Does anyone have a boiler startup plan?

Boiling method 3.2.3.1 Regulations on chemicals used for boiling The amount of chemicals used for boiling depends on the cleanliness of the boiler: see Table 4. a) The new boiler, from manufacturing to its first boiling, takes no more than nine months; it suffers little from oxidation and corrosion and is in good condition after cleaning ； b) The new boilers are stored outdoors, suffering from significant oxidation and rust, resulting in poor cleanliness ； c) Boilers that have been out of use for a long time contain scale in addition to rust. Table 4 Dosage of alkali for boiling (kg/ton of water) Boiler cleanliness: I II III Sodium hydroxide 2–3 3–4 5–6 Trisodium phosphate 2–3 2–3 5–6 For boilers with severe dirt and rust, the dosage listed in the table may be increased by 50%–100%. 3.2.3.2 Method of adding chemicals: The concentration of the chemical solution should be around 20%. NaOH can be added in its calculated amount all at once, while Na3PO4 can have 50% of the calculated amount added first, with the remaining 50% being added during the furnace heating process. Before adding chemicals to the boiler, the drum should first be filled with water up to the lowest visible water level. 3.2.3.3 Boiler boiling step: a) Boiler water is introduced into the boiler system for cyclic flushing; the water is considered acceptable if its turbidity is less than 10×10-6; if not, flushing and discharge continue; b) Steam at 1.0 MPa is introduced from the drain outlet at the bottom of the waste boiler to heat the boiler water to a boiling state, and dosing begins while maintaining the lowest visible water level in the drum; c) After dosing, the boiler is left to boil for about 24 hours, with the process ending when the oil concentration in the water reaches saturation and remains unchanged; water quality is analyzed every 2 hours; d) During boiling, the alkalinity of the water is monitored; if phosphate levels are too high, the water is discharged, and if they are too low, additional chemicals are added; it is important to maintain a high water level during this process; e) After the boiling process is complete, all drain valves and low-point drain valves are opened to release the alkaline water, and at the same time, circulation and steam heating are stopped ； After draining the alkaline water, close all drain and bleed valves; f) Introduce boiler water into the system for flushing until the pH value of the water is below 8.5 and the effluent is clear. 3.2.3.4 Standards for a properly cooked boiler: After cooking, the manhole of the steam drum should be opened for inspection; the metal interior surface of the boiler shall be qualified if a metallic luster becomes visible after wiping it with water or cotton yarn. After heating the furnace, special attention should be paid to ensure that all drain and bleed valves are not blocked by dirt. 3.2.3.5 After the boiler has been cleaned with boiler water upon completion of the heating process, adjust the process parameters and proceed with a new leak test and startup of the boiler.

　　　 　　　Steam boilers: Newly installed boilers and boilers that have undergone major repairs must be dried out and boiled before use. Steam boiler 1.1 Boiler drying: The purpose of boiler drying is to allow the refractory concrete and insulation concrete on the boiler to dry slowly and properly. 1.2 Furnace drying operation: 1.2.1 When drying the furnace at atmospheric pressure, first remove the safety valve; the boiler must not have its pressure increased. 1.2.2 Bring the boiler water to the normal level. 1.2.3 Heat the furnace using a low flame; maintain intermittent burning to allow the insulation layer to slowly release moisture (at this time, the insulating rock wool inside the boiler’s outer casing will also dry out and may emit moisture). 1.2.4 Dry until the moisture content of the refractory concrete drops below 7%, after which proceed with furnace heating. II. Steaming of Steam Boilers 2.1 Purpose of steaming: It is to remove rust, oil deposits, and other impurities from inside the boiler in order to ensure the quality of the steam and the proper operation of the boiler; therefore, steaming must be carried out before using the boiler. 2.2 Reagents for boiler descaling: Sodium hydroxide and trisodium phosphate are used for boiler descaling. The amount of these chemicals required is calculated based on the volume of water in the boiler, per cubic meter, taking into account the thickness of rust and scale inside the boiler. The amounts of chemicals needed for descaling are shown in the table. 　　　Chemical dosing table for boiler cleaning: Drug name, Dosing amount (kg/m3 of water), Thin rust, Thick rust, Water with rust and scale. Sodium hydroxide: 2–3, 3–4, 5–6; Trisodium phosphate (Na3PO4·12H2O): 2–3, 2–3, 5–6. If trisodium phosphate is not available, sodium carbonate (Na2CO3) can be used as a substitute, at a dosage of 1.5 times that of trisodium phosphate; sodium carbonate can also be used alone for boiler cleaning, with a dosage of 6 kg/m3 of water. 2.3 Preparation of the boiler heating solution 2.3.1 The maintenance technician opens the manhole cover on top of the boiler. 2.3.2 Operators should wear work clothes, rubber gloves, and protective glasses. 2.3.3 Take a certain mass of hydroxide solution, place it in a plastic bucket, and stir it evenly. A uniform solution with a concentration of 20% is prepared and injected into the boiler through the access hatch at the top of the boiler. 