What are the key points for the shutdown operation planned for the semi-water gas desulfurization system maintenance?

Parking Step A: After receiving the parking instruction, gradually stop each blower following the normal parking procedure. B Gradually stop the desulfurization pump and the regeneration pump following the normal shutdown procedures. C Gradually stop the cold water pump and hot water pump following the normal shutdown procedure. D Stop the axial flow fan. Precautions: A Assign a dedicated person to stay in the control room to monitor system pressure fluctuations and adjust them using the main return valve, in order to prevent excessive system pressure from damaging the water seal. When stopping the blower, it is necessary to contact the control room and the compression team; only after all compressors have stopped can the blower be turned off, in order to prevent the compressors from creating a negative pressure. Caused an accident. After the C blower stops, it is necessary to turn the shaft manually promptly to prevent coal tar from sticking to the blades. D: Whether to seal the water seal at the outlet of the gas holder is determined in accordance with the dispatch instructions.