JPH072110B2 - Continuous sterilizer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a continuous sterilizer. More specifically, it relates to a continuous sterilization apparatus suitable for continuous culture.

(B) Conventional technology In order to sterilize a liquid medium, it is necessary to keep it at a predetermined high temperature for a predetermined time. In the case of fermentation of microorganisms and the like, as a method of continuously sterilizing a liquid medium for fermentation to be supplied to a fermenter, a medium supply pipe line arranged from the medium supply tank to the fermenter has a double tube structure, The medium is transferred to the inner line of this line and steam is passed to the outer line to sterilize the medium by heat treatment during the transfer of the line. In such a case, continuous sterilization will be achieved, for example, by holding the medium transferred through the above-mentioned conduit for at least 120 ° C. for 10 minutes.

(C) Problems to be Solved by the Invention However, in the above method, it takes time to heat and the temperature distribution of the medium becomes uneven. This means that when sugar is contained in the medium, the medium is kept at a high temperature for a long time to cause coupling, resulting in deterioration of the medium.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a continuous sterilizer capable of continuously sterilizing a medium by high-temperature treatment in a short time.

(D) Means for Solving the Problems Thus, according to the present invention, the steam heating sterilization tank and the liquid heated therein are provided on the flow path for transferring the liquid medium from the liquid medium supply unit to the culture tank or the medium temporary storage tank. A flow path for holding the culture medium for a short time and a flow path for heat exchange cooling to a predetermined temperature are provided, and the sterilization tank is provided with a steam supply unit equipped with a supply amount adjusting means, and the tank is provided with the steam supply unit. There is provided a continuous sterilizer having a steam supply port near the inner bottom.

According to the present invention, the liquid medium is brought into direct contact with the high-pressure steam during the transfer to instantly heat it to a predetermined temperature, and the heating state is transferred for a predetermined time so that the liquid medium is transferred directly and continuously on the transfer channel. The apparatus is characterized in that it can be sterilized.

The liquid culture medium supply unit used in the device of the present invention is preferably configured by a liquid culture medium storage tank and a liquid feed pump for feeding the liquid culture medium to the flow channel. The liquid delivery pump may be any pump such as a peristaltic pump or a plunger pump.

The steam heating sterilization tank used in the apparatus of the present invention is composed of a culture medium storage section having an introduction path and a discharge path connectable to the liquid culture medium transfer flow path, and a steam supply section connected to this. The steam supply unit is composed of a steam generator and a steam introduction pipe connected to the medium storage unit from the steam generator via a supply amount adjusting means and arranged so as to be open near the inner bottom of the storage unit. The ones given are suitable. A normal throttle valve or the like may be used as the supply amount adjusting means.
Further, the supply amount adjusting means may be provided with a temperature controller capable of operating the above means according to the temperature state of the heated liquid medium. It is preferable that the steam introducing pipe is provided with a filter or the like capable of removing impurities such as oil contained in normally generated steam. For these matters, the description of Examples given later is referred to. The heat sterilization tank is preferably composed of a heat insulating member. The temperature of the steam introduced by the steam introducing pipe is at least 140
It is set to a high temperature such that it can be heated above ℃.

In the apparatus of the present invention, the flow path for holding the heated liquid medium for a short time means a flow path capable of holding and transferring the temperature of the liquid medium heated in the steam heating sterilization tank for a predetermined time. Therefore, the flow path is, for example, a pipe line which is connected to the steam heating sterilization tank and is constituted by a heat insulating member over a predetermined distance from the tank. The predetermined distance is appropriately a distance that allows connection for at least 4 seconds when the temperature of the liquid medium to be heated is about 140 ° C. as described above, and is appropriately set according to the flow rate of the liquid medium. In addition, examples of the adiabatic structure include forming a flow path with a heat insulating member. Examples of the material include glass wool and asbestos, and glass wool is preferable.

The cooling channel provided in the device of the present invention has a channel for transferring the heated liquid medium transferred from the heating and holding channel, and a cooling unit which is provided in contact with the channel in a heat exchange manner. Is suitable, and has an internal conduit for passing a high-temperature fluid, and an external conduit for passing cooling water, which has an introduction pipe and a discharge pipe and through which cooling water can flow in contact with the outside of the internal conduit. An ordinary heat exchanger consisting of a double tube structure with is suitable. From the viewpoint of cooling effect, the cooling flow passage may be configured by connecting a plurality of heat exchangers as described above in series.

