From the following aspects, the nitrogen machine is compared and analyzed: the rationality of system design; Carbon molecular sieve loading technology and pressing method; Service life of the control valve; R&d manufacturing experience, user performance;

Second, the factors affecting the cost of the nitrogen machine: the service life of the entire system with a one-time investment; Molecular sieve; Parts life and cost requirements during operation and maintenance, maintenance costs; Consumption of electricity, water, compressed air;

Third, the factors that affect the stability of the nitrogen machine: the nitrogen machine involves mechanical, electrical, and instrumentation to set up a high-tech product, which is particularly important in the long-term use of equipment stability.

We see that it is not difficult to make self-made nitrogen units, affecting the stability as follows: Control valve: pressure swing adsorption nitrogen machine, must have the following properties: valve, material properties without leakage; 0.02 seconds to receive the control signal, complete the opening and closing action; Can withstand frequent opening and closing to ensure a long enough life;



The nitrogen machine needs to pay attention to the operation of the state is conducive to improving the life of the nitrogen machine and saving the cost of normal operation: the following safety parts need to be tested;

1, air compressor

Preferably a C filter will be installed. In order to prevent smoke from entering the air, the air compressor operation time is generally not more than 30 minutes, and keep the exhaust fan running, and conditional enterprises can increase the exhaust fan backup interlock. We must do a good job of circulating water nitrogen management, conditional enterprises can use water softener, and anti-scaling device compressor circulation water pipe, slow or reduce the sludge deposition of scale layer deposit, oil cooling double oil cooling, and can be switched.

2, pre-cooling

Conditional enterprises to prepare two sets of cold drying machine, one is the WCD group of traditional cold drying machine, the second is a group series of energy saving and environmental protection refrigerator, or when the molecular sieve carbon dioxide concentration will stop. Because the outlet pipe of the cold and dry machine is easy to corrod for a long time, resulting in a decrease in the flow area, an increase in resistance, and an increase in the outlet pressure of the cold and dry machine, it is recommended to use the reverse purging nitrogen adsorption tower before the renovation begins.

3. Purification

The air operation of molecular sieve is slow and stable, preventing the effect of air, the nitrogen machine layer, and the formation damage caused by zeolite powder into the tower. The problem of molecular sieve gas valve, which will lead to fluctuations in air conditions is closed, it is recommended to use high reliability, the air can be independent of the German Baud or cap pneumatic valve, the pneumatic valve gas feedback signal is sensitive, once the valve is not in place, the alarm time.

4. Supercharger

It is recommended to use the airbag pressure vessel or auxiliary oil pump coupling, once the inertia driven auxiliary oil pump stops rotating, can meet the expansion machine stop lubrication. Pump starting conditions generally have sealing gas pressure, pump interlock state or an independent state should seal gas pressure interlock starting conditions. Early nitrogen machines are prone to accidents because they ignore the independent state of starting conditions.

5. Liquid storage tank

General atmospheric tank pressure control at about 10kPa, insulation effect is not good, resulting in more liquid or liquid evaporation, small exhaust pipe, easy to cause high reservoir pressure; It should be noted that the exhaust valve is closed in the accident state of the gas valve, so as to avoid design or installation errors, resulting in the accident state of the dispersed air valve closed, so that the reservoir overpressure; Strict implementation of the corresponding liquid tank truck nitrogen management regulations, fill liquid oxygen, liquid nitrogen tank volume does not exceed 90%; An electrostatic grounding display device is recommended for oxygenation.

6, the main cold protection

The main priority of cold protection is to consider the safety management of air separation production. Atmospheric CmHn petrochemical enterprises generally high, must do daily air quality analysis; Must be a wind vane, always grasp the four winds; Nitrogen emission and meteorological records, and canhn accumulation control analysis must be established; The air compressor outlet gas must be included in the monitoring system and checked regularly.

7, we must pay attention to the quality of the circulating water in the air cooling tower, such as turbidity, COD, oil content, whether to add fungicides and foams. It is recommended that conditional enterprises try to use closed-circuit circulation to reduce external interference, but attention should be paid to regular replacement and the breaking of waterproof quality

8, reduce the entrance temperature of molecular sieve as much as possible, improve the adsorption capacity of impurities molecular sieve; When atmospheric conditions deteriorate or high temperature nitrogen machine emergency discharge, molecular sieve regeneration, shorten the operation cycle to reduce the amount of hydrocarbon to the tower as much as possible guaranteed; Deep pair sun regeneration; Strengthen the export quality control of molecular sieve, including dew point. Co2 and hydrocarbon analysis, a combination of online and offline.