The Study On The Flow-through Ballast Water Exchange On Ship

The paper discusses the design of the flow-through BW (i.e.ballast-water) system which is applied on ship.Firstly, the paper introduces the environment pollution, which results from the unwanted organisms in BW. Then it introduces the worldwide feedbacks for the pollution and the current BW management methods, some of which are applied on ship and another of which are under studying.Secondly, the paper does some researching on the problems emerged when the flow-through BW exchange is applyed on board, on the base of which the design principles of flow-through BW system are brought forward. The paper also gives examples of various types of ships'design and expenses of modifying their BW system (including bulk, oil tank, container and cruise ship).The optimized selection of BW pump is emphasized in the paper. The resistance of pipe net is calculated by the finite element method in order to get the parameters of the pump in rated load (including P, Q and H). The paper also gets the function between the rated flow and the the rated pressure of the pump on ships whose BW pipe net is uniform and line is different, which provides a new method for the selection of BW pump.The hydraulics of over-flow outlet is analysed and brings forward the demands of the over-flow outlets' selection in the building and built ships.The paper offers the references for the design of BW system when applying the flow-through BW exchange, and it is practical.