DEMAGNETISATION DEVICE AND METHOD OF LONG FERROMAGNETIC ITEMS Russian patent published in 2011 - IPC H01F13/00 

FIELD: electricity.

SUBSTANCE: demagnetisation device of long ferromagnetic items includes solenoid (1), demagnetisation coil of low frequency (2), demagnetisation coil of high frequency (3), which are located coaxially one relative to the other and which are connected to power units of low frequency (4) and high frequency (5) respectively. Power control devices (6) and (7) are connected on one side to the appropriate power units (4) and (5) and on the other one - to control unit (8). End sensors (9) and (10) are installed at inlet and outlet of solenoid housing (1). Demagnetisation method involves creation of alternating magnetic field by means of coils of solenoid with low and high frequency alternating magnetic fields created with coaxially located low and high frequency coils which are connected to power supply units of low and high frequency respectively. At that, demagnetisation of ends of the item is performed at demagnetisation current increase by three times in comparison to demagnetisation current of middle part of the item at ratio of currents of high and low frequencies of 1/5.

EFFECT: reducing the level of remaining magnetisation of items, reducing energy consumption, enlarging the range of sizes of demagnetised long items.

5 cl, 2 dwg