US-12617662-B2 - Cleaning method for sterilization line and sterilization line

Abstract

A sterilization line comprising upstream-side and downstream-side tanks for storing liquid which are connected by a conduit for transferring the liquid, holding tubes for sterilizing the liquid which are disposed in an intermediate section of the conduit, heating units for heating the liquid in stages which are disposed in a section of the conduit from the upstream-side tank to the holding tubes, and cooling units for cooling the product liquid in stages which are disposed in a section of the conduit from the holding tubes to the downstream-side tank. A swing bend is used to perform switching between a section of a liquid flow path located on the upstream side of multiple intermediate piping systems and a cleaning solution path for a cleaning-in-place operation and switching between a section of the liquid flow path located on the downstream side and the cleaning solution path for the cleaning-in-place operation.

Inventors

• Atsushi Hayakawa

Assignees

• DAI NIPPON PRINTING CO., LTD.

Dates

Publication Date

20260505

Application Date

20240405

Priority Date

20180205

Claims (2)

1. 1 . A sterilization line comprising: a connecting conduit through which a product liquid is transferred; one or more stages of heating parts that are provided in a middle section of the connecting conduit and sterilize the product liquid; and one or more stages of cooling parts that cool the product liquid from the one or more stages of the heating parts in a stepwise manner, wherein the sterilization line further comprises a plurality of parallel intermediate piping systems in a section thereof from the one or more stage of the heating parts that lies in a temperature range in which the product liquid can be burned to the one or more stages of the cooling parts that lies in the temperature range in which the product liquid can be burned, wherein the section includes at least one of the one or more stages of the heating part that lies in the temperature range in which the product liquid can be burned, the plurality of parallel intermediate piping systems being provided with a cleaning in place (CIP) unit that cleans the plurality of parallel intermediate piping systems, and a sterilization process for the product liquid in the plurality of parallel intermediate piping system and CIP of the plurality of parallel intermediate piping system is performed by switching between the plurality of parallel intermediate piping systems, where a swing bend is provided to achieve switching between a flow path of the product liquid and a flow path of a cleaning solution used for the CIP upstream of the plurality of intermediate parallel piping systems and switching between the flow path of the product liquid and the flow path of the cleaning solution used for the CIP downstream of the plurality of parallel intermediate piping systems, and wherein the swing bend is provided in a shielded chamber, and the sterilization line is provided with a sterilization unit that sterilizes an interior of the shielded chamber before the switching between the flow paths, the sterilization unit being provided with a steam inlet and a steam outlet.
2. 2 . The sterilization line according to claim 1 , wherein the plurality of parallel intermediate piping systems are provided with a sterilizing in place (SIP) unit that performs SIP that sterilizes an interior of the plurality of parallel intermediate piping systems after or at the same time as the CIP of the interior of the plurality of parallel intermediate piping systems and a positive pressurization unit that keeps the interior of the plurality of parallel intermediate piping systems at a positive pressure after the SIP.

Description

CROSS REFERENCE TO RELATED APPLICATION This application is a division of U.S. application Ser. No. 16/962,134, filed Jul. 14, 2020, which is a continuation of International Application No. PCT/JP2019/003613, filed Feb. 1, 2019, the entireties of which are incorporated herein by reference. TECHNICAL FIELD The present invention relates to a cleaning method for a sterilization line that sterilizes a product liquid such as a drink in an aseptic filling machine that aseptically fills a container with a drink, and the sterilization line. BACKGROUND ART Conventionally, before an aseptic filling machine for a drink or the like starts filling a container such as a bottle with a drink, a supply piping system for the drink or the like is subjected to Cleaning in Place (CIP) for removing impurities and bacteria from the inside of the piping system and Sterilization in Place (SIP) for sterilizing the interior of the supply piping system (see Patent Literature 1). The CIP is performed by circulating a mixture of water and an alkali cleaning agent such as caustic soda or an acidic cleaning agent as an additive in the supply piping system, for example. The CIP removes impurities such as drink residues on the inside of the supply piping system (see Patent Literatures 1, 2, and 3). The SIP is performed by circulating heated steam, hot water or the like in the supply piping system cleaned by the CIP, for example. The SIP sterilizes the interior of the supply piping system and makes it aseptic (see Patent Literature 1). The supply piping system of an aseptic filling system that handles a large amount of product liquid is provided with a sterilization line. The sterilization line includes an upstream-side tank that stores a prepared product liquid such as a drink and a downstream-side tank that stores the product liquid having been sterilized and supplies the product liquid to a filling machine. The upstream-side tank and the downstream-side tank are connected to each other by a conduit through which the product liquid is transferred. The conduit is provided, in a middle section thereof, with a holding tube that sterilizes the product liquid. The conduit is provided, in a part thereof between the upstream-side tank and the holding tube, two stages of heating parts that heat the product liquid in a stepwise manner. The conduit is provided, in a part thereof between the holding tube and the downstream-side tank, three stages of cooling parts that cool the product liquid in a stepwise manner. Since pluralities of stages of heating parts and cooling parts are provided, even a large amount of product liquid can be properly and smoothly heated to a sterilization temperature and smoothly cooled to room temperature. In general, when the filling machine fills a container such as a PET bottle with the product liquid, the product liquid fed under pressure through the conduit from the upstream-side tank to the downstream-side tank is heated from room temperature to about 65° C. in a first-stage heating part, further heated from about 65° C. to about 140° C. in a second-stage heating part, heated and maintained at about 140° C. for about 30 to 60 seconds and thus sterilized in the holding tube, then cooled from about 140° C. to about 90° C. in a first-stage cooling part, further cooled from about 90° C. to about 45° C. in a second-stage cooling part, and further cooled from about 45° C. to about 30° C. in a third-stage cooling part. The downstream-side tank stores the product liquid at 30° C. coming from the third-stage cooling part. The product liquid is fed from the downstream-side tank to the filling machine, and the filling machine fills a large number of containers such as PET bottles with the product liquid while the containers are traveling at high speed. With regard to the sterilization line described above, there has been proposed a method of reducing the time required to start production of the next product liquid by providing a similar piping system in parallel with the piping system from the second-stage heating part to the first-stage cooling part, which lies in a temperature range in which the product liquid can be burned, and completing the CIP and the SIP for one piping system while the other piping system is used to feed the product liquid (see Patent Literature 4). CITATION LIST Patent Literature Patent Literature 1: Japanese Patent Laid-Open No. 2007-22600Patent Literature 2: Japanese Patent Laid-Open No. 2007-331801Patent Literature 3: Japanese Patent Laid-Open No. 2000-153245Patent Literature 4: Japanese Patent Laid-Open No. 2013-91018 SUMMARY OF INVENTION Technical Problem With the conventional sterilization line for a product liquid, sterilization of the product liquid and the CIP and other processes can be performed in parallel by alternately switching between two piping systems, and therefore, the efficiency of production of product liquid packages can be improved. However, the piping system described above requires