Basic process design elements

A process plant is a classification of factory which transforms materials in bulk. The feedstock and products may be transported by pipeline or conveyor, or in discrete quantities such as truckloads or bags, but they are recognized by their bulk properties. Examples of process plants are oil refineries, sugar mills, metallurgical extraction plants, coal washing plants, and fertilizer factories. The products are commodities rather than articles. 

In addition there are inevitably offsite facilities such as access roads, bulk power and water supplies, security installations, offices not directly associated with the plant, and employee housing these are not considered to be part of the process plant. 

A process plant is fundamentally represented by a process flowsheet. This sets out all the process stages (essentially discrete pieces of process equipment) and material storage points, and the material flows between them, and gives corresponding information on the flowrates and material conditions (chemical and physical). This information is usually provided for  

For thermal processes, the mass balance may be supplemented by a heat and/or energy balance. 

DESCRIPTION MILL OIF SLURRY MILL DlUniON SOLUTION MILL STEEL BAIL CONSUMPnON OREFEED TO MILL O.S.W.TO MILL DISCHARGE PUMP MILL SUMP DILUTON SOLUTION TROMMEL SCREEN 0/SIZE SCREEN SPRAY WATER 

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Part 1 of this series analyzed the basic necessary design elements of the simplest self-replicator (SSR), including necessary components, functions, processes, and information. Having established the minimum requirements for the design, this part will discuss the physical implementation of the SSR. 

In most adsorption processes the adsorbent is contacted with fluid in a packed bed. An understanding of the dynamic behavior of such systems is therefore needed for rational process design and optimization. What is required is a mathematical model which allows the effluent concentration to be predicted for any defined change in the feed concentration or flow rate to the bed. The flow pattern can generally be represented adequately by the axial dispersed plug-flow model, according to which a mass balance for an element of the column yields, for the basic differential equation governing llie dynamic behavior,... 

The material offered in this chapter is only a condensed treatment of basic elements of chemical reactor engineering needed to approach a process design problem. The reader should have already a good knowledge of this discipline. As study or refreshment material, we recommend in the first place the classical textbooks due to Levenspiel (recent edition in 1999) and Fogler (1992). Other remarkable books have been published by Carberry (1976), Westerterp, van Swaaij and Beenackers (1984), as well as by Froment and Bishop (new edition in 1990). More advanced treatment of different subjects in chemical reaction engineering can be found in the monograph edited by Carberry and Varma (1987) with contributions of experts in each field. 

Basic Process Control System (BPCS) - A collection of measurements, control and sequential functions, final control elements, alarms, and interlocks that normally maintain the process operation within acceptable operating limits. Interlocks that are designed to mitigate Class D E events are part of the BPCS. 

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