Control of desulfurization tower resistance during wet desulfurization of coke oven gas
Thread Content
The complexed iron catalyst is applied in the desulfurization units for coking furnace gas; it replaces the PDS desulfurization process in the existing HPF desulfurization method, offering advantages such as high desulfurization efficiency, high sulfur dissolution rate, fast reaction speed, one-step reaction completion, and reduced operating costs. However, in actual operation, due to differences in on-site operating conditions and control methods, the operating cycle of the desulfurization packing tower may become shorter. Through process adjustments during operation, combined with the proper selection of packing, it is entirely possible to control the operating cycle of the desulfurization packing tower. 1. High-flow flushing of the desulfurization tower. If the conveying capacity of the circulation pump permits, the spray density in the packed tower should be maintained at over 50 m3/m2h. During desulfurization using complexed iron, the desulfurization tower maintains a high flow rate for circulation; as a result, large sulfur particles have difficulty adhering to the surface of the filler inside the tower, thereby **reducing the likelihood of sulfur clogging the gaps in the filler**. 2. Flue gas desulfurization liquid flow control to prevent frequent and significant changes in the solution circulation volume. At the beginning of the operation of the desulfurization tower, maintaining a certain flow rate of solution and keeping the upward flow rate of liquid in the tower (the flow rate of the lean liquid) stable is beneficial for controlling the operating resistance of the tower. 3. Maintain the temperature range of the desulfurization liquid to prevent fluctuations in its temperature. In winter, the temperature of the desulfurization liquid drops as the ambient temperature falls. At such times, it is necessary to adjust the heat exchanger appropriately to keep the temperature of the desulfurization liquid above 35 degrees, with the temperature difference maintained within 2 degrees, thereby preventing the salts in the desulfurization liquid from precipitating too rapidly and causing blockages in the packing. 4. Choose structured packing in place of loose packing; plastic structured packing yields the best results. The structured packing is arranged neatly, with orderly liquid channels between the packing elements; the liquid flows from top to bottom through the packing, which facilitates the flushing out of particulate matter entrained in the solution from the desulfurization tower. In actual operation, in desulfurization towers with bulk packing, even when the quality of the desulfurization liquid is excellent, the packing layer can still become clogged due to the accumulation of sulfur paste after more than 1 year of operation ； In a desulfurization tower with structured packing, proper operation control ensures that the resistance of the tower does not increase over a period of 3 years of operation.
In the wet desulfurization process of coke oven gas, controlling the resistance of the desulfurization tower is an important aspect to ensure the stable operation of the facility. Here are some methods for controlling the operating resistance of desulfurization towers: 1. Flush the tower with a high flow rate: Maintain a high spray density in the desulfurization tower (for example, above 50 m3/m2h) to ensure that sulfur particles do not easily adhere to the surface of the packing, thereby reducing the likelihood of blockages. 2. Control the flow rate of the desulfurization solution: It is necessary to maintain a steady flow rate of the solution, especially during the initial startup phase of the desulfurization tower. Avoiding frequent and significant adjustments to the solution circulation rate helps to control the operating resistance of the tower. 3. Maintain the temperature of the desulfurization fluid: Keep the temperature of the desulfurization fluid constant; especially when the ambient temperature drops in winter, adjust the heat exchanger accordingly to ensure that the temperature remains above 35°C, and control the temperature difference within 2°C, in order to prevent salts from precipitating too rapidly in the desulfurization fluid and causing blockages in the packing. 4. Use structured packing: Compared to loose packing, structured packing, with its neat arrangement and orderly pores, facilitates the flow of liquid and helps to wash away solutions containing particles. This effectively reduces blockages caused by the accumulation of sulfur paste in the packing layer, thereby extending the operational life of the desulfurization tower. Through these measures, combined with appropriate selection of fillers and process adjustments, it is possible to effectively extend the operating life of the desulfurization tower, reduce downtime for maintenance due to blockages, and ensure desulfurization efficiency as well as production stability. .