JP7176555B2 - Sterilization method for air supply piping provided with sterilization filter - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for sterilizing an air supply pipe provided with a sterilization filter for removing bacteria and the like in the air used in an aseptic filling machine.

The aseptic filling machine that aseptically fills bottles with beverages etc. removes foreign matter from the supplied preforms, sprays sterilizing agents when sterilizing preforms, removes sterilizing agents, blow molds preforms into bottles, sterilizes Sterilized compressed air is used at various points such as blowing aseptic air onto preforms to maintain sterility during preform transport, spraying sterilizing agent when sterilizing bottles, removing sterilizing agent, cap chute during cap supply, etc. is used. Air pipes to which aseptic compressed air is supplied and sterilization filters that remove germs must be sterilized before operation of the aseptic filling machine.

Aseptic compressed air piping and sterilization filters are usually heated by steam. However, steam sterilization has the problem that the service life of the sterilizing filter is shortened, and a method of sterilizing the sterilizing filter with hydrogen peroxide has been proposed (Patent Documents 1 and 2). In Patent Document 1, hydrogen peroxide water is sprayed, heated, and then fed into a sterilization filter in a gaseous state. In Patent Document 2, hydrogen peroxide is supplied to an air pipe, and the hydrogen peroxide adhering to the pipe is vaporized by heated air and sent to a filter. In both cases, the sterilization filter is sterilized with gasified hydrogen peroxide. As described above, when sterilizing a sterilizing filter, there are a method using steam heating and a method using gasified hydrogen peroxide.

The beverage supply system piping of aseptic filling machines is usually sterilized with hot water or steam. In order to prevent excessive sterilization at this time, it is proposed to introduce F value control. For example, when thermally sterilizing the beverage supply system piping that sends the beverage from the beverage heat sterilization unit to the filling machine with hot water or steam, the temperature at multiple points of the beverage supply system piping is measured at predetermined intervals and the F value is calculated, and the sterilization process is terminated when the smallest F value among them reaches the target value (Patent Document 3).

In addition, when hot water or steam is sent to the beverage supply system piping that sends the beverage to the filling nozzles and the hot water or steam is discharged from the filling nozzles to sterilize the insides of the filling nozzles, the temperature inside all the filling nozzles is maintained for a predetermined time. It is also proposed to calculate the F value while detecting each time, and terminate the sterilization process when the smallest F value among them reaches the target value (Patent Document 4).

JP-A-10-16925 JP 2017-42309 A International publication 2014/103787 JP 2015-6920 A

Sterilization of a sterilization filter that sterilizes compressed air is performed with heated steam or gasified hydrogen peroxide. The sterilization filter uses resin for the filter material support, filter material, O-ring, end cap, etc., and has the problem of being deteriorated by the heat of heated steam and gasified hydrogen peroxide, shortening the service life.

Hydrogen peroxide has the problem that it is adsorbed by the resin constituting the sterilization filter and remains there, so it is preferable to sterilize it with heated steam. However, when the sterilization filter is sterilized with heated steam, the heat load on the resin forming the sterilization filter is large, and there is a risk of deterioration. Therefore, a sterilization method and a sterilization apparatus for a sterilization filter are desired that reduce the heat load on the sterilization filter as much as possible and prolong the service life of the sterilization filter.

An object of the present invention is to provide a sterilization method and a sterilization device for a sterilization filter that can solve such problems.

