Severe ash accumulation in the synthesis gas pipeline inside the gasifier
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Every time the synthesis gas pipeline in the Texaco gasifier is inspected after a shutdown, a large amount of dust accumulation is found inside the pipeline. I would like to ask if anyone has any good methods to minimize dust accumulation in the synthesis gas pipeline!
Based on the description, it is mainly caused by incomplete washing of the syngas.
Isn’t there a spray water line in the syngas outlet pipeline, aimed at preventing dust accumulation?
The water keeps running at a rate of 10 m3/h
Appropriately increase the water injection in the synthesis gas pipeline, as well as the level and flow rate of the quench water. Be careful to operate smoothly and avoid large fluctuations in operating conditions.
Increase the water spray volume in the gas washer at the process gas outlet; by doing so, scaling is inevitable. The task then is to find ways to reduce scaling in order to extend the operational life of the system.
Personally, I believe that, given the low liquid level in the gasifier, increasing the amount of spray water at the outlet will only exacerbate scaling in the pipelines; the real issues lie in controlling the ash content of the coal and the liquid level in the gasifier. Maintain a high liquid level in the gasifier to reduce water entrainment in it. It is also important to control the water volume and level in the trays of the carbon scrubber tower; after all, the syngas coming out of the quench chamber still has a viscosity of around 240, and it becomes more viscous when it comes into contact with water.
Okay, I’ll try making some adjustments. I’m wondering if any manufacturers have carried out technical modifications, such as adding a baffle at the syngas inlet pipeline. . . . . . I’m not sure if it’s feasible
First, considering the coal quality, factors such as high ash content, poor water quality in the system, total hardness, alkalinity, calcium and magnesium ion levels, and pH value come into play. Next is the operation: increase the washing water at the syngas outlet and maintain the amount of quench water within the designed range, as more quench water is not necessarily better. The syngas, along with a large amount of water vapor and fine ash, is carried away after passing through the quench water bath; it then returns after passing through the baffle plates. If the amount of quench water is too large, the syngas will carry away the liquid water present in the quench chamber, and the fine ash won’t have time to return to that chamber and will be carried away as well, thereby creating opportunities for scaling in the pipelines.
Isn’t there a baffle at the outlet of the syngas from your gasifier?
If the vaporizer is already in use, water must be sprayed at the bends in the pipelines; if dust accumulation is severe, more spraying is required. Simply adding baffles to a scrubber tower isn’t very useful. Over time, dust also accumulates at the baffle. If the operation inside the furnace is not proper, it is mainly due to insufficient quenching and mixing, which leads to the entrainment of a large number of bubbles. If the coal feed rate or type cannot be changed, try reducing the oxygen-to-coal ratio; however, the range of load that can be adjusted is limited.