Controlled dosing of liquid cryogen

Abstract

A liquid cryogen dosing head has a liquid cryogen reservoir in communication with a dosing outlet, a dosing valve stem having a lower, distal end configured to selectively open and close the dosing outlet, and an electromagnetic actuator attached to an upper end of the dosing valve stem above the liquid cryogen reservoir and operable to move the dosing valve stem to open and close the dosing outlet. The electromagnetic actuator is disposed above the liquid cryogen reservoir and the dosing valve stem extends through the liquid cryogen reservoir, preferably concentrically, to open and close the dosing outlet by blocking an orifice of the dosing outlet.

Dependencies are inferred from the claim text.