A method for sterilizing an air supply pipe equipped with a sterilizing filter according to the present invention is a method for sterilizing an air supply pipe equipped with a sterilizing filter for supplying air to a chamber of an aseptic filling machine, comprising:
supplying heated steam to the sterilization filter that sterilizes the supplied air , discharging the heated steam from the downstream of the sterilization filter, and sterilizing the sterilization filter with the supplied heated steam; Close the valve downstream of the sterilization filter and the valve for discharging the heated steam , supply the gas of the sterilant or the mist of condensed gas or a mixture thereof from the downstream of the valve, and the sterilant supplied Sterilize from the valve downstream of the sterilization filter to the chamber to which the air is supplied, close the valve for supplying the sterilant and the valve for supplying heated steam to the sterilization filter, and close the valve for supplying heated steam to the sterilization filter. A valve that supplies air is opened, a valve near the chamber that supplies the air to the chamber is closed, the air is supplied to the sterilization filter, and the sterilization is performed by the sterile air that has passed through the sterilization filter. It is characterized by maintaining sterility from the downstream of the filter to the valve near the chamber that supplies the air to the chamber until the aseptic filling machine starts operating. Further, a method for sterilizing a sterilizing filter according to another embodiment of the present invention includes supplying heated steam to a sterilizing filter that sterilizes supplied air, and sterilizing the sterilizing filter with the supplied heated steam. a sterilizing agent is supplied from the downstream of the sterilizing filter, and the supplied sterilizing agent sterilizes from the downstream of the sterilizing filter to the chamber to which the air is supplied.

Further, in the method of sterilizing an air supply pipe equipped with a sterilizing filter according to the present invention, the temperature of the heated steam supplied to the sterilizing filter and discharged from the downstream of the sterilizing filter is measured at predetermined time intervals. Preferably, an F value is calculated from the measured temperature, and sterilization of the sterilizing filter is terminated when the F value reaches a target value.

を用いて演算すると好適である。 Further, in the method of sterilizing an air supply pipe equipped with a sterilizing filter according to the present invention, the F value is the following formula

It is preferable to calculate using

Moreover, in the method of sterilizing an air supply pipe provided with a sterilizing filter according to the present invention, it is preferable that the supplied air has a pressure of 0.01 MPa or more.

Further, in the method of sterilizing an air supply pipe provided with a sterilizing filter according to the present invention, it is preferable that the air is supplied to the sterilizing filter after removing dust, oil and moisture from the air.

A sterilization device for a sterilization filter according to another embodiment of the present invention supplies heated steam to the sterilization filter between an air supply device and a sterilization filter that sterilizes the air supplied by the air supply device. A heating steam supplying means for sterilizing the sterilizing filter is provided, and a sterilizing agent supply device is provided for sterilizing the chamber to which the air is supplied from the downstream of the sterilizing filter with a sterilizing agent.

A sterilizing apparatus for a sterilizing filter according to another embodiment of the present invention includes a temperature sensor for measuring the temperature of the heated steam supplied from the heated steam supply means and discharged from the downstream of the sterilizing filter. a computing device for measuring the temperature of the discharged heated steam at predetermined time intervals and computing an F value based on the measured temperature; and sterilizing the sterilizing filter when the F value reaches a target value. It is preferred to finish.

According to the present invention, the aseptic filling machine removes foreign matter from the supplied preform, sprays a sterilant when sterilizing the preform, removes the sterilant, blows the preform into a bottle, and sterilizes the preform. Blow sterilized air onto preforms to maintain sterility during transportation, spray sterilizing agent when sterilizing bottles, remove sterilizing agent, sterilize compressed air used for cap chute, etc. when supplying caps. When sterilizing the sterilizing filter for sterilization, by controlling the F value for the management of the heated steam used for sterilization, it is possible to unnecessarily raise the temperature of the heated steam and reduce the time to supply the heated steam to the sterilizing filter. It is possible to shorten the sterilization time of the sterilization filter and reduce the heat load on the sterilization filter, thereby extending the useful life of the sterilization filter.

FIG. 4 is a circuit diagram showing a state when the sterilizing filter according to the embodiment of the present invention is sterilized; FIG. 4 is a circuit diagram showing a state when sterilizing an air supply pipe for supplying air to the aseptic filling machine according to the embodiment of the present invention; FIG. 4 is a circuit diagram showing a state when operating the aseptic filling machine according to the embodiment of the present invention; 4 is a graph showing the relationship between the temperature of heated steam and the sterilization time when sterilizing the sterilizing filter according to the embodiment of the present invention. 7 is a graph showing the relationship between the temperature of heated steam and the sterilization time when sterilizing a conventional sterilizing filter. 1 shows a cross section of a hydrogen peroxide supply device for sterilizing compressed air piping according to an embodiment of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