2. Boiling operation: 2.4.1 After the boiler is ignited, the pressure increase in the boiler must occur slowly; this process generally takes 2 to 3 hours. 2.4.2 When the drum pressure rises to 0.05–0.1 Mpa, close the drum air valve and flush the drum level gauge. The sequence for flushing the water level gauge is as follows: a. First, open the drain valve to flush the steam pipe, water pipe pathways, and the glass tube. b. Close the water tap to flush the steam pipe, water pipe passages, and glass tubes. c. Open the water valve and then close the steam valve, so as to flush the water pipe pathway and the glass tube. d. Open the steam valve and slowly close the water valve; at this point, the water level should rise rapidly with slight fluctuations. Check this by comparing it with another gauge to verify its accuracy. e. Finally, close the steam valve first, then close the drain valve to restore the water level to normal. Note: If the water level rises very slowly, it indicates that there is a blockage in the water gauge, which should be flushed again or replaced. 2.4.3 When the air pressure rises to 0.1–0.15 Mpa, the trap of the pressure gauge should be flushed ； Open the three-way valve on the pressure gauge to release the water stored in the elbow; close the three-way valve once steam begins to emerge. If the pressure gauge pointer can return to its position before flushing, it indicates that the trap is unobstructed; otherwise, flush it again or replace it. 2.4.4 When the steam pressure rises to near 0.3 Mpa, it is necessary to check for any leaks at the various connections of the boiler itself. Tighten the manholes, handholes, and flanges that were removed during maintenance, ensuring stable steam pressure at this time. After the steam pressure increases, the bolts must not be tightened again. 2.4.5 When the steam pressure rises to 0.4 Mpa, maintain it for 12 hours, then stop the combustion and allow the pressure to drop gradually to atmospheric level. Once the water temperature falls below 70°C, open the drain valve to release all the water from the boiler. Trial supply water equipment and sewage discharge devices ； Fill the boiler with water before draining it, and pay attention to the water level during drainage – it must not drop below the lowest safe level indicated by the gauge. After confirming that the drain valve operates smoothly and normally, close it tightly and check for any leaks in the valve and piping. 4. When the steam pressure rises to 0.6 Mpa, the main steam valve should be slightly opened to warm the pipes, and the warming time should be at least 0.5 hours. 5. When the drum pressure reaches more than 50% of the operating pressure (above 0.63 Mpa), a comprehensive inspection of the boiler unit should be carried out. If any abnormalities are detected, the pressure increase should be stopped; pressure raising can resume only after the faults have been resolved. 2.5 Normal pressure rise operation: 2.5.1 After the boiler is ignited, the process of increasing its pressure must proceed slowly, typically taking 2 to 3 hours. 2.5.2 When the drum pressure rises to 0.05–0.1 Mpa, close the drum air valve and flush the drum level gauge. The sequence for flushing the water level gauge is as follows: a. First, open the drain valve to flush the steam pipe, water pipe pathways, and the glass tube. b. Close the water tap to flush the steam pipe, water pipe passages, and glass tubes. c. Open the water valve and then close the steam valve, so as to flush the water pipe pathway and the glass tube. d. Open the steam valve and slowly close the water valve; at this point, the water level should rise rapidly with slight fluctuations. Check this by comparing it with another gauge to verify its accuracy. e. Finally, close the steam valve first, then close the drain valve to restore the water level to normal. Note: If the water level rises very slowly, it indicates that there is a blockage in the water gauge, which should be flushed again or replaced. 2.5.3 When the air pressure rises to 0.1–0.15 Mpa, the trap of the pressure gauge should be flushed ； Open the three-way valve on the pressure gauge to release the water stored in the elbow; close the three-way valve once steam begins to emerge. If the pressure gauge pointer can return to its position before flushing, it indicates that the trap is unobstructed; otherwise, flush it again or replace it. 2.5.4 When the steam pressure rises to near 0.3 Mpa, it is necessary to check for any leaks at the various connections of the boiler itself. Tighten the manholes, handholes, and flanges that were removed during maintenance, ensuring stable steam pressure at this time. After the steam pressure increases, the bolts must not be tightened again. 2.5.5 When the steam pressure rises to 0.4 Mpa, the feedwater equipment and blowdown device should be used ； Fill the boiler with water before draining it, and pay attention to the water level during drainage – it must not drop below the lowest safe level indicated by the gauge. After confirming that the drain valve operates smoothly and normally, close it tightly and check for any leaks in the valve and piping. 2.5.6 When the steam pressure rises to 0.6 Mpa, the main steam valve should be slightly opened to warm the pipes, and the warming time should be at least 0.5 hours. 2.5.7 When the drum pressure reaches more than 50% of the operating pressure (above 0.7 Mpa), a comprehensive inspection of the boiler unit should be carried out. If any abnormalities are detected, pressurization should be stopped; pressurization can resume only after the faults have been resolved.

