since gases can be mixed smoothly.

When the volume of the gas phase inside the fermenter becomes large, the turbulence of the gas increases depending on the temperature, which destroys the acetic acid bacteria film floating on the surface layer of the mash. According to experiments conducted by the present inventors, the oxygen consumption rate when the oxygen consumption rate is highest during acetic acid fermentation in a static acetic acid fermenter is QNg/hr in the gas phase. Volume: 1.5. ~2. A finishing touch is suitable.

Next, the gas exchange device 22 receives the gas discharged from the gas phase of the fermenter, and the fermenter! Part or all of the gas that has become highly concentrated inside the fermenter, i.e., carbon dioxide gas, is discharged outside the system, and the gas that has become low in concentration inside the fermenter, that is, oxygen (or air), is taken in from outside the system and replenished. It is something. Moreover, this device is required not to scatter gaseous alcohol or acetic acid outside the system.

As a gas exchange device having such a function, the present invention uses a device in which a gas permeable membrane is a silicone membrane, a silicone composite membrane, or the like. The device is equipped with an air suction port 23 and a gas exchange blower 24 through which fresh air is introduced. On the other hand, the gas-exchanged air containing carbon dioxide is discharged from the discharge port 25 to the outside of the yarn.

The circulating gas returned to the fermentation tank via the gas exchange device has an oxygen concentration of about 18 to 21%, and the accompanying gaseous alcohol and acetic acid are also returned as they are, but before being introduced into the fermentation tank, a gas cooling dehumidifier 30 is used. Let it pass.

The gas cooling dehumidifier 30 is shown in its -B form in Fig. 2, and the temperature of the gas increases or decreases as the pressure increases or decreases with gases other than ideal gases, and the gas containing nearly saturated water vapor increases or decreases. This method takes advantage of the fact that when pressure-cooled, water vapor condenses into water.

The gas in this gas cooling dehumidifier is pressurized, has a high concentration, has high thermal conductivity, and also has a high temperature due to the power consumption and pressurization of the blower. There is a large temperature difference between water and water, making it easy to cool. Therefore, it is not necessary to use excessively low-temperature cooling water, but the amount used can be small, and the heat transfer area of the cooling pipes can be relatively small.At this stage, the amount of water vapor per unit volume is Although there is not much difference, the partial pressure of water vapor in the total pressure of the gas decreases, making it possible to dehumidify.

The cooled and dehumidified gas is returned to the fermenter via the flow rate adjustment valve 33, but since the pressure inside the fermenter is approximately atmospheric pressure,
The returned gas is rapidly depressurized and its temperature further reduced. The temperature has decreased in this way, and the gas with reduced water vapor is returned to the fermenter and mixed with the gas in the tank, thereby making it possible to offset the increase in temperature and humidity in the fermenter.

In addition, since the pressure of the gas sent into the fermenter is higher than the pressure inside the fermenter, it is introduced in a jet stream, mixing the gas in the fermenter and making the temperature of the gas phase uniform. Cheap. Moreover, this jet stream of gas destroys the gas barrier between the acetic acid bacteria and the acetic acid bacteria membrane floating on the surface layer of the mortar, thus promoting the supply of oxygen to the acetic acid bacteria and contributing to shortening the fermentation time.

Since the cooled and dehumidified gas is forced into the fermenter, it promotes the evaporation of water in the fermentation tank and takes away a large amount of the heat of vaporization, increasing the cooling effect of the gas in the fermentation tank. do.

When operating the gas cooling dehumidifier at high pressure, it is necessary to increase the amount of gas circulation, in other words, when the oxygen consumption in the fermenter is large and the amount of heat generated is large. be. Therefore, the gas-cooled dehumidifier used in the present invention exhibits a large cooling capacity when the amount of heat generated in the fermenter is large, and is a rational cooler.

Next, embodiments of the device of the present invention will be described with reference to the drawings.

