How many steps are required to start up a atmospheric and vacuum distillation unit? What are the key points for starting work?

Preparations before starting work: water, electricity, gas, and air supply systems. Chemical agents, ammonia solution, are ready. Blind plates shall be installed and removed as required. Instrument calibration completed, interlock testing passed. All moving equipment passed the trial operation successfully. Personnel for electrical, mechanical maintenance, instrumentation, and other operations are in place. The safety facilities and equipment are complete, with all safety valves in operation. The issues identified during the purging and pressure testing have been resolved. Fill the oil-water separation tank at the top with water to the normal level to create a liquid seal. Contact production scheduling to arrange for all the materials required to start production. Contact the crude oil tank farm to obtain analytical data on the moisture content, sulfur content, acid value, specific gravity, boiling range, etc., of the crude oil in use. Contact the laboratory to prepare for sampling and analysis. Guide the fuel gas to the valve at the base of the furnace burner. If possible, introduce process gasoline to the initial normal pressure overhead separator tank to establish a normal liquid level.

II. Establishing a cold oil circulation using crude oil (4 hours) 1. Check and adjust the crude oil intake process. Crude oil inlet valve → Pre-dehydration heat exchanger → Electrodesalination tank → Post-dehydration heat exchanger → Initial distillation tower → Top oil heat exchanger → Atmospheric furnace → Atmospheric distillation tower → Vacuum furnace → Residue heat exchanger → Cold residue line → Tank farm. 2. Revise the tower top system flow. Open the inlet and outlet valves of the heat exchangers, water coolers, and air coolers in the tops of each tower; also open the vents for the initial distillate gas, normal distillate gas, and reduced distillate gas at the top of the oil-water separation tank. 3. Introduce crude oil (2 hours). Contact the tank farm to start the crude oil pump so that the plant can receive oil, with the oil loading rate controlled at 400 t/h to 500 t/h. Along the way, open the equipment’s drain valves to allow water to be drained, ensuring that personnel are present wherever oil is located. When the liquid levels at the bottoms of each tower reach 60%–80%, oil is sent from the startup circulation line to the tank farm via the return line, thereby establishing an open-loop circulation. After 2 hours of open-loop operation, a sample is taken at the sampler before the residue exits the unit to analyze the water content in the crude oil; once the water content is less than 3.0%, the operation mode of the unit is changed from open-loop to closed-loop. 4. Establish a cold cycle (2 hours). Maintain the circulation rate at 240 t/h, and keep the liquid levels at the bottoms of each tower between 30% and 80%. Switch the pumps at the bottom of each tower once to remove water accumulated in the pumps and to test them. Contact the laboratory to test the water content in the circulating oil once every 1 hour of operation ；

III. Hot oil circulation (16 hours) 1. Keeping the circulation volume constant, the hot circulation process is the same as the cold circulation process. Light two eternal lamps and turn on the burners to start heating up. 2. Before igniting the vacuum furnace, the depressurized steam is used to improve convection in the furnace’s convection chamber; simultaneously, the drain valve of the steam drain silencer is opened, and the amount of steam drained is controlled based on the superheated steam outlet temperature TI1307 in the furnace’s convection chamber ； 3. The atmospheric-pressure furnace is heated at a rate of 25°C per hour; when the temperature at the furnace outlet reaches 100°C, the standby pump is switched in, and equipment such as heat exchangers and control valves are used to bypass the water in the system. 4. When the outlet temperature of the furnace reaches 120°C, the electric desalination tank is activated; when the outlet temperature reaches 150°C, heating is stopped and constant-temperature dehydration begins, with the equipment undergoing its first thermal tightening. 5. After ignition, activate the corresponding water coolers and air coolers. Operators on site should conduct regular inspections and adjust the amount of cooling water as necessary based on the temperature after cooling. The temperature of the residue oil leaving the unit should be kept between 85°C and 100°C, to prevent overflow in the storage tanks due to excessively high oil temperatures ； 6. During the heating and dehydration stage, in coordination with the pilot plant, analyze the water content in the circulating oil every 2 hours; if the water content is less than 1.0%, the dehydration is considered successful ； 7. Strengthen the inspection of the liquid level and interface level in the tower top reflux tank, and enhance water separation.

IV. Heat tightening at a constant temperature of 250°C (3 hours) 1. The furnace at atmospheric pressure continues to heat up at a rate of 30°C per hour until it reaches 250°C. 2. Field operators should strengthen the inspection of leakage conditions in all the plant’s heat exchange equipment, towers, vessels, pipelines, flanges, instruments, etc.; upon detecting any leakage, they must immediately contact the relevant units to carry out hot tightening. 3. The superheated steam is directed to the vent in front of the tower to discharge the condensate in the drain line. 4. When the initial top temperature is above 100°C and the normal top temperature is above 100°C, start top reflux to control the tower top temperature. 5. Select initial top circulation or normal top circulation based on the load condition at the top of the tower; when putting it into use, make sure to check carefully the procedures for replacing 1007A,B and 1003A,B. 6. Strengthen dehydration at the bottom of the three towers, and switch the standby pumps at the bottom of the towers every 2 hours. Switch the bottom pump to push the water out of all the pump inlet and outlet pipelines.

