Regarding the setup of the inlet pipeline K1301 for the shell gasification unit

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In the shell gasification units that have been built and put into operation to date, the inlet pipeline of K1301 has two streams: one is saturated and purified crude syngas at around 160 degrees Celsius after being washed by C1601, and the other is hot dry gas containing 1–20 mg/Nm3 of ash at around 330 degrees Celsius before washing. After mixing, this mixture enters K1301 at approximately 200 degrees Celsius; after compression, the outlet temperature is around 230 degrees Celsius, and the gas then reaches the quenching point thanks to heat tracing for insulation. The design of K1301’s inlet pipeline with a cold main line combined with a heating auxiliary line is likely intended to ensure that the inlet and outlet pipes of K1301, along with their associated components, the unit itself, and the quenching ports of the gasifier, all remain in an overheated state. This helps to prevent condensation-induced corrosion, especially to avoid scale formation on the impellers that could lead to imbalance. But this also leads to problems: 1. During startup and shutdown, the gas exiting C1601 tends to be supersaturated or even contain water; in addition, poor heat tracing of the pipelines can result in condensation, which wettes the inlet pipes ； 2. Gases such as H2S, NH4Cl, and HCN present after driving can also cause slow corrosion of wet pipes, leading to the formation of dirt on the pipe walls ； 3. Dust in the uncleaned hot dry gas also gradually accumulates and adheres to the pipe walls. When these layers of corrosive scale on the inlet pipe wall of K1301 accumulate to a certain extent, they will flake off onto the inlet filter of K1301, causing the pressure difference to increase gradually and ultimately affecting long-term operation. Many manufacturers have been severely affected by it and have taken some countermeasures, achieving certain results. We will not discuss the various measures and their effects here, as rectifications later on require financial investment. Rather, I wonder why the design institute doesn’t start making thorough improvements from the stage of engineering design For example: 1. Install a economizer behind the waste heat boiler to reduce the temperature of the crude syngas to 230–250 degrees, and direct one stream of this gas to K1301. This prevents scaling from causing an increase in pressure difference, and it also **reduces the load on the C1601 system** ； 2. Remove the hot dry gas stream; instead, use the cold saturated gas coming from the C1601 outlet. A demister can be installed before the gas enters K1301. After being compressed by K1301, the temperature rises to around 190 degrees. Since there is no dust-containing gas present, scaling does not occur. To prevent condensation-related corrosion, it is even possible to add a heat exchanger to the inlet pipe during the initial design in order to raise the temperature by 10–20 degrees. The above are merely some immature ideas, meant to bring a smile to everyone’s face; I hope you can offer some guidance.