In Figure 1, 1 is a stationary acetic acid fermentation tank, 2 is a manhole, the lid and main body flange are coated with silicone rubber, a 3 mm thick sheet of polydimethylsiloxane is used as a gasket, and the lid is fixed with bolts. There is. 3 is a heat insulating material wrapped in styrofoam with a thickness of 0.
Covered with a 5mm stainless steel plate. 4 is a liquid thermometer, 5 is a gas phase thermometer, 6 is an oxygen gas concentration meter, and 7 is an exhaust port.

8 is a raw material tank, 9 is a heat exchanger, and 10 is a charging pump.

Reference numeral 11 denotes a charging pipe, in which the charging liquid stored in the raw material tank 8 is heated to 35° C. by a heat exchanger 9, and then transferred to the stationary acetic acid fermentation tank (■) via the charging pipe 11 using a charging pump 1O. send. 12 is a lead-in port, 13 is a draw-down valve, 14 is a lead-in pump, 15 is a lead-in pipe, and 16 is a continuous solid-liquid separator.

17 is a feeding tank, 18 is an in-tank cleaning pump, 19 is a sower nozzle, and 20 is a plate for receiving bacterial membrane.

When the fermentation is completed, open the pull-down valve 13 and remove the pull-out valve 12.
．． Unloading valve 13. Plumbing 15 via unloading pump 14
is sent to the continuous solid-liquid separator 16. The clear liquid from which the acetic acid bacteria membrane has been removed by the continuous solid-liquid separator 16 is sent to the feeding tank 1.
7 will be introduced.

When the unloading was almost completed, when the tank cleaning pump 1B was operated, the clear drawn liquid was sprayed from the shower nozzle 19 onto the inner wall of the stationary acetic acid fermentation tank 1, and it adhered to the inner wall of the stationary acetic acid fermentation tank 1. The acetic acid bacteria film can be washed away. In addition, when the liquid level in the fermenter 1 is lowered during the control process (in the process, when the liquid level passes the upper end of the plate 20, the acetic acid bacteria membrane is collected on the plate 20 along with a small amount of moromi). be done.

The collected acetic acid bacteria film will be used for the next preparation, when the liquid level in the static acetic acid fermentation tank 1 passes through the plate 20, the bacteria film plate will collect the acetic acid bacteria on the liquid level in the plate 20. The membrane floats on the surface of the preparation solution and is automatically inoculated with the acetic acid bacteria used previously.

21 is an exhaust pipe, 22 is a gas exchange device, 23 is an air suction port, 24 is a gas exchange blower, 925 is an air discharge port, 26 is an air supply pipe, 27 is a gas circulation blower, 128 is an inverter, 29 is a gas flow meter, 30 is a gas cooling dehumidifier.

A part of the gas in the static acetic acid fermenter l is transferred to the gas circulation blower 2.
7 through an exhaust pipe 21 to a gas exchange device 22 for gas exchange, and then an air supply pipe 26. Gas circulation blower 27, gas flow meter 29. The gas is supplied to the stationary acetic acid fermentation tank 1 again through the gas cooling dehumidifier 30.

The rotation speed of the gas circulation blower 27 can be freely changed by the inverter 28, and the flow rate of the circulating gas and the discharge pressure of the gas circulation blower 27 can also be adjusted.

Next, the gas cooling dehumidifier shown in FIG. 2 will be explained. 26A is a circulating gas inlet, 26B is a circulating gas outlet, 33
34 is a flow rate adjustment valve, 34 is a cooling pipe, 35 is a cooling water amount adjustment valve, 36 is a drain reservoir, 37 is a drain valve, 38 is a drain recovery pipe, 39 is a thermometer, and 40 is a pressure gauge.

The circulating gas whose temperature has been increased by being pressurized by the gas circulating blower 27 enters the gas cooling dehumidifier 30 from the circulating gas port 26A, is cooled by the cooling pipe 34, and the water vapor in the circulating gas is condensed and flows into the drain reservoir 36. Accumulate.

When the amount of drain in the drain reservoir 36 increases, the drain valve 37 is opened and the drain is returned to the stationary acetic acid fermentation tank 1 using the drain collection pipe 38.

