JP2002347715A - Method for sterilizing inside of liquefied gas flow device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To readily sterilize the inside of the whole device body including a sterilizing filter without deteriorating the air cleanliness of a sterile atmosphere around the device body set in the sterile atmosphere, prior to the storage of a liquefied gas in the device body through the sterilizing filter, in a liquefied gas flow device for sterile filling in which the device body is set in the high-level sterile atmosphere. SOLUTION: In this liquefied gas flow device for the sterile filling in which the liquefied gas sterilized by being filtrated by a sterilizing filter 3 resistant to low and high temperature is stored in a device body 1 and a predetermined amount of the liquefied gas is allowed to flow down in a container, before the liquefied gas supplied from a liquefied gas bomb 2 is stored in the device body 1 through the sterilizing filter 3, high-temperature steam supplied through a steam sterilization unit 4 is allowed to flow into the device body 1 through the sterilizing filter 3 to previously sterilize the sterilizing filter 3 and the inside of the device body 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a production line for cans of beverages, in which an inert low-temperature liquefied gas is supplied to the head space of each can between filling an empty can with a beverage and covering the can with a can lid. BACKGROUND OF THE INVENTION The present invention relates to a liquefied gas flow-down device which is made to flow down by a fixed amount, and particularly to a method for sterilizing the inside of a liquefied gas flow-down device used in the production of beverage cans by an aseptic filling method.

[0002]

2. Description of the Related Art When canning non-carbonated beverages such as coffee, black tea, green tea, oolong tea, and fruit juice, the beverage is filled into a can body having a thin body wall such as a DI (squeezed ironing) can and sealed. In doing so, a small amount of low-temperature liquefied gas such as an inert gas such as liquid nitrogen is added to the liquid level in the can filled with the beverage, and then the can lid is tightly wound around the opening of the can and sealed. This has been done in the past.

[0003] That is, by adding a liquefied gas before sealing the can, the liquefied gas added on the surface of the beverage in the can is vaporized in a short time and its volume becomes several hundred times larger. The internal pressure of the head space of the can sealed with the can lid (the space where there is no beverage in the upper part of the can) becomes higher than the atmospheric pressure, and a small amount of pressure is required to keep pushing the can wall from inside to outside. Even when external pressure is applied, the thin body wall does not deform.

[0004] Further, by adding such a liquefied gas,
Part of the liquefied gas added to the beverage evaporates instantaneously and increases the volume, and acts to expel the air in the headspace out of the can, thereby reducing the amount of oxygen remaining in the headspace (due to oxidation of the beverage). This also has the effect of reducing the deterioration.

On the other hand, in the canned non-carbonated beverage as described above, a retort sterilization method or a hot filling method (hot pack) has been generally used as a sterilization treatment to prevent the filled beverage from spoiling. However, in such a method, since the content of the beverage is kept at a high temperature for a relatively long time, the beverage itself (for example, freshly squeezed juice, coffee, tea, green tea, The problem is that the taste and aroma of oolong tea or the like that has just been made fall off or the color changes.

[0006] Therefore, in order to reduce the heat history of the beverage as much as possible during the production of the can, and to produce a beverage can that retains the original taste, aroma and color of the beverage as much as possible, it is necessary to sterilize at a high temperature in a short time and rapidly The so-called aseptic filling method, in which sterilized beverages that have been cooled down to a sterile empty can can be filled in a nearly sterile atmosphere with clean air and sealed with a sterilized can lid, Has been studied in various ways.

As an air purifying system for maintaining a sterile atmosphere in such an aseptic filling method, in a space in a clean room, a filling region of a beverage and a tightening region of a can lid are of a higher class than other spaces. It has been known from the prior art (Japanese Patent Laid-Open Publication No. 4-79956), etc., to maintain the air cleanliness of the present invention.

That is, the inside of the clean room is divided into a region having a medium level of air cleanliness (classes 1,000 to 10,000) and a region having a high level of air cleanliness (classes 10 to 100). The supply path of the sterilized can lid, around the beverage filling machine, the transport path from the beverage filling machine to the can lid wrapping machine, and the area around the can lid wrapping machine with air cleanliness of class 10 to 100, and other canned transport paths Etc. class 1,000-10,
It is considered that the air cleanliness is 000.

[0009] The above-mentioned class is NASA
The cleanliness of the air is indicated by the number of reference particles (particle diameter 0.5 micron or more) existing per a predetermined space (ft ³ ). is a 0-1 / ft ^3, class 10 is a 2-10 / ft ^3, class 100 11-10
0 / ft ³ .

