Process and cryogenic liquids sampling installation, such as air separation plant with such an installation

摘要

To sample contaminated low temperature liquid gases, e.g. liquid oxygen or nitrogen, the gas(es) is (are) fed into an evaporator (24) connected to the insulated (20) bleed line (8) through a junction (44), so that the gas drops down through the evaporator. The evaporator walls in contact with the gas are maintained at a temperature over the sublimation or vaporizing level of the least volatile impurity in the liquid gas. The gas phase is evacuated (46) downstream of the evaporator to be transferred through a flow control (52) to an analysis unit (54). The evaporator acts as a heat exchanger using free ambient air to vaporize wholly the liquid gas(es).