Impinging jet cleaning of tank walls: Effect of jet length, wall curvature and related phenomena

The effect of jet length and wall curvature on the flow patterns generated by an impinging water jet were quantified and the effect on cleaning investigated in a brief study. The length of time taken to establish steady flow was characterised. Jet impingement on a flat vertical wall was investigated for jets of diameter 2–4mm for lengths, L, up to 1m. The amount of liquid lost to splatter was measured and found to be insensitive to L for short L (1.5dm3min−1). The cleaning of two viscoplastic model food soils was studied briefly: a hydrophobic petroleum jelly and Carbopol®, a water-soluble gel. The splatter correction was not able to account for all the differences observed in cleaning at different jet lengths. There was no appreciable effect of curvature on cleaning behaviour. Soaking of the Carbopol® increased its cleaning rate.Funding for MWLC from Newnham College, Cambridge, and a Commonwealth Scholarship for RKB are gratefully acknowledged, as is travel funding for DIW to attend the FCFP2018 conference from Jesus College, Cambridge. Authors TVA, NT, SAW and RLW were all MEng research project students