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For all gas media that pose a risk of explosion or spontaneous combustion when mixed with air and oxygen, their delivery pipelines and operating equipment must be purged with nitrogen before use to ensure production safety. This post was last edited by *aoye613 on 2009-3-11 at 11:11.]

There are too many; I’ll answer one first and address the rest slowly when I have time: 31: Since the operating temperature in a conversion furnace is very high, flexible pigtail pipes are used to connect it to the gas collection pipe, thereby providing some compensation for expansion due to temperature changes

40: Methane emission content. The high content at the outlet of the two-stage furnace, at 0.4%, has a significant impact on subsequent units, especially the synthesis system. Too much ammonia is lost each year.

1. Airtightness test: ① Purpose: To ensure that, at the specified maximum operating pressure, there are no leaks in areas such as the lid, flanges, valves, pipes, and welds of the high-pressure vessel within the static pressure testing system, thereby preparing it for production. ②Methods for checking for leaks: For a rough check, one can use their ears and hands to determine whether there are any leaks; for a more thorough inspection, a suction bulb or brush is used to apply soapy water to the cover, flanges, valve gaskets, and welds, with bubbles being observed to determine if there is air leakage. ③Before pressurizing the system, the following valves should be opened: the main valve, the system bypass valve, the oil outlet valve, the water cooling inlet valve, the cold and hot feed lines for each layer, as well as the main and bypass valves and the gas control valve ； Close the following valves: cold exchanger valve, ammonia release valve, oil discharge valve, vent valves before and after the tower, and all other valves. ④Contact the compression section to supply air. Use a pressure-boosting valve to introduce air into the system and raise the pressure to 5.0 MPa at a rate of ≤0.4 MPa/min; maintain this pressure for half an hour. If any leaks are detected, mark them with chalk, and then handle the issue after reducing the pressure ； After passing the inspection, pressure testing is carried out in four stages: 5.0 MPa, 10.0 MPa, 15.0 MPa, and 20.0 MPa. Once the pressure reaches 20.0 MPa, the air supply valve is closed. After confirming that there are no leaks, the pressure is maintained for 24 hours; a total pressure drop of ≤0.9 MPa indicates success. 5. Integrated commissioning: After the airtightness test, maintain a pressure of 20.0 MPa and proceed directly with the integrated commissioning of the entire system. Testing steps: A. Start the circulation pump in accordance with the standard operating procedures. B. Close the circulator vent valve before pressurization. C. Slowly open the inlet valve of the circulation pump; once the pressures at the inlet and outlet are equal, open the outlet valve while fully opening the inlet valve. D. Gradually close the bypass valve of the circulation pump based on the current of the circulation pump and the system resistance, in order to increase the load. E. Check whether the air inflation volume of the circulation machine is normal. F. Check whether the noise of the frictioning components of the circulation machine is normal, and whether the packing is overheating or leaking. G. Check the vibration of equipment, valves, and pipelines. H. Ensure that the resistance in the synthesis tower does not exceed 0.5 MPa, and the system resistance does not exceed 2.0 MPa. I. Check whether each instrument is normal, accurate, and sensitive. J. Check whether the water, electricity, and gas connection pipes to the external work area are properly connected and unobstructed. K. Operate continuously for 8 hours and keep operation records; it is considered qualified if there are no abnormal conditions. 6. Second airtightness test: This is carried out after the catalyst is installed in the synthesis tower. The pressure is increased in stages to 10.0, 15.0, 20.0, 25.0, and 28.0 MPa respectively; after each increase in pressure, the gas supply is cut off for inspection, using the same method as in the first airtightness test. 7. System purging: A. Purpose of purging: The mixture of air and hydrogen can form an explosive gas; therefore, it is necessary to remove the air from the equipment and pipelines before starting up the system. B. Preparation before replacement: Before replacement, the following valves should be opened: the main valve, the system bypass valve, the hot and cold branch valves for floors 1, 2, and 3, the oil outlet valve, the inlet and outlet valves of the circulation pump, and the bypass valve ； The following valves should be closed: make-up air valve, make-up and vent valves before and after the tower, cold exchanger, ammonia release valve, oil separation drain valve, and circulation pump vent valve. C. Displacement: ① Once the gas production for inerting is qualified, notify compression to supply the inert gas. ②Open the gas supply valve to pressurize the system to 2.0–3.0 MPa; then open the vent valve at the back of the tower to perform system purging. Carry out purging while continuing to supply gas, keeping the pressure at or below 5.0 MPa. Take samples three times in succession from the vent at the back of the tower; if the oxygen content is ≤0.2%, the result is considered satisfactory. Turning off the air supply stops air delivery. The system maintains a pressure of 2.0–3.0 MPa. ③After purging the high-pressure system with inert gas, the low-pressure system is purged using the remaining high-pressure gas. The pressure gauge on the flash tank is removed (on-site), and the vent pipe of the flash tank is opened; the replacement pressure is controlled using a heat exchanger and an ammonia release valve. The ammonia cooling unit and the flash tank are repeatedly pressurized for purification, and samples are taken at the pressure gauge on the flash tank for analysis – a oxygen content of ≤0.2% indicates compliance. Then, the ammonia addition valve on the flash tank is opened, and the gas is used to purge the pipes; samples are taken from the valve after the main ammonia addition pipe and from the outlet of the new connection pipe of the refrigeration machine. If the oxygen content is ≤0.2% in three consecutive analyses, it is considered compliant. ④Replacement of the ammonia discharge main: Ammonia release is controlled using ammonia distribution or cold exchange; the outlet is located before the inlet valve of the ammonia tank, and it is considered satisfactory if the oxygen content measured three times in a row is ≤2%. ⑤After inerting the low-pressure system, release any excess high-pressure gas, and then purge it with a qualified mixture of N2 and H2. For high-pressure and low-pressure systems, the replacement method is the same; replacement is considered successful when the oxygen content at the outlet is ≤0.2%. The system is maintained at a pressure of 10.0 MPa, ready for heating and reduction.