In the aseptic filling machine, a sterilizer that sterilizes containers such as target bottles, a cleaning device that cleans the sterilized containers, a filling device that fills the cleaned containers with sterilized contents, and the contents are filled The aseptic chamber 1 accommodates a sterilization device for the lid material that seals the container, a sealing device that seals the container with the sterilized lid material, a discharge device that discharges the sealed container to the outside of the aseptic filling machine, etc. 1, air is supplied from an air supply device 2 through an air supply pipe.

The air supplied from the air supply device 2 to the aseptic chamber 1 is sterilized by removing bacteria and the like by the sterilizing filter 4 . When the aseptic filling machine is stopped, the aseptic chamber 1 is opened and becomes contaminated with germs or the like. Contaminated air in the sterile chamber 1 may flow back through the air supply line and contaminate the downstream side of the sterile filter 4 . Moreover, although the sterilization filter 4 is replaced after being used for a certain period of time, the surface of the new sterilization filter 4 to be replaced is contaminated with bacteria or the like.

Therefore, after stopping the aseptic filling machine or after replacing the sterilization filter 4, the sterilization filter 4 must be sterilized. Also, the inside of the air supply pipe from the sterilizing filter 4 to the aseptic chamber 1 must be sterilized.

FIG. 1 is a circuit diagram showing a state when the sterilizing filter 4 is sterilized. From the heated steam supply means 3 provided between the air supply device 2 and the sterilization filter 4 for sterilizing the air supplied by the air supply device 2, by closing the on-off valve 6 coupled to the air supply device 2, Heated steam is supplied to the sterilization filter 4 . At this time, the on-off valves 7, 8 and 11 are opened. The heated steam supplied from the heated steam supply means 3 is supplied to the sterilization filter 4 and discharged from the open/close valve 11 . In FIGS. 1, 2 and 3, black on-off valves are closed and white valves are open.

A temperature sensor S is provided downstream of the sterilization filter 4 and downstream of the on-off valve 11. When heated steam is supplied to the sterilization filter 4, the temperature sensor S detects the temperature of the discharged heated steam for a predetermined time. The measured temperature information is sent to the controller 15, the F value is calculated by the controller 15 equipped with a calculation device for calculating the F value, and when the F value reaches the target value, the heated steam is sent by the signal from the controller 15 The supply of heated steam from the supply means 3 is stopped, and the sterilization of the sterilization filter 4 is completed.

Based on the temperature measured by the temperature sensor S and sent to the controller 15, the F value is obtained by the following arithmetic expression.

Assuming that Tr in the calculation formula is 121.1° C., when the temperature measured by the temperature sensor S reaches 121.1° C., the calculation device provided in the controller 15 starts calculating the F value. The Z value of spore-forming bacteria to be sterilized is 7° C. to 11° C., and the Z value may be set to 10 for calculation. The Z-value and target F-value can be arbitrarily tailored to the required sterilization strength of the contents to be filled with the aseptic filling machine.

Also, when the pH of the content is less than 4 to 4.6, the reference temperature Tr can be set to 85°C and the Z value = 7.8°C, and when the pH of the content is less than 4, the reference temperature Tr can be set to 65. °C, Z value = 5 °C, but can be changed as appropriate. When the pH is 4.6 or more, the calculation can be performed with the reference temperature Tr=121.1°C and the Z value=10°C.

As shown in FIG. 4, the F value is calculated from when the temperature reaches 121.1° C., and when the F value, which is the area of the hatched portion calculated from the temperature measured by the temperature sensor S, reaches the target value. Finish sterilization. The conventional case is shown in FIG. 5. When the temperature measured by the temperature sensor S provided in the heated steam discharge pipe reaches 130 ° C. 10 minutes after the heated steam is supplied, the timer is activated, and sterilization ends after 30 minutes. It took 5 minutes to cool. That is, it took about 45 minutes from the start of sterilization of the sterilization filter 4 to the end of cooling. As shown in FIG. 4, by controlling the F value of the sterilization time, it takes 5 minutes to raise the temperature to 121.1 ° C., and 8 minutes to reach F = 233 (130 ° C., equivalent to 30 minutes). The cooling time of the filter 4 is about 5 minutes, and the total time until the end of cooling is 18 minutes, and the time required for sterilization of the sterilizing filter 4 is shortened by about 60% compared to the total time of 45 minutes in the conventional case. be able to.

