Distillation column feed

The two principles are not contradictory; if the temperature of the material as it enters the tower is the same as that of the liquid on the tray, then after entering simultaneously, both the material and the liquid on the tray will have the same temperature and pressure. As a result, the components that are lighter than those in the liquid on the tray will rise as gas.

It is sufficient as long as the component concentrations are the same.

Determine the feed position based on the components. Different temperatures can be adjusted through other methods. Feedstocks are generally classified into saturated liquid, gas-liquid mixture, superheated, subcooled, and other feed types. Composition is the main influencing factor and should be given top priority.

The temperature can be adjusted; as long as the component concentrations are consistent

The composition should be the main factor; the temperature can be adjusted through the preheater of the feed, and after entering the tower it can also be adjusted via the reboiler and the top reflux.

At a certain operating pressure, changes in the feed temperature of the crude oil affect changes in the vaporization rate. Typically, a distillation column should be fed at the bubble point temperature. Because entering the tower in the bubble point state allows for better mixing with the saturated liquid in the feed plate and contact with the rising saturated vapor-liquid mixture at the lower part, thereby achieving the best distillation results. There is an optimal value for the feed temperature of the tower; if the temperature is too high, it will increase the vapor load on the upper trays above the feed inlet, and in severe cases, this can lead to foam entrainment. At the same time, the large amount of feed evaporating leads to improper separation of the various components in the trays above the feed plate, thereby reducing the efficiency of the tower. If the feed temperature to the tower is too low, it increases the load on the heating furnace; in severe cases, the bottom temperature of the tower fails to meet the required levels, resulting in incomplete separation of the components and affecting the operation of downstream units. The bubble point temperature of oil is closely related to its composition; therefore, when the composition of the crude oil changes, it is necessary to adjust the feed heater in accordance with the results of bubble point analysis, so as to maintain the feed temperature at the bubble point level. Of course, after the change in raw materials, in order to maintain the quality specifications of the oil at the bottom of the tower, the temperatures at the top and bottom of the tower must be adjusted accordingly.

The teaching of chemical engineering principles must be strengthened. The question asked by the poster can be found in the textbook; the feeding position is determined by both thermal state parameters and composition.

The position of the feed plate is determined based on the composition of the feed. If the feed contains a high proportion of light components, the feed position should be adjusted downward to improve the separation of these light components in the distillation section; conversely, if the feed has a high proportion of heavy components, the position should be moved upward to enhance the separation efficiency in the stripping section. Last edited by TDI5 on 2009-4-8 17:29.]

The best practice is to feed at the bubble point at trays with similar compositions; the bubble point temperature of the material is closely related to its composition, and the material can be brought to the bubble point state through methods such as preheating!

The distillation feed is a bubble-point feed, and the tray temperature includes an option for sensitive tray temperature.