GAS PIPELINE INSIDE DEHYDRATION AT NEGATIVE TEMPERATURES Russian patent published in 2016 - IPC F26B7/00 F26B3/04 F26B5/04 

FIELD: heating.

SUBSTANCE: gas line inside is evacuated to measure in preset equal time intervals the parameters describing the thermodynamic state of the medium inside the gas line. Measured parameters are compared with preset tolerances to disconnect the vacuum pumps at the minimum absolute preset pressure inside the gas line. Rarefaction is terminated and the gas line is kept at the minimum absolute pressure for time required to reach the 100%-saturation of steam-air mix above the ice surface inside the gas line. The dew point reached, the vacuum pumps are actuated to pump water vapours from inside the gas line. Water vapours evacuation and pipe line drying are terminated after the definite dew point is reached over the entire volume of gas line. At evacuation at the medium temperature inside the gas line equal to that of water crystallization start temperature the gas pipeline is purged with nitrogen, Said purging is performed at the pipe open end at barometric pressure. Purging with nitrogen and pipe line drying are terminated after the definite dew point is reached over the entire volume of gas line.

EFFECT: higher efficiency of drying at negative temperatures of drying medium.

2 cl, 4 dwg, 1 tbl