[0010]

By the way, in the manufacture of beverage cans by the aseptic filling method as described above, for can bodies having a thin body wall such as DI cans, each can is sealed before the can is sealed. It is necessary to add a liquefied gas to the head space of the liquefied gas flow-down device near the transfer path from the beverage filling machine to the can lid wrapping machine in a substantially sterile atmosphere using clean air. In addition to installing the liquefied gas, the entire inside of the piping and the inside of the device (the entire liquefied gas passage from the filter for sterilization to the nozzle through the storage tank to the nozzle) is used in order to make the liquefied gas flow down under aseptic conditions. It is necessary to sterilize before starting.

However, when the liquefied gas flow-down device is installed in such a high-level aseptic atmosphere (class 10 to 100), if the entire inside of the device is to be sterilized, the sterilization around the device is performed by the operation. In the aseptic filling method, it is difficult to add a liquefied gas by a liquefied gas flowing device because the air cleanliness of the atmosphere is reduced.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems. A liquefied gas flow-down device for aseptically filling a liquefied gas in which an apparatus body is installed in a high-level aseptic atmosphere is liquefied through a filter for sterilization. Before storing the gas in the apparatus main body, the inside of the apparatus main body including the filter for sterilization is not reduced without reducing the air cleanliness of the sterile atmosphere around the apparatus main body installed in the sterile atmosphere. It is an object to easily sterilize.

[0013]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides an apparatus for removing a liquefied gas which has been sterilized by filtering through a sterilizing filter having low-temperature and high-temperature resistance. For a liquefied gas flow-down device for aseptic filling that is stored in the main body and allowed to flow down into the container by a predetermined amount, before the liquefied gas is stored in the device body through the filter for sterilization, A high-temperature steam is caused to flow into the apparatus main body through the filter to sterilize the sterilizing filter and the apparatus main body in advance.

Further, in such a method for sterilizing the inside of a liquefied gas flowing-down device, as described in claim 2 above,
Before storing the liquefied gas in the device main body through the filter for sterilization, high-temperature steam flows into the device main body through the filter for sterilization to sterilize the filter for sterilization and the inside of the device with steam. From, further, by flowing dry gas into the device body through a filter for sterilization,
It is characterized in that moisture is removed from the filter for sterilization and the inside of the apparatus body.

Further, in such a method for sterilizing the inside of a liquefied gas flowing-down apparatus, as described in the third aspect, the liquefied gas supply pipe, the steam supply pipe, and the dry gas supply pipe are sterilized. After connecting appropriately to the upstream of the filter for the filter, and connecting to the device body through the filter for sterilization, by providing an open / close control valve on each supply pipe upstream of the connection between the supply pipes Further, any one of the liquefied gas, steam and dry gas is caused to flow into the apparatus main body through the filter for sterilization by switching by control of the respective on-off control valves.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a method for sterilizing an inside of a liquefied gas flowing-down apparatus according to the present invention will be described below in detail with reference to the drawings.

FIG. 1 schematically shows an example of a beverage canning production line by an aseptic filling method provided with a liquefied gas flow-down device to which the internal sterilization method of the present invention is applied, in which a canning production line is installed. Clean room (Class 1)
000), the air cleanliness level is medium (Class 1,
000-10,000) area, and furthermore, an area with a high level of air cleanliness (class 10-100) is defined as a clean booth, and a conveying path for sterilized empty cans. , Around the beverage filling machine, around the transport path from the beverage filling machine to the can lid wrapping machine, around the can lid wrapping machine, and the supply path of the sterilized can lid, the air cleanliness level is high (Class 10). ~ 100) in a clean booth.

[0018] In such a canned production line by the aseptic filling method, the liquefied gas flow-down device is configured such that the main body of the device is moved from a beverage filling machine to a can lid in a clean booth having a high level of air cleanliness (class 10 to 100). Although not shown, each pipe, which is disposed in the middle of the transport path to the winder and connected to the apparatus main body, is connected to the apparatus main body in the clean booth from outside near the clean booth.

