Tanker Electrostatic Explosion-proof Technology

Though Shell Petroleum Corporation began researching electrostatic problems of tankers during filling from 1933, yet people hadn't paid enough attention to the electrostatic hazards to tankers. Until Dec.1969, three VLCC (very large crude carrier) exploded in less than three weeks, which shook the shipping field in the world. After these accidents, a lot of corporations and industrial groups, especially, ICS (the international chamber of shipping) and API (American Petroleum Institute), took on or imbursed the research on these accidents. A lot of countries, for example, Europe, America and Japan, their specialists and scholars carried through experiments for a variety of possible ignitable sources in order to find the explosive causes, including to mechanical bouncing, dropping objects in the cabin and throwing metals when spraying seawater to wash the cabin or personal blames. But at last, they focused on the static electricity. It is very possible to cause the tankers explosion by electrostatic discharge. In 1970's, some large tankers exploded because of the static electricity from ballasting water's surging or letting out. Since 1950's, the tankers electrostatic accidents hadn't been interrupted due to the velocity of loading and unloading oils is very high and other causes. With a view to these description above, apparently the tankers electrostatics became the one of important problems which affects shipping safety. A lot of countries carried through the research on the tanker electrostatics. With the tanker electrostatics and the whole electrostatics developing, the charging mechanism and law of tankers have been found by people. A variety of technical protective measures to prevent tankers static hazards have been developed continually. A series of safe technical codes have been set down. In China, the tankers static accidents also happen usually, which results in belongings loss or personnel casualty severely. So it is the one of important tasks for Chinese shipping safety to strengthen to research electrostatics of tankers, to draw appropriate protective measures and to pay much attention to educate a large number of sailors. The paper describes the basic principle ?electric double layer theory, discusses in detail the mechanism of the static electricity in conveying oil tubes, washing the cabin and the ship ballasting water. At the same time, the potential and the electric field intensity in the rectangle oil cabin and the column oil cabin have been discussed. Based on these, the paper brings forward the static explosion- proof measures and safety suggestions. Above all, based on strict theory, the paper resolves the one of explosion-proof technique of tankers in China: the new technique of ship-shore electric safety joining. The subject is sponsored by the Shanghai natural science fund. By a year hard work, considering the configuration and technical demands of the insulating flange, we selected the insulating rubber as basic materials, and then, we tried to change functions of the insulating rubber by adding the conductive carbon black in the insulating rubber. At the same time, we did experiments on the adding quantity of the conductive carbon black, refine and molding methods, the...