Close the ammonia differentiation furnace, nitrogen outlet valve and sampling valve, close the power switch of the ammonia differentiation furnace. Pay attention to investigate whether the pressure of the two adsorption tanks and the operation of the pneumatic valve are normal. First turn the air compressor knob to no-load, and close the air compressor after no-load operation for 2 minutes. Open the drain valve in the lower part of the air buffer tank to empty the oil and water in the tank. The open air compressor can be judged according to the pressure change of the two adsorption tanks. After the pressure of the compressed air buffer tank reaches more than 0.8MPa, the nitrogen switch of the control cabinet is opened.

Turn the power switch of ammonia separator on the electric control cabinet of PLC master station clockwise. The upper limit of oxygen content is set on the oxygen separator in the control cabinet of the ammonia differentiation furnace, and the device works normally. According to the pressure change of the two adsorption towers to determine whether the two adsorption towers are normal switching, the pressure of the regeneration tower is zero, and the pressure of the two towers should be close to half of the pressure of the original operating tower. It is necessary to close the whole system and its parts; When the pressure of the adsorption tank of the ammonia differentiation furnace reaches 0.6MPa, investigate whether the nitrogen production system is operating normally. Open the power switch of the oxygen meter, adjust the appropriate sampling flow rate, and investigate the oxygen content.

The system and pipeline need to be thoroughly depressurized; The exhaust gas discharged from the system is concentrated oxygen, pay attention to fire safety, indoor air circulation dredging; The sampling pressure reducing valve of the conditioning oxygen analyzer will adjust the pressure to 1.0bar, adjust the sampling flowmeter, and adjust the gas volume to 1, pay attention to the sampling volume should not be too large. Start to detect the purity of nitrogen. Discharge discharge valve on time during the work of air compressor.

Adjust the opening of the purity valve according to the required nitrogen purity, and actively switch into the nitrogen storage tank after the purity is qualified, and the nitrogen storage pressure of the nitrogen storage tank is usually 0.6-0.8mpa. Before the maintenance operation begins, pay attention to whether the oxygen content indicated by the oxygen meter meets the requirements. The purity and flow of nitrogen can be adjusted by adjusting the opening of the nitrogen outlet valve. Slowly open the vent stop valve and adjust the flow rate to 1/2 of the additional flow rate. When the purity of nitrogen reaches the demand, slowly open the pure gas outlet stop valve, adjust the flow rate to the required flow rate, close the blow-off outlet stop valve, and the equipment can be put into use under normal operation.