Slurry steam generator
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Originally designed to produce 35 kilograms of steam, it was later modified to produce 10 kilograms of steam – what impact does this have on the distillation process?
It has no impact on the operation; it’s just that the steam pressure produced is different. Personally, I think it is better for the slurry steam generator to produce low pressure; at least it will not leak easily due to high pressure, and the tubes can be used for a longer period of time.
High steam production indicates a large heat exchange load on the slurry, which results in a lower temperature in the tower; vice versa. If the amount of steam generated by the slurry steam generator is reduced, it is necessary to pay attention to changes in the slurry temperature to prevent coking
The impact isn’t very significant. However, many factories these days use back-pressure turbines, and the steam pressure has dropped from 3.5 Mpa to 1.0 Mpa; as a result, there is an excess of steam at 1.0 Mpa. If the slurry steam generator continues to produce steam at 1.0 Mpa, it will lead to excessive usage of this steam and thus waste
Personally, I think the operational impact is not very significant, but it will affect the utilization rate of the waste heat from the catalytic slurry, thus having a certain impact on the steam balance of the entire plant. In fact, the heat required to generate a certain amount of saturated steam is more or less the same, as it is mainly the heat of phase change that matters; therefore, the heat needed to produce 10 kilograms of steam is roughly the same as that needed to produce 35 kilograms of steam. However, the utilization efficiency of 10 kilograms and 35 kilograms of steam after superheating differs significantly, which also affects the steam balance of the entire plant. Personal opinion.
Probably, after changing the production process, the main thing to consider is the load on the equipment; the amount of gas produced when generating the same amount of heat differs between 35 kilograms and 10 kilograms. The efficiency of heat recovery may decrease to some extent.
Discuss it in two parts: ① The process remains unchanged; only the slurry steam generator uses steam at 1.0 MPa instead of 3.5 MPa. It is certain that the temperature of the slurry decreases after the replacement, and the reduced temperature of the slurry returning to the tower affects the amount of slurry that flows back； ②After the adjustment of the slurry steam generator, the steam pressure changed from 3.5 MPa to 1.0 MPa; this is merely a equipment-related issue, with the operating pressure and temperature of the equipment decreasing, but the impact is not significant.
Does the large cap flange of your slurry steam generator leak normally? Is it easy to fix once a leak occurs?
We missed it; we tightened it and still had leaks, and after the leaks we tightened it again, but we never considered changing the steam generator to 1.0 MPa, mainly because we still had to take into account the fact that medium-pressure steam is more expensive than low-pressure steam, yet it offers a higher heat utilization efficiency. At the very least, in the event of a steam interruption in the 3.5MPa system, our facility can still maintain its own operation.