Reasons for the increase in pressure difference

1. The resistance in the synthesis tower is high. First, synthesis was caused by catalyst scorching due to severe overheating ； Secondly, when loading and unloading the catalyst, damage to the bottom mesh led to the catalyst entering the heat exchanger, thereby increasing the resistance ； Third, poor concentricity during the installation of the internal components in the synthesis tower results in uneven annular gaps. High resistance ； Fourth, damage to the insulation layer leads to an increase in resistance ； Fifth, inherent design flaws result in high resistance. 2. The resistance of the circulating gas heat exchanger is high. Insulation materials for the internal components of the synthesis tower, catalysts, copper melt introduced into the system from the copper washing section, as well as oil contamination entering the heat exchangers during production, all cause pressure to rise ； 3. The gas-oil filler is blocked by oil contamination, resulting in an increase in pressure ； 4. The ammonia cooler has high resistance. Mainly due to oil contamination, the freezing of water in the feed gas causes an increase in resistance ； 5. The resistance to cold mixing increases. In actual production, it is mostly caused by carbon dioxide crystallization ； 6. There is a copper washing section process; this may be due to improper operation or issues with the copper washing section itself. The presence of liquid in the synthesis process leads to an increase in resistance.

1. Carbon ammonium crystals form, leading to blockages； 2. [Valve core dislocation or low opening degree on system pipes] ； 3. Severe catalyst pulverization, blockage of the heat exchanger tubes, and high bed resistance ； 4. Poor quality of the internal components; debris is blocking both the inside and outside of the tubes ； 5. The catalyst is severely overheated and heavily caked, resulting in increased resistance ； 6. If the internal components are not installed concentrically, it can result in uneven gaps in the sleeves surrounding those components, or damage to the insulation material used to insulate them; moreover, the insulation material may block the air passages, thereby increasing resistance ； 7. Failure of the pressure gauge leads to an increased apparent resistance ； 8. Air leakage from the system outlet pressure transmitter can also lead to an increase in surface resistance ；

1. First, check the meter to confirm there are no issues. 2. Check whether the trace levels in the system are too high, and look for any ammonium salt crystals. 3. Reduce the circulation volume and observe the decrease in pressure difference to determine whether it is due to issues inside the tower. 4. Check the temperature of each layer and compare the changes in these temperature values over the course of a month. If there is a problem with the tower internals, it can be detected based on temperature. 5. Has the catalyst ever experienced overheating and caking?

The reasons for the increased pressure difference are as follows: 1. The catalyst in the synthesis tower clumps due to high temperature and pressure, resulting in increased resistance. 2. During the loading and unloading of the catalyst, the stainless steel mesh at the bottom gets damaged, allowing the catalyst to enter the heat exchanger and cause blockages; or the particle size of the catalyst used is too small, which also leads to increased resistance. 3. The resistance in the recycle preheater increases. Insulation material inside the synthesis tower, oil contamination, and small catalyst particles enter the recycle gas preheater, causing blockages in the gas passages and an increase in pressure difference. 4. The catalyst becomes poisoned and loses its efficiency over time, resulting in increased resistance. 5. If the internal components are not installed properly, the gaps between them become uneven, or the insulation material around these components is damaged; this can lead to blockages in the gas passages and increased resistance. 6. The packing in the oil separator gets clogged by oil, leading to increased resistance. 7. The ammonia cooler experiences high resistance due to water accumulation and freezing inside the coils, which in turn blocks the coils and creates resistance. 8. The resistance in the heat exchangers also increases. 9. Excessively high levels of trace substances in the purified gas, upon entering the synthesis system, react with ammonia to form carbonate crystals that block pipes or equipment, thereby increasing resistance

To identify the causes of increased system pressure differences in the production process due to synthetic circuits, one should first examine two aspects: whether the pressure difference in the synthesis tower and that in the circulation pump are within normal ranges These two are the main suspects. If these two are normal, then check other devices and pipelines. It’s to see how the two extreme pressures are distributed. It is very likely to get blocked between these two extreme pressures

