The problem of quenching with low moisture content
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The principle of low-moisture coking quenching is to supply water in stages throughout the quenching process, depending on the flow rate of the quenching water, that is, variable-flow water spraying for coking quenching. The quenching water flow has two speeds: it is at a low speed at the beginning of the quenching process, with a flow rate that is 40% to 50% of the high-speed flow rate. This low-speed phase usually lasts for 10 to 20 seconds; it serves to cool the top layer of coke and stabilize its surface, thereby preventing the coke from splashing out of the quenching chamber when the water flow is at high speed ； Thereafter, the water flow increases to high speeds; when the quenching water comes into contact with the red coke, the rapid expansion force as the water turns into steam causes the steam to flow upward through the coke layer. This mechanism relies on steam moving from bottom to top to quench the coke inside the vessel, while the excess water is quickly removed from the vessel. Our plant uses this low-moisture coking method. However, there are still some issues: 1. A large amount of red coking remains ； 2. The moisture content of coke is still relatively high ； 3. Approximately 3 to 5 seconds after the coke quenching car carrying red coke enters the coke quenching tower, it begins to discharge water. Who can help me solve these three problems?
Low-moisture coking: the design time for low water flow is 0–30 seconds, and for high water flow it is 0–75 seconds; the water pressure is controlled accordingly. We also use low-moisture coking, with the moisture content of coke kept at around 7%; the design value is 4%, which is slightly higher than that. Also, the opening degrees of the valves along the pipeline should not be consistent; the openings on both sides are small while that in the middle is large. Check the area with red coke and adjust the valve opening degrees accordingly. High moisture content in coke is mainly caused by an inappropriate distribution of quenching water; the key is to adjust the quenching time and water pressure. It is a design feature of the process that the coking quench vehicle stays inside the coking quench tower for 3-5 seconds before starting the quenching process (a 3-5 second delay in quenching); there is no need to eliminate this.
In low-moisture coking, can a high-level water tank be replaced by a high-flow water pump? Thank you!
This technology is not good; the spraying method we use works well.
Adjust the direction of the nozzle; in areas with more red coke, especially in the middle section, tilt the nozzle accordingly. Here, we keep the low pressure at 45% intensity for 10 seconds, and the high pressure at 100% intensity for 90 seconds (adjusting according to the ignition situation). Additionally, the delayed water injection is part of the design, so there’s no need to cancel it. It is recommended to use a slurry pump instead of a single-flow valve – this would be better
Why isn’t anyone responding to this question? In low-moisture coking, can a high-level water tank be replaced by a high-flow water pump?
Haha, the same thing happened when our office was first put into use. The main reason is that low-water coking results in localized coking; thus, the coke in the coking car is higher in the middle and lower on the sides. The water supply in the water supply pipes inside the coking tower is essentially uniform, which results in red coke in the middle and higher moisture levels in the coke on both sides. The method of adjustment is quite simple: adjust the opening degrees of the control valves used for water supply – reduce the opening degrees on both sides slightly, while keeping the opening degree in the middle at its maximum. By resolving the water supply issue, all the problems you mentioned above will be solved as well. If you have any further questions, feel free to contact me; I work at Pangang Coking. 13551749451 I have several solutions for dealing with problems like yours
It’s not that it’s impossible, but the investment is too high, and time is also difficult to control.
It is better not to use it; the purpose of the high-mounted slot is to ensure that the water pressure and flow rate remain constant every time coking is stopped.
Where are you from? It’s easy to resolve that. As for your specific work issue, I’ve already dealt with it effectively here
The main principle of low-moisture coking quenching is to extinguish the coke at the upper part first, and then use large amounts of water to extinguish the coke at the lower part, generating a large volume of steam; the coke ends up in a boiling state, thereby mixing thoroughly with the quenching water and steam. So, the upper surface after coking is completed appears to be fairly flat. If what you say is correct, then it might be necessary to reduce the duration and intensity of the low-flow water application, while increasing the intensity and duration of the high-flow water application, so that the water can penetrate through the upper layer of coke and reach the lower layer, thereby promoting boiling there.