Prize for the original startup plan for the synthesis tower
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Original startup plan for the synthesis tower – large prize available. Last edited by jindin312 on 2009-3-15 at 13:52.]
It’s not synthetic ammonia; I’m not sure if it’s possible. I. Initial preparation for driving: (1) Includes passivation of pipelines and equipment, as well as preparation of materials. (2). Check whether there are any debris or dirt remaining inside the container, and then seal it ； (3). Clean the slag, rust, and other debris within the cleaning system; the water discharged should be neutral, colorless, free of suspended particles, and clear and transparent, with a conductivity of ≤10μS/cm. (4). The rotating equipment shall be operated continuously for at least 24 hours in accordance with the installation and operating procedures, and the single-unit test shall proceed normally. (5). Check whether the markings and range of the instruments, as well as the open/closed position and sensitivity of the control valves, meet the requirements, and whether the DCS is functioning properly. (6). Check whether the layout of the process pipelines is correct, and whether there are any missing equipment, pipelines, pressure gauges, sampling valves, etc., as well as any blind plates that have not been removed. (7). The system has passed pressure testing and leak checks; the valves in all sections operate smoothly without any internal or external leaks, and the volumes of all tanks, vessels, and containers have been accurately calibrated. II. Objectives, steps, and tasks of water testing: Objective: To use water as a substitute for the working fluid, and N2 as a substitute for H2, in order to simulate the material circulation process. 1) Check the equipment, instruments, and pipelines for any issues that could interfere with operation ； 2) Training of operating workers ； 3) Pressure testing, leak testing, and system cleaning. Steps: Pure water -> Extraction tower -> Raffinate separator -> Working fluid metering tank -> Drying tower -> Alkali settler -> Alkali separator -> Clay bed -> Circulating working fluid storage tank -> Circulating working fluid pump -> Circulating working fluid filter -> Working fluid heat exchanger -> Working fluid preheater -> Upper section of hydrogenation tower (pure water and nitrogen) -> Lower section of hydrogenation tower -> Liquid-liquid separator for hydrogenated liquid -> Nitrogen -> Hydrogenation off-gas condenser -> Condensate metering tank -> Vent -> Water -> Clay bed for hydrogenated liquid, Filter for hydrogenated liquid -> Working fluid heat exchanger -> Storage tank for hydrogenated liquid -> Pump for hydrogenated liquid -> Cooler for hydrogenated liquid -> Upper section of oxidation tower (hydrogenated liquid from the upper section of the oxidation tower) -> Middle section of oxidation tower -> Liquid-liquid separator a for oxidized liquid -> Liquid-liquid separator b for oxidized liquid -> Cooler for oxidized liquid -> Storage tank for oxidized liquid -> Pump for oxidated liquid -> Extraction tower ； ->Flue gas from the upper section of the oxidation tower -> Oxidation flue gas condenser -> Flue gas separator -> Aromatic intermediate tank -> Flue gas heat exchanger -> Ammonia cooler -> Flue gas separator -> Flue gas treatment unit. Pure water from the bottom of the extraction tower -> top of the purification tower -> dilute product separator. Task: Work during the water test run (1) Check whether the positional differences of various equipment are appropriate, whether the pipes are unobstructed, and whether there are any air blockages. Check whether the installation heights of each discharge pipe and U-tube are appropriate, and whether there is any material leakage or accumulation ； (2) Check the cleanliness of the equipment and pipelines (in particular, operate the bypass valves several times to ensure that the pipelines and valves are thoroughly cleaned). You can observe whether the pure water in the system is clear and transparent through the sight glass, and check whether there is any welding slag, rust, sediment, or other debris being discharged from the waste outlet ； (3) Check whether rotating equipment such as pumps and compressors are operating properly, and whether their basic performance parameters (pressure, flow rate, sealing performance) meet the requirements ； (4) Observe whether the discharge from each separator is uniform and whether the liquid level is within the required range ； (5) Check that the instruments and DCS, as well as the display, recording, control, and automatic regulation functions, are all accurate; adjust them if necessary ； (6) Conduct repeated start-up and shutdown tests to check the level changes of various equipment during these operations, and provide staff with training on how to carry out start-up and shutdown procedures. Once the above tasks are completed with satisfactory results, the water testing phase can be concluded. III. Drainage and Drying: Except for the processes of extraction, oxidation, and post-treatment (before the alkali separator), where the water drained from equipment, pipelines, and valves does not need to be dried, all other equipment, pipelines, valves, etc. that come into contact with the working fluid must be dried using clean air after the water has been drained. Additionally, at the lowest points of the equipment and pipelines, drain valves should be opened to allow drainage, or the flanges should be removed for drainage purposes. At the same time, remove mechanical impurities deposited at the lowest parts of the equipment and pipes.
Initial state S0: Construction is completed, inspection and acceptance are passed, and the system is ready for operation. 3.2.1 General principles for starting up: 3.2.1.1 General principle for starting up the unit: Ensure successful operation on the first attempt. 3.2.2 Develop a plan and coordinate with relevant departments. 3.2.3 Purge the system after maintenance is complete. 3.2.3.1 Purge instrument air pipelines. 3.2.3.2 Purge air pipelines. 3.2.3.3 Purge fuel gas pipelines. 3.2.3.4 Purge process gas pipelines. 3.2.3.5 Purge steam pipelines. 3.2.4 Check for air tightness and conduct pressure testing on the system. 3.3.4.1 Coordinate with the dispatch team to establish N5, N80, and N120 pipeline networks. 3.3.4.1.1 Establish the N5 pipeline network. 3.3.4.1.2 Establish the N80 pipeline network. 3.3.4.1.3 Establish the N120 pipeline network. 3.2.4.2 Check for air tightness and conduct pressure testing on the fuel gas system. 3.2.4.3 Check for air tightness and conduct pressure testing on the process gas system. 3.2.4.4 Conduct pressure testing of the water system (see Category C). 3.2.5 Perform purging. 3.2.5.1 Purge the fuel gas system. 3.2.5.2 Purge the process gas system. State S1: All preparations for startup are complete; the system is ready for use in the production process. 3.2.6 Coordinate with the dispatch team to introduce CW water and primary water to establish a water circulation system. 3.2.7 Coordinate with the dispatch team to start the instrument air compressor in order to establish instrument air and plant air pipeline networks. 3.2.8 Coordinate with the dispatch team to establish a steam pipeline network and introduce external medium-pressure steam. 3.2.9 Coordinate with the dispatch team to have natural gas supplied from the gas distribution station. 3.2.10 Coordinate with the dispatch team to introduce deionized water, and verify the status of the DW valve leading to Boiler No. 4. 3.3.10.1 Introduce deionized water to Boiler No. 4. 3.3.10.2 Introduce deionized water to the 101-U deaerator. 3.3.10.3 Flush the 101-U deaerator and establish the proper liquid level. 3.3.11 Coordinate with the dispatch team to start the water filling and pressure testing process for Drum No. 104-JA. 3.2.12 Reverse the blind flanges in the low-temperature converter loop, and coordinate with the dispatch team to fill the loop with N5. 3.2.13 Coordinate with the dispatch team to start J66402, thereby establishing a circulation in the low-temperature converter and raising the temperature of the catalyst to 180°C. 3.2.14 Reverse the blind flanges in the conversion unit’s nitrogen circulation loop, and coordinate with the dispatch team to introduce N80 into the conversion system and pressurize it to 1. 2MPa。 3.2.15 Contact the dispatch team to initiate the conversion of 102-J in order to establish a large nitrogen cycle. 3.2.16 Verify that the PCV-1602 blind valve at the gas distribution station is set to the \"open\" position, while the N5 blind valve is set to the \"closed\" position; then contact the dispatch team to ignite the fuel gas. 3.2.17 The analysis of furnace 103-B shows satisfactory results; ignition can be carried out, and the gas is combustible
