Nitrogen generators need to pay attention to the state of their operation during normal operation, which is beneficial to greatly improve the life of the nitrogen generator and save costs. Therefore, it is necessary to test the safety performance of the following components.
1, air compressor
It is best to install the filter first. In order to prevent the soot from entering the compressed air, the low-pressure running time of the air compressor can not exceed 30 minutes, and the operation and maintenance of the exhaust fan can be done well. The qualified enterprise can add a spare parallel lock for the exhaust fan. It is necessary to do a good job in the management of circulating water quality. Enterprises with nitrogen generators can use demineralized water and add anti-scaling devices to the circulating water pipes of the compressor to slow down or reduce the deposition of scales and sludge. The oil cooling should be double oil-cooled. And can switch online.
2, pre-cooling device
Conditional enterprises should prepare two cold dryers as far as possible, one is a traditional type of dryer and the other is an energy-saving and environment-friendly refrigerating dryer. Otherwise, it will stop when the molecular sieve outlet carbon dioxide concentration rises. Since the outlet line of the dryer is prone to rust for a long time, the flow area is reduced, the resistance is increased, and the outlet pressure of the dryer is increased. Therefore, it is recommended to use the nitrogen generator adsorption tower gas for reverse purge before starting the inspection.
The molecular sieve inlet operation should be slow and stable to prevent the airflow from impacting the nitrogenous machine tool layer, causing the molecular sieve to be powdered into the tower and forming a hazard. There is a problem with the molecular sieve pneumatic valve, which will cause the air separation condition to fluctuate and be stopped. It is recommended to use a pneumatic valve with high reliability and independent air source, and the feedback signal of the pneumatic valve should be sensitive. Once the valve is not working or the action is not in place, The alarm can alarm in time.
It is recommended to use a hydraulic container with an air bag or an auxiliary oil pump to link to the expander. Once the stop is driven by inertia, the auxiliary oil pump can be rotated to meet the lubrication requirements of the expander when it stops. The starting condition of the oil pump generally has the sealing gas pressure. The oil pump should be interlocked with the sealing gas pressure starting condition regardless of whether it is in the interlocking state or in the independent state. Early nitrogen generators are prone to accidents because they ignore the starting conditions in an independent state.
5. Liquid storage tank.
Generally, the pressure of the atmospheric pressure storage tank is controlled at about 10KPa. Because the heat insulation effect is not good, the evaporation amount is large due to the liquid recovery or liquid return, and the venting line is thinner, the pressure of the storage tank is high. It is necessary to pay attention to the vent valve in the accident state. Whether it is a gas shut-off valve, so as to avoid the vent valve closing in the accident state due to design or installation error, causing the tank to overpressure; strictly implement the corresponding liquid tanker nitrogen generator filling management regulations, filling liquid oxygen, liquid nitrogen Do not exceed 90% of the tank volume; an electrostatic grounding display is recommended for liquid oxygen filling.
6, the main cold explosion-proof.
Main cold explosion protection is the top priority of air separation safety production management. The atmospheric CmHn of petrochemical enterprises is generally high, and the air quality must be analyzed once a day. The wind vane must be set up to keep track of the wind direction of the four seasons; the nitrogen generator discharge and meteorological account must be established to analyze and control the accumulation of CanHn; the air compressor must be exported. Gas is incorporated into the monitoring system and periodically tested.
7, the air cooling tower must pay attention to the quality of circulating water, such as turbidity, COD, oil content, whether to add fungicides to produce foam. It is recommended that qualified enterprises adopt closed-circuit circulation as much as possible to reduce external interference, but pay attention to regular replacement to prevent deterioration of water quality.
8. It is necessary to reduce the inlet temperature of the molecular sieve as much as possible to improve the ability of the molecular sieve to adsorb impurities. When the atmosphere is deteriorated or the nitrogen generator is discharged urgently, the molecular sieve should be regenerated at a high temperature, and the operation cycle should be shortened as appropriate to minimize the CmHn entering the tower. Quantity; to ensure the thoroughness of molecular sieve regeneration; to strengthen the monitoring of molecular sieve export quality, including dew point, C02 and CmHn, online and offline analysis combined.