Effect of high reflux liquid temperature
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This post was last edited by TDI5 on 2009-12-31 12:18. Micro positive pressure operation of the distillation tower. The high temperature of the top reflux liquid condensed from the top condenser will have any impact on the operation of the distillation tower (note: My tower top temperature is controlled within the normal range at this time, but the temperature of the liquid at the top of the tower condenser is high. The high temperature of the liquid at the condenser makes the temperature of the reflux liquid to the tower through the reflux tank high. What impact does this high-temperature reflux liquid have on the distillation column? Thanks. )
1. The cooling water may be turned on too low, and material may leak out easily in the emptying area.； 2. The cooling area of the condenser is not enough, and it is easy for the material to run out when emptied. ； 3. The evaporation volume is too large, the gas flow rate is too fast, the condenser tube is too short, and it is easy for materials to run out of the emptying area. ；
It depends on whether you need to get the product at the top of the tower or in the tower kettle. Qualified products are obtained at the top of the tower. High reflux temperature may cause the content of heavy components in the top product to increase, making the product unqualified. The main production costs of distillation production are the amount of steam in the tower kettle and the amount of cooling water at the top of the tower. Appropriately increasing the tower top temperature can help reduce the amount of steam in the tower kettle, the amount of cooling water at the top of the tower, and reduce the production of products. However, it should not be too high. If it is too high, it will destroy the distribution of the temperature gradient and material concentration gradient of the distillation tower, reduce the distillation effect, and affect product quality.
The main reason for this is that the top liquid component is too high and the pressure increases, which affects your subsequent process.
If the reflux temperature is high, the most likely problem is that the temperature and pressure at the top of the tower will increase. If it is not treated for a short time, the distillation of the entire tower will be destroyed.
To meet the same tower top temperature, if the reflux temperature is higher, the reflux flow rate will increase accordingly. What you mean is that various indicators are still normal now, right? The most dangerous thing is that if the backflow is too large, an accident will occur if the system enters the flood zone. If it is not to this extent, the greater the return flow, the greater the load on the condensation cooling system, and the higher the temperature after cooling, forming a vicious cycle. ； In addition, due to the increase in top pressure, if the original top temperature is maintained, the composition of the top product will become lighter. If the work cannot be stopped, find ways to clean the cooler online, lower the circulating water temperature, increase the circulating water flow, etc. to fundamentally solve the problem.
1. Affects the heat balance in the tower 2. Affects the balance of gas and liquid phases in the tower, causing fluctuations in production quality 3. Destroys the balance of pressure in the tower
If the tower top pressure is within the adjustable range and the tower top temperature does not change much, it will have little impact on the distillation tower.
Personally think: This problem is strange. It has something to do with your tower structure, the precision required for distillation (required purity of the product, and the boiling point of the product), the number of components in the material, the melting point, boiling point of the top material, etc... It all has something to do with it.
How high does the original poster mean? Are there any fluctuations in the temperature, flow rate and pressure of the circulating water? Does the current load exceed the heat exchange load of the condenser?