Steam-replacement deaeration method for use in bag packaging and nozzle for use in steam-replacement deaeration

Abstract

A steam-replacement deaeration method uses a nozzle having a double-tube structure of an inner first nozzle member and an outer second nozzle member. An insert part of the first nozzle member that is to be inserted into a bag has a flat cross-sectional configuration. The body of the second nozzle member has a circular cross-section and surrounds the insert part of the first nozzle member. At a first stage of steam injection, both the first and second nozzle members are inserted into the bag, and steam is injected from the spouts of both of them. Next, only the second nozzle member is removed from the bag, and the steam injection therefrom is stopped. While the steam injection from the first nozzle member being continued, the bag mouth is brought into a tensed state. Next, the first nozzle member is removed from the bag, and the bag is moved to the subsequent step with the bag mouth kept in the tensed state.

1 . A nozzle for use in steam-replacement deaeration in bag packaging, said nozzle comprising:
 a first nozzle member comprising an insert part adapted to be inserted into a bag, said insert part comprising a flat cross-section, said first nozzle member comprising an interior connected to a first steam supply path; and   a second nozzle member comprising an insert part adapted to be inserted into the bag, said insert part comprising a cross-section that at least partially occupies an area around the insert part of said first nozzle member, said second nozzle member comprising an interior connected to a second steam supply path.   
   
   
       2 . The nozzle of  claim 1 , wherein the insert part of said second nozzle member surrounds said insert part of said first nozzle member. 
   
   
       3 . The nozzle of  claim 2 , wherein said cross-section of said insert part of said second nozzle member is substantially circular. 
   
   
       4 . The nozzle of  claim 1 , wherein said insert part of said second nozzle member comprises two insert part portions located at laterally opposite sides of the flat cross-section of the insert part of said first nozzle member and comprising bow-shaped cross-sections, respectively, wherein straight-line portions of the bow-shaped cross-sections of said two insert part portions face each other and extend in a longitudinal direction of the flat cross-section of the insert part of said first nozzle member. 
   
   
       5 . The nozzle of  claim 1 , wherein said first nozzle member and second nozzle member are integrally constructed, said second nozzle member being positioned so that a distal end of a spout thereof is axially rearward of a distal end of a spout of said first nozzle member. 
   
   
       6 . The nozzle of  claim 1 , wherein said second nozzle member is axially movable relative to said first nozzle member. 
   
   
       7 . A steam-replacement deaeration method for use in bag packaging, said method comprising the steps of:
 providing a nozzle comprising a first nozzle member and a second nozzle member, said first nozzle member comprising a first insert part adapted to be inserted into a bag, said first insert part comprising a flat cross-section, said first nozzle member comprising an interior connected to a first steam supply path, said second nozzle member comprising a second insert part adapted to be inserted into the bag, said second insert part comprising a cross-section that at least partially occupies an area around the insert part of said first nozzle member, said second nozzle member comprising an interior connected to a second steam supply path;   inserting said nozzle into a bag whose mouth is open;   injecting steam from said first nozzle member and second nozzle member;   removing said second nozzle member from the bag, stopping injection of steam from said second nozzle member, and bringing the mouth of said bag into a tensed state; and   removing said first nozzle member from the bag, and moving said bag to a subsequent step with the mouth of said bag kept in the tensed state.   
   
   
       8 . The method of  claim 7 , wherein said step of providing a nozzle comprises providing a nozzle wherein said first nozzle member and second nozzle member are integrally constructed, said second nozzle member being positioned so that a distal end of a spout thereof is axially rearward of a distal end of a spout of said first nozzle member. 
   
   
       9 . The method of  claim 7 , wherein said step of providing a nozzle comprises providing a nozzle wherein said second nozzle member is axially movable relative to said first nozzle member.