A Coil Magnetic System Generating Gradient Weak Magnetic Field

Abstract

The invention discloses a coil magnetic system capable of generating a gradient weak magnetic field. The coil magnetic system comprises a hollow pipeline and a plurality of coil assemblies wound on the hollow pipeline. The multiple coil assemblies are sequentially arranged at intervals in the axial direction of the hollow pipeline. Each coil assembly is provided with a plurality of layers of coils wound on the hollow pipeline in the radial direction, and the number of turns and the number of layers increase gradually assembly by assembly from one end to the other end of the hollow pipeline. After exciting currents are applied to the coil magnetic system, an inverted top-shaped background magnetic field is generated in a hollow cavity of the hollow pipeline and around the coil assemblies, the gradient change of the magnetic field generated in the axial direction of the hollow cavity of the hollow pipeline is small, and the magnetic field intensity is distributed uniformly; in addition, the gradient of the magnetic field in the radial direction increases firstly, then decreases to zero, finally increases sharply to the maximum value in the opposite direction and then decreases sharply, the gradient changes repeatedly in this way, and a state with one climax following another is formed. By means of the magnetic field with the characteristics, the recycling rate of fine particle magnetic minerals can be increased, and the magnetic particle loss caused by magnetic inclusion between magnetic particles and gangue particles is reduced.

Description

technical field [0001] The invention relates to the technical field of coil magnetic systems, in particular to a coil magnetic system for generating gradient weak magnetic fields. Background technique [0002] Coils are seldom directly used as the magnetic system in existing mineral processing equipment or other fields, but a magnetic pole-type magnetic system is added to the center of the coil as a magnetic pole-type magnetic system, and the outside of the magnetic system is used, such as an electromagnet. This magnetic pole-type magnetic system produces The magnetic field is strong, but it cannot produce a weak magnetic field with a large range and uniform radial distribution. However, the magnetic field generated by a single group of energized coils in the center of the coils has a wide distribution range, and it is selected as a prerequisite for the required magnetic system. [0003] The existing theory analyzes the electromagnetic field, and uses the finite element met...

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Problems solved by technology

[0004] First, the magnetic field generated by a single set of coils is too weak; at the same time, the gradient of the magnetic field generated by a single set of coils in the hollow part is too simple, and the radial magnetic field strength is uneven, which restricts the large-scale equipment and its application in this field

[0005] Second, as the size of the carrier part of the magnetic system (that is, the wear-resistant hollow pipe) becomes larger, the magnetic field strength in the pipe required for design is greater. In order to generate enough magnetic field strength to meet the requirements of a single set of coils, a large number of coils are required Wound around the central material to form a coil with dense turns, which leads to the radial space occupied by the magnetic system is too large, and it is not easy to dissipate heat

[0006] Third, the increase in the number of windings forms a strong magnetic field on the pipe wall, which easily leads to the accumulation of magnetic particles on the wall, affecting the separation of magnetic particles and non-magnetic particles

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