US 12,031,680 B1
Controlled dosing of liquid cryogen
Erik Robert Showers, Boxford, MA (US); John Walker Ross, Ipswich, MA (US); and David Tucker, Groveland, MA (US)
Assigned to Vacuum Barrier Corporation, Woburn, MA (US)
Filed by Vacuum Barrier Corporation, Woburn, MA (US)
Filed on Jan. 29, 2024, as Appl. No. 18/425,621.
Claims priority of provisional application 63/623,393, filed on Jan. 22, 2024.
Int. Cl. F17C 13/04 (2006.01); B67C 3/00 (2006.01); B67C 3/26 (2006.01)
CPC F17C 13/04 (2013.01) [B67C 3/005 (2013.01); B67C 3/26 (2013.01); F17C 2205/0326 (2013.01); F17C 2221/014 (2013.01); F17C 2223/0161 (2013.01); F17C 2260/038 (2013.01); F17C 2270/059 (2013.01)] 19 Claims
OG exemplary drawing
 
1. An aseptic liquid cryogen dosing head, comprising
a liquid cryogen reservoir in communication with a dosing outlet;
a dosing valve stem extending through the liquid cryogen reservoir and having a lower, distal end configured to selectively open and close the dosing outlet;
an electromagnetic actuator attached to an upper end of the dosing valve stem and operable to move the dosing valve stem to open and close the dosing outlet;
a seal extending about the dosing valve stem and separates the liquid cryogen reservoir from a cavity between the seal and the electromagnetic actuator, the seal providing an air-tight seal during operation; and
a controller operable to perform a head leakage test, including
pressurizing the cavity with a pressure higher than a pressure within the reservoir, to check for leakage past the seal; and
pressurizing the reservoir to check for leakage from the liquid cryogen reservoir.