(1) All equipment, pipelines, valves, analysis sampling points, as well as electrical appliances and instruments must be in good working condition. (2) Check the open and closed positions of all valves in the system; they should meet the requirements for starting up the system. (3) Contact the compression section to supply air for system purging. (4) Coordinate with sections such as compression to first supply inert gas and refined gas to purge the system until the oxygen content is below 0.2%. (5) Conduct a gas-tightness test using refined gas. (6) Coordinate with the water and power supply departments sowie the compression, copper cleaning, freezing, conversion, and other units to prepare for startup. (7) Before starting the machine, sufficient water should be added to the synthesis waste boiler, and all soft water heaters should be supplied with water to operate. (8) Slightly open the air supply valve to allow the system to be pressurized slowly to 5.0–6.0 MPa (with a pressure increase rate of 0.4 MPa/min); once the system pressure is slightly higher than that of the synthesis tower, open the main inlet valve of the synthesis tower. (9) Follow the normal startup procedures for the machine, start the circulator, open the system bypass valve and the circulator circuit valve, and the gas will begin to circulate. (10) After checking that the insulation resistance of the electric heater is >0.2MΩ, turn on the electric heater. Based on the increase in the temperature of the catalyst bed, the power is gradually increased, along with an increase in the amount of circulating gas. (11) The temperature rise of the catalyst bed is achieved by adjusting the power of the electric heater and the gas circulation rate in the system. The heating rate from room temperature to 350°C is 30–40°C/h. (12) When the catalyst temperature is greater than 200°C, activate the water cooler ； At 400°C, ammonia begins to be released from the bottom of the ammonia separator and the cold exchanger. (13) Once the catalyst bed reaches the reaction temperature, slow down the heating rate to 5°C/h, gradually increase the amount of make-up gas and circulating gas, thereby reducing the axial temperature difference in the catalyst bed. (14) Depending on the temperature of the catalyst bed, gradually reduce the power of the electric heater until it is turned off, after which normal production can resume. (15) Continuously monitor the liquid level in the synthesis waste boiler and the temperature of each soft water heater; once production returns to normal, inform the shift responsible for conversion to stop using boiler steam.
Operating Procedures for the Synthesis Tower – I. Position Operation Method (1) Tasks of this position This position represents the final stage in ammonia synthesis; it involves combining hydrogen and nitrogen gases in specific proportions, after they have been purified and refined, and then synthesizing ammonia through catalytic action at high temperature and pressure. (II) Brief description of the process flow: The gas is supplied by a circulation machine; it is cooled in Tower No. 1 before entering the new ammonia cooler. After that, it passes through the original ammonia cooler for further cooling, and then merges with fresh gas to enter Tower No. 2. There, residual liquid ammonia is separated, after which the gas goes back to Tower No. 1 for heat exchange. As the temperature rises, the gas splits into two streams – one stream exits to an external heat exchanger, while the other enters the synthesis tower. The synthetic gas exits from the secondary outlet of the tower and goes to an intermediate boiler for heat exchange; from there it proceeds to another external heat exchanger, and finally to a water cooler for cooling. After cooling, the gas enters an ammonia separation unit where most of the liquid ammonia is separated out. The resulting liquid ammonia then passes through a manual (or automatic) control valve regulated by a level gauge, before being sent to the main ammonia pipeline and stored in the ammonia tank for measurement. (III) Chemical reaction takes place in the synthesis tower: 3H + N2 → NH3 + Q (high temperature, high pressure, catalyst, exothermic reaction, reversible).
(IV) Specifications of main equipment:
| Serial No. | Name | Specifications | Remarks |
|-------------|------|--------------|---------|
| 1 | Synthesis tower shell | Diameter: Φ1000 mm; Effective height: 13800 mm | Catalyst basket diameter: Φ934×16; Upper catalyst height: 5582 mm; Lower catalyst height: 578 mm. Number of cooling tubes: 62 each of Φ44×2.5, Φ29×2.5, and Φ22×1. Heat exchange area: E = 40 m²; Heat exchange height: 236 mm. Number of tubes of Φ10×1.5: 3084; Heat exchange area: 224 m². Regulator power: 650 V, 710 A, 800 KVA. Catalyst loading capacity: 15 tons or 3 m³. |
| 2 | Condenser tower shell | Diameter: Φ900 mm; Height: 8210 mm | Double-layer shell-and-tube heat exchanger; Heat exchange area: F = 165 m². Tower No. 1; Tower No. 2 serves only for separation purposes. |
| 3 | Ammonia cooler | Diameter of tubes: Φ25×4; Number of tubes: 628 | Shell-and-tube type with a header; Heat exchange area: F = 226 m². 2 units available. |
| 4 | Ammonia separator | Shell diameter: Φ1000 mm; Height: H = 4625 mm | 1 unit available. |
| 5 | Water cooler | Horizontal shell-and-tube heat exchanger; Heat exchange area: F = 199 m² | 3 units available. |
(V) Operating procedures:
1. Normal startup
(1) Preparation work: Check whether the system equipment, pipes, and valve connections are secure, whether the blind plates have been installed correctly, and whether water, electricity, and gas supplies are functioning properly. Contact the electrician and instrumentation technician to check whether the electrical equipment and instruments are in good condition and ready for use. Check the protective measures, ensure that the fire-fighting equipment is complete and functional, and that the lighting is suitable for driving. (2) Exhaust replacement: Check the valves: the large valve at the filter outlet, the inlet and outlet valves of the first-stage water cooler of the compressor (for two or more valves), the valve for ammonia production, the large valve on the main pipeline, and the fresh gas vent valve. Valves to be closed: fresh gas ball valve, fresh gas main valve, system bypass valve, main and auxiliary valves at the inlet of the synthesis tower, ball valve at the inlet of the ammonia separator, inlet and outlet main valves of #1, #2, and #3 circulators, vent valves before and after the tower, as well as all ammonia transfer valves and ammonia addition valves. Contact the high-pressure compressor and send air to Section 6 at 8.13; first exhaust air from the fresh gas main, then close the fresh gas vent valve completely. Open the fresh gas valve, the fresh gas main valve, and the vent valve at the front of the tower to exhaust gas from there; ensure that the O2 concentration is ≤0.2%, which meets the requirements, and then close the vent valve at the front of the tower. Open the main valve at the inlet of the synthesis tower, the ball valve at the inlet of the ammonia separator, and the vent valve at the back of the tower to carry out venting from behind the tower; the exhaust pressure should not exceed 2.0 Mpa, and the venting time should be 5 minutes. During pressurized exhaust, when the pressure exceeds 2.1 Mpa, open the ammonia transfer ball valve and inform the ammonia storage facility to open the main ammonia inlet. Check for any gaps at the same time. (3) Leak testing: After the exhaust replacement is successful, close all vent valves and use fresh gas to conduct a leak test across the entire system. Leak testing is carried out at pressures of 10, 20, 25, and 31.5 Mpa, with the pressure being increased by 4 Mpa per minute. If a leak is detected, the pressure must be reduced to below 5 Mpa before the