In the beverage canned production line as described above,
First, the untreated empty can continuously supplied by the empty can supply conveyor is passed through a chemical spraying device on the outer surface of the can to apply a sterilizing treatment liquid (5% by weight of hydrogen peroxide) to the outer peripheral surface of the can body and the outer surface of the can bottom. Aqueous solution), sprayed through the chemical spraying device on the inner surface of the can, and further sprayed with a sterilizing chemical (5% by weight aqueous solution of hydrogen peroxide) on the inner surface of the empty can. Send in.

Then, in a heat sterilization oven, the empty can having the chemical solution sprayed on the inner surface and the outer surface is heated by high-temperature (about 250 ° C.) hot air from a heating furnace to remove the hydrogen peroxide of the chemical solution attached. By disassembly and removal, the sterilization of the empty can is completed.

Next, the sterilized empty cans from the heat sterilization oven were placed in a substantially sterile atmosphere (air cleanliness class 1).
In the tunnel of 00), the surrounding air is cleaned by a clean air replacement device, and then the sterilized empty can is sprayed with sterile water by a cooling device to empty the heated empty can to the filling temperature of the contents. After cooling to the vicinity, it is supplied to a beverage filling machine in a substantially sterile atmosphere (air cleanliness class 100).

Then, in the clean booth, the cooled sterilized empty cans are heat-sterilized in a beverage sterilizer at a high temperature for a short time, and then the sterilized beverage cooled to the filling temperature is subjected to:
After a predetermined amount is filled by the beverage filling machine, the beverage-filled cans are supplied to the can lid winding machine by a timing conveyor in the clean booth.

Then, in the clean booth, the liquified gas flow-down device is sterilized from the main unit of the liquefied gas flow-down device with respect to each of the beverage-filled cans being conveyed toward the can lid tightening machine by the conveyer timing conveyor. By flowing a predetermined amount of the low-temperature liquefied gas (liquid nitrogen) of the inert gas, a predetermined amount of the liquefied gas is respectively added to the head space above the inside of the can filled with the beverage.

Next, the cans filled with the beverage and to which the liquefied gas has been added are sterilized in a clean booth and supplied from a can lid sterilizer through a chute in a substantially aseptic atmosphere (air cleanliness class 100) in a clean booth. After placing the can lid,
After being wound and sealed by a can lid winder, the product is carried out by a carry-out conveyor as a canned sterilized product containing a beverage as a content.

FIG. 2 schematically shows an example of a liquefied gas flow-down device used in a beverage canning production line by the aseptic filling method as described above. The liquefied gas supplied from the pipe through the pipe is passed through the filter 3 for sterilization, and is temporarily stored in the storage tank 11 with the liquid surface opened to the atmosphere and the liquid surface maintained at a predetermined height. The nozzle 1 capable of controlling the flow rate of the liquefied gas stored in the storage tank 11 in a state where a substantially constant pressure is constantly applied by its own gravity.
3 to flow down. As the filter 3 for sterilization, a ceramic filter having low-temperature and high-temperature resistance is used because of its low temperature resistance corresponding to liquefied gas and high temperature resistance corresponding to sterilization steam.

An apparatus main body 1 of the liquefied gas flow-down apparatus includes:
Storage tank 1 from cylinder 2 through filter 3 for sterilization
1 to the piping for supplying the liquefied gas to the entire inside of the device (the storage tank 1 through the sterilization filter 3 from the piping).
Each pipe for sterilizing the entire liquefied gas passage 1 and the nozzle 13 through the liquefied gas chamber 12 is connected to the apparatus main body 1 as a steam sterilizing unit 4.

In the apparatus main body 1 of the liquefied gas flow-down device, a storage tank 11 having an open upper surface is provided following the filter for sterilization 3 and a liquefied gas chamber extending vertically below the storage tank 11. A liquefied gas chamber 12 is provided so that the bottom of the storage tank 11 and the upper part of the liquefied gas chamber 12 communicate with each other, and a nozzle 13 for flowing down is formed at the lower end of the liquefied gas chamber 12. The opening degree of the nozzle 13 is controlled by changing the position of a plug at the lower end of the rod 14 by changing the vertical position of the rod 14 by a rod 14 for flow control that is vertically movably inserted into the storage tank 11. The liquefied gas stored in the liquefied gas chamber 1
2, the liquid flows downward at a flow rate corresponding to the opening of the variable flow rate nozzle 13.

