METHOD OF CLEANING SURFACES FROM HYDROCARBON CONTAMINATION Russian patent published in 2003 - IPC

FIELD: methods of cleaning surfaces from hydrocarbon contamination, such as oil, petroleum products, grease, fats, oils; mechanized washing of technological and transport facilities. SUBSTANCE: method includes preparation of washing compound containing 2-4 mas.% of nonionogenous surfactant on base of alkoxylate of fatty alcohol and active component containing only soda ash or partial replacement of it by sodium salts of phosphorous acid; used as nonionogenous surfactant is hydroxyethylated polyoxypropylene glycol derivatives of ethylenediamide or ethylenediamine; proposed method includes also washing the surface with aqueous solution of detergent, discharging emulsion thus obtained, separating the emulsion into aqueous and organic phases by passing it through self-cleaning thin- layer settler made in form of plane-parallel vertical coalescence plates forming slotted clearances followed by return of aqueous phase to cleaning cycle and periodic removal of organic phase to receiver. EFFECT: simplified procedure; increased extraction of hydrocarbon contaminants; improved service parameters. 3 cl, 1 dwg, 3 tbl