In atmospheric distillation, if the temperature difference between the bottom draw temperature of the atmospheric column and the feed section temperature is within 5 degrees, it is possible to increase the amount of stripping steam appropriately. Why?

This temperature difference of 5 degrees reflects the amount of oil and gas that evaporates; it can reach over 15 degrees. The greater the temperature difference, the lower the energy consumption of the unit and the higher the yield of light oil. There are many factors that influence this temperature difference, such as the properties of the crude oil, the temperature at the furnace outlet, the flow rate and temperature of the stripping steam, the tower pressure, the flow rates of materials returning to the tower at various stages and their temperatures, as well as material balance. Increasing the amount of stripping steam does so in a certain proportion – more isn’t always better. One can try increasing the amount by 0.1 cubic units at a time, while keeping all other parameters of the atmospheric pressure tower unchanged, and then observe the change in the temperature difference between the feed and the bottom of the tower. If the temperature difference decreases, it means the current amount of stripping steam is appropriate; if it increases, then increase the amount by another 0.1 cubic units, gradually finding the optimal values

The previous post mentioned material balance; the other influencing factors can be categorized as vapor-liquid phase balance and heat balance. These three types of balance are crucial for safe operation, especially in plants with a production capacity of over 5 million tons per year. If any one of these balances is disrupted over a long period, accidents are likely to occur, while smaller plants are less prone to such problems. It’s like a small boat that can turn easily, whereas a large boat finds it difficult to do so – that’s exactly the principle at play here