10. The purpose of ammonia cracking is generally to obtain a hydrogen source for use in hydrogenating the cobalt-molybdenum catalyst at the beginning of operation. Of course, it would be best if nearby factories had a hydrogen source; our factory generally obtains hydrogen from Chemical Plant No. 1. This post was last edited by Grandiose fabrication on 2009-3-18 20:52.]

Isn’t what the original poster has done just using some of the common skill assessment questions used by typical ammonia production plants for their employees?

It seems that generality is crucial; I’ve worked in ammonia synthesis at Kellogg for 21 years, yet I don’t know most of the proprietary terms used there – shame on me! For example, in the case of furnace F1201, it is unclear whether F1201 is the code for the entire furnace, or whether it is a component of that furnace, or perhaps a component located ahead of the furnace. China did well in this regard last century, making it convenient for people to communicate with each other. The methanol washing process is currently in complete disarray; how can communication be facilitated?

5: The effect of raising the nitrogen temperature is to increase the system’s temperature, preventing steam from condensing into water during the subsequent steam heating process and thus avoiding the catalyst from becoming fragmented. The reason steam was used instead of nitrogen for heating later on is that water has a higher specific heat than nitrogen, allowing for faster heating. 6: Commissioning of the air compression turbine: 1. Operation test of the speed control system 2. Startup of the condensation system 3. Startup of the exhaust pump (after one hour of rotor rotation) 4. Heating of the main steam pipes and the turbine casing 5. Verification of the speed control devices and interlock protections. a: The lubrication oil pump and the standby condensate pump are put into automatic mode. b: The compressor and process piping drain lines are completely drained. c: Verify FCV-4 manual full open position against the on-site valve position. d: Three-stage inlet 6B valve open. Section 4 exit HCV-4B is open. e: Machine room, sealed steam; the safety valve and drain valve is open. f: Lubricant temperature 40–45°C. g: Water is supplied to each intercooler. The function of the reclaimer is primarily to recover water and reduce water consumption. 9: Final criteria for nitrogen temperature rise: outlet temperature at the first stage furnace is 400–430°C, at the second stage furnace it is 300–350°C, and the temperature in the high-varyability bed layer is 200–220°C.

4# Exaggerated claims: We use the Kellogg process, and some of the issues you raised are not applicable in general

Conversion rate = A% – B%/(A% × (1 + B%)). Here, A% represents the CO content in the imported material, while B% represents the CO content in the exported material. This formula was developed by the company; there’s no need to memorize it by heart. If you forget it, you can simply calculate it – it’s very simple.