maintenance crew can tighten the bolts and conduct further leak testing until the system is leak-free. After the leak test is successful, the rear vent valve on the same tower is used to reduce the system pressure to 6–8 Mpa, in preparation for using the circulation pump and electric furnace to raise the temperature. (4) Increase the temperature to put the valves in the following states: Valves that should be closed include the inlet valve of the synthesis tower, the main valve and ball valve for fresh gas, all ammonia transfer stop valves, ammonia addition valves, all vent valves as well as the oil and water release valves, and the ball valve of the circulator. Valves to be opened: main valve at the inlet of the synthesis tower, system bypass valve, ball valve at the ammonia inlet, inlet and outlet valves of the circulator, and auxiliary valve of the circulator. Open the inlet and outlet ball valves of the circulation pump, connect it to the system, and use the bypass valve of the circulation pump as well as the system’s bypass valve to check the circulation rate. The electrician turns on the electric furnace; the first voltage increase should be less than 50V, and subsequent increases must not exceed 20V each time. During the operation of the electric furnace, pay attention to issues such as grounding and short circuits. Stay in touch with the electrical personnel at any time. If any abnormality is detected in the electric furnace, the voltage should be stopped immediately, or the voltage reduced until the furnace is shut down. It is absolutely necessary to ensure that the electric furnace has sufficient airflow for safety, to prevent the heating elements from overheating and getting damaged. When the circulation machine trips, immediately cut off the power to the electric furnace. Strictly control the heating rate within the specified range. The temperature difference across the catalyst plane must not exceed 10°C. For the temperature rise of the electric furnace, in principle, an operation method with a high furnace power and large circulation volume should be used to ensure an adequate amount of safety air flow. Water is added to the water cooler when the hotspot temperature reaches 100°C, and ammonia is added to the ammonia cooler when the hotspot temperature reaches 350°C. At the same time, it is important to ensure that the liquid ammonia level in the ammonia cooler does not exceed the specified limit. After the temperature rises to 400°C, a compressor can be used to supply air, or the valve labeled “69” connected to 8.13 can be slowly opened until pressure is balanced, after which it can be fully opened to start production. During the valve opening process, the catalyst temperature rose sharply above the specified limit, so the circulation rate was used for control. While pressurizing, start reducing the load on the electric furnace; after the reduction is complete, and once the catalyst and temperature are both back to normal and normal production has resumed, then shut down the electric furnace. (5) Method for pressurization and temperature increase: During short-term shutdowns when the hotspot temperature is above 380°C, depending on the catalyst’s activity, fresh gas can be used for pressurization, with the reaction heat being utilized to raise the catalyst temperature to normal levels. (If the tower is shut down due to mild poisoning, pressurization and temperature increase are prohibited.) The valves in the system are in the following states: Valves that should be open: the ball valve at the fresh gas inlet, the main valve on the ammonia pipeline, and the ammonia transfer valve (this ball valve should be opened when the system pressure reaches 2.0 Mpa; meanwhile, the ammonia storage facility should be informed to open the main inlet valve for ammonia transfer). The inlet and outlet valves of the water coolers for the first stage of the high-pressure compressor (for two or more compressors), as well as the inlet and outlet ball valves of the circulation pump. Valves to be closed: main fresh gas valve, main and auxiliary valves of the synthesis tower, system bypass valves, fresh gas vent valve, inlet and outlet valves of the circulator, ball valve at the inlet of the ammonia separator, vent valves before and after the tower, as well as all ammonia transfer valves and ammonia addition valves. Fill the water cooler with water, and fill the ammonia cooler with ammonia. Open the fresh gas main valve to pressurize the area in front of the tower; once the pressure there is higher than that inside the tower, slightly open the main valve on the tower’s control panel and gradually increase the pressure inside the tower. Prepare the circulation pump and start it to bring the pressure up to match the pressure inside the tower; keep the bypass valve fully open, and keep the inlet and outlet ball valves fully closed. When the rise in temperature stops, slightly open the ball valve at the inlet of the ammonia separator; depending on the operating conditions, slightly open the vent valve at the back of the tower as well to release some gas, thereby allowing the temperature inside the tower to continue rising steadily. When the catalyst hotspot temperature approaches the target value, the circulation pump can be introduced into the system, and the load can be increased gradually; subsequently, the circulation rate can be increased step by step based on the catalyst temperature, allowing normal production to resume. Control the ammonia transfer pressure properly. 2. Shutdown (1) Short-term shutdown (planning to resume production in the near future). Before shutting down, raise the catalyst temperature to the upper limit specified; inform the high-pressure compressor to gradually reduce its load, close the auxiliary valves at the same time. Reduce the circulation rate to the minimum possible, strive to keep the catalyst temperature from dropping, and pay attention to the ammonia level and the level of the secondary cooling liquid. After the supply of fresh gas has been completely stopped, the circulation pump is disconnected from the system, and the following valves are closed: the main and auxiliary valves at the inlet of the synthesis tower, the ball valve at the inlet of the ammonia separator, the fresh gas valve, the vent valves before and after the tower, as well as all the ammonia transfer valves and ammonia addition valves. The ammonia supply ball valve may be closed only when the system pressure is less than 2.5 MPa; in such cases, the main inlet valve of the ammonia storage tank should also be closed. Under other circumstances, it is not permitted to close the aforementioned valves completely. (2) Long-term shutdown (when production cannot be resumed immediately and the equipment in this system requires maintenance): Ammonia feeding to the ammonia cooler should be stopped 4 hours before the shutdown. The high-pressure compressor gradually reduces its load, while controlling the flow rate to facilitate cooling, with the cooling rate being strictly kept within the specified limits. After the high-pressure compressor stops supplying gas, the circulation pump continues to assist with cooling, while pushing the liquid ammonia from the ammonia separator and condenser tower into the ammonia storage tank. When the temperature is reduced to 100°C, the circulation pump can be shut off, water supply to the water cooler is stopped, and the pressure is released through the vent valve at the back of the tower. If the synthesis tower itself is disassembled for inspection, catalyst passivation or pressurization with gaseous ammonia is required. (3) Emergency stop: Command the high-pressure compressor to cease gas supply and shut down the circulation pump. The following valves must be closed promptly in sequence: the line connected to the synthesis tower, the main valve, the ball valve at the inlet of the ammonia separator, all ammonia addition valves and ammonia release valves, the system bypass valve, and the fresh gas valve. Carry out the necessary post-stopping procedures, including pushing the condenser tower, ammonia fraction, and liquid ammonia into the ammonia storage facility. 