(E) Action According to the present invention, the liquid medium introduced from the liquid medium supply unit into the heat sterilization tank is directly contacted with the high-pressure steam supplied therein in the tank and is instantly stirred at a predetermined high temperature.・ It is heated. This heated liquid medium is transferred while maintaining its temperature for a predetermined short time even if it is discharged from the above tank, and then cooled to a predetermined temperature as it is transferred through a flow path for heat exchange cooling. , Transferred to a culture tank or a temporary medium storage tank.

Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited thereto.

(F) Embodiment FIG. 1 is a structural explanatory view of an example of the continuous sterilization apparatus of the present invention. In the figure, the continuous sterilizer (1) includes a medium tank (2), a liquid feed pump (3), a cleaning pump (3 '),
A steam mixer (4) for directly mixing the medium and steam, a holding header (5) for keeping the medium at a constant high temperature, a first heat exchanger (6) for cooling the high temperature medium to a low temperature, A second heat exchanger (7) for further cooling the medium cooled in the heat exchanger (6) to a predetermined temperature,
It mainly comprises a temperature controller (8) for controlling the temperature of the medium entering the holding header (5) and a cleaning liquid supply tank (9) for cleaning the inside of the continuous sterilizer (1).

The steam mixer (4) is configured to include a medium storage part having a medium introduction pipe and a discharge pipe, and a steam introduction pipe opening to the inner bottom of the storage part. A steam supply pipe (a) is connected to the steam introduction pipe, which is connected to a steam generator (not shown) via a filter section (41) and a temperature control solenoid valve (42) in this order.

The holding header (5) is composed of a conduit body that has a flow path portion (51) connected to the medium discharge path of the steam mixer (4) and is connected to the first heat exchanger (6). . This holding header (5) is made of stainless steel with an inner diameter of 50 mm, and the flow path (51) is approximately 140 mm.
Is set to the length of. At 250 l / hr, the temperature detection part (5) is provided at the connection part of the holding header (5) with the steam mixer (4) and the flow path part (51).
2) and (53) are set.

Each of the first heat exchanger (6) and the second heat exchanger (7) has an internal pipe passage for passing a high temperature fluid, an introduction pipe and a discharge pipe, and a contact flow of cooling water to the outside of the internal pipe passage. What is constructed is a normal double pipe structure with a possible cooling water line. If the temperature of the high temperature fluid introduced at a flow rate of 250 to 300 l / hr into the internal pipe is 140 ° C when the cooling water of 25 ° C is brought into contact flow, the first heat exchanger (6)
It is designed to have a heat exchange capacity that can be cooled to 0 ° C and discharged from the internal conduit. On the other hand, the second heat exchanger (7)
When the cooling water of 25 ℃ is contacted and flowed, 250
If the temperature of the high temperature fluid introduced at a flow rate of up to 300 l / hr is 80 ° C, it has a heat exchange capacity capable of being cooled to 40 ° C and discharged from the internal conduit.

The temperature controller (8) is electrically connected to the temperature detection parts (52) (53) of the holding header (5) and the temperature control solenoid valve (42) set in the steam supply pipe (a). , The temperature adjusting solenoid valve (42) is operated based on the signals output from the temperature detecting sections (52) (53) to adjust the amount of steam introduced into the steam mixer (4) to be heated. It is configured to control the temperature of the medium.

The steam mixer (4), the holding header (5), the first heat exchanger (6), and the second heat exchanger (7) are connected in this order to form a sterile medium supply path (b). . The sterile culture medium supply path (b) is further extended from the second heat exchanger (7) to a fermentation tank (not shown).

On the other hand, the medium supply passage (c) is a pipe connected to the introduction pipe of the cooling water pipe of the first heat exchanger (6) through the medium tank (2) and the liquid feed pump (3) in this order. It comprises a channel (c ₁ ) and a channel (c ₂ ) connected from the discharge pipe of the cooling water channel to the medium introduction channel of the steam mixer (4).

In the figure, (9) is a cleaning tank, (d) and (f) are pure water supply paths (v ₁ ) (v ₃ ) (v ₄ ) (v ₅ ) are solenoid valves. Further, the washing pump (3 ') is stopped during the sterilization operation, and in this stopped state, the flow path is kept open and the culture medium supply pipe (c) is opened. Further, at the time of washing after the sterilization operation, the washing liquid (pure water) is sent to the medium supply pipe (c) by the operation of this pump (3 ').

