Electricity: electrical systems and devices – Control circuits for electromagnetic devices – Systems for magnetizing – demagnetizing – or controlling the...
Patent
1980-11-25
1983-02-08
Pellinen, A. D.
Electricity: electrical systems and devices
Control circuits for electromagnetic devices
Systems for magnetizing, demagnetizing, or controlling the...
114240R, 361143, B63G 906
Patent
active
043731740
DESCRIPTION:
BRIEF SUMMARY
In vessels of steel or vessels of wood with a large iron mass, for example in the engine and the engine bed, a permanent magnetization (magnetic remanance) is often obtained because of the terrestrial magnetism. Such a magnetization can trigger magnetic mines, and for this reason protective magnetization of the vessel is provided. For the protective magnetization of the vessel while in motion, so that the magnetization which is more or less powerful depending on the position of the vessel in the earth's magnetic field, is constantly suppressed by applying a counteracting magnetic field, adapted to the strength of the magnetization caused by the earth's magnetic field, magnetic loops are used in the vessel, placed athwartships as well as fore-and-aft. The loops can then receive current in dependence on the heading of the vessel in accordance with a programmed predetermined relation between heading and current strength. A signal which is representative of the heading is supplied by the compass of the vessel (magnetic compass or gyrocompass). It is also known to control the current through the magnetic loops by means of magnetic probes in dependence on variations in the magnetic component of the earth's field on pitching and rolling movements of the vessel and on changes of course.
The protective magnetization which is achieved in this manner is not satisfactory, partly because the magnetization takes place with a certain inertia in relation to the angular movement of the vessel and partly above all because alterations in the iron mass of the vessel, which act on the field strength of the magnetic field, are not taken into consideration.
The purpose of the invention is to provide a control of the protective magnetization, which is more adaptable to the prevailing conditions, and for this purpose the invention provides a method for protective magnetization of vessels by using a magnetic loop which is energized in dependence on the heading of the vessel and on the longitudinal and transverse inclination thereof, with the characteristics which can be seen from claim 1.
By this means, the effect is achieved that the protective magnetization always follows the magnetic remanance actually existing at the present moment. Because the Hall generator has a limited range, it does not detect the field strength of the earth's magnetic field but the field strength of the magnetic field surrounding the vessel, which provides an important advantage because as a result the Hall generator will control the energization of the magnetic loop also in dependence on those alterations in the field strength of the magnetic field surrounding the vessel, which are caused by alterations in the iron mass of the vessel, for example as a result of the loading and unloading of a cargo containing iron.
In order to illustrate the invention, examples of carrying out the method are described in more detail below with reference to the accompanying drawing in which
FIG. 1 is a diagram of an installation for carrying out the method, and
FIG. 2 is a diagram illustrating the relation between a control signal which depends on the field strength of the magnetic field surrounding the vessel, and the current generated for the protective magnetization.
FIG. 1 shows diagrammatically a vessel 10 in which there is provided a magnetic loop 11 which is laid fore-and-aft and which can be of conventional construction. Only one loop is shown here but a plurality of fore-and-aft loops coupled in parallel can be provided, and they may lie in the longitudinal central plane of the vessel or at each side of the central plane. Under the vessel, at the lower side of the bottom thereof or in a tube or the like, passed through the bottom of the vessel, there is disposed a Hall generator 12. In order to control a magnetic loop 11 disposed fore-and-aft, this Hall generator should have the plane of its plate in the fore-and-aft direction of the vessel, as indicated in the drawing in FIG. 1, and the Hall generator should be mounted in the central fore-and-aft plane of the ves
REFERENCES:
patent: 2267838 (1941-12-01), Polin
patent: 2421583 (1947-06-01), Stuart, Jr.
patent: 2519395 (1950-08-01), Perlow et al.
patent: 2715198 (1955-08-01), Tolles
patent: 2793602 (1957-05-01), Haglolnd
patent: 2832041 (1958-04-01), Trachtenberg
patent: 3110282 (1963-11-01), Foerster
patent: 3215904 (1978-07-01), Burt
patent: 3482163 (1969-12-01), Peek et al.
patent: 3801877 (1974-04-01), Griese et al.
Pellinen A. D.
Schroeder L. C.
LandOfFree
Method for protective magnetization of vessels does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method for protective magnetization of vessels, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for protective magnetization of vessels will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-51440