3. Operational precautions: (1) The synthesis tower unit is one of the most important units in production; it is essential to maintain proper control over the temperature of the synthesis tower to prevent drops in temperature as well as overheating. (2) Pay attention to the ammonia level and the liquid level in the condenser tower to prevent damage to the circulation pump due to ammonia presence or a drop in temperature in the synthesis tower. (3) To ensure the safety of the electric furnace during heating, its circulation rate must be adjusted according to the furnace’s power level. It is strictly prohibited to use a high circulation rate when heating a furnace with high power. If the circulation stops (for example, if the circulation pump fails completely), the furnace must be shut down immediately to prevent damage to the components. (4) Communication has been established with the ammonia storage facility; when the system pressure is greater than 2.5 Mpa, the ammonia transfer ball valve and the main ammonia inlet cannot be in a closed state. (5) Coordinate well with 8.13; be absolutely clear about the switching status of the “69” connection valve. (6) Control the ammonia transfer pressure carefully to prevent high pressure from leaking into the low-pressure system. ( VII ) Accident handling sequence, phenomena, causes, handling methods, and remarks: 1. Drop in catalyst bed temperature: 1. Excessive circulation rate; 2. Too high ammonia content in the material entering the synthesis tower: A. Insufficient amount of ammonia added to the ammonia cooler. B. Excessively high pressure in the main ammonia pipeline. C. Excessive oil and water in the ammonia cooler. D. Low cooling efficiency of the water cooler. E. High level of the secondary cooling fluid. 3. Too high hydrogen-to-nitrogen ratio. 4. Too high content of inert gas. 5. The main valve of the tower is opened too little or the auxiliary valve is opened too much. 1. Open a bypass in the system or reduce the circulation volume using the auxiliary valve of the circulator. 2. Reduce the amount of ammonia entering the system. A. Increase the ammonia addition valve. B. Operate the ice machine more frequently. C. Remove oil and water from the system. D. Increase the amount of cooling water used appropriately. E. Lower the liquid level. 3. Reflect the temperature. 4. Discharge the inert gas or recover hydrogen. 5. Gradually increase the opening of the main valve while reducing the opening of the auxiliary valve. The valve should not be opened to a large extent; the intervals between activations should be 3–5 minutes. The temperature of the catalyst layer rises due to: 1) insufficient circulation volume, 2) the main valve of the synthesis tower being opened too wide or the auxiliary valves being opened too narrow. 3. Increase the fresh air volume by 1; reduce the valve on the system’s bypass or circulation pump. 2. Reduce the main valve or increase the auxiliary valve. 3. Adjust the dosage accordingly; if it is already at full capacity, reduce the amount slightly. 3. Drop in pressure in the synthesis tower: 1. Insufficient compressor airflow; 2. Leaks in the system; 3. Excessive exhaust gas; 4. Low liquid level causing gas leakage. 1. Contact the compressor for inspection; 2. Shut down the system for repair if the issue is severe; 3. Control the amount of exhaust gas; 4. Maintain an appropriate liquid level. 4. Rise in pressure in the synthesis tower: 1. Decreased catalyst temperature; 2. Too low circulation volume of gas; 3. High ammonia content in the gas entering the tower; 4. High load; 5. Imbalanced hydrogen-to-nitrogen ratio; 6. High level of inert gases. 1. Contact the compressor for inspection; 2. Shut down the system for repair if the issue is severe; 3. Control the amount of exhaust gas; 4. Maintain an appropriate liquid level; 5. Excess system resistance: 1. Inaccurate pressure gauges; 2. Blocked pipes or valves that are not in proper position; 3. Excessive circulation volume; 4. High nitrogen content. 1. Reduce the circulation volume and use alternative routes within the system; 2. Increase the circulation volume of gas; 3. Reduce the ammonia content in the gas; 4. Reduce the load if levels exceed specifications; 5. Notify the dispatch team; 6. Send the gas to hydrogen recovery or discharge it. 6. High temperature on the walls of the synthesis tower: 1. Too low circulation volume and valves being opened too wide; 2. Damage to the internal components of the tower. 1. Increase the circulation volume; 2. Shut down the system for repair if necessary. 7. Excessively high temperature at the outlet of the synthesis tower: 1. Too low circulation volume; 2. Main valve of the tower opened too little while auxiliary valves are opened too wide; 3. Low level of inert gases; 4. High load. 1. Increase the circulation volume; 2. Gradually open the main valve more and close the auxiliary valves; 3. Reduce or stop gas leakage, as well as emissions, and send the gas to hydrogen recovery; 4. Reduce the load as appropriate. 8. Drop in catalyst layer temperature with a sudden rise in tower pressure: 1. High levels of CO+CO2, causing catalyst poisoning; 2. Copper solution or ammonia entering the tower, leading to catalyst poisoning; 3. High level of coolant liquid, allowing liquid and gas to enter the tower. 1. Reduce the output of the high-pressure compressor as specified; control the circulation volume to maintain temperature. If pressure remains high, discharge gas from behind the tower. If CO+CO2 levels reach 100 PPm, shut down the tower for repairs. 2. Emergency tower shutdown 3. Control the liquid level properly. 9 Water cut-off: 1. Soft water supply interrupted in the middle tank; 2. Water cut-off in the water cooler. 1. The control cycle for the secondary inlet temperature of the sight tower is to either reduce the load or shut down the tower. 2. Lower the temperature of the ammonia cooler; if the inlet temperature of the circulation pump does not remain within the specified range, shut down the tower urgently if the water cut-off lasts for a long time. 10 Power outage or malfunction of electrical equipment – treat as an emergency shutdown. 11 Shutdown of the circulation machine or emergency shutdown: 1. Fault in the power distribution station or interlock mechanism; 2. Fault in the circulation machine – for emergency shutdown: 1. Reduce the flow rate as appropriate; 2. Shut down the tower completely. 12 Explosion, fire, severe gas leakage, or other situations requiring immediate tower shutdown. 13 Stop in the supply of fresh gas: 1. Fault with the gas supply; 2. Fault in the high-pressure compressor; 3. Faults in the purification or copper washing processes – resulting in tower shutdown. 14 Sudden increase in system pressure: 1. Damaged, detached, or loose connections of valves within the system; 2. Valves installed in the wrong direction, airflow blockage, or other reasons. 1. Reduce the circulation volume, maintain temperature, keep the system pressure within specified limits, and reduce the output of the high-pressure compressor accordingly; 2. Identify the cause. 15 Complete or partial failure of instruments – interruption or malfunction of instruments: Maintain the current operating conditions, contact the instrument maintenance team, or shut down the tower. VIII. Communication during operation: 1. Maintain close communication with the personnel responsible for the circulation machine to adjust the circulation volume. 2. The amount of addition and subtraction is closely related to the high-pressure machine operator. 3. It is closely related to copper washing based on temperature changes. 4. Controlling ammonia feed and ammonia addition pressure is closely linked to the ammonia reservoir. 5. In case of an emergency when the team leader and on-duty shift supervisor are not present, one can directly contact the control room for prompt handling, and report afterwards. II. Equipment Maintenance System (I) Scope of Management 1. The synthesis tower, as well as its connected pipes, fittings, valves, etc. 2. 