NIT processes by their very definition are concerned with the equipmentin which chemical reactions are .carried on in OUT factories. This may he divided into two phasesthatrepresantjngthe pilot plant stageand that concerned with the msnufscturingestablishmentitaelf. Adequate pilot plant operations enable the factory to he designed properly and to function evenly and economically. Hence, it is timely in theae symppsia to stress mme aapect of the equipment; in the sympmium of this year pilot plants are given some attentiou. In the commercial development of the chemical proeeae, two main t y p of pilot plants are met with-those specially designed and those -bled from standard pieces of equipment. Both should he, 88 far as possible, replicas of what the larger plant is expected to he in order that pilot plants d answer the question: Is this equipment what should he used in the manufacturing plant? In the Speeisuy designed pilot plant there will usually he much equipment of new design. Hence,care and engineering skill are required to build such a plant appropriately. In the ease of most large manufacturing establishments, the pilot plant will be of this special deaign. Frequently in such c a w *e will he eeveral stages in the development of the plant 88 difficulties are encountered in the pilot plant and are ehnated by improvements in the design with expariQCB &ed from the process. Here is demonstrated the *om of the old saying to make your mistakes on a small W. It is cheaper and quicker. With the completion of the necemary pilot plant runs, such a specially designed plant is usually dlsssaembled and only minor parts are available for other construction. How-
ever, in certain ~ ~ 9 the 8 8 last pilot plant is kept in running order for trgingmoditicationsand experiments until the m u factui-ing process is o p t i n g at its highest perfection. The seoond type of pilot plant is utilised by some m u facturers of chemicals. Here the equipment needed for the unit chemical process or the unit physical operation can he largely arranged from more or laas standardized pieces of equipment such 88 hydrogenatore., nitrators, pumps, entrifugea, filters, stilk, and the like. Assembled pilot plants of this nature can be qui&y put into working order. Many of the questions to be answered are involved in the choice of the coordinating sequences and suitable sizes. In the latter case,when the proteas being piloted or tried out moves into the factory, the stsndsrdiaed equipment need only he cleaned and rearranged for the next process of this chea which is to be investigated. Such sasembled pilot plaots are frequently placed in special room with the necessary services (steam, water, electricity, cooling brine, gas) arranged permaneutly in overhead pipes provided with convenient outlets for connections with the various equipment. The full use of pilot plants is necessary to ensure the smooth working of any new chemical manufacturing prom dure.
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