METHOD OF CLEANING HYDRAULIC SYSTEM PIPELINES FROM OIL AND SERVICE CONTAMINANTS WITH SUPERCRITICAL CARBON DIOXIDE Russian patent published in 2019 - IPC B08B3/00 B08B9/27 B08B7/00 

FIELD: technological processes.

SUBSTANCE: disclosed method relates to methods of cleaning using liquid, can be used in various industries for cleaning pipelines from oil and operational contaminants. In the method, carbon dioxide is used as a working medium. Working medium from the supply tank is supplied to the pump, then it is directed along the pressure line to the flushed pipeline; the above flushed pipeline is flushed with the help of the working medium, and then the working medium is returned to the delivery tank through the filter. In the feed tank, carbon dioxide is in a liquid state. Pump creates and maintains working medium pressure higher than critical for carbon dioxide. After the pump, the working medium is supplied to the evaporator of the recuperative temperature maintenance system, which includes an evaporator, a condenser and a coolant compressor circulating in said system, which heats to temperature higher than critical for carbon dioxide, thereby converting carbon dioxide into supercritical fluid state. After cleaning, working medium passes through condenser of recuperative system to maintain temperature mode, cooling it to temperature below critical for carbon dioxide. Filter, through which working medium passes before returning to supply tank, is coalescent. Residual carbon dioxide from flushed pipeline is removed into atmosphere after washing.

EFFECT: efficient cleaning of pipelines against oil and operational contaminants without formation of oil-containing water solutions requiring further processing and recycling.

1 cl, 1 dwg