Light-load operation of the atmospheric and vacuum distillation unit
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This post was last edited by qhhqhh on 2019-6-4 at 16:50. Hello everyone: A friend of mine who works for the owner’s company has a vacuum distillation unit that is currently operating at reduced capacity due to the company’s needs, at around 50% of its designed operating level. The device is now experiencing issues such as substandard product quality. I told him a few points: 1. When the processing volume is below the designed range, the trays are prone to leaking, resulting in poor separation efficiency and products that do not meet quality standards ； 2. Appropriate steam injection can be applied to the vacuum furnace tube to increase the flow rate ； 3. This cannot be resolved simply by performing a steady-state simulation using Aspen; on-site operation is more important. I don’t have much production experience, but I think this is a good problem to work on; there isn’t much information available online either. I hope everyone can be educated on this: D: If low-load operation is required, what measures can be taken in production operations? 1. Control product quality ； 2. Ensure the stable operation of the device ； 3. Or what other measures are beneficial for production?
I’ve never encountered such a low load before; considering only the pumps, can they achieve the minimum flow rate?
Yes, I also reminded him about the pump problem. He said that the pump is operating normally for now
Thank you. I think their problem should be solved by improving staff training. Fluctuations in raw materials and changes in processing volume are common in production, but the principle remains unchanged.
All designs have a minimum load value, typically ranging from 60% to 110%; if this value is too low, the system cannot operate – the furnace tubes suffer from coking, the bottom of the vacuum distillation tower also experiences coking, and the flow rate in the heat exchangers becomes too slow, leading to blockages. When the heat exchange network is out of balance and thermal stresses change, accidents are likely to occur. . .
That’s how it is; if orders come from above, they have to be carried out below. As for whether it’s suitable or not, well… . . . So I also want to take this opportunity to see if any friends in the production field can give some feedback.
At low load, the coking problem in atmospheric and vacuum distillation units must be taken into account; diesel and wax oil injection can be used as a solution
Yes, not only the furnace, but the heat exchanger as well.
There is reflux at the bottom of the vacuum tower to prevent coking