Further, a vacuum heat insulating chamber 15 for insulating low-temperature liquefied gas from outside air is formed in the apparatus main body 1 so as to cover the storage tank 11 and the liquefied gas chamber 12 from the outside. In order to prevent the water vapor in the atmosphere from freezing and adhering to the vicinity of the outlet of the nozzle 13 due to the flow of the low-temperature liquefied gas, the lower end of the apparatus main body 1 covers the periphery of the nozzle 13 with an anti-frost. Nozzle heater 16 is detachably mounted.

The liquid level of the liquefied gas stored in the storage tank 11 is determined by the liquid level controller 17.
By controlling the flow of the liquefied gas into the storage tank 11 by detecting the height of the liquid level, the liquid level is always maintained at a substantially constant level.
Regarding the opening degree of 3, the constant internal pressure control unit 18
The position of the plug at the lower end of the rod is changed by changing the vertical position of the rod 14 based on the feedback of the information on the pressure inside the can after sealing (the detection result of the X-ray level monitor, the contact pressure monitor, or the internal pressure monitor of a canned type). By changing, the opening is controlled to an appropriate flow rate.

Further, the liquefied gas flow-down device is attached to the apparatus main body 1 such that the lower end opening of the nozzle heater 16 is detachably closed only during cleaning and sterilization of the apparatus main body by steam and thereafter during cooling and drying. A separate sterilization cap 19 is provided.

FIG. 3 shows a connection structure of each pipe to an apparatus main body 1 for flowing liquid nitrogen as a liquefied gas in the liquefied gas flow-down apparatus as described above. An intake pipe 22 extending from a vacuum pump 21 is connected to the chamber 15, and a pressure switch 2 is provided in the intake pipe 22 near the vacuum pump 21.
3 are installed.

A liquid nitrogen supply pipe 24 for feeding liquid nitrogen from the cylinder into the storage tank 11 is provided inside the apparatus main body 1 covered by the vacuum heat insulating chamber 15 with a filter for sterilization (0.2 μm). The liquid nitrogen supply pipe 24 is connected through a mesh ceramic filter 3.
A manual opening / closing valve 25 is installed on the upstream side (cylinder side), and two opening / closing control valves 2 are provided at appropriate intervals downstream of the manual opening / closing valve 25.
6, 27 are installed.

Further, in order to sterilize the entire inside of the apparatus,
A steam supply pipe 28 for supplying steam for sterilization is connected to the liquid nitrogen supply pipe 24 on the downstream side of the on-off control valve 27, and in the middle of the steam supply pipe 28, the upstream side A manual opening / closing valve 29, a pressure reducing valve 30, a steam filter 31, an opening / closing control valve 32, a safety valve 33, and an opening / closing control valve 34 are respectively provided from the (steam supply side) to the downstream side (apparatus body side).

In order to cool and dry the inside of the apparatus after sterilization with steam, a nitrogen gas supply pipe 35 for supplying nitrogen gas for cooling and drying is connected to the liquid nitrogen supply pipe 24 by an opening / closing control valve 27 thereof. In the middle of the nitrogen gas supply pipe 35, from the upstream side (nitrogen gas supply side) to the downstream side (apparatus main body side), a manual opening / closing valve 36 and a nitrogen gas heating pipe are connected. A line heater 37, a pressure reducing valve 38, a check valve 39, and two opening / closing control valves 40 and 41 at appropriate intervals are provided, respectively.

On the other hand, in order to exhaust the nitrogen gas generated by the vaporization of the liquid nitrogen stored in the storage tank 11 from the apparatus main body 1 of the liquefied gas flow-down apparatus, it is necessary to prevent the invasion of the outside air and to simultaneously discharge the nitrogen gas to the outside. An exhaust pipe 43 is connected via an exhaust shutter 42 for guiding the exhaust pipe 43, and an opening / closing control valve 44 is provided in the middle of the exhaust pipe 43. The end of the exhaust pipe 43 is opened to the atmosphere. I have.

A steam discharge pipe 45 is branched from an upstream side of the opening / closing control valve 44 of the exhaust pipe 43 (device main body side). An opening / closing control valve 46 is provided on the side), and a manual opening / closing valve 47 is provided on the terminal side thereof.

A gas return pipe 48 is provided so that the nozzle heater 16 and the exhaust shutter 42 communicate with each other. From the middle of the gas return pipe 48, steam is discharged and nitrogen gas is introduced. The discharge / introduction pipe 49 is branched, and a sterilization filter 50, an opening / closing control valve 51, and a manual opening / closing valve 52 are provided in the middle of the discharge / introduction pipe 49 from the apparatus main body side to the terminal side. .

