What are the advantages and disadvantages of operating a 65-bar water-coal slurry gasifier at 40 bar in terms of process and equipment?

This issue may be related to the set pressures of certain valves and instruments; overall, the changes required should be minimal. When the pressure at the burner decreases, the pressures in the system and various units will decrease as well. There will be some changes in the amount of water and steam used by certain devices, and the relevant pipes may need to be adjusted slightly. Since the material used has a high design pressure rating, no changes are necessary when reducing the pressure – it’s just like using a powerful engine for a small task, which is somewhat wasteful.

It’s not easy to lift it, right? How is the volume increased? How should oxygen pressure and flow be adjusted?

Personally, I think this is only suitable for theoretical discussion; there is no practical need for it, as it is designed for 65 kilograms – why operate it at 40 kilograms? As for the specific measures for rectification, I believe it is only possible to explain them in detail after understanding the gasification parameters for 40 kilograms.

It seems that this pressure level has been developed over several decades, and it can be said to represent the optimal balance between investment and returns.

There must be serious problems; the most fundamental industrial parameters have changed significantly, and other process conditions specified in the design also need to be adjusted. In my opinion, it’s difficult to operate under these conditions

Operating at a reduced load may result in less gas production compared to the level achieved at 65 bar; it is therefore necessary to conduct simulations of the entire gasification system to determine whether the pipeline equipment meets the process requirements. Also, it is necessary to ensure that the burner can meet the atomization requirements in order to guarantee the carbon conversion rate.

This post was last edited by Qingfeng Yao Mingyue on 2009-11-26 at 16:56. Let’s not make too many changes! The equipment, pipes, and valves meet the requirements; it’s sufficient to adjust some of the limits of the safety interlock system to match 4.0 MPa. However, the vaporization load will be considerably lower than before, and there’s no need to make the burners so large

Operating below the designed pressure will first affect the temperature at the syngas outlet, preventing the proper operation of the subsequent systems. This is due to insufficient heat and an inadequate water vapor ratio; as a result, the amount of wastewater discharged decreases, and the water in the system contains more ash and has higher hardness. This vicious cycle will cause significant problems for the system.

In my opinion, aside from the issues related to valves and instruments that need to be adjusted, as mentioned by some users above, there are also the following problems: 1. Whether the size of the oxygen pipeline is suitable for the oxygen pressure and flow rate; 2. Especially when the load decreases, the flow rate of the coal slurry also drops, which may cause water in the coal slurry to separate out and block the pipes; 3. With a decrease in pressure, the processing capacity of the burners decreases as well, and the atomization effect worsens, possibly requiring the burners to be replaced; 4. A decrease in pressure leads to a lower saturated vapor pressure of water vapor, resulting in significant changes in the heat exchange efficiency of the quenching chamber, as well as a reduction in the water vapor ratio. This situation can also occur in the scrubber tower. 5. The flow rate of the black water has decreased; the pipes of larger diameter were subject to severe scaling due to the reduced flow velocity of the black water. 6. The pressure in the black water flash evaporation system needs to be adjusted again

In a process with reduced pressure, the gas flow velocity increases, which can easily damage the slag outlet. Key chain values need to be adjusted; self-control is no longer effective, etc