The main hazards of excessive pressure difference in the ammonia synthesis system are: 1. It can easily damage equipment such as the internals of the synthesis tower, the heat exchange components of the cold exchangers, and the internals of the recycle gas preheater. 2. It increases power consumption, causing the circulation pump to trip or even get damaged. 3. Reduce production capacity. Main reason 1: High resistance in the synthesis tower. 1. The resistance of the synthetic catalyst gradually increases due to caking caused by high temperature or pressure. 2. When the catalyst was loaded or unloaded, the stainless steel mesh at the bottom was damaged, causing catalyst particles to fall into the heat exchanger and leading to blockages. Either the particle size of the catalyst used is too small or the amount filled in is excessive, resulting in high resistance. 3. The concentricity of the internal components during installation is not satisfactory, resulting in uneven gaps in the sleeves of these components; or the insulation material surrounding them is damaged, and this insulation material blocks the air passages, thereby increasing resistance. 4 The design and manufacturing of the internal components are defective, resulting in high resistance. 2. The circulation heater has high resistance; impurities such as insulation materials inside the synthesis tower, oil residues, copper melt, and fine catalyst particles enter the circulation heater, causing blockages in the gas passages and an increase in pressure difference. 3. The oil separator packing is clogged with oil, increasing resistance. 4. The ammonia condenser experiences high resistance; water accumulated inside the coil freezes, blocking the coil and creating resistance. 5. The cold exchanger and some pipelines have high resistance. The elevated level of carbon dioxide in the refined gas enters the synthesis system where it reacts with ammonia in the recycle gas, forming ammonium carbonate crystals that clog the heat exchange sections of the cold exchangers as well as the pipelines ahead of the synthesis tower, thereby creating resistance. 6. The molten copper introduced into the synthesis system increases the system resistance. Treatment method 1: For the large pressure difference caused by the synthesis tower, identify the cause, replace the catalyst or internal components, readjust the gap between the inner and outer cylinders, or repair the insulation of the internal components. 2. Resistance caused by the circulator heater; stop the operation for maintenance and remove foreign objects from the internal components. 3. In cases of high resistance caused by issues such as cold exchangers, oil contamination, ammonia condensers, and blocked pipes, steam cleaning or heating is used during shutdown to remove crystallizations, oil residues, and copper liquid from the system.

What are the reasons for the increase in pressure difference in the synthesis tower?

1. Problem with the differential pressure gauge. 2. As the nitrogen supply increases, the pressure difference will be higher than the normal value, but not by much. 3. As the circulation volume increases, the pressure difference must increase as well. 4. Towards the end of its life, the catalyst in the synthesis tower suffers from caking due to high-temperature conditions, which increases the catalyst resistance. 5. Catalyst quality issues; powdering may occur toward the end of its usage life. 6. Problems occur with the internal components of the tower, such as a broken center tube, gas taking a shortcut, and catalyst sintering.

Reasons: ① The catalyst in the synthesis tower clumps due to high temperature and pressure, resulting in increased resistance. ② During the loading and unloading of the catalyst, the stainless steel mesh at the bottom gets damaged, allowing the catalyst to enter the heat exchanger and cause blockages; or the particle size of the catalyst used is too small, which also leads to increased resistance. ③ The resistance in the recirculation preheater increases. Insulation material inside the synthesis tower, oil contamination, and small catalyst particles enter the recycle gas preheater, causing blockages in the gas passages and an increase in pressure difference. ④ The catalyst becomes poisoned and loses its effectiveness over time, which leads to an increase in resistance. ⑤ If the internal components are not installed evenly, this results in uneven gaps between the components’ sleeves; or if the insulation material around these components is damaged, it can block the gas passages and increase resistance. ⑥ The packing in the oil separator gets clogged by oil, leading to increased resistance. ⑦ The ammonia cooler experiences high resistance due to water accumulation and freezing inside the coils, which blocks those coils and creates resistance. ⑧ The resistance in the heat exchangers also increases. ⑨Excess trace amounts in the purified gas, upon entering the synthesis system, react with ammonia to form carbonate crystals that block pipes or equipment, thereby increasing resistance

In addition to the reasons mentioned by the above individuals, an imbalance in the gas composition that leads to changes in system pressure, or improper adjustment of the flow rate and the amount of gas in the bypass lines, are also among the causes.