Liquid nitrogen injection system with flexible dosing arm for pressurization and inerting containers on production lines

A liquid-nitrogen dosing head for injecting metered droplets of liquid nitrogen into a product moving along a packaging assembly line, comprising:

• a valve body including an input chamber, an output chamber and an injection valve in between;
• a single feed port disposed in a near end of the valve body for receiving a circulating liquid nitrogen flow from a vacuum-insulated liquid-nitrogen reservoir into said input chamber;
• and
• a pair of return ports disposed in a distal end near the top of the valve body for returning said circulating liquid nitrogen flow from said output chamber to said vacuum-insulated liquid-nitrogen reservoir;
• wherein, during operation any circulating liquid nitrogen flow that is not passed out through said injection valve toward a food product on a production line is returned through at least one of the pair of return ports.

A system for injecting liquid nitrogen into a container on a high speed production line just before environmental sealing, comprising:

• a vacuum-insulated liquid-nitrogen reservoir for mounting higher in elevation than a moving production packaging assembly line and positioned off to one side;
• a dosing head for mounting directly above said moving production packaging line, and including a control valve for injecting metered droplets of liquid nitrogen into a product moving along said production packaging assembly line;
• a flexible extension arm with vacuum-insulated feed and return conduits for circulating a flow of liquid nitrogen between the reservoir and said control valve in the dosing head;
• a valve body disposed within the dosing head and including a needle valve to control said injecting metered droplets of liquid nitrogen;
• and
• a pair of return lines connected to the valve body that circulate liquid nitrogen from the dosing head back to the reservoir;
• wherein, the flexible extension arm provides for an elevation adjustment of the vacuum-insulated liquid-nitrogen reservoir relative to the dosing head and adjustment of a dosing liquid pressure.