分馏塔结构英文文献和中文翻译(2)
with a cooling sur- face of 50 iT12 each. The volume of the reflux vessel was 10 m a. To keep the feedstock in the assembly, three vessels with capacity of about 100 m 3 were provided, and two with a volume of about 19 m 3. Aside from this, in work with a heavy feedstock, a furnace of 4million kcal/h output was included in the scheme of the unit. The scheme and lay-out of the unit ensured operation over a wide range of change in load with respect to vapor and liquid. The maximum load allowed one to obtain a vapor velocity equal to 3 m/see (calculated across the whole column cross section). A large amount of feedstock was required to carry out an extended continuous process; therefore operatice~ of the unit was accomplished with a continuous closed cycle. Distillate from the top of the column and residue from the bottom of the column entered a mixing vessel, whence they were again fed by a pump through heat exchangers, and into the column (as feedstock). The unit allowed operation under a pressure up to 10 kg/cm 2. The basic purpose of this unit is to enable one to determine the effective and stable region of oper- ation of plates of various constructions, their hydraulic resistance, and other characteristics which describe plate operation and which allow development of design methods (in Fig. 1 we showed an operator unit). In the units described and the remaining six in the "Giproneftemash, " the operation of over 50 constructions of both foreign and domestic plates has been studied. The experimental-constructional Determining the region of application of these constructions allowed drawing the conclusion that the use of a single construction for the whole persity of petrochemical processes is inexpedient. Knowing this, the "Giproneftemash" has worked out a series which includes the basic types of plates presently used in the petroleum refining or petrochemical industry. To these types belong fractionating columns with S-shaped, mesh-work or sieve plates having baffle elements. Later, four types of columns with valved once-throughplateswere produced and introduced at the institute. Of the four types presented, two types of plate - valved once-through plates and sieve plates with baffle elements - were developed on an inventive level and have definite advantages compared to the best foreign samples. As a result of the investigative work carried out, it was established that the indicated column types completely provide for both petroleum refining operations and petrochemical processes. For example, columns with S-shaped plates are expediently used in processes taking place at atmospheric or somewhat elevated pressures (at medium loads with respect to liquid). In vacuum distillation pro- cesses, which are distinguished by large vapor flow rates and low liquid flow rates, it is more desirable to use sieve plates with baffles, which have high productivity and low hydraulic resistance. In processes which require a high degree of separation or which are accompanied by significant load changes, the use of valved once-through plates is economically justified.
下一篇：空调节能技术英文文献和中文翻译