How to operate the distillation process?
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This post was last edited by jmdc on 2019-7-28 22:18. How to operate the distillation process? For example, in the process flow diagram below, it shows a mixture of xylene and water; to purify the xylene, distillation is used to separate the water, which is then collected in a water reception tank, while steam is used to heat the jacket surrounding the reaction vessel. In the diagram, what is the function of the diverter? How does it work? What are the states of valve 1 and valve 2 during production? Is there an error in this image?
There is basically no problem with the diagram above; the separator is used to separate water from xylene, and the separated xylene is then sent back to the distillation vessel for further distillation. Valves 1# and 2# are kept open during normal production.
It seems that valves 1 and 2 are functioning properly and are both open; the distributor separates gaseous and liquid media. Valve 2’s pipeline should serve as a balance line, and both the water receiving tank and the separator also need a balance line – which is not present here. This is just my humble opinion: victory:
Under ideal normal conditions, with proper temperature control of the reactor, the separation tank is mainly filled with water; in this case, it’s sufficient to control the opening degree of valve 1 using the level sensor in the separation tank. Valve 2 can serve to balance pressure, and a small opening degree is sufficient. Just my personal opinion.
Valve 1 adjusts its opening degree based on the liquid level in the gas-liquid separation tank, ensuring that the tank does not become empty. Valve 2 should be fully open to serve as a balancing element, thereby preventing the liquid level in the gas-liquid separation tank from rising too high, which could affect the condenser
Vapor separation is the process of separating water from xylene. The gas that evaporates is mainly water, but it also contains some xylene. Therefore, after the gas condenses, a stratification occurs in the demister, with xylene on the upper layer and water on the lower layer. Generally, at the start of distillation, valve 1 is closed and valve 2 is opened for a period of full reflux; once distillation stabilizes, the opening degree of valve 2 can be adjusted to maintain balance in the layers within the demister. In the later stages of distillation, when there are fewer tax-related considerations, valve 2 can be closed by manually operating the valve switch.
With both Valve 1 and Valve 2 open, will there be a liquid level in the diverter? How can there be reflux without a liquid level?
Why is full reflux required for a period of time at the start of distillation? “What is “tax law”?
Open it, but not fully – the liquid level needs to be controlled
At the start, the steam volume is unstable – either too much or too little – which results in either too much or too little benzene being produced. Therefore, full reflux is used to stabilize the operation
Please have the original poster learn about the principle, structure, performance, and applications of oil-water separators.