船舶压载水取样工具对比测试及实船试验

Comparative test of ship ballast water sampling tools and ship test

针对压载水中浮游生物捕集率低、难以取到代表性样本等关键缺陷,本文研究了浮游生物网取样效能影响。通过对比试验的方法,考察取样流速、浮游生物浓度和尺寸对2种不同材质浮游生物网(孔径为50μm的不锈钢网和筛绢网)收集率和透过率的影响,并进行了实船试验。结果显示:在不同条件下,不锈钢网对不小于50μm浮游生物的收集率超过60%,高于筛绢网,同时在合理范围内可通过降低实船压载水取样流速(小于0.88 m/s)和浮游生物网网孔尺寸(小于50μm),来提高不小于50μm浮游生物的收集率。在实船试验过程中,不锈钢网对不小于50μm浮游生物的收集数量均高于筛绢网,且不锈钢网材料结实,不易破损,因此推荐不锈钢网作为实船压载水的取样工具。

To deal with the critical defects of low plankton capture rate in ballast water and the difficulty in obtaining representative samples,the influence of the sampling efficiency of plankton nets was researched in this study.The comparative test method was used to investigate the effects of the flow rate of sampling,plankton concentration,and size on the collection rate and pass rate of plankton nets with two different materials(stainless steel net and screen silk net,with an aperture size of 50μm).A real ship test was conducted.Results show that the collection rate of the stainless steel net exceeds 60%under different conditions,which is higher than that of the screen silk net;at the same time,the flow rate of ballast water and the mesh size of the plankton nets in real ships can be reduced to a reasonable range(less than 0.88 m/s and 50μm,respectively)to improve the collection rate.In the ship test,the collection rate of the stainless steel net is higher than that of the screen silk net,and the stainless steel net is strong and not easily damaged.Therefore,the stainless steel net is recommended as a sampling tool for ballast water in real ships.