Not only is the time for sterilizing the sterilization filter 4 shortened, but also the time during which the sterilization filter 4 is exposed to the heated steam can be shortened, and the temperature at which the sterilization filter 4 is exposed to the heated steam can also be lowered. As a result, deterioration of the support material, filter material, O-ring, end cap, etc. of the filter material constituting the sterilization filter 4 can be reduced, thereby extending the service life of the sterilization filter 4 .

The heated steam supply means 3 heats water with electricity or fuel to produce steam, and the water used may be purified through a reverse osmosis membrane. For the can body that converts water into steam, a cleaning agent, a condensate treatment agent, etc. are used, and food additive grade is used. Moreover, it is preferable that the can body and the conveying pipe are made of stainless steel. In order to remove foreign matter, ions, chemicals, etc. in the heated steam, it may be passed through a filter, activated carbon, or an ultrafiltration membrane. Further, the heated steam supply means 3 is preferably a reboiler that generates heated steam by exchanging heat with the water that has passed through the reverse osmosis membrane using the heated steam as a heat source.

The heated steam supplied to the sterilization filter 4 has a temperature of 121.1°C to 150°C. If the temperature is less than 121.1°C, the sterilization temperature is low, and if it exceeds 150°C, the member of the sterilization filter may deteriorate.

The sterilization filter 4 is of a hollow cylindrical type, and the hollow cylindrical filter is housed in a detachably attached housing so that it can be attached to and detached from the housing. An air inlet is formed in the housing so that air can be supplied to the hollow cylindrical filter from the outside, and an outlet is formed in the housing through which the air that has passed through the hollow cylindrical filter is discharged through the hollow part. . A drain sump is formed in the lower portion of the housing and an automatic drain trap is attached to the housing in communication with the drain sump.

The filter of the sterilization filter 4 can remove bacteria, fungi, spores, etc., has pores of about 0.1 μm to 0.5 μm, and is made of regenerated cellulose, nitrocellulose, polytetrafluoroethylene, or the like. For example, a filter having such pores is sandwiched between supporting materials, which are nonwoven fabrics made of polypropylene or celluloses, and the obtained laminate is folded into a hollow shape, and the inside and outside of the folded hollow are made of mesh stainless steel. It is fixed with a support core, and the upper and lower ends are closed with end caps made of heat-resistant plastic such as polyphenylsulfone to form a bactericidal filter 4. - 特許庁One of the end caps is formed with a discharge port for discharging pressure air from the hollow portion, and is fixed to the discharge port of the housing using an O-ring made of silicone rubber.

Heated steam is supplied to the sterilization filter 4, and when the F value calculated from the temperature measured by the temperature sensor S reaches the target, the sterilization of the sterilization filter 4 is completed, and as shown in FIG. The valves 7, 8 and 11 are closed, the on-off valves 9 and 10 are opened, and the inside of the air supply pipe from the on-off valve 8 downstream of the sterilization filter 4 to the sterile chamber 1 is sterilized. If this part is also sterilized with heated steam, the time that the sterilization filter 4 is exposed to the heated steam becomes longer, and the members of the sterilization filter 4 deteriorate. Only the parts marked with Sterilization in the air supply pipe from the on-off valve 8 to the aseptic chamber 1 is performed with a sterilizing agent such as hydrogen peroxide or peracetic acid.

