Forming An Ice Plug Inside A Horizontal High Diameter Pipeline (200 mm Nominal Diameter) Using A 15% Nitrogen Vapours Exhaust Nozzle Restriction

The ice plug isolation technology of a large diameter horizontal pipeline is specific for components repair / replacements in thermo-hydraulic installations without shutting down the entire plant or the water supply. The freezing device is in the form of a sleeve composed of two approximately identical subassemblies bolted together on the outside of the pipe. In order to limit the pressure in the freezing compartment, liquid nitrogen vapours are discharged through the specialty provided nozzle. We chose two experiments for an analysis: with and without a 15% restriction mounted between the freeze device's exhaust nozzle and exhaust pipe. They were conducted during two experimental campaigns without a flow of water and on the same testing pipe. The paper is dedicated to specialists working in research and technological engineering. (author).