V. Start crude oil processing at 300°C–320°C; start the side stream at atmospheric pressure (4 hours). 1. Increase the number of burners in both furnaces as appropriate depending on the situation； Start the fans; switch both furnaces to forced ventilation, and direct the flue gas from both furnaces through the air preheater and the exhaust fan before discharging it into the chimney. Heat up to 300°C at a rate of 40–50°C/h. 2. When the outlet temperature of the atmospheric-pressure furnace reaches 300°C, steam is introduced at the bottom of the tower; the flow rate is between 1 t/h and 2 t/h. After introducing the steam, it is necessary to control properly the level in the reflux tank at the top of the tower, and gradually increase the steam flow rate to between 3 t/h and 4 t/h. 3. After steam is introduced at the bottom of the tower, side streams are established in the atmospheric pressure tower from top to bottom; once a liquid level is reached in each section of the stripping tower, the corresponding side stream pumps are started, and the unqualified oil is sent out of the plant via these side streams. 4. Procedure for establishing side streams under atmospheric pressure. 300°C at normal pressure, single line ； Reflux at 310°C ； 320°C at normal pressure, two-wire ； Reflux at 330°C with two reactors ； 340°C at normal pressure, three wires ； 4-wire at 350°C and normal pressure. 5. Once Line 3 is operating normally, the reboiler on Line 1 can be activated, and Line 3 can supply oil to the seal oil system. 6. When the outlet temperature of the atmospheric pressure furnace reaches 300°C–320°C, contact the dispatch team to switch to crude oil, change the flow path to send residue out of the unit, activate the residue cooler, and control the temperature of the discharged material at ≤100°C; simultaneously close the valve that directs the residue to the startup circulation line. 7. After switching to crude oil, start up the electrodesalination tank and supply power to it; keep the temperature of the crude oil entering the tank between 120°C and 125°C. Check the voltage of the electrodesalination tank, and once it is normal, begin adding water. Add demulsifier to the crude oil before desalination, and adjust the operation of the electrodesalination tank to ensure that the electrodesalination system operates properly. 8. Enable the three-injection system; ammonia, corrosion inhibitor, and water are injected at the tower top to gradually bring the parameters back to normal levels. 9. During operation, close attention must be paid to temperature changes at various points in the vacuum tower. The exit temperature of the atmospheric pressure furnace should increase at a rate of 20–30°C/h. When the temperature at the top of the vacuum tower reaches 70–80°C, diesel from the normal three-line system is passed through the mixed diesel line to the wax oil line in order to create a reflux flow; this helps keep the top temperature at or below 110°C. All the gas and water coolers at the top of the vacuum tower must be in use.

VI. Reduce pressure and evacuate, open the reduced-pressure side line (3 hours). 1. Once the atmospheric pressure tower is operating normally, the reduced-pressure furnace begins to heat up gradually until it reaches the values specified in the process sheet. 2. When the outlet temperature of the vacuum furnace reaches 330°C–350°C, start the secondary vacuum pump and monitor the vacuum level at the top of the furnace; as appropriate, activate the primary vacuum pump as well. Once the vacuum level stabilizes, turn on the booster to maintain a vacuum level of over 98.5 kPa. 3. Depending on the liquid level in the roof oil-water separation tank, start the roof oil pump and the water pump in a timely manner to drain the oil and water outward, thereby preventing overflow of the tank. 4. Depending on the liquid level in the oil collection tanks on each side of the pressure relief system, an appropriate amount of paraffin oil can be sent to the cold paraffin tank area, with the temperature of the paraffin oil exiting the unit controlled between 80°C and 110°C℃ ； 5. Implement measures to reduce backflow within Line 1 and reduce backflow within Line 3 ； 6. Introduce a small amount of steam at the bottom of the pressure relief tower ； 7. Once the reduction of the first line is back to normal, use the diesel from that line as sealing oil instead.

VII. Adjustment operations (2 hours) 1. Adjust the flame to stabilize the outlet temperatures of the constant-pressure and reduced-pressure furnaces; continue to add more burners to both furnaces, ensuring multiple burners with short flames and uniform flame heights. Once the wax oil meets the required standards, contact the catalysis team to switch to direct supply of the heated wax oil. 2. Adjust the heat extraction ratios of the reflux at the top of the atmospheric pressure tower and the recycle reflux in the middle section, in order to increase the proportion of heat extraction from higher temperature areas as much as possible. 3. Adjust the proportion of heat extraction from the circulating reflux in the middle section of the vacuum distillation tower, aiming to increase the proportion of heat extraction from the higher-temperature zone as much as possible. 4. Contact the scheduler to implement the product quality control plan. Once the product is discharged through the side line, the Quality Control Center is notified to take samples for analysis every 2 hours. After two consecutive sample analyses are successful, contact the scheduler promptly to have the product routed through the qualified production line. 5. Introduce the quench oil to the vacuum distillation tower in a timely manner to keep the temperature of the material drawn from the bottom of the tower at no more than 360°C, thereby preventing coking. 6. The temperature of the product exiting the unit is controlled as follows: 40°C to 45°C for reformed feed, 40°C to 45°C for kerosene, 40°C to 65°C for light diesel, 60°C to 90°C for heavy diesel, 60°C to 110°C for wax oil, and 90°C to 135°C for residue oil. 7. Adjust the temperature, pressure, and flow rates to meet the process specifications and quality requirements; stabilize the flow rates and temperatures in all side streams, and arrange for the calibration of all instruments in use. 8. Start the light hydrocarbon compressor, and divert the initial, normal, and reduced pressure non-condensable gases to the light hydrocarbon compression and recovery system. 9. Determine whether to route through the finished product line to exit the plant based on the analysis of the side-stream oil. 10. Gradually increase the processing volume of the device until it reaches normal levels.

Hey, does anyone have Word? Please send it to me. Thanks: 719588875@qq.com

You can just copy, paste, and edit it, right?