A nitrogen gas introduction pipe 53 is branched from the middle of the discharge introduction pipe 49 from between the sterilization filter 50 and the opening / closing control valve 51. The other end of the nitrogen gas introduction pipe 53 is connected to the nitrogen gas introduction pipe 53. It is connected between the line heater 37 of the supply pipe 35 and the pressure reducing valve 38, and in the middle of the nitrogen gas introduction pipe 53, from the side of the nitrogen gas supply pipe 35 to the side of the discharge introduction pipe 49, And check valve 55 and open / close control valve 56
Are installed respectively.

A cap steam discharge pipe 57 is connected to the sterilization cap 19 for detachably closing the lower end opening of the nozzle heater 16 only during sterilization with steam and subsequent cooling and drying with nitrogen gas. A manual on-off valve 58 is installed near the end of the cap steam discharge pipe 57.

Further, a temperature sensor and a pressure sensor are provided at appropriate places of the apparatus main body 1 and each pipe, and based on the detection results, management of steam flow during sterilization and internal pressure of each pipe by a pressure reducing valve. Is being managed.

Each pipe connected to the apparatus main body 1 is
The steam sterilization unit is integrated in the vicinity of the clean booth with respect to the apparatus main body 1 arranged in the clean booth. By replacing the steam sterilization unit, it can be easily changed to a pipe of a conventional apparatus that is not used for aseptic filling. It can be done.

The internal sterilization method for the liquefied gas flow-down device according to the present embodiment, which is performed in the liquefied gas flow-down device for aseptic filling having the above-mentioned piping structure, includes preparation for sterilization,
Each of the sterilization step, the cooling and drying step, the preparation for the liquefied gas flow, the liquefied gas flow step, and the post-treatment step will be described below with reference to FIGS.

In using the liquefied gas flow-down apparatus, first, in preparation for sterilization by steam, the lower end opening of the nozzle heater 16 attached to the lower end of the apparatus main body 1 is closed with a sterilization cap 19 and the apparatus main body 1 is closed. After the nozzle 13 formed at the lower end of the pipe is opened, all the manual open / close valves of each pipe are opened with all the open / close control valves of each pipe closed, and the line heater 37 and each sensor are turned on. And keep it.

Then, as shown in FIG. 4, in order to sterilize the entire inside of the apparatus with steam, the opening and closing control valves 32 and 34 of the steam supply pipe 28 are opened, and the opening and closing control valves 46 of the steam discharge pipe 45 are opened. Opening / closing control valve 51 of discharge / introduction pipe 49 and
Control is performed so that opening and closing are alternately repeated at intervals of 15 seconds.

Accordingly, the steam supplied from the steam supply pipe 28 is introduced into the apparatus main body 1 through the sterilizing filter 3 and passes through the entire inside of the apparatus main body 1. While being intermittently discharged from the exhaust pipe 43 through the exhaust shutter 42, a part of the gas is returned from the lower part of the apparatus main body 1 to the exhaust shutter 42 through the nozzle heater 16 through the gas return pipe 48. The others are intermittently discharged from the steam discharge pipe 45 and the others from the discharge introduction pipe 49, and as a result, the entire inside of the apparatus main body 1 is sterilized by the steam.

In this embodiment, the supply amount of steam at this time is set at 125 ° C. based on the detection result of the temperature sensor provided on the sterilization cap 19.
Thus, the opening degree of the opening / closing control valve 32 of the steam supply pipe 28 is controlled so as to sterilize for 30 minutes (controlled by a timer).

After the entire interior of the apparatus main body 1 has been sterilized with steam as described above, as shown in FIG.
The opening and closing control valve 32 of the nitrogen gas supply pipe 35 is closed at the same time as the opening and closing control valve 34 of the steam supply pipe 28 is closed.
And open / close control valves 40, 41 of the nitrogen gas supply pipe 35.
60 seconds after opening, the opening / closing control valve 44 of the exhaust pipe 43 is completely opened, and the opening / closing control valve 46 of the steam discharge pipe 45 is opened for 60 seconds.
After opening for a second, close and open / close control valve 5 of discharge / introduction pipe 49
1 is opened for the first 30 seconds and then closed, and the opening and closing control valve 56 of the nitrogen gas introducing pipe 53 is controlled to be opened after a predetermined time.

