Heavy medium cyclone for re-purifying coal gangue and automatically adjusting ash content of product

The utility model discloses a dense medium cyclone for re-purifying coal gangue and automatically adjusting product ash content, which comprises a dense medium cyclone and an on-line adjusting system, the dense medium cyclone is used for separating coal gangue, the on-line adjusting system is electrically connected with the dense medium cyclone, and the on-line adjusting system is used for monitoring ash content and adjusting the dense medium cyclone; according to the scheme, the central pipe is movably arranged in the dense medium cyclone, meanwhile, the stretching-in amount of the central pipe is controlled through the telescopic oil cylinder and the hydraulic system, and therefore the recovery rate during coal gangue separation is increased, the online adjusting system is arranged and can monitor the actual ash content of separated clean coal in real time, and the coal gangue separation efficiency is improved. After the telescopic range is calculated through comparison with the preset ash content, an analo