In the above continuous sterilization apparatus (1), at the time of the sterilization operation, first, the washing pump (3 ') is set to the flow path open state, and the steam temperature passing through the filter section (41) of the steam supply pipe (a) is adjusted. The temperature of the medium passing through the inside of the holding header (5) is adjusted to 14 ° C by the temperature controller (8).
Adjust so that the temperature is maintained at 0 ° C.

In the continuous sterilizer (1) configured as described above,
For example, a liquid medium containing 10% glucose, 1% polypeptone, and 1% yeast extract is kept at 25 ° C and prepared in the medium tank (2), and the liquid feed pump (3) feeds 250
Adjust to ~ 300l / hr. If the liquid medium is fed by the liquid feed pump (3) under these conditions, the medium feeding pipe (c ₁ )
The medium to be transferred is further transferred to the medium supply pipe (c ₂ ) through the first heat exchanger (6) and introduced into the steam mixer (4). Steam regulated at 145 ° C is directly bubbled into the medium in the steam mixer (4), whereby the medium is instantly heated to about 140 ° C. The high temperature medium heated to about 140 ° C. is transferred from the steam mixer (4) to the holding header (5). While being transferred through the holding header (5), the high temperature medium is insulated from the outside and the high temperature state is maintained for a predetermined time (about 4 seconds in this case), whereby sterilization is performed and then the first heat exchange. It is introduced into the vessel (6). The high temperature state of the medium transferred in the holding header (5) is monitored by two temperature detectors (52) (53), and the temperature detected by either of the detectors is a predetermined temperature ( In this case, about 140 ℃)
This signal is output to the temperature controller (8), and the temperature controller (8) controls the temperature control solenoid valve (4) of the steam supply pipe (a).
2) is operated to adjust the amount of steam introduced into the steam mixer (4) so that the temperature detected by the temperature detector becomes a predetermined temperature.

The high temperature (about 140 ° C) medium introduced into the first heat exchanger (6) is heat-exchanged with cooling water (in this case, 25 ° C medium) and cooled to a predetermined temperature (80 ° C in this case). It is discharged from the heat exchanger. The medium discharged from the heat exchanger (6) is further introduced into the second heat exchanger (7), cooled to a predetermined temperature (40 ° C. in this case), and supplied to the fermenter.

By the above operation, the medium supplied to the fermenter is continuously sterilized during the transfer. Further, since this sterilization treatment is carried out in a short time, continuous sterilization can be carried out without causing coupling of saccharides of medium components.

If the supply of the medium is complete, the solenoid valve _{(v 1 1) (v 3} ) (v
₄ (V ₅ ) is switched and the washing pump (3 ') is operated to supply washing water into the medium supply passage (c) and the sterilized medium supply passage (b) to wash them. Further, pure water is supplied through the pure water supply pipes (d) and (f) to prepare for the next sterilization process.

(G) Effect of the Invention According to the present invention, the medium can be subjected to high-temperature treatment in a short time to continuously sterilize it. Since the medium is heated instantly and evenly,
It is possible to prevent deterioration of the medium due to coupling or the like. Because of the direct heating method, the heating means can be made small in scale and the cost can be reduced. Moreover, since the thermal efficiency is good, the running cost is small.

[Brief description of drawings]

FIG. 1 is a structural explanatory view of an example of the continuous sterilization apparatus of the present invention. (2) …… Medium tank, (3) …… Liquid transfer pump, (4)
…… Steam mixer, (5) …… Holding header, (6) …… First heat exchanger, (7) …… Second heat exchanger, (8) …… Temperature controller, (9) …… Cleaning tank,
(41) ...... filter section, (42) ... temperature control solenoid valve,
(51) …… Flow path section, (52) (53) …… Temperature detection section,
(A) ...... steam supply pipe, (b) ...... sterile medium supply path, (c) ...... medium supply _{path, (c 1) (c 2} ) ...... medium supply conduit, (d) (f) ... Pure water supply channel.

Claims (1)

[Claims] 1. A steam heating sterilization tank and a flow path for holding the heated liquid culture medium for a short time on the flow path for transferring the liquid culture medium from the liquid culture medium supply section to the culture tank or the temporary culture medium storage tank, and heat to a predetermined temperature. A continuous sterilization that is provided with a steam supply section equipped with a supply amount adjusting means, and a steam supply port is provided near the bottom of the tank through a flow path for exchangeable cooling. apparatus.