MECHANOTHERMOCHEMICAL CLEANING OF OBJECTS FROM HYDROCARBON CONTAMINATIONS Russian patent published in 2001 - IPC

FIELD: washing of transportation and process vessels, parts and units of mechanisms, ground from such contaminants as oil products, lubricants, fats and oil. SUBSTANCE: method is realized by closed cycle with aqueous solution of detergent forming unstable emulsion with hydrocarbon contaminants. Method includes stage of object washing and stage of regeneration of washing solution by phase separation of emulsion with subsequent separation of phases and return of aqueous washing solution to cleaning cycle. Detergent is used in the form of substance based on modified sodium salt of polyacrylic acid. Cleaning of object is effected in three stages. The first stage, before object cleaning, covers sampling of contaminant for determination of character and quantity of contaminants to select cleaning process parameters. The second stage includes heating of washing solution to temperature of 45-55 C and its supply at pressure of 1.0-1.5 MPa with the help of washing plant to provide for mechanical cleaning of surface contaminants and subsequent treatment for 5-30 min depending on character of contamination. The third stage includes regeneration of washing solution by separation of formed mixture into three phases: organic, aqueous and solid contaminants with subsequent monitoring of components content in solution and correction of their concentration automatically following the linear law up to required values before solution return to cleaning cycle. EFFECT: higher quality of cleaning, stable process of cleaning and reduced its duration. 2 cl, 2 tbl