1# and 2# condensation towers and their connecting fittings, etc. 3. Water condensation towers 1#, 2#, 3# and their connecting fittings, etc. 4. New and original ammonia coolers, gaseous ammonia demisters, as well as their connecting fittings, valves, etc. 5. Ammonia separator and its connecting fittings, valves, etc. 6. The external heat exchanger, as well as its connecting fittings, valves, etc. 7. Centralized boiler and its connecting fittings, valves, etc. 8. Ammonia transfer and addition pipelines, etc. (II) Equipment maintenance 1. Strictly implement the post responsibility system and technical operating procedures to prevent operation under conditions of excessive temperature, pressure, or load. 2. The pressure and temperature in the synthesis tower should be adjusted at strictly specified rates; load changes must be made gradually to avoid sharp fluctuations. During normal operation, it is necessary to maintain stability in the temperature of the catalyst layer, with fluctuations not exceeding acceptable limits. 3. After the catalyst is installed in the synthesis tower, backflow of gas inside the tower is strictly prohibited; therefore, care must be taken when opening the inlet and outlet valves of the synthesis tower. (1) When the pressure inside the tower is high, open the outlet valve first; when the pressure outside the tower is high, open the inlet valve first. (2) If the main valve and auxiliary valves of the tower are not fully closed, venting before starting the tower is not possible. 4. When using an electric furnace, it is necessary to first turn on the circulation machine to supply air; only once the air supply volume from the circulation machine reaches a certain level can the electric furnace be turned on. The operation of electric furnaces should be carried out in accordance with the regulations for their use. 5. When shutting down the synthesis tower, it is necessary to maintain a positive pressure inside the tower to prevent air from entering and damaging or burning the catalyst. 6. In the event of a shutdown caused by copper-containing liquid entering the tower or minor poisoning, the method of pressurizing and raising temperature shall not be used. 7. All equipment, pipes, instruments, etc. must not be struck casually. It is necessary to regularly check the vibration of high-pressure pipelines, as well as for any leaks or cracks in various equipment and valves, to report such issues promptly and address them right away. 8. Eliminate running, leaking, dripping, and seeping wherever possible. 9. Conduct thorough inspections as required and install signs. 10. Conduct cleaning as required. 11. Control the liquid level properly to prevent high levels from flowing into lower levels, as well as accidents involving liquid entering the tower or cylinders.
(IV) Specifications of main equipment:
| Serial No. | Name | Specifications | Remarks |
|-------------|------|--------------|---------|
| 1 | Synthesis tower shell | Diameter: Φ1000 mm; Effective height: 13800 mm | Catalyst basket diameter: Φ934×16; Upper catalyst height: 5582 mm; Lower catalyst height: 578 mm. Number of cooling tubes: 62 each of Φ44×2.5, Φ29×2.5, and Φ22×1. Heat exchange area: E = 40 m²; Heat exchange height: 236 mm. Number of tubes of Φ10×1.5: 3084; Heat exchange area: 224 m². Regulator power: 650 V, 710 A, 800 KVA. Catalyst loading capacity: 15 tons or 3 m³. |
| 2 | Condenser tower shell | Diameter: Φ900 mm; Height: 8210 mm | Double-layer shell-and-tube heat exchanger; Heat exchange area: F = 165 m². Tower No. 1; Tower No. 2 serves only for separation purposes. |
| 3 | Ammonia cooler | Diameter of tubes: Φ25×4; Number of tubes: 628 | Shell-and-tube type with a header; Heat exchange area: F = 226 m². 2 units available. |
| 4 | Ammonia separator | Shell diameter: Φ1000 mm; Height: H = 4625 mm | 1 unit available. |
| 5 | Water cooler | Horizontal shell-and-tube heat exchanger; Heat exchange area: F = 199 m² | 3 units available. |
(V) Operating procedures:
1. Normal startup
(1) Preparation work: Check whether the system equipment, pipes, and valve connections are secure, whether the blind plates have been installed correctly, and whether water, electricity, and gas supplies are functioning properly. Contact the electrician and instrumentation technician to check whether the electrical equipment and instruments are in good condition and ready for use. Check the protective measures, ensure that the fire-fighting equipment is complete and functional, and that the lighting is suitable for driving. (2) Exhaust replacement: Check the valves: the large valve at the filter outlet, the inlet and outlet valves of the first-stage water cooler of the compressor (for two or more valves), the valve for ammonia production, the large valve on the main pipeline, and the fresh gas vent valve. Valves to be closed: fresh gas ball valve, fresh gas main valve, system bypass valve, main and auxiliary valves at the inlet of the synthesis tower, ball valve at the inlet of the ammonia separator, inlet and outlet main valves of #1, #2, and #3 circulators, vent valves before and after the tower, as well as all ammonia transfer valves and ammonia addition valves. Contact the high-pressure compressor and send air to Section 6 at 8.13; first exhaust air from the fresh gas main, then close the fresh gas vent valve completely. Open the fresh gas valve, the fresh gas main valve, and the vent valve at the front of the tower to exhaust gas from there; ensure that the O2 concentration is ≤0.2%, which meets the requirements, and then close the vent valve at the front of the tower. Open the main valve at the inlet of the synthesis tower, the ball valve at the inlet of the ammonia separator, and the vent valve at the back of the tower to carry out venting from behind the tower; the exhaust pressure should not exceed 2.0 Mpa, and the venting time should be 5 minutes. During pressurized exhaust, when the pressure exceeds 2.1 Mpa, open the ammonia transfer ball valve and inform the ammonia storage facility to open the main ammonia inlet. Check for any gaps at the same time. (3) Leak testing: After the exhaust replacement is successful, close all vent valves and use fresh gas to conduct a leak test across the entire system. Leak testing is carried out at pressures of 10, 20, 25, and 31.5 Mpa, with the pressure being increased by 4 Mpa per minute. If a leak is detected, the pressure must be reduced to below 5 Mpa before the maintenance crew can tighten the bolts and conduct further leak testing until the system is leak-free. After the leak test is successful, the rear vent valve on the same tower is used to reduce the system pressure to 6–8 Mpa, in preparation for using the circulation pump and electric furnace to raise the temperature. (4) Increase the temperature to put the valves in the following states: Valves that should be closed include the inlet valve of the synthesis tower, the main valve and ball valve for fresh gas, all ammonia transfer stop valves, ammonia addition valves, all vent valves as well as the oil and water release valves, and the ball valve of the circulator. Valves to be opened: main valve at the inlet of the synthesis tower, system bypass valve, ball valve at the ammonia inlet, inlet and outlet valves of the circulator, and auxiliary valve of the circulator. Open the inlet and outlet ball valves of the circulation pump, connect it to the system, and use the bypass valve of the circulation pump as well as the system’s bypass valve to check the circulation rate. The electrician turns on the electric furnace; the first voltage increase should be less than 50V, and subsequent increases must not exceed 20V each time. During the operation of the electric furnace, pay attention to issues such as grounding and short circuits. Stay in touch with the electrical personnel at any time. If any abnormality is detected in the electric furnace, the voltage should be stopped immediately, or the voltage reduced until the furnace is shut down. It is absolutely necessary to ensure that the electric furnace has sufficient airflow for safety, to prevent the heating elements from overheating and getting damaged. When the circulation machine trips, immediately cut off the power to the electric furnace. Strictly control the heating rate within the specified range. The temperature difference across the catalyst plane must not exceed 10°C. For the temperature rise of the electric furnace, in principle, an operation method with a high furnace power and large circulation volume should be used to ensure an adequate amount of safety air flow. Water is added to the water cooler when the hotspot temperature reaches 100°C, and ammonia is added to the ammonia cooler when the hotspot temperature reaches 350°C. At the same time, it is important to ensure