The chemical solution for boiler treatment is ready; the dosage is 3–4 kg/m3 of sodium hydroxide per meter cube of water, and 2–3 kg/m3 of trisodium phosphate per meter cube of water. 2.3.3.4 Boiling method 2.3.3.4.1 Boiling heat source: Steam at 1.0 MPa is introduced from the drum blowdown line as the heat source for boiling. 2.3.3.4.2 Chemicals for boiler boiling: The dosage is as follows – 3–4 kg of sodium hydroxide per cubic meter of water, and 2–3 kg of trisodium phosphate per cubic meter of water. The concentration of the solution should be around 20%. NaOH can be added in its calculated amount all at once, while 50% of the required amount of Na3PO4 can be added initially, with the remaining 50% being added during the boiling process. 2.3.3.4.3 Boiling time and pressure: The pressure in each boiling equipment should be increased to 0.1 MPa(g), after which the boiling process should continue for 1–3 days (depending on the results of water analysis). 2.3.3.4.4 Discharge of waste liquid: The waste liquid resulting from furnace boiling is discharged into the gutter through the waste drainage system. 2.3.3.4.6 Boiler cooking procedure: Drain deoxygenated water into the steam generator for flushing; the flow rate of the flushing water should be around 1.5 meters per second. The blowdown valve is opened to drain water until it is clean, after which the blowdown valve is closed. Water is added until the liquid level reaches 90%. During the boiler cooking process, the water level in the drum should be maintained at the highest visible level. Remove the safety valve connector to use it as the chemical dosing inlet for adding chemicals. The chemical requirements are 3–4 kilograms of sodium hydroxide per cubic meter, and 2–3 kilograms of trisodium phosphate per cubic meter. Water vapor is introduced using a drain valve to raise the temperature of the boiler water, with the rate of temperature increase not exceeding 40°C/h. When the water temperature reaches 100°C, a large amount of steam is released from the open container. Control the amount of steam used, and at the same time pay attention to monitoring the pressure in the other side; open the corresponding drain valve to release some of the gas from that side. Cook like this for several hours (2–3 hours), then stop the steam heating. This process is repeated several times to steam away the grease and other organic and inorganic impurities from the equipment. During boiler cleaning, the alkalinity of the boiler water must not be lower than 45 mmol/l; otherwise, trisodium phosphate solution should be added. Every 2 hours during this process, samples should be taken to analyze the alkalinity and phosphate levels. If the phosphate concentration is high, it needs to be removed, and if it is low, additional chemicals should be added. When the content of trisodium phosphate ceases to change or stabilizes, it indicates that the chemical reactions between the chemicals in the water and the rust, scale, etc. on the inner surface of the boiler have essentially come to an end, and the boiler cleaning process can be concluded. After the boiling process is complete, open all drain valves and low-point drain valves to release the alkaline water, while simultaneously stopping circulation and steam heating ； Cool down the boiler, drain all the remaining water, and clean the interior of the boiler using deoxygenated water, in order to prevent high-alkalinity solutions remaining in the boiler from causing foam formation in the boiler water and thereby affecting the quality of the steam. After scrubbing, it is also necessary to inspect the inner walls of the boiler drum and header, removing all debris completely; the metal surface should be free of rust spots and appear grayish-white. The wastewater from the boiler grate, due to its high alkalinity, cannot be discharged directly. It must be routed through a temporary pipeline to a neutralization tank, where an appropriate amount of hydrochloric acid is added for neutralization; only after the pH level reaches 6–9 can it be discharged. It is also necessary to carefully inspect the drain valve and level gauge to prevent deposits formed during boiler operation from blocking the passages. They’re more or less the same; there are differences among individual companies in detail!