FIG. 2 shows a circuit diagram for sterilizing the inside of the air supply pipe from the open/close valve 8 to the sterile chamber 1. As shown in FIG. First, the sterilant is supplied from the sterilant supply device 5 into the air supply pipe from the on-off valve 9 to the aseptic chamber 1 . As shown in FIG. 6, the sterilant supply device 5 includes a sterilant supply unit 12, which is a two-fluid spray nozzle that supplies the sterilant in drops, and a sterilant supplied from the sterilant supply unit 12. and a vaporization unit 13 that heats the liquid to a temperature below the temperature to vaporize the liquid. The sterilant supply unit 12 takes in the sterilant and compressed air from the sterilant supply path 12 a and the compressed air supply path 12 b , respectively, and sprays the sterilant into the vaporization unit 13 . The vaporization part 13 is a pipe having a heater 13a sandwiched between the inner and outer walls, and heats and vaporizes the sterilant blown into the pipe. The vaporized sterilant gas is ejected from the lower end of the vaporizing section 13 to the outside of the vaporizing section 13 . Instead of the heater 13a, the vaporizing section 13 may be heated by dielectric heating.

By connecting the lower end of the vaporization part 13 to the sterilant spray nozzle 14 , the sterilant gas or mist or a mixture thereof is sprayed from the sterilant spray nozzle 14 into the air supply pipe to the aseptic chamber 1 . The sterilant gasified in the vaporization unit 13 may condense and become a mist before being sprayed from the sterilant spray nozzle 14, and the sterilant sprayed into the air supply pipe up to the aseptic chamber 1 is gas or mist. or a mixture of these.

Heated aseptic air may be supplied between the lower end of the vaporizing part 13 and the sterilant spray nozzle 14 to mix the sterilant gas or mist generated by the sterilant supply device 5 or a mixture thereof with the heated sterilized air. do not have.

As for the operating conditions of the sterilant supply unit 12 of the sterilant supply device 5, for example, the pressure of the compressed air is adjusted within the range of 0.05 MPa to 0.6 MPa. Further, the sterilant may be dropped by gravity or pressure may be applied, and the supply amount can be freely set. For example, 1 g/min. ~100 g/min. supplied in the range of Further, the inner surface of the vaporization part 13 is heated from 140° C. to 450° C., thereby vaporizing the sprayed sterilant.

Preferably, the disinfectant contains at least hydrogen peroxide. Its content is suitably in the range of 0.5% by mass to 65% by mass. If it is less than 0.5% by mass, the bactericidal power may be insufficient, and if it exceeds 65% by mass, it becomes difficult to handle safely. More preferably, it is 0.5% by mass to 40% by mass, and 40% by mass or less is easier to handle.

In addition, although the disinfectant contains water, one or two of alcohols such as methyl alcohol, ethyl alcohol, isopropyl alcohol, normal propyl alcohol and butyl alcohol, ketones such as acetone, methyl ethyl ketone and acetylacetone, glycol ethers, etc. It may contain more than seeds.

In addition, disinfectants include alkaline compounds such as peracetic acid, acetic acid, chlorine compounds, sodium hydroxide and potassium hydroxide, compounds having a disinfecting effect such as nitric acid, ozone, and acid water, cationic surfactants, nonionic surfactants. Additives such as agents and phosphoric acid compounds may also be included.

After supplying the sterilant into the air supply pipe from the opening/closing valve 8 to the aseptic chamber 1, to remove the sterilant remaining in the air supply pipe, and to increase the sterilization effect by heating the remaining sterilant. Heated aseptic air or room-temperature aseptic air may be supplied into the air supply pipe. The on-off valves 6, 8 and 10 may be opened and the on-off valves 7, 9 and 11 may be closed to supply sterile air from the air supply device 2 through the sterilization filter 4 into the air supply pipe.

After removing the sterilant remaining in the air supply pipe from the opening/closing valve 8 to the aseptic chamber 1, open the opening/closing valves 6 and 8 as shown in FIG. This is to maintain sterility in the air supply piping.

