What should be paid attention to in the safety monitoring and management of air separation plants in petrochemical enterprises

What should be paid attention to in the safety monitoring and management of air separation plants in petrochemical enterprises

Users of air separation equipment in petrochemical enterprises should focus on strengthening management and monitoring of air separation equipment in the following links:

　　 The air compressor system is best to replace the back-blowing bag filter with a pulse self-cleaning air filter. In order to prevent oil fume from entering the compressed air, the low-pressure operation time of the air compressor should generally not exceed 30 minutes, and the operation and maintenance of the smoke exhaust fan should be carried out. Enterprises with conditions can add a spare parallel lock of the exhaust fan. Water quality management of circulating water must be done well. Enterprises with conditions can use demineralized water, and add anti-scaling devices to the compressor circulating water pipeline to slow down or reduce scale deposits and sludge deposits. Double oil cooling should be used for oil cooling. Switch online.

　　 Pre-cooling system. Enterprises with conditions should try to prepare two ice machines, otherwise they will be forced to shut down when the carbon dioxide concentration at the molecular sieve outlet increases. Since the outlet pipeline of the pre-cooling water pump is prone to corrosion during long-term operation, the flow area is reduced, the resistance increases, and the outlet pressure of the water pump rises. Therefore, it is recommended to use air cooling tower gas for reverse purge before starting the maintenance.

　　 purification system. The molecular sieve air intake operation should be slow and stable to prevent the air flow from hitting the bed layer, causing the molecular sieve to powder into the tower and cause harm. The molecular sieve switching valve has a problem, which will cause the air separation condition to fluctuate and passively stop. It is recommended to use a three-dimensional eccentric hard seal valve with high reliability and independent air source, and the feedback signal of the switching valve should be sensitive. Once the valve does not operate Or the action is not in place, you can call the police in time.

　　 Pressurized expansion system. It is recommended to use an oil pressure vessel with an air bag or an auxiliary oil pump to link the expander. Once stopped, the auxiliary oil pump is driven to rotate by inertia to meet the lubrication requirements of the expander when it is stopped. The start condition of the oil pump generally has the sealing gas pressure, and the oil pump should have the sealing gas pressure start condition interlock regardless of the interlocking state or the independent state. Early air separation plants were prone to accidents due to ignoring the starting conditions in the independent state.

　　 cold box. Pay attention to the distance between the cold box and the control room. In addition, the lightning protection and anti-static grounding of the cold box must be separated from the electrostatic grounding of the main cold equipment through insulation facilities.

　　 liquid storage tank. Generally, the pressure of the atmospheric storage tank is controlled at about 10KPa. Due to poor thermal insulation, large evaporation caused by liquid recovery or liquid return, and thin venting pipelines, it is easy to cause high pressure in the storage tank; pay attention to the vent valve in an accident state Whether it is a gas shut-off valve, so as not to close the vent valve in an accident state due to design or installation errors, causing overpressure in the storage tank; strict implementation of the corresponding liquid tank truck filling management regulations, filling liquid oxygen and liquid nitrogen must not exceed 90% of the tank volume; it is recommended to use an electrostatic grounding display device when filling liquid oxygen.

　　 Main cold explosion-proof. The main cold explosion protection is the top priority of air separation safety production management. The atmospheric CmHn of petrochemical companies is generally high, and air quality must be analyzed once a day; weather vanes must be set up to keep track of the four seasons wind direction; installation discharge and weather accounts must be established to analyze and control CanHn accumulation; air compressor outlet gas must be included Monitor the system and conduct regular inspections.

　　 Air cooling towers must pay attention to the water quality of the circulating water, such as turbidity, COD, oil content, and whether to add fungicides to produce foam. It is recommended that qualified enterprises try their best to adopt a closed loop method to reduce external interference, but they should pay attention to regular replacement to prevent deterioration of the waterproof quality.

The inlet temperature of the molecular sieve should be reduced as much as possible to improve the ability of the molecular sieve to adsorb impurities; when the atmospheric conditions deteriorate or the device is discharged in an emergency, the molecular sieve should be regenerated at high temperature, and the operating period should be shortened appropriately to reduce the amount of CmHn into the tower as much as possible; 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 are combined with each other.