At this point, the line heater 37
Is already ON, but the nozzle heater 16
Is turned on, the driving of the vacuum pump 21 is started, and after that, the pressure switch 23 is turned on to bring the vacuum insulation chamber 15 of the apparatus main body 1 into a vacuum state.

As a result, the drying nitrogen gas heated by the line heater 37 and supplied from the nitrogen gas supply pipe 35 is introduced into the apparatus main body 1 through the sterilization filter 3, and the entire inside of the apparatus main body 1 is removed. From the top of the apparatus body 1, through the exhaust shutter 42,
During the first 60 seconds, the gas is discharged from the steam discharge pipe 45, and then discharged from the exhaust pipe 43. From the lower part of the apparatus main body 1, the gas is returned from the nozzle heater 16 through the gas return pipe 48 for only the first 30 seconds. The gas is discharged from the introduction pipe 49, and as a result, the entire inside of the apparatus main body 1 and the inside of the pipe through which the steam passes are cooled and dried by the heated nitrogen gas (dry gas).

Then, the nozzle heater 16 of the apparatus body 1 is
When the sterilization cap 19 is removed from the apparatus, after a certain time, the nitrogen gas is heated by the line heater 37,
The gas is supplied from the nitrogen gas introduction pipe 53 to the nozzle heater 16 through the discharge introduction pipe 49, and a part thereof is supplied to the nozzle heater 1.
6 is discharged to the vicinity of the tip of the nozzle 13, and the remainder is passed from the gas return pipe 48 through the exhaust shutter 42 to the exhaust pipe 4.
It is discharged from 3.

As described above, after the entire inside of the apparatus main body 1 is sterilized and cooled and dried, as shown in FIG. 6, liquid nitrogen is stored in the storage tank 11 until a predetermined liquid level is reached. After the liquid level controller 17 is turned on and the nozzle 13 at the lower end of the apparatus main body 1 is completely closed, the opening and closing control valves 40 and 41 of the nitrogen gas supply pipe 35 are closed to open and close the liquid nitrogen supply pipe 24. The valves 26 and 27 are opened, and when the liquid level in the storage tank 11 reaches a predetermined height, the opening / closing control valve 26 is controlled to be closed.

As a result, the liquid nitrogen supplied from the cylinder is sent from the liquid nitrogen supply pipe 24 into the storage tank 11 through the sterilization filter 3, and is filled in the liquefied gas chamber 12 before being stored in the storage tank 11. When the liquid level is filled up to the predetermined liquid level, the open / close control valve 26 of the liquid nitrogen supply pipe 24 is closed by feedback control based on the detection of the liquid level controller 17, and preparation for the liquid nitrogen flow is completed.

As shown in FIG. 7, when a predetermined amount of liquid nitrogen is allowed to flow into each can, the apparatus main body 1
When the nozzle 13 is opened, liquid nitrogen flows down and is filled in each can, and the opening degree of the opening / closing control valve 26 of the liquid nitrogen supply pipe 24 is controlled by feedback control by the liquid level controller 17 (the other opening / closing). By fully opening the control valve 27), the liquid flowing down from the liquid nitrogen supply pipe 24 through the sterilization filter 3 to keep the liquid level in the storage tank 11 always within a certain height range. Is continuously supplied to the apparatus main body 1.

At this time, the opening / closing control valve 4 of the exhaust pipe 43
4 is open, most of the nitrogen gas vaporized from the liquid level in the storage tank 11 is discharged from an exhaust port provided in the upper lid portion of the storage tank 11, but the exhaust shutter 42.
Through the exhaust pipe 43 to the atmosphere, the space above the liquid level inside the apparatus main body 1 covered by the vacuum insulation chamber 15 is always substantially equal to the atmospheric pressure. As a result, a constant amount of liquid nitrogen flows down from the nozzle 13 in accordance with the nozzle opening while a substantially constant pressure is always applied by the gravity of the liquid nitrogen itself.

Further, the nitrogen gas is heated by the line heater 37 from the nitrogen gas introduction pipe 53 through the discharge introduction pipe 49 so that the nitrogen gas is heated to a high temperature.
Is continuously discharged from the nozzle heater 16 to the vicinity of the tip of the nozzle 13, so that water vapor in the atmosphere is prevented from approaching the vicinity of the outlet of the nozzle 13, and as a result, water vapor is frozen near the outlet of the nozzle 13. It is reliably prevented from adhering.