The air supply device 2 is, for example, an air compressor, and supplies air by operating a motor continuously or intermittently. The motor rotates and supplies atmospheric air to the air compressor tank, increasing the pressure in the tank. A pressure detection sensor is provided in the tank, and the motor stops rotating when the pressure reaches the upper limit setting. Air is used to lower the pressure in the tank, and when the pressure sensor detects that the pressure is below the lower limit set pressure, the operation of the motor is restarted and the pressure in the tank rises. The pressure of the air supplied in the embodiment is 0.01 MPa to 4.9 MPa. Low pressure air is used in air guns and the like used in the aseptic chamber of cap conveying and aseptic filling machines. High-pressure air is used as blow air in aseptic filling machines to form preforms into bottles. A blower may be used instead of an air compressor for supplying air.

Air supplied by an air compressor contains dust, moisture, oil, organic chemicals, and the like. It is preferable to provide a filter between the air supply device 2 and the opening/closing valve 6 to remove them. An air dryer is provided for cooling the air supplied by the air supply device 2 and for condensing moisture in the air. Condensed moisture is discharged by an automatic drain valve located at the bottom of the air dryer. Further, by providing a filter with pores exceeding 0.5 μm, dust and oil can be removed. Furthermore, a filter made of fibrous or granular activated carbon may be provided to adsorb the organic chemical substances to the activated carbon to remove them. Impurities such as dust, moisture, oil, and organic chemicals are preferably removed from the air before it is supplied to the sterilization filter 4 . If these impurities are removed by the sterilizing filter 4, the service life of the sterilizing filter 4 may be shortened.

Although the present invention is configured as described above, it is not limited to the above-described embodiment, and various modifications are possible within the scope of the present invention.

DESCRIPTION OF SYMBOLS 1... Aseptic chamber 2... Air supply device 3... Heated steam supply means 4... Sterilization filter 5... Sterilant supply apparatus S... Temperature sensor

Claims (5)

A method for sterilizing an air supply pipe equipped with a sterilization filter for supplying air to a chamber of an aseptic filling machine,
supplying heated steam to the sterilization filter that sterilizes the supplied air , discharging the heated steam from the downstream of the sterilization filter, and sterilizing the sterilization filter with the supplied heated steam; Close the valve downstream of the sterilization filter and the valve for discharging the heated steam , supply the gas of the sterilant or the mist of condensed gas or a mixture thereof from the downstream of the valve, and the sterilant supplied sterilizing from the valve downstream of the sterilization filter to the chamber to which the air is supplied ;
The valve for supplying the sterilant and the valve for supplying heated steam to the sterilization filter are closed, the valve for supplying air to the sterilization filter is opened, and the valve near the chamber for supplying the air to the chamber. is closed, the air is supplied to the sterilization filter, and the aseptic air that has passed through the sterilization filter controls sterility from the downstream of the sterilization filter to the valve near the chamber that supplies the air to the chamber. A method of sterilizing an air supply pipe equipped with a sterilizing filter, characterized by maintaining the sterilization until the aseptic filling machine starts operating. 2. The method for sterilizing an air supply pipe equipped with a sterilizing filter according to claim 1, wherein the temperature of the heated steam supplied to the sterilizing filter and discharged from the downstream of the sterilizing filter is measured at predetermined time intervals. A method of sterilizing an air supply pipe equipped with a sterilizing filter, comprising: calculating an F value from a measured temperature; and ending sterilization of the sterilizing filter when the F value reaches a target value. In the method for sterilizing an air supply pipe provided with the sterilizing filter according to claim 2,
The F value is the following formula

A method of sterilizing an air supply pipe equipped with a sterilization filter, characterized by calculating using In the method for sterilizing an air supply pipe provided with the sterilizing filter according to any one of claims 1 to 3,
A method of sterilizing an air supply pipe equipped with a sterilizing filter, wherein the supplied air is air having a pressure of 0.1 MPa or higher. In the method for sterilizing an air supply pipe provided with the sterilizing filter according to claim 4,
A method for sterilizing an air supply pipe provided with a sterilizing filter, characterized in that the air is supplied to the sterilizing filter after removing dust, oil and moisture from the air.

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