that the liquid ammonia level in the ammonia cooler does not exceed the specified limit. After the temperature rises to 400°C, a compressor can be used to supply air, or the valve labeled “69” connected to 8.13 can be slowly opened until pressure is balanced, after which it can be fully opened to start production. During the valve opening process, the catalyst temperature rose sharply above the specified limit, so the circulation rate was used for control. While pressurizing, start reducing the load on the electric furnace; after the reduction is complete, and once the catalyst and temperature are both back to normal and normal production has resumed, then shut down the electric furnace. (5) Method for pressurization and temperature increase: During short-term shutdowns when the hotspot temperature is above 380°C, depending on the catalyst’s activity, fresh gas can be used for pressurization, with the reaction heat being utilized to raise the catalyst temperature to normal levels. (If the tower is shut down due to mild poisoning, pressurization and temperature increase are prohibited.) The valves in the system are in the following states: Valves that should be open: the ball valve at the fresh gas inlet, the main valve on the ammonia pipeline, and the ammonia transfer valve (this ball valve should be opened when the system pressure reaches 2.0 Mpa; meanwhile, the ammonia storage facility should be informed to open the main inlet valve for ammonia transfer). The inlet and outlet valves of the water coolers for the first stage of the high-pressure compressor (for two or more compressors), as well as the inlet and outlet ball valves of the circulation pump. Valves to be closed: main fresh gas valve, main and auxiliary valves of the synthesis tower, system bypass valves, fresh gas vent valve, inlet and outlet valves of the circulator, ball valve at the inlet of the ammonia separator, vent valves before and after the tower, as well as all ammonia transfer valves and ammonia addition valves. Fill the water cooler with water, and fill the ammonia cooler with ammonia. Open the fresh gas main valve to pressurize the area in front of the tower; once the pressure there is higher than that inside the tower, slightly open the main valve on the tower’s control panel and gradually increase the pressure inside the tower. Prepare the circulation pump and start it to bring the pressure up to match the pressure inside the tower; keep the bypass valve fully open, and keep the inlet and outlet ball valves fully closed. When the rise in temperature stops, slightly open the ball valve at the inlet of the ammonia separator; depending on the operating conditions, slightly open the vent valve at the back of the tower as well to release some gas, thereby allowing the temperature inside the tower to continue rising steadily. When the catalyst hotspot temperature approaches the target value, the circulation pump can be introduced into the system, and the load can be increased gradually; subsequently, the circulation rate can be increased step by step based on the catalyst temperature, allowing normal production to resume. Control the ammonia transfer pressure properly. 2. Shutdown (1) Short-term shutdown (planning to resume production in the near future). Before shutting down, raise the catalyst temperature to the upper limit specified; inform the high-pressure compressor to gradually reduce its load, close the auxiliary valves at the same time. Reduce the circulation rate to the minimum possible, strive to keep the catalyst temperature from dropping, and pay attention to the ammonia level and the level of the secondary cooling liquid. After the supply of fresh gas has been completely stopped, the circulation pump is disconnected from the system, and the following valves are closed: the main and auxiliary valves at the inlet of the synthesis tower, the ball valve at the inlet of the ammonia separator, the fresh gas valve, the vent valves before and after the tower, as well as all the ammonia transfer valves and ammonia addition valves. The ammonia supply ball valve may be closed only when the system pressure is less than 2.5 MPa; in such cases, the main inlet valve of the ammonia storage tank should also be closed. Under other circumstances, it is not permitted to close the aforementioned valves completely. (2) Long-term shutdown (when production cannot be resumed immediately and the equipment in this system requires maintenance): Ammonia feeding to the ammonia cooler should be stopped 4 hours before the shutdown. The high-pressure compressor gradually reduces its load, while controlling the flow rate to facilitate cooling, with the cooling rate being strictly kept within the specified limits. After the high-pressure compressor stops supplying gas, the circulation pump continues to assist with cooling, while pushing the liquid ammonia from the ammonia separator and condenser tower into the ammonia storage tank. When the temperature is reduced to 100°C, the circulation pump can be shut off, water supply to the water cooler is stopped, and the pressure is released through the vent valve at the back of the tower. If the synthesis tower itself is disassembled for inspection, catalyst passivation or pressurization with gaseous ammonia is required. (3) Emergency stop: Command the high-pressure compressor to cease gas supply and shut down the circulation pump. The following valves must be closed promptly in sequence: the line connected to the synthesis tower, the main valve, the ball valve at the inlet of the ammonia separator, all ammonia addition valves and ammonia release valves, the system bypass valve, and the fresh gas valve. Carry out the necessary post-stopping procedures, including pushing the condenser tower, ammonia fraction, and liquid ammonia into the ammonia storage facility. 3. Operational precautions: (1) The synthesis tower unit is one of the most important units in production; it is essential to maintain proper control over the temperature of the synthesis tower to prevent drops in temperature as well as overheating. (2) Pay attention to the ammonia level and the liquid level in the condenser tower to prevent damage to the circulation pump due to ammonia presence or a drop in temperature in the synthesis tower. (3) To ensure the safety of the electric furnace during heating, its circulation rate must be adjusted according to the furnace’s power level. It is strictly prohibited to use a high circulation rate when heating a furnace with high power. If the circulation stops (for example, if the circulation pump fails completely), the furnace must be shut down immediately to prevent damage to the components. (4) Communication has been established with the ammonia storage facility; when the system pressure is greater than 2.5 Mpa, the ammonia transfer ball valve and the main ammonia inlet cannot be in a closed state. (5) Coordinate well with 8.13; be absolutely clear about the switching status of the “69” connection valve. (6) Control the ammonia transfer pressure carefully to prevent high pressure from leaking into the low-pressure system. ( VII ) Accident handling sequence, phenomena, causes, handling methods, and remarks: 1. Drop in catalyst bed temperature: 1. Excessive circulation rate; 2. Too high ammonia content in the material entering the synthesis tower: A. Insufficient amount of ammonia added to the ammonia cooler. B. Excessively high pressure in the main ammonia pipeline. C. Excessive oil and water in the ammonia cooler. D. Low cooling efficiency of the water cooler. E. High level of the secondary cooling fluid. 3. Too high hydrogen-to-nitrogen ratio. 4. Too high content of inert gas. 5. The main valve of the tower is opened too little or the auxiliary valve is opened too much. 1. Open a bypass in the system or reduce the circulation volume using the auxiliary valve of the circulator. 2. Reduce the amount of ammonia entering the system. A. Increase the ammonia addition valve. B. Operate the ice machine more frequently. C. Remove oil and water from the system. D. Increase the amount of cooling water used appropriately. E. Lower the liquid level. 3. Reflect the temperature. 4. Discharge the inert gas or recover hydrogen. 