As described above, the opening degree of the nozzle 13 formed at the lower end of the apparatus main body 1 is controlled by the constant internal pressure control unit 18 to obtain information on the internal pressure of the can after sealing (X-ray level). Based on the feedback of the monitor and the contact pressure monitor or the canning type internal pressure monitor), by changing the vertical position of the rod 14 and the position of the plug at the lower end thereof, the opening can be adjusted to an appropriate flow rate. Is controlled.

Thereafter, as for the post-treatment after the use of the liquefied gas falling device, as shown in FIG. 8, the opening and closing control valves 26 and 27 of the liquid nitrogen supply pipe 24 are closed to stop the supply of the liquid nitrogen. Then, when liquid nitrogen is further allowed to flow down and liquid nitrogen is completely extracted from the inside of the apparatus main body 1, the nozzle 13 is closed, the vacuum pump 21 is stopped, and the opening / closing control valves 40 of the nitrogen gas supply pipe 35 are closed. , 41 are opened to fill the inside of the apparatus body 1 and the piping with nitrogen gas, and then all the on-off control valves and the manual on-off valves are closed.
The line heater 37 and the nozzle heater 16 are turned off to prepare for the next use.

According to the internal sterilization method of the liquefied gas flow-down device of the present embodiment, which is carried out in each step as described above, the disinfection filter 3 is installed downstream of the liquid nitrogen supply pipe 24. This filter for sanitization 3
The liquid nitrogen is supplied into the apparatus main body 1 through the apparatus, so that the sterilization and sterilization of the liquid nitrogen supplied into the apparatus main body 1 can be reliably performed by the sterilization filter 3 and the steam supply pipe 28. A sterilizing filter 3 is installed on the downstream side of the apparatus, and sterilizing steam is supplied from the steam supply pipe 28 into the apparatus main body 1 through the sterilizing filter 3, so that operation in a sterile atmosphere is performed. Accordingly, the sterilization filter 3 and the inside of the apparatus main body 1 can be easily sterilized without lowering the air cleanliness of the sterile atmosphere around the apparatus main body 1.

In the present embodiment, the filter 3 for disinfection is installed on the downstream side, and after sterilization by steam,
Since the nitrogen gas (dry gas) heated by the line heater 37 is supplied from the nitrogen gas supply pipe 35 into the apparatus main body 1 through the sterilization filter 3, the sterilization filter 3 sterilized by steam is supplied. In addition, it is possible to completely remove moisture from the inside of the apparatus main body 1 and sufficiently dry them.

In addition, with respect to the liquid nitrogen supply pipe 24 connected to the apparatus main body 1 through the filter 3 for sterilization, a steam supply pipe 28 for sterilization is provided upstream of the filter 3 for sterilization.
And the nitrogen gas supply pipes 35 for cooling and drying are connected to each other, and the respective open / close control valves are provided on the upstream side of the connection portions of the respective supply pipes. In this manner, the operations from sterilization inside the apparatus and pipes to post-processing after use of the apparatus are continuously and automatically performed without reducing the air cleanliness of the sterile atmosphere around the apparatus main body 1. be able to.

In this regard, if a pipe through which liquid nitrogen passes and a pipe through which high-temperature sterilizing steam passes are connected, liquid nitrogen is usually connected to both sides of the open / close control valve in either of the pipes. Since high-temperature sterilizing steam directly confronts, as a result, vaporization of liquid nitrogen is promoted in the relevant portion, and there is a possibility that the inside of the pipe becomes high pressure, so such a connection of the pipe is practically impossible. It has become something.

Similarly, when connecting a pipe through which liquid nitrogen passes and a pipe through which heated nitrogen gas passes, similarly, liquid nitrogen and heated nitrogen gas are directly applied to both sides of the on-off control valve. Because of the opposition, such connection of the pipes is not preferable.

However, in the present embodiment, each of the liquid nitrogen supply pipe 24 and the vapor supply pipe 28 is provided with two opening / closing control valves at intervals, so that any of the pipes can be used in any of the pipes. Since liquid nitrogen and high-temperature sterilizing steam do not directly face each other across one open / close control valve, the liquid nitrogen supply pipe 24 and the steam supply pipe 28 can be connected. Become.

In this embodiment, the liquid nitrogen supply pipe 2
Since two open / close control valves are provided at intervals also in the nitrogen gas supply pipe 35 connected to 4, liquid nitrogen and heated nitrogen gas are provided on both sides of one open / close control valve. Since there is no direct opposition, the connection between the liquid nitrogen supply pipe 24 and the nitrogen gas supply pipe 35 can be performed without any problem.

