4. Read and translate

Figure 8.1 depicts an industrial fractionation column separating a feed stream into one distillate fraction and one bottom fraction. However, many industrial fractionation columns have outlets at intervals up the column so that multiple products having different boiling ranges may be withdrawn from a column distilling a multicomponent feed stream. The lightest products with the lowest boiling points exit from the top of the columns and the heaviest products with the highest boiling points exit from the bottom. Industrial fractionating columns use external reflux to achieve better separation of products. Reflux refers to the portion of the condensed overhead liquid product that returns to the upper part of the fractionating column as shown in figure. Inside the column, the downflowing reflux liquid provides cooling and condensation of upflowing vapors thereby increasing the efficacy of the distillation tower. The more reflux and more trays provided, the better is the

t ower’s separation of lower boiling materials from higher boiling materials. Bubble-cap “trays” or “plates” are one of the types of physical devices which are used to provide good contact between the upflowing vapor and the downflowing liquid. In industrial uses, sometimes a packing material is used in the column instead of trays, especially when low pressure drops across the column are required, as when operating under vacuum.

Fig. 8.1. The schematic of a continuous fractionating column

https://en.wikipedia.org/wiki/Fractionating_column

5. Decide whether the statements below are true or false according to the information in exercise 4

1. The lightest products with the lowest boiling points exit from the bottom of the column.

2. To achieve better separation of products, fractionating columns use external reflux.

3. The contact between upflowing and downflowing streams in the column is always good, so no additional physical devices are needed.

4. The less reflux and more trays are provided, the better is the tower’s separation.

5. Fractionation columns are used for mixing various liquid compounds.

6. The temperature conditions are the main characteristic of a fractionation column.

6. Find the English equivalents for the fractionation process components listed below. Describe the fractionation process

Рис.8.2. Схема ректификационной колонны непрерывного действия

сборник кубовый продукт продукт перегонки колонна подача исходного продукта сборник орошающей фракции ребойлер конденсатор линия отходящего газа водосброс орошение ректификационной колонны