5. Gradually increase the opening of the main valve while reducing the opening of the auxiliary valve. The valve should not be opened to a large extent; the intervals between activations should be 3–5 minutes. The temperature of the catalyst layer rises due to: 1) insufficient circulation volume, 2) the main valve of the synthesis tower being opened too wide or the auxiliary valves being opened too narrow. 3. Increase the fresh air volume by 1; reduce the valve on the system’s bypass or circulation pump. 2. Reduce the main valve or increase the auxiliary valve. 3. Adjust the dosage accordingly; if it is already at full capacity, reduce the amount slightly. 3. Drop in pressure in the synthesis tower: 1. Insufficient compressor airflow; 2. Leaks in the system; 3. Excessive exhaust gas; 4. Low liquid level causing gas leakage. 1. Contact the compressor for inspection; 2. Shut down the system for repair if the issue is severe; 3. Control the amount of exhaust gas; 4. Maintain an appropriate liquid level. 4. Rise in pressure in the synthesis tower: 1. Decreased catalyst temperature; 2. Too low circulation volume of gas; 3. High ammonia content in the gas entering the tower; 4. High load; 5. Imbalanced hydrogen-to-nitrogen ratio; 6. High level of inert gases. 1. Contact the compressor for inspection; 2. Shut down the system for repair if the issue is severe; 3. Control the amount of exhaust gas; 4. Maintain an appropriate liquid level; 5. Excess system resistance: 1. Inaccurate pressure gauges; 2. Blocked pipes or valves that are not in proper position; 3. Excessive circulation volume; 4. High nitrogen content. 1. Reduce the circulation volume and use alternative routes within the system; 2. Increase the circulation volume of gas; 3. Reduce the ammonia content in the gas; 4. Reduce the load if levels exceed specifications; 5. Notify the dispatch team; 6. Send the gas to hydrogen recovery or discharge it. 6. High temperature on the walls of the synthesis tower: 1. Too low circulation volume and valves being opened too wide; 2. Damage to the internal components of the tower. 1. Increase the circulation volume; 2. Shut down the system for repair if necessary. 7. Excessively high temperature at the outlet of the synthesis tower: 1. Too low circulation volume; 2. Main valve of the tower opened too little while auxiliary valves are opened too wide; 3. Low level of inert gases; 4. High load. 1. Increase the circulation volume; 2. Gradually open the main valve more and close the auxiliary valves; 3. Reduce or stop gas leakage, as well as emissions, and send the gas to hydrogen recovery; 4. Reduce the load as appropriate. 8. Drop in catalyst layer temperature with a sudden rise in tower pressure: 1. High levels of CO+CO2, causing catalyst poisoning; 2. Copper solution or ammonia entering the tower, leading to catalyst poisoning; 3. High level of coolant liquid, allowing liquid and gas to enter the tower. 1. Reduce the output of the high-pressure compressor as specified; control the circulation volume to maintain temperature. If pressure remains high, discharge gas from behind the tower. If CO+CO2 levels reach 100 PPm, shut down the tower for repairs. 2. Emergency tower shutdown 3. Control the liquid level properly. 9 Water cut-off: 1. Soft water supply interrupted in the middle tank; 2. Water cut-off in the water cooler. 1. The control cycle for the secondary inlet temperature of the sight tower is to either reduce the load or shut down the tower. 2. Lower the temperature of the ammonia cooler; if the inlet temperature of the circulation pump does not remain within the specified range, shut down the tower urgently if the water cut-off lasts for a long time. 10 Power outage or malfunction of electrical equipment – treat as an emergency shutdown. 11 Shutdown of the circulation machine or emergency shutdown: 1. Fault in the power distribution station or interlock mechanism; 2. Fault in the circulation machine – for emergency shutdown: 1. Reduce the flow rate as appropriate; 2. Shut down the tower completely. 12 Explosion, fire, severe gas leakage, or other situations requiring immediate tower shutdown. 13 Stop in the supply of fresh gas: 1. Fault with the gas supply; 2. Fault in the high-pressure compressor; 3. Faults in the purification or copper washing processes – resulting in tower shutdown. 14 Sudden increase in system pressure: 1. Damaged, detached, or loose connections of valves within the system; 2. Valves installed in the wrong direction, airflow blockage, or other reasons. 1. Reduce the circulation volume, maintain temperature, keep the system pressure within specified limits, and reduce the output of the high-pressure compressor accordingly; 2. Identify the cause. 15 Complete or partial failure of instruments – interruption or malfunction of instruments: Maintain the current operating conditions, contact the instrument maintenance team, or shut down the tower. VIII. Communication during operation: 1. Maintain close communication with the personnel responsible for the circulation machine to adjust the circulation volume. 2. The amount of addition and subtraction is closely related to the high-pressure machine operator. 3. It is closely related to copper washing based on temperature changes. 4. Controlling ammonia feed and ammonia addition pressure is closely linked to the ammonia reservoir. 5. In case of an emergency when the team leader and on-duty shift supervisor are not present, one can directly contact the control room for prompt handling, and report afterwards. II. Equipment Maintenance System (I) Scope of Management 1. The synthesis tower, as well as its connected pipes, fittings, valves, etc. 2. 1# and 2# condensation towers and their connecting fittings, etc. 3. Water condensation towers 1#, 2#, 3# and their connecting fittings, etc. 4. New and original ammonia coolers, gaseous ammonia demisters, as well as their connecting fittings, valves, etc. 5. Ammonia separator and its connecting fittings, valves, etc. 6. The external heat exchanger, as well as its connecting fittings, valves, etc. 7. Centralized boiler and its connecting fittings, valves, etc. 8. Ammonia transfer and addition pipelines, etc. (II) Equipment maintenance 1. Strictly implement the post responsibility system and technical operating procedures to prevent operation under conditions of excessive temperature, pressure, or load. 2. The pressure and temperature in the synthesis tower should be adjusted at strictly specified rates; load changes must be made gradually to avoid sharp fluctuations. During normal operation, it is necessary to maintain stability in the temperature of the catalyst layer, with fluctuations not exceeding acceptable limits. 3. After the catalyst is installed in the synthesis tower, backflow of gas inside the tower is strictly prohibited; therefore, care must be taken when opening the inlet and outlet valves of the synthesis tower. (1) When the pressure inside the tower is high, open the outlet valve first; when the pressure outside the tower is high, open the inlet valve first. (2) If the main valve and auxiliary valves of the tower are not fully closed, venting before starting the tower is not possible. 4. When using an electric furnace, it is necessary to first turn on the circulation machine to supply air; only once the air supply volume from the circulation machine reaches a certain level can the electric furnace be turned on. The operation of electric furnaces should be carried out in accordance with the regulations for their use. 5. When shutting down the synthesis tower, it is necessary to maintain a positive pressure inside the tower to prevent air from entering and damaging or burning the catalyst. 6. In the event of a shutdown caused by copper-containing liquid entering the tower or minor poisoning, the method of pressurizing and raising temperature shall not be used. 7. All equipment, pipes, instruments, etc. must not be struck casually. It is necessary to regularly check the vibration of high-pressure pipelines, as well as for any leaks or cracks in various equipment and valves, to report such issues promptly and address them right away. 8. Eliminate running, leaking, dripping, and seeping wherever possible. 9. Conduct thorough inspections as required and install signs. 10. Conduct cleaning as required. 11. Control the liquid level properly to prevent high levels from flowing into lower levels, as well as accidents involving liquid entering the tower or cylinders.