The amount of cooling water flowing through the cooling pipe 34 is adjusted by a cooling water amount adjustment valve 35. The temperature of the supplied cooling water is usually 18
~24℃, and the circulating gas in the gas-cooled dehumidifier is 27~
Cooled to 35°C and dehumidified.

By incorporating an automatic control mechanism into the apparatus of the present invention, static acetic acid fermentation can be carried out more efficiently. FIG. 3 shows the am. In the figure, 41 is an automatic acidity measuring device, 42 is a programmable controller, and 43 is a power source. The automatic acidity measuring device 41 is operated by the programmable controller 42 immediately after the preparation and after the preparation is completed.
After that time and every hour thereafter, the acidity is measured by sampling and inputted into the programmable controller 42 together with the indicated value of the gas phase thermometer 5 at that time. The programmable controller 42 performs calculations based on the input data, uses the calculation results to control the frequency emitted by the inverter 28, and automatically adjusts the rotational speed of the gas circulation blower 27. This regulates the pressure within the gas-cooled dehumidifier and appropriately regulates the temperature of the gas fed into the fermenter. As a result, it is possible to control the temperature of the fermenter gas phase within a range of ±0.3°C of the set value. In addition, as is clear from FIG. 3, the heat exchanger 9. Feeding pump 10, feeding valve 13. The unloading pump 14 is also controlled by the programmable controller 42.

The capacity of the charging pump 10 is appropriately determined based on the capacity of the fermenter 1, but in the experiment, a constant flow pump was used which completes charging in 40 minutes. Therefore, the charging pump 10 is automatically stopped by the programmable controller 42 after 40 minutes have passed since the start of charging. Furthermore, when the measured acidity of the moromi reaches 4.90% or more, the programmable controller opens the circulation valve 13 and at the same time operates the circulation pump 14 to pump the moromi in the fermentation tank to the circulation port 121.
It is routed through the continuous solid-liquid separator 16 to the unloading tank 1.
Sent to 7.

Thereafter, operations are performed in the same manner as in the embodiment shown in FIG.

Next, an example in which static acetic acid fermentation was actually performed using the static acetic acid fermentation tank of the present invention will be described.

Example: Into a static acetic acid fermentation tank 1 with a capacity of 2.8 kl, a stock solution prepared by adjusting the seed vinegar and raw materials so that the alcohol content is 3.16% and the acidity is 2.0% is added from the raw material tank 8 using a heat exchanger 9. Heat to 35°C and pump the charging pump 10. It was supplied through the feed pipe 11.

(In the case of normal stationary acetic acid fermentation, there is a lot of alcohol scattering in the charging liquid, so alcohol'/74 degrees is set to 3.5%.) The volume of the charging liquid was set to be exactly 2.0 kl. The liquid transport capacity of the charging pump 10 is 3.0 d per hour, and 40 d per hour.
The charge was poured into the fermenter in portions.

Next, confirm that the temperature of the preparation liquid is 35°C with the liquid thermometer 4, open the manhole 2, inoculate the surface of the preparation liquid with preserved acetic acid bacteria for static acetic acid fermentation, and then open the manhole 2. closed.

Next, the gas exchange blower 24 is operated. Furthermore, the gas circulation blower 27 is operated with the inverter 28 set to the minimum rotation speed.

After the preparation is completed, a small sample is taken from the sampling cock 31 every 4 hours to measure the acidity, and the liquid thermometer 4 is used to measure the acidity.
．． Gas phase thermometer 5, oxygen gas concentration meter 6 and thermometer 39.
The reading on the pressure gauge 40 was also checked.

Based on the acidity measurement results, the rate of increase in acidity over the next four hours is predicted and the rotational speed of the gas circulation blower 27 is adjusted by the inverter 28.

Further, when the indicated value of the gas phase thermometer 5 falls below the set value, the rotation speed of the gas circulation blower 27 is lowered by the inverter 28. However, in this case, if the indicated value of the oxygen gas concentration meter also decreases, the cooling water amount adjustment valve 35 may be slightly closed.

