1.2 million tons heavy medium coal washing plant fine coal desliming screen

Thread Content

Technical improvement plan for the under-screen chute of the clean coal desliming screen in the heavy medium coal washing plant: Due to the negligence of the operator of the desliming screen, impurities (such as wood) present in the clean coal ended up in the under-screen chute along with the clean coal itself. This caused a blockage at the outlet of the lower section of the under-screen chute; the blockage was not detected in time, until the clean coal entered the medium system and blocked the magnetizer. After such an accident, production is often delayed for several hours. To prevent such accidents from occurring, our desliming screen operators must promptly remove debris from the clean coal stream. In the event of a blockage accident, to enable timely detection, the chute below the desliming screen is being modified as shown in the figure below. A square hole (20 cm high and 30 cm wide) is made near the bottom of the half-height of the section below the 4th layer of the undersize chute; then a cover is installed over this hole (sized to fully cover it), and the cover can be opened and closed easily via a horizontal shaft above it and bearings fixed to the chute. A proximity switch (220V) is connected to the lower part on the outside of the cover plate; this proximity switch is part of the electric bell circuit. When the outlet is blocked, the grade coal level rises inside the chute; once the level reaches the square opening and continues to rise, the side pressure of the grade coal pushes the cover aside, triggering the contact switch and thus closing the circuit for the alarm bell. When the electric bell rings, it alerts the operator that the lower section of the chute is blocked. Weld two limit hooks to the chutes on both the left and right sides of the cover plate, so that the cover plate can only be lifted a limited distance. 10 cm below the square hole, another square hole with a height of 10 cm and a width of 40 cm is created. An inclined chute is welded to the outside of this hole so that the coal that flows down from the upper hole in case of an accident can accumulate there; once the system returns to normal, the coal will automatically fall into the chute.