Abstract

Today, ship hull fouling is managed through fouling-control coatings, complemented with in-water cleaning. During cleaning, coating damage and wear must be avoided, for maximum coating lifetime and reduced antifoulant release. When possible, cleaning should target early stages of fouling, using minimal forces. However, such forces, and their effects on coatings, have not yet been fully quantified. In this one-year study, minimal cleaning forces were determined using a newly-designed immersed waterjet. The results show that bi-monthly/monthly cleaning, with maximum wall shear stress up to ∼1.3 kPa and jet stagnation pressure ∼0.17 MPa, did not appear to cause damage or wear on either the biocidal antifouling (AF) or the biocide-free foul-release (FR) coatings. The AF coating required bi-monthly cleanings to keep fouling to incipient slime (time-averaged results), while the FR coating had a similar fouling level even without cleaning. The reported forces may be used in matching cleaning parameters to the adhesion strength of the early stages of fouling.

摘要

如今，船体结垢是通过结垢控制涂层进行管理，并辅以水中清洁。在清洁过程中，必须避免涂层损坏和磨损，以延长涂层寿命并减少防污剂的释放。在可能的情况下，清洁应以最小的力瞄准结垢的早期阶段。然而，这种力及其对涂层的影响尚未完全量化。在这项为期一年的研究中，使用新设计的浸入式水刀确定了最小的清洁力。结果表明，每两个月/每月清洁一次，最大壁剪切应力高达〜1.3  kPa，喷射停滞压力〜0.17 MPa似乎对杀菌防污（AF）或不含杀菌剂的污垢释放（FR）涂层均未造成损坏或磨损。AF涂层需要每两个月清洗一次，以保持污垢至初期的粘液（时间平均结果），而FR涂层即使不清洗也具有相似的污染水平。报告的力可用于使清洁参数与结垢早期阶段的粘附强度相匹配。