Research On Influence Of The External Magnetic Structure On Dense Medium Cyclone Separation Effects Under Magnetic Field

As an efficient separation equipment,three products dense-medium cyclone has been widely used in coal preparation industry.However the second section density of the cyclone is difficult to online control which has always been a core problem to be solved in coal preparation industry.This paper uses the magnetic structure on the external coil of the dense medium cyclone to study the influence of the magnetic structure on the separation effects of the dense medium cyclone.The medium distribution rule was studied by arranging magnetic structure in the upper and lower part of the coil acting on the different position of dense medium cyclone.After adding magnetic structure,compared to coil,density of overflow and underflow are constant in the trend of variation,changed in the amplitude of variation.The coarse slime separation experiment is conducted by acting magnetic structure on the interface of cylinder and cone,40mm?80mm?120mm and160 mm below the interface and study the influence law of separation densitywith magnetic structure in different positions of cyclone in appropriate current.Studies show that,upper magnetic structure which acts on the interface and40 mm below the interface,can further increase the separation when current is5.0A.Upper magnetic structure which acts 160 mm below the interface,ash of clean coal and tail decrease when current is 5A and increase when current are20A?25A?30A.The magnetic structures of different inserted depths were designed to applied to the upper part of the coil and the medium distribution rule was studied by arranging magnetic structures on the interface of cylinder and cone.The research shows that,magnetic structures of different inserted depths can all influence the medium distribution of dense medium cyclone and density of overflow and underflow are constant in the trend of variation,changed in the amplitude of variation.The magnetic field characteristics of upper magnetic structure with coil and magnetic structures of different inserted depths are analyzed by using the electromagnetic field analysis function of ANSYS software.We can know: the magnetic structure has blocking effect on the magnetic field,which can make the magnetic lines not found out.So,the concentrated magnetic lines can produce higher magnetic force in the specific region,which can affect the movement of the heavy medium in cyclone and present the change of separation density through macro view.However,with the increase of the inserted depth,the magnetic field becomes smaller due to the effect of magnetic shielding.When the inserted depth of magnetic structure is 20 mm,the improvement of separation density is most obvious.