英文翻译蒸馏

Distillation蒸馏Separation operations achieve their objective by the creation of two or more coexisting zones which differ in temperature pressure, composition and or phase state Each molecular species in the mixture to be separated reacts in a unique way to differing environments offered by these zones Consequently as the system moves toward equilibrium each establishes a different concentration in each zone and this results in a separation between the species分离过程通过形成在温度、压力、组成和相态上有区别的两个或多个共存区来达到它的目的。

每一种待分离的在混合物中的分子种类以一种独特的17方式与这些区域提供的不同的环境相互作用。

结果是随着系统向平衡移动每个物质都在每个区域形成不同的浓度这样就可以使这些物质的到17分离。

The separation operation called distillation utilizes vapor and liquid phases at essentially the same temperature and pressure for the coexisting zones Various kinds of device such as dumped or ordered packings and plates or trays are used to bring the two phases into intimate contact Trays are stacked one above the other and enclosed in a cylindrical shell to form a column Packings are also generally contained in a cylindrical shell between hold-down and support plates利用在共有区中拥有相同温度和压力的汽油和液相的分离操作叫做分离。

不同种类的装置例如规整填料和乱堆整料和塔板或塔盘被用来使两相充分接触。

塔盘是一个堆着一个排列的并且被装入到一个圆柱形的外壳中形成一个塔。

填料通常也被装入一个在压具板和支撑板之间的圆柱形外壳中。

1 Continuous DistillationThe feed material which is to be separated into fractions is introduced at one or more points along me column shell Because of the difference in gravity between vapor and liquid phases, liquid runs down me column cascading from tray to tray while vapor floats up the column contacting liquid at each tray.1、连续蒸馏将要被分离成馏分的进料通过一个或多个沿着管壳的点被引入到塔中。

由于气相和液相之间重力的不同，液体在塔中从一个塔盘到另一个塔盘呈阶梯形向下流动。

同时气体在塔中向上流动并与液相在每个塔盘接触。

Liquid reaching the bottom of the column is partially vaporized in a heated reboiler to provide boil-up which is sent back up the column The remainder of the bottom liquid is withdrawn as bottoms or bottom product Vapor reaching the top of the column is cooled and condensed to liquid in the overhead condense Part of this liquid is returned to the column as reflux to provide liquid overflow. The remainder of theoverhead stream is withdrawn as distillate, or overhead product.液体到达塔底被一个加热的再沸器部分汽化来提供蒸汽。

蒸汽重新返回塔中。

塔底的残余物作为釜液或塔底产品被取出。

达到塔底的气相在塔底冷凝器中被冷却并冷凝成液体。

部分被冷凝的液体回流到塔中从而提供液体溢流。

塔顶馏分的剩余物作为馏分或塔顶产品被取出。

This overall flow pattern in a distillation column provides countercurrent contacting of vapor and liquid stream on all the trays through the column Vapor and liquid phases on a given tray approach thermal pressure and composition equilibriums to an extent dependent the efficiency of the contacting tray 在蒸馏塔中的整个流动模式为气相和液相提供了一个在每一个塔盘逆流接触的机会。

气相和液相在特定的塔盘上达到热量压力以及组成的平衡这在一定程度上取决于接触的塔板的效率。

The lighter(lower-boiling)components tend to concentrate in the vapor phase,while the heavier(higher-boiling)components tend toward the liquid phase The result is vapor phase that becomes richer in light components as it passes up the column and a liquid phase that becomes richer in heavy components as it cascades downward. The overall separation achieved between the distillate and the bottoms depends primarily on the relative volatilities of the components, the number of contacting trays, and the ratio of the liquid—phase flow rate to thevapor-phase flow rate.低沸点的轻组分倾向于气相中富集而同时高沸点的重组分倾向于在液相中富集。

这个结果是当它沿着塔向上移动的时候气相变得富含轻组分，而当液体沿着塔积极向下移动的时候液相变得富含重组分。

要在塔顶产品和釜液之间达到整个分离主要依赖于组分的相对挥发度，接触塔盘的数目和液相和气相流动的比例。

If the feed is introduced at one point along the column shell the column is divided into an upper section which is often called the rectifying section, and a lower section which is often referred to as the stripping section. These terms become rather indefinite in multiple-feed columns and columns from which a product sidestream is withdrawn somewhere along the column length in addition to the two end-product streams.如果进料从塔壳的某一个点引入这个塔被分成一个向上部分，这个部分通常叫做精馏段，还有一个向下的部分，这个部分叫做提馏段。

这些术语在多口进料塔中变得相当不确定。

侧线产品沿着塔的某个地方被取中的塔会有两个最终产品馏分。

Equilibrium-Stage ConceptEnergy and mass—transfer processes in an actual distillation column are much too complicated to be readily modeled in any direct way This difficulty is circumvented by the equilibrium—stage model in which vapor and liquid streams leaving an equilibrium stage are in completeequilibrium with each other and thermodynamic relations can be used to determine the temperature of and relate the concentrations in the equilibrium streams at a given pressure. A hypothetical column composed of equilibrium stages (instead of actual contact trays)is designed to accomplish the separation specified for the actual column The number of hypothetical equilibrium stages required IS then converted to a number of actual trays by means of tray efficiencies which describe the extent to which the performance of an actual contact tray duplicates the performance of an equilibrium stage平衡级的概念实际的蒸馏塔中的能量以及质量传递过程太复杂以至于不能从一种方式直接做成模型。