In reality, inverter 2 is
8, it was possible to control the temperature and oxygen gas concentration in the stationary acetic acid fermentation tank by simply adjusting the rotation speed of the gas circulation blower 27.

The acidity measurement is continued by sampling from the sampling cock 31 every 4 hours, and when the measured acidity value reaches 4.9% or more, the circulation valve 13 is opened and the circulation pump 14 is operated to drain the fermented moromi. Pull-out valve 13 from the lead-in port 12. The clear liquid from which the acetic acid bacteria membrane has been removed is sent to the continuous solid-liquid separator 16 via the oil pipe 15 via the draw-down pump 14, and is transferred to the draw-down tank 1.
I saved it to 7.

The liquid transport capacity of the pulling pump 14 was 3 kl/hour, and the unloading was completed in about 40 minutes.

For the second and subsequent preparations, the acetic acid bacteria membrane left on the plate 20 could be used as it was, so the fermentation could be carried out without opening the manhole 2.

Table 1 shows a comparison of the average values of data obtained by repeating static acetic acid fermentation three times with those obtained by the conventional method.

As is clear from Table 1, a similar product can be produced even if the alcohol concentration of the charging solution is reduced from 3.5% in the conventional method to 3.16%. Furthermore, with the conventional method, the volume of production decreased by 6.5%, but according to the present invention, the decrease in volume of production almost disappeared.

As a result, the amount of raw alcohol used could be reduced by about 10%, and the product yield could be increased by about 7%.

However, with the method of the present invention, there are almost no routes for contamination with bacteria, so static acetic acid fermentation using only excellent acetic acid bacteria is possible, and compared to vinegar produced using conventional methods, A more mellow vinegar was created.

In addition, as a gas exchange device, the diameter is 1.5n+ and the length is approximately 1m.
Approximately 1,500 silicone hollow particles were bundled together, placed in a vinyl chloride column with a diameter of about 10 marks, the outside of the column was reinforced with metal, and two of the 4 pieces were connected in parallel.

When we sampled the gas discharged from the fermenter and analyzed it with a mass spectrometer after dehumidifying it, we found nitrogen and oxygen.

and argon ratio was 80:19:1. Also,
The gas that exited the gas exchange device was sampled in the same manner, and after dehumidification was analyzed using a mass spectrometer, and it was found to be nitrogen.

The ratio of oxygen and argon was 79:20:I.

The flow rate of the circulating gas was measured with a gas flow meter 29, and varied between below the lower measurement limit and 55Q1/min.

Further, the gas cooling dehumidifier 30 is a can with a capacity of 751 mm made of stainless steel with a wall thickness of 5 mm. The cooling pipe 34 has a diameter of 1
9 Tsuru uses a coiled stainless steel pipe with a wall thickness of 1m, and uses water at a temperature of 18 to 24 degrees Celsius to flow at 300 to 5,000 liters per hour.
It flowed. The pressure and temperature of the gas in the gas cooling dehumidifier varied depending on the rotation speed of the gas circulation blower 27, but the reading on the thermometer 39 was 27 to 35°C, and the reading on the pressure gauge 40 was 1.
It was in the range of ~3 atmospheres.

Furthermore, the temperature of the gas phase within the fermenter was maintained at 35±0.3°C.

[Brief explanation of the drawing]

FIGS. 1 and 3 are schematic diagrams showing an embodiment of the apparatus of the present invention, and FIG. 2 is a schematic diagram showing an embodiment of a gas-cooled dehumidifier used in the present invention. 1... Stationary acetic acid fermenter, 8... Raw material tank. 17... Leading tank, 22... Gas exchange device. 27... Gas circulation blower 2 30... Gas cooling dehumidifier

Claims (1)

[Claims] (a) A stationary acetic acid fermenter capable of continuously supplying and exhausting air, (b) A gas exchange device equipped with a gas permeable membrane, (
c) A stationary acetic acid fermentation device equipped with a gas-cooled dehumidifier capable of cooling and dehumidifying under pressure and (d) a blower and connected through a piping system.