It would be perfect if **on the 5th floor, the process parameters that affect the manufacturing process could be provided**
An authentic original startup plan for a synthetic system (just after setting up a new system). (I) Conditions required before starting operation: 1. The foundation construction, plant building, and secondary grouting of equipment must be completed, with qualified completion inspection documents available. 2. The equipment and pipelines have been installed, meet quality standards, and come with complete and proper installation completion documents. 3. There are records of strength tests for the equipment, pipes, and valves; among these, the internal components of the cold exchanger, the internal components of the hot exchanger, the internal components of the heat exchangers inside the tower, the high-pressure pipes of the waste heat boiler, the cylindrical components inside the synthesis tower, the cold tube bundles, the center tube, the high-pressure pipes of the ammonia cooler, and the high-pressure pipes of the water cooler must all undergo pressure testing as individual units to ensure they meet the required standards. 4. The electric furnace underwent temperature-raising tests outside the tower; the voltage regulator and fans passed the individual testing by operating continuously for 8 hours, and there are completion acceptance documents available. 5. The instrument control system has been fully installed and is complete; it has passed inspection and acceptance and meets the production requirements. 6. The equipment, pipelines, and valves come with certificates confirming that their materials meet the required standards; in addition, there are documents showing that the equipment, pipelines, and welds have passed magnetic particle and radiographic inspection. 7. The circulation pump system must have a completion acceptance certificate obtained after individual testing, and the safety valves must be adjusted. 8. Equipment, pipelines, and pipe racks are firmly fixed; safety devices are complete and functional. Gas protection equipment and fire-fighting supplies are stored in appropriate locations for easy use. The transportation, lighting, and the cleanliness of the control room are all up to standard and meet the production requirements. 9. Develop a proper startup plan for the φ1400 synthesis system, operating procedures, as well as plans for catalyst loading and temperature rise/reduction; ensure that the relevant personnel receive training and pass the assessments. 10. Prepare all the tools, spare parts, equipment, records, reports, temperature rise curve charts, etc., required for the commissioning of the new system. 11. Before starting the machine, the associated equipment, pipelines, valves, electrical and instrumentation systems, as well as the process flow, must be inspected on-site by the company’s commissioning team to confirm that they are ready for commissioning. (II) Hydrostatic testing plan for the synthesis system 1. Purpose of hydrostatic strength testing: To assess the capacity of equipment, pipelines, valves, etc. to withstand loads, that is, their macroscopic strength, in order to ensure production safety. The strength testing of equipment and pipelines is carried out after the system installation is complete; it involves conducting hydrostatic tests on the equipment, pipelines, valves, level gauges, electrical and instrumentation systems, as well as the analysis and control systems that are set to be put into operation. These hydrostatic tests are performed before the equipment is insulated or coated for corrosion protection. 2. Content and scope of the hydrostatic test: The entire system, from the outlet of the recirculation pump to its inlet, must undergo a hydrostatic test. Main equipment: Vessels such as oil separators, cold exchangers, synthesis towers, heat exchangers, ammonia coolers, waste boilers, ammonia separators, and synthesis water coolers require individual pressure testing or must come with certificates confirming successful individual pressure testing. The cold exchanger internals, the shell side of the ammonia cooler, the catalyst baskets in the synthesis tower, the tubes of the heat exchangers inside the tower, the tubes of the hot exchanger, and the shell side of the waste heat boiler must also undergo individual pressure testing or have valid pressure testing certificates; among these, the internals of the synthesis tower must be tested for leaks using nitrogen. All the above pressure tests were conducted at 1.5 times the maximum operating pressure or pressure difference; after the tests were successful, any accumulated water had to be drained completely. 3. Methods and steps for pressure testing: During pressure testing, conduct a thorough inspection to ensure that the blind flanges used for isolation are safe and reliable. ①For process gas pipelines operating at 31.4 MPa, the pressure test was conducted at 47 MPa for 15 minutes; no leaks were observed visually, and no deformation was detected, which qualifies them. For high-temperature pipelines, the pressure test must reach 59 MPa and be maintained for 15 minutes; no leakage visible to the eye and no deformation are considered acceptable. ②Apart from the water cooler, oil separator, and ammonia separator, no other equipment shall be used for pressure testing; individual units and internal components must be tested separately, or they must have a certificate confirming successful pressure testing. ③The hydrostatic test pressure for gaseous ammonia pipelines and liquid ammonia pipelines is 1.5 times the operating pressure. ④The hydrostatic test pressure for steam pipelines and desalination water pipelines is 1.25 times the nominal pressure. ⑤All high and medium pressure pipes, valves, fittings, including oil drainage pipes and vent pipes, must be pressure-tested section by section without any omissions. ⑥Immediately after the hydrostatic test, blow air through the equipment’s pipes and valves to remove any water, thereby preventing rust. Special attention should be paid to drying out any water accumulated in the oil-containing components and various valves. ⑦For pipes below DN80, a ball passing test must be carried out as specified. (III) Purging of equipment pipes 1. The purpose of purging is to remove rust, dust, slag, water accumulation, and other debris from within the equipment pipes, thereby preventing such debris from entering the equipment, pipes, valves, or the catalyst, which could cause blockages and severely affect normal operation as well as the lifespan of the catalyst. 2. Medium for blowing: air (start a new compressor). 3. Purge pressure: Pipeline
Each has its own features; on the fifth floor, there are the more authentic equipment operation procedures.