According to the energy-saving device and method for graded pressure charging and releasing of the
coal feeding device of the
coal gasifier, the
control system is used for coordinating the two
coal feeding systems to alternately execute coal feeding, pressure charging, discharging and pressure releasing operations. And during coaling, opening the coal lock upper valve of the coal lock of the corresponding coaling
system, and enabling the coal in the coal
bunker to fall into the coal lock through the coaling chute until the set coaling quantity is reached. During pressurizing, the
control system sequentially opens the pressurizing valves in the pressurizing branches according to the pressure grade from low to high, and the coal lock gas in the coal lock gas buffer
pipe is used for pressurizing the coal lock. And during discharging, a coal lock lower valve of the coal lock is opened, and coal enters the gasification furnace from the transition bin. During pressure relief, according to the same principle, the
control system sequentially opens the pressure relief valves in the pressure relief branches from the
high pressure level to the low
pressure level until pressure relief is completed. Through the graded pressure charging and discharging design, graded collection is performed according to pressure grades during pressure discharging, and meanwhile, the
system is recycled as a pressure charging gas source, so that the
system is more efficient, energy-saving and environment-friendly, the configuration scale of the coal lock
gas compressor can be effectively reduced, and the
energy consumption loss is reduced.