Problems with chemical feeding in 101-B

The poster is referring to 101-B; it should be a stage of feeding materials into the furnace, right? Many factories have different numbers, and their Chinese names should be indicated. Our company’s code is B0101. The conditions that must be met for feeding materials (introducing natural gas) into the first-stage furnace are as follows: (1) The exit temperature of the first-stage furnace should be between 720 and 760°C, with the system pressure exceeding 0.5 MPa. (2) After the desulfurization, heating, and reduction processes are complete, the sulfur content in the raw material gas at the ZnO outlet is less than 0.1 PPm and remains stable. The desulfurization temperature is normal. (3) The pressure in the steam pipeline network is stable; sufficient steam is available outside the boundary area for operation, with the process steam flow reaching 20 t/h and remaining stable. II. Temperature rise and reduction schedule: (For reference only; the on-site plan takes precedence.) Phase, Temperature range, Temperature rise rate (°C/hr), Time (h), Cumulative time (h), Remarks: Gas-assisted reduction: 720–780, 60, 1, 1; Gas-assisted reduction up to ~780: 0, 7, 8. III. Principles of the reduction reactions: NiO + H2 = Ni + H2O – Q; NiO + CO = Ni + CO2 + Q. IV. Steps for feeding materials into the first-stage furnace: (1) Remove the blind flange behind the electric valve of the first set of coils. (2) The control operator slowly opens the system pressure relief valve based on the pressure, closes the front valve of the compressor, and adjusts the load control valve; meanwhile, the inspector closes the large valve on the pipeline that leads back to the compressor for the desulfurization cycle before the compressor. Change the temperature increase in the desulfurization cycle to occur during system venting, and stop the temperature increase in the desulfurization process. At the same time, system pressure is used for venting control to keep the ZnO outlet pressure slightly higher than the process steam pressure of the first-stage furnace. (3) Use a single burner at the top of the furnace for full combustion; inspection personnel should pay attention to the burning condition at the top and adjust the flame in the furnace, ensuring that it is blue, short, and firm. The control operator adjusts the top combustion remote control valve based on the furnace temperature in order to regulate the negative pressure in the furnace. (4) During inspection, open the pilot drain valve of the electric valve; manually adjust the load control valve to a certain opening degree. Once dry gas is discharged, close the pilot drain valve, then slowly open the electric valve on site. Depending on the amount of natural gas flowing in, gradually open the electric valve fully before switching it to remote control. The main control adjusts the load control valve to regulate the amount of natural gas, with an initial setting of 500 Kg/h. Adjust the load control valve to maintain a water-to-carbon ratio of around 18:1. At this point, the catalyst should exhibit initial activity, as a decrease in bed temperature can be observed, indicating that an endothermic reaction is taking place. If no reaction occurs after a long period of time, the feed gas should be cut off, the cause identified, and then fed back in again. Notify the control room of the commissioning of the online methane analyzers AIR-102 and AR-103. (5) Adjust the combustion load of a section of the furnace in a timely manner to prevent a drop in bed temperature. While introducing natural gas, pay attention to the pressure and reduce the system pressure in a timely manner until the process is completed. During the inspection, close the large valve between the ZnO outlet and the water cooling system, and inform the maintenance team to install a blind flange. (6) The system increases the amount of feed gas at a rate of 500 Kg/h until the load control valve reaches 3000 Kg/h, ensuring that the water-to-carbon ratio remains above 7:1. Gradually open the load control valve, and use the load control valve along with the inlet pressure control valve of the atmospheric compressor to regulate the system load. While increasing the feed gas, adjust the burner load and furnace negative pressure to keep the outlet temperature of the first stage furnace above 720°C at all times. (7) Early reduction stage: One hour after the introduction of natural gas, analysis of the sulfur content and methane content at the outlet of Section 1 began, with analyses conducted every 30 minutes. (8) Post-reduction stage: When the levels of S in the exhaust gas from the furnace are ≤0.1 PPm and CH4 is ≤12.84%, and the values remain stable for three consecutive times or more, the bed temperature can be increased to around 780°C and maintained for 7 hours to ensure complete reduction. Then reduce the temperature to 760°C. (9) At the end of the reduction process, increase the flow rate of the feed gas at a rate of 500 kg/h until the load is raised to around 5500 kg/h, while maintaining the carbon-to-water ratio in the furnace at 4–4.2:1. And appropriately increase the system pressure. V. Precautions for feeding materials into a single-stage furnace: (1) Strengthen on-site inspections to observe the expansion and contraction of spring hangers as well as the condition of the furnace tubes. In case of any abnormalities, increase the water-to-carbon ratio to 7:1, reduce the feed gas flow rate to 1950 kg/h, and extend the reduction time by 4 hours. (2) During the reduction process, strict attention must be paid to controlling the water-to-carbon ratio; carbon deposition is strictly prohibited. (3) Pay attention to adjusting the top combustion condition and the negative pressure in the furnace of Section 1, to ensure a uniform heat load in that section. The furnace chamber should be clear and well-lit ； The flame is blue, short, and stiff ； The temperature difference between the upper and lower parts of the furnace chamber should not exceed 30°C, and the color of the furnace tubes should be uniform with no hot spots. (4) Pay attention to the temperature at NO.2 and adjust the amount of protective steam in a timely manner to prevent overheating. (5) Pay attention to the liquid level in the water jacket; it should always be at an overflow level to prevent a lack of water supply. (6) Pay attention to checking the pressure drop in the first and second stage furnaces. (7) Pay attention to the pressure increase in the steam drum. (8) Adjust the flow rate of the medium and the flue gas temperature in each group of coils to prevent overheating of the coils, as well as to avoid a decrease in the flue gas heat recovery rate.

Conditions required for feeding: Confirm that the temperature of 110-D rises to 350℃； Confirm that the temperature at the inlet of the pre-conversion process, TICA-04111, rises to 450°C (applicable only to manufacturers with a pre-conversion process) ； It was confirmed that the H2 content at the 108-DA outlet is 4-5%, and the total S3% of A2 at the 110-D outlet is 3%.