[0065]

According to the method for sterilizing the inside of a liquefied gas flow-down device of the present invention as described above, the liquefied gas supplied to the inside of the device can be sterilized and sterilized with a sterilizing filter without fail. Before supplying the liquefied gas into the apparatus main body, by supplying sterilization steam into the apparatus main body through the filter for sterilization, even if the apparatus main body is installed in a high-level aseptic atmosphere. In addition, the sterilization filter and the inside of the apparatus main body can be easily sterilized in advance without lowering the cleanliness of the air around the apparatus main body by working in a sterile atmosphere.

[Brief description of the drawings]

FIG. 1 is an explanatory view schematically showing a production line for a beverage can by an aseptic filling method equipped with a liquefied gas flow-down device to which the internal sterilization method of the present invention is applied.

FIG. 2 is an explanatory view schematically showing an apparatus main body of a liquefied gas flowing down apparatus to which the internal sterilization method of the present invention is applied.

FIG. 3 is an explanatory diagram showing a connection state of each pipe to a device main body in a liquefied gas flowing down device to which the internal sterilization method of the present invention is applied.

FIG. 4 is an explanatory view showing a flow in each pipe in a sterilization step in the liquefied gas flow-down device shown in FIG.

FIG. 5 is an explanatory view showing a flow in each pipe in a cooling and drying step in the liquefied gas flowing-down device shown in FIG. 3;

FIG. 6 is an explanatory diagram showing a flow in each pipe in a liquefied gas flow-down device shown in FIG. 3 in a preparation stage for liquefied gas flow.

FIG. 7 is an explanatory view showing a flow in each pipe in a liquefied gas flowing step in the liquefied gas flowing device shown in FIG. 3;

FIG. 8 is an explanatory diagram showing a flow in each pipe in a post-processing step in the liquefied gas flow-down device shown in FIG. 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Device main body (of liquefied gas flow-down apparatus) 3 Filter for disinfection 24 Liquid nitrogen supply pipe (liquefied gas supply pipe) 26 Opening / closing control valve (of liquid nitrogen supply pipe) 27 (Opening / closing control valve of liquid nitrogen supply pipe) 28 Steam supply pipe 32 (steam supply pipe) on / off control valve 34 (steam supply pipe) on / off control valve 35 nitrogen gas supply pipe (dry gas supply pipe) 40 (nitrogen gas supply pipe) on / off control valve 41 (nitrogen gas) Supply pipe) open / close control valve

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Tetsuya Takatomi 4081 Soya, Hadano-shi, Kanagawa Prefecture (72) Inventor Shigeki Matsuura 2-15-16, Hashimoto, Sagamihara-shi, Kanagawa Prefecture (72) Inventor Norihiko Osaku Musashimurayama-shi, Tokyo 5-89-1 Zanbori F-term (reference) 3E053 AA04 BA01 CA01 CA06 DA03 EA02 FA07 GA14 JA10

Claims (3)

[Claims] 1. An aseptic filling for storing a liquefied gas, which has been sterilized by filtering through a sterilizing filter having low-temperature and high-temperature resistance, in an apparatus main body and flowing down a predetermined amount in a container. Before storing the liquefied gas through the filter for sterilization, the high-temperature steam flows into the apparatus main body through the filter for sterilization before the liquefied gas flowing down the device. A method for sterilizing the inside of a liquefied gas flow-down device, wherein the filter and the inside of the device main body are sterilized. 2. Before the liquefied gas is stored in the apparatus main body through the filter for sterilization, high-temperature steam flows into the apparatus main body through the filter for sterilization, so that the filter for sterilization and the inside of the apparatus main body are separated. After steam sterilization,
2. The liquefied gas flow-down device according to claim 1, wherein moisture is removed from the filter for sterilization and the inside of the device body by flowing dry gas into the device body through the filter for sterilization. Internal sterilization method. 3. A supply pipe for liquefied gas, a supply pipe for steam, and a supply pipe for dry gas are appropriately connected upstream of the filter for sterilization, and then connected to the apparatus main body through the filter for sterilization. At the same time, by providing an open / close control valve on each supply pipe upstream of the connection between the supply pipes, any one of the liquefied gas, steam, and dry gas is removed by switching by controlling each open / close control valve. 3. The method according to claim 2, wherein the liquid is allowed to flow into the apparatus main body through a filter for bacteria.