Removal of oil films from stainless steel tubes

Abstract

The removal of oil films from the inner surface of a stainless steel tube cell using aqueous cleaning solutions was studied. The two oils used in the cleaning experiments, Sunquench 1042 and heavy mineral oil, contained P32 labeled tributyl phosphate (TBP) as a radioactive tracer. The β‐ particles emitted from the radioactive TBP were detected by a CaF2 scintillator and used as a measure of the amount of oil remaining in the tube cell. Cleaning experiments performed at different flow rates, surface treatment, and surfactant concentrations indicated that initially the oil films were removed rapidly. At the end of the experiments, the oil removal rate reduced significantly, eventually becoming negligible. The stainless steel morphology affected oil removal significantly, and the rougher tube tended to retard the oil removal. The rate and extent of the decontamination were significantly increased in the presence of sodium dodecyl sulfate, a nonionic surfactant. Experimental data were compared to a hydrodynamic model based on the removal of a liquid contaminant from a solid surface by an immiscible fluid. The model deviated from the experimental data due to the presence of instabilities at the oil‐water interface.

Removal of yield‐stress fluids from pipework using water

“…Removal of these patches dictates the cleaning time, perhaps due to increased friction (and energy loss) in the presence of a wavy residual film. Similar behavior was seen in removal of oil from tubes …”

Effect of Poly(aspartic acid) on the Removal Rates of Brushite Deposits from Stainless Steel Tubing in Turbulent Flow

“…For this reason, the main objective of this work is to determine the mechanisms by which PASP affects deposit removal of pure DCPD films at various pHs and fluid velocities. This work uses a solid scintillation technique applied in previous research by our group ,− to experimentally study the removal of DCPD deposits from stainless steel pipes under turbulent flow conditions in the presence of PASP. By comparing DCPD deposit removal in the presence and absence of PASP, we establish how the sequestrant affects the shear-controlled cleaning rate.…”

Use of Sodium Polyaspartate for the Removal of Hydroxyapatite/Brushite Deposits from Stainless Steel Tubing

“…This technique involves the use of an experimental flow system equipped with solid scintillation detection equipment. We have used this system previously to study the removal of both mineral (e.g., calcium phosphate) and oil contaminants from stainless steel tubes (Yan et al, 